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Ogwuda, Olisanwendu Ikechukwuka. "Materials science appraisal of recycled construction materials for roadways." Thesis, Abertay University, 2007. https://rke.abertay.ac.uk/en/studentTheses/70d295b3-60d9-427e-a012-c9cc05ac83e1.
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This thesis reports on a materials science appraisal for recycled construction materials in roadways, that supports engineering decision-making. Inconsistent performance criteria for roadway materials and the variable nature of material source have prompted the need for this research. The aim of the study is to investigate the application of a materials science appraisal to recycled construction materials for use in roadways. The investigation is undertaken through a literature review of roadways, conceptual development of the materials science appraisal methodology, and demonstration of the application of the materials science appraisal to recycled construction materials; and how this supports engineering decision-making. The literature review revealed that there are numerous and proven uses of recycled and secondary materials in roadway applications but there was a lack of necessary integration of materials into categories by material-type, which can better describe behaviour in an engineering situation. Three novel fundamental material types (ceramic, metallic, and polymeric) have been described. The conceptual development of the innovative and novel materials science appraisal, based on material-type, has defined how materials science through a systematic step-by-step procedure can be used to achieve engineering sustainability in roadways and provide support in engineering decision-making. The application of the novel concept of the materials science appraisal to recycled construction materials is shown through the essence of laboratory testing. The results from the materials science appraisal, together with sensitivity analysis, give an informed engineering decision on product choice. The appraisal is novel in that it is proposing a new theory on materials science and developed a paradigm shift in the evaluation of recycled construction materials. The appraisal overcomes the absence of materials science thinking in the field of roadway engineering. The materials science appraisal is of benefit to various stakeholders (client, consultant, supplier and contractor) as it provides a method for addressing material uncertainties. A system now exists for introducing into designs and any contract the principles of the materials science appraisal that will be of great benefit to industry.
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Rad, Taghi. "Microstructural characteristics of recycled cementitious materials." Thesis, University of Hertfordshire, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.340038.
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Rogetzer, Patricia, Lena Silbermayr, and Werner Jammernegg. "Sustainable sourcing of strategic raw materials by integrating recycled materials." Springer Nature, 2018. http://dx.doi.org/10.1007/s10696-017-9288-4.
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In this paper we investigate a manufacturer's sustainable sourcing strategy
that includes recycled materials. To produce a short life-cycle electronic good,
strategic raw materials can be bought from virgin material suppliers in advance of
the season and via emergency shipments, as well as from a recycler. Hence, we take
into account virgin and recycled materials from different sources simultaneously.
Recycling makes it possible to integrate raw materials out of steadily increasing
waste streams back into production processes. Considering stochastic prices for
recycled materials, stochastic supply quantities from the recycler and stochastic
demand as well as their potential dependencies, we develop a single-period
inventory model to derive the order quantities for virgin and recycled raw materials
to determine the related costs and to evaluate the effectiveness of the sourcing
strategy. We provide managerial insights into the benefits of such a green sourcing
approach with recycling and compare this strategy to standard sourcing without
recycling. We conduct a full factorial design and a detailed numerical sensitivity
analysis on the key input parameters to evaluate the cost savings potential. Furthermore,
we consider the effects of correlations between the stochastic parameters.
Green sourcing is especially beneficial in terms of cost savings for high demand
variability, high prices of virgin raw material and low expected recycling prices as
well as for increasing standard deviation of the recycling price. Besides these
advantages it also contributes to environmental sustainability as, compared to
sourcing without recycling, it reduces the total quantity ordered and, hence, emissions
are reduced.
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Lidelöw, Sofia. "Environmental assessment of construction with recycled materials." Doctoral thesis, Luleå, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-26269.
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The use of industrial residues as raw materials in construction raises concerns over the potential leaching and dispersal of hazardous constituents from them into the environment. Their leaching behaviour has been studied in laboratory assays, but leaching processes in the field over larger spatial and temporal scales are more complex due to variations in the conditions the materials are exposed to, and less well understood. Hence, estimates of the potential environmental loads associated with the use of such materials based on laboratory tests may be inaccurate. This thesis addresses the environmental implications of using recycled materials in road and landfill cover constructions. The focus is primarily on the leaching of inorganic constituents from six types of materials: incineration ashes, copper smelter slag, blast-furnace slag, recycled concrete, natural rock and contaminated soil. The leaching behaviour of constituents from these materials were assessed in both laboratory batch leaching tests and monitoring programs in which the water percolating through them in field applications were sampled over one to ten years. Leaching data were evaluated using statistical and geochemical modelling. In addition, assessment methods and criteria to judge the environmental suitability of substituting natural materials for recycled materials in construction were reviewed. It was found that leachates from recycled materials in the constructions contain higher concentrations of several constituents than natural water and leachates from conventional materials. However, the rates and extent of constituent leaching were affected by the application methods in various ways that are explored and discussed. The results of simplified leaching tests did not always reflect the leaching behaviour in the field, which highlight the importance of developing assessment methods that allow case-specific factors to be taken into account. The environmental impacts of leaching must also be considered in relation to the expected impacts of the default alternative, i.e. landfilling of industrial residues and exploitation of natural resources. Combinations of case-specific assessments and system analyses would be the ideal approaches to evaluate impacts at both local and regional scales.Användningen av industriella restprodukter som konstruktionsmaterial inom anläggningsbyggande väcker frågan om möjlig utlakning och spridning av förorenande ämnen från materialen till omgivande miljö. Materialens lakningspotential bestäms vanligen genom lakförsök utförda under kontrollerade förhållanden i laboratorium. Lakningsprocesser i fält sker dock över större rums- och tidskalor och är mer komplexa på grund av variationer i miljön som materialen exponeras för. Uppskattningar av materialens möjliga miljöpåverkan baserade på laboratorietester kan därför vara felaktiga. Den här avhandlingen handlar om den miljömässiga betydelsen av att använda återvunna material som konstruktionsmaterial i vägar och deponisluttäckningar. Fokus är i huvudsak på utlakningen av oorganiska ämnen från sex typer av material: förbränningsaskor, kopparslagg, hyttsten, återvunnen betong, naturligt berg och förorenad jord. Utlakningen från dessa material undersöktes med hjälp av både skakförsök i laboratorium och kontrollprogram där vatten som perkolerade materialen i fältapplikationer (sk. lakvatten) provtogs under ett till tio år. Lakvattendata utvärderades med hjälp av statistisk och geokemisk modellering. Dessutom granskades olika bedömningsmetoder och kriterier som kan användas för att bedöma den miljömässiga lämpligheten av att använda återvunna istället för naturliga material i anläggningskonstruktioner. Lakvatten från återvunna material i de undersökta konstruktionerna innehöll högre koncentrationer av flera ämnen än naturliga vatten och lakvatten från naturliga material. Dock var hastigheten och omfattningen av utlakningen beroende av hur materialet användes, vilket har undersökts och diskuteras i avhandlingen. Resultaten från förenklade skakförsök överensstämde inte alltid med observationerna i fält, vilket understryker vikten av att utveckla bedömningsmetoder där fallspecifika faktorer kan tas i beaktande. Miljöpåverkan orsakad av lakning måste också ses i relation till den påverkan som kan uppstå om restprodukterna istället deponeras och naturliga material exploateras. Kombinationer av fallspecifika och systemövergripande analyser skulle därför vara det ideala sättet att utvärdera både lokala och regionala effekter av en möjlig användning av återvunna material.
Godkänd; 2008; 20081003 (ysko)
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Carreon, Delfin G. "Stabilization of marginal soils using recycled materials." [Tampa, Fla] : University of South Florida, 2006. http://purl.fcla.edu/usf/dc/et/SFE0001700.
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Lacalle, Jiménez Helena Isabel. "Airfield pavement design with cold recycled materials." Thesis, University of Nottingham, 2017. http://eprints.nottingham.ac.uk/44286/.
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The UK has adopted the concept of sustainable development and the construction industry is playing a key role in improving the efficient use of materials. The aim is to minimise the waste generated and maximise quantities of materials reused or recycled, minimising raw material consumption. Using Reclaimed asphalt pavement (RAP) is a rehabilitation technique which involves recycling materials from asphalt layers that have already been in service. This reduces the use of new bitumen and aggregates and avoids disposal. However, UK pavements constructed prior to 1980 or surfaced in the late 1980’s may contain tar, a carcinogenic substance that cannot be reheated and, therefore, cannot be recycled into hot mix asphalt (HMA). Recycling these pavements into unbound materials is also prohibited; consequently, disposal or cold recycling are the two available options. Cold recycling of asphalt is a proven technique that reduces material disposal and raw material and energy consumption. The reduction in energy consumption is largely achieved by avoiding aggregate drying and mixing of the material at ambient temperature. In this sense, using cold recycled bound materials (CRBMs) becomes the most economic and sustainable option. However, despite the increasingly common use of CRBM in roads, the specifications for the use of these materials in airfields are under-developed and there is no guidance to ensure that pavement design with these materials is trustworthy. This is the reason why this Thesis focuses on airfield pavement design with CRBM. The aim of this investigation is to develop a design methodology to use CRBMs in airfield pavements. For this purpose, the objectives were to review past experience on performance of these materials, measure and analyse the effect of key variables on performance to establish material limitations and develop a design methodology, proposing design guidance for airport authorities and practitioners. To achieve the project aims and objectives, a literature review was carried out focusing on pavement engineering, airfield pavement design and CRBM. The objective was to gain sufficient knowledge on key areas to conduct the research. Based on this literature review it was decided to use foamed bitumen as the cold technology and Kenlayer as pavement analytical design software. It was also found that the current design methodology for using CRBM in airfields is to conservatively equate material properties to those of a HMA commonly used in airfield base course (HDM50). Therefore, this practise should be analysed to decide if it is correct or if it can be improved. Subsequently, a laboratory programme was established to analyse CRBM mechanical properties and, therefore, understand the material’s behaviour and performance under cyclic loading. RAP, fly ash, cement and foamed bitumen were used to manufacture laboratory specimens, compacted with a gyratory compactor. These specimens were tested to analyse densities, air voids, stiffness, strength, permanent deformation and fatigue. For developing a new design methodology, Kenlayer was used to analyse strains and stresses within the airfield pavement. The first step was to ascertain Kenlayer adequacy and establish inputs related to loading, traffic and subgrade condition. For this purpose, 96 case studies were analysed with HMA, with different aircraft types, traffic and subgrade conditions. These cases were compared to those of a well-established airfield design guide, namely DMG 27. Then the software could be used to model pavements containing CRBM and with the knowledge gained in the laboratory about its behaviour, establish layer thicknesses to bear traffic during the pavement design life. With the results obtained from the laboratory investigation it was concluded that CRBM mixes have acceptable properties for use in airfield pavements. Resistance to permanent deformation, fatigue, temperature susceptibility and durability results show that these materials give reasonable performance; however, they differ from conventional hot mixes. Thus, current practice can be improved, justifying the need for design guidance for using CRBM in airfields. As fatigue is one of the main failure modes in asphalt mixtures and flexible pavements, a deeper study into fatigue behaviour of CRBM was carried out using Indirect Tensile Fatigue Tests (ITFT) in strain control mode and Wheel Track Test (WTT). The results showed different failure mechanisms for CRBM from those of HMA; thus, a new failure criterion was established. In HMA the failure criterion of 50% stiffness reduction is related to the appearance of macro cracks. CRBM develops dispersed micro-cracking that lowers the mixture stiffness without producing macro cracks until late in the material’s life. Macro cracks only tend to appear at 70% stiffness reduction; therefore, this was established as new failure criterion for CRBM. Once CRBM properties were defined, the pavement structure could be modelled. The results obtained from HMA modelling showed that the software and the inputs selected were appropriate for this investigation. Then the HMA base properties were substituted with CRBM properties obtained in the laboratory. The results showed that DMG 27, Chart 7, can be used for designing airfield pavements using CRBM increasing the base thickness by 9%, with a minimum Dry Lean Concrete (DLC) layer of 150 mm. A deterioration analysis was also carried out with the design software. In this case the aim was to analyse how strains distribute within the CRBM layer and how this affects the pavement life. With these analysis, it was highlighted how different CRBM behaves compared to HMA. Strains distributed linearly within the HMA layer; however, this does not happen with the CRBM. Moreover, this analysis showed how fatigue data can be used to obtain a more accurate pavement life taking into account different strain levels. Nevertheless, the study carried out here is based on laboratory performance of one type of CRBM. There is need for further investigation to establish a relationship between fatigue behaviour in the laboratory and the field and confirm how micro cracking affects the bearing capacity of the CRBM layer, establishing shift factors to optimise CRBM layer thickness. Moreover, the laboratory study has been carried out analysing CRBM in the same way as HMA; therefore, further study is needed to analyse the adequacy of the testing methodology. Also, modelling has been done comparing one CRBM to one HMA, namely HDM50; therefore, further investigation is needed to open the model to other HMA. Consequently, the design guidance presented here is a first step towards an airfield pavement design guide and further study is needed to optimise it.
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Vu, Quoc Hung. "Modelling pollutants leaching from recycled construction materials." Thesis, Queensland University of Technology, 2019. https://eprints.qut.edu.au/130795/1/Quoc%20Hung_Vu_Thesis.pdf.
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This research developed new models to replicate metal leaching characteristics from recycled concrete aggregate (RCA) and reclaimed asphalt pavement (RAP). Model development was supported by a comprehensive experimental and analytical program with multiple influential factors. New models were developed so that they are readily applicable in commercial models to replicate pollutant leaching and solute transport in soil environments. Outcomes of this study will enhance the sustainable use of waste products such as RCA and RAP in the construction industry and relieve the stresses on natural quarry products.
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Palmquist, Shane M. "Compressive behavior of concrete with recycled aggregates /." Thesis, Connect to Dissertations & Theses @ Tufts University, 2003.
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Thesis (Ph.D.)--Tufts University, 2003.Adviser: Daniel C. Jansen. Submitted to the Dept. of Civil Engineering. Includes bibliographical references (leaves 146-152). Access restricted to members of the Tufts University community. Also available via the World Wide Web;
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Krezel, Zbigniew Adam, and n/a. "Recycled aggregate concrete acoustic barrier." Swinburne University of Technology, 2006. http://adt.lib.swin.edu.au./public/adt-VSWT20060821.154340.
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This document reports on a research project aimed at developing a concrete acoustic barrier
made from Recycled Aggregate (RA) Concrete. The research project was undertaken in
response to the needs expressed by the Victorian concrete recycling industry. The industry,
the scientific community conducting research into relevant disciplines, and the community
at large, represented by Victorian government agencies, are of the opinion that there is a
need to devise a higher value utilisation application for selected concrete recycling
products.
This document outlines the rationale and objectives of the research project which involves
the examination of Recycled Concrete (RC) Aggregate, the design and examination of RA
Concrete, and finally the development of an acoustic barrier made from RA Concrete.
The literature review presented in this report examines aspects of concrete recycling and
concrete technology pertaining to traditional and alternative constituent materials for
concrete production. Firstly, the importance and influence of fine and coarse aggregate on
basic properties of concrete is introduced. Secondly, an account on the use of alternative
materials in concrete technology, especially of coarse recycled aggregates and
supplementary cementitious materials (SCM) is described. Thirdly, some of the physical
and mechanical properties and how the use of RC Aggregate and SCM changes these
properties are discussed. Fourthly, a number of commonly used techniques and neutron
scattering techniques to investigate aggregate and concrete properties are introduced and
discussed. Fifthly, the porosity of aggregate and concrete including durability are
specifically discussed and testing methods are reasoned. The literature review also
discusses the use of no-fines concrete; its physical, mechanical and acoustic properties.
Finally it presents an account of the use of concrete in transportation traffic noise
attenuation devices.
This document continues with an outline of a methodology that was adopted in this
research project. It outlines experimental work aimed at examining the properties of RC Aggregate which amongst other properties includes porosity, particle size distribution,
water absorption, shape and density. It continues examining RA Concrete properties and
includes, among other properties, compressive strength, porosity and durability as well as
sound absorption of acoustic barrier. The methodology introduces standard and purposely
modified test procedures used in the examination of aggregates, concrete and acoustic
barrier. An account of various research techniques is presented, spanning from simple
visual observations to more sophisticated neutron scattering techniques. The summary of
test procedures follows a description of test specimen composition and their sizes, and a
suite of tested specimens. It also introduces statistical methods used to analyse test results.
After a detailed description of the aggregate, concrete and RA Concrete acoustic barrier,
the document outlines a summary of data generated through the experimental program of
this research project. The data on fine aggregate, on selected 14/10mm coarse RC
Aggregate, on concrete made from natural and recycled aggregate and on acoustic barrier
are presented and discussed. Test results of various physical, mechanical and acoustic
properties of aggregate, concrete and barrier are reported, analysed and discussed. The data
from observations, visual assessment and scientific experimentation of specific properties
are then crossed analysed in a search for relationships between properties of fine and coarse
aggregates and properties of concrete made from such aggregates. A cross analysis of data
on ?less-fines? RA Concrete and on the acoustic performance of barrier is examined, and
the relationship between the volume of interconnected voids in a porous part of ?less-fines?
concrete, and the sound absorption of acoustic barrier is discussed and reported.
The document then presents a synthesis of the literature review results, project aims
adopted within the experimental program and test results in the three main areas of this
research project. These areas include recycled concrete aggregate, recycled aggregate
concrete and acoustic barrier made from RA Concrete.
Finally, conclusions reached through the course of this investigation are summarised and
recommendations are proposed in relation to the RA Concrete acoustic barrier. The main
conclusion is that selected RC Aggregate can be used in the production of concrete of a compressive strength of 25MPa, if the moisture content and water absorption in the
aggregate are closely monitored, and the foreign material content is kept below 1.5%. The
author concludes that acoustic barrier made from selected RC Aggregate has unique sound
absorption characteristics that can easily be tunable by a selection of appropriate aggregate
and by specific concrete mix designs. Recommendations for further research are also
proposed.
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Krezel, Zbigniew Adam. "Recycled aggregate concrete acoustic barrier." Australasian Digital Theses Program, 2006. http://adt.lib.swin.edu.au/public/adt-VSWT20060821.154340.
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Thesis (PhD) - Swinburne University of Technology, 2006.Submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Civil Engineering, Swinburne University of Technology - 2006. Typescript. Includes bibliographical references.
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Fung, Wing-kun. "The use of recycled concrete in construction." Click to view the E-thesis via HKUTO, 2005. http://sunzi.lib.hku.hk/hkuto/record/B30517643.
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McDonald, Rory Morgan. "Recycled Materials Relational Database: Design and Implementation Aspects." [Tampa, Fla.] : University of South Florida, 2004. http://purl.fcla.edu/fcla/etd/SFE0000388.
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Younis, Khaleel Hassan. "Restrained shrinkage behaviour of concrete with recycled materials." Thesis, University of Sheffield, 2014. http://etheses.whiterose.ac.uk/5966/.
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The construction industry is responsible for some of the most serious sustainability and environmental issues the world is currently facing. Recycled materials such as recycled aggregate (RA) -generated from processed construction waste- and recycled tyre steel fibres (RTSF) -extracted from post-consumer tyres- in new constructions can potentially conserve natural aggregates (NA), eliminate unnecessary consumption of limited landfill areas and reduce energy consumption. However, the variability in the characteristics of recycled materilas, and the low density, high water absorption and porosity of RA, can lead to poor quality concrete and shrinkage cracks, particularly under restrained conditions. This study aims to examine the use of recycled materials such as RA and RTSF in the production of structural concrete and in particular to contribute towards understanding the shrinkage behaviour of NA concrete (NAC) and RA concrete (RAC) under restrained conditions. An extensive experimental study to characterise the properties of both NA and RA and identify the effect of various key parameters on the performance of RAC is undertaken. Approaches to improve the properties of RA and RAC are explored. A new restraining frame for restrained shrinkage test and a procedure to quantify the post-shrinkage mechanical properties (compressive and flexural strength and flexural elastic modulus) of concrete are developed and assessed. The mechanical performance of concrete mixes incorporating RA and RTSF, as well as mixes with NA and industrial steel fibres (ISF), is examined under free and restrained conditions. It is shown that the compressive strength of RAC can be predicted using a predictive model that takes into account: particle density, LA value, water absorption and RA content. Surface treatment of RA using reactive and non-reactive microfillers, as well as the utilization of RTSF, helped improve the compressive strength of RAC by up to 30%. For unrestrained specimens, it is shown that there is a significant difference in shrinkage strains with depth, resulting in significant shrinkage curvatures. Under restrained conditions, stress history, which depends on the rate of development of stiffness and shrinkage, plays a key role in governing the failure of concrete. Shrinkage induced cracks can reduce the compressive strength, flexural strength and flexural elastic modulus of plain concrete by up to 14%, 24% and 29%, respectively. The addition of RTSF and surface treatment of RA resulted in better flexural performance of RAC compared to that of NAC without fibres and comparable to that of NAC with fibres. It is shown that whilst ISF do not affect shrinkage strains, RTSF increase initial shrinkage strains due to higher air content. Despite that, it is concluded that RTSF control well shrinkage induced microcracking, enhance tensile relaxation and promote auto-healing of microcracks, leading to an overall better flexural performance even when using RAC.
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Espert, Ana. "Natural fibres/polypropylene composites from residual and recycled materials." Licentiate thesis, KTH, Fibre and Polymer Technology, 2003. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-1667.
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Natural fibres fulfil all the requirements in order toreplace inorganic fillers in thermoplastic composites. Naturalfibres are inexpensive, renewable, biodegradable, present lowerdensity and their mechanical properties can be compared tothose of inorganic fillers. However, several disadvantagesappear when natural fibres are used for composites. First ofall, the poor compatibility between the hydrophilic fibres withthe hydrophobic thermoplastic matrix leads to a weak interface,which results in poor mechanical properties. On the other hand,the hydrophilic nature of the fibres makes them very sensitivetowards water absorption, which leads also to the loss ofproperties and the swelling and dimensional instability.
In order to enhance the compatibility fibre-matrix, thefibres were chemically surface modified by five differentmethods: a) graft copolymerisation withpolypropylene-graftedmaleic anhydride copolymer (PPgMA), b)modification by PPgMA during processing, c) modification byorganosilanes, d) acetylation, e) modification with peroxideoligomers. Modified fibres led to improved mechanicalproperties and thermal behaviour when used in composites withpost-industrial polypropylene (PP) containing ethylene vinylacetate copolymer (EVA). Modification with peroxide oligomersshowed very promising results, but modification with PPgMA waschosen for further preparation of composites due to itssimplicity.
Two sets of composites were prepared using two differentpolypropylene types as matrix: virgin polypropylene (PP) andthe above mentioned post-industrial polypropylene (PP/EVA).Four different types of cellulosic fibres were used as fillers:cellulose fibres from pulping, sisal fibres, coir fibres andLuffa sponge fibres. The mechanical properties of thecomposites were dependent mostly on the fibre loading andslightly on the type of fibre. The fibers changed thecharacteristics of the material leading a higher stiffness buta lower toughness.
Water absorption of composites was studied at threedifferent temperatures: 23°C, 50°C and 70°C. Thewater absorption kinetics were studied and it was found thatwater is absorbed in composites following the kineticsdescribed by the Fickian diffusion theory. After absorption, animportant loss of properties was observed, due to thedestruction of the fibre structure due to the waterabsorbed.
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Karabulut, Metin. "Production And Characterization Of Nanocomposite Materials From Recycled Thermoplastics." Master's thesis, METU, 2003. http://etd.lib.metu.edu.tr/upload/1255728/index.pdf.
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Nanocomposites are a new class of mineral-field plastics that contain relatively small amounts (<10%) of nanometer-sized clay particles. The particles, due to their extremely high aspect ratios (about 100-15000), and high surface area (in excess of 750-800 m2/g) promise to improve structural, mechanical, flame retardant, thermal and barrier properties without substantially increasing the density or reducing the light transmission properties of the base polymer. Production of thermoplastic based nanocomposites involves melt mixing the base polymer and layered silicate powders that have been modified with hydroxyl terminated quaternary ammonium salt. During mixing, polymer chains diffuse from the bulk polymer into the van der Waals galleries between the silicate layers. In this study, new nanocomposite materials were produced from the components of recycled thermoplastic as the matrix and montmorillonite as the filler by using a co-rotating twin screw extruder. During the study, recycled poly(ethylene terepthalate), R-PET, was mixed with organically modified quaternary alkylammonium montmorillonite in the contents of 1, 2, and 5 weight %. Three types of clays were evaluated during the studies. For comparison, 2 weight % clay containing samples were prepared with three different clay types, Cloisite 15A, 25A, 30B. The nanocomposites were prepared at three different screw speeds, 150, 350, 500 rpm, in order to observe the property changes with the screw speed. Mechanical tests, scanning electron microscopy and melt flow index measurements were used to characterize the nanocomposites. The clay type of 25A having long alkyl sidegroups gave the best results in general. Owing to its branched nature, in nanocomposites with 25A mixing characteristics were enhanced leading to better dispersion of clay platelets. This effect was observed in the SEM micrographs as higher degrees of clay exfoliation. Nearly all the mechanical properties were found to increase with the processing speed of 350 rpm. In the studies, it was seen that the highest processing speed of 500 rpm does not give the material performance enhancements due to higher shear intensity which causes defect points in the structure. Also the residence time is smaller at high screw speeds, thus there is not enough time for exfoliation. In general, the MFI values showed minimum, thus the viscosity showed a maximum at the intermediate speed of 350 rpm. At this processing speed, maximum exfoliation took place giving rise to maximum viscosity. Also, the clay type of 25A produced the lowest MFI value at this speed, indicating the highest degree of exfoliation, highest viscosity, and best mechanical properties.
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Pournoman, Sara. "Oxidative Aging of Binders with High Recycled Asphalt Materials." Thesis, University of Nevada, Reno, 2017. http://pqdtopen.proquest.com/#viewpdf?dispub=10282654.
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The objectives of this research effort focused on the oxidative aging of binders with high recycled asphalt materials. A coordinated program of forced-draft oven aging experiments was conducted on eleven sorts of binder blends including three different types of base binders from TX, NH, and NV, two different types of recycled material (RAP/RAS), and two different types of recycling agents (RA). Implementing the Fourier-Transform Infrared Spectroscopy (FT-IR) and Dynamic Shear Rheometer (DSR) isothermal frequency sweep tests, the oxidation kinetics and rheological performance were determined for the evaluation materials. Results indicated that the oxidative aging rates were influenced by the aging temperature, duration, base binder type, as well as the utilized asphalt modifier, i.e. recycled materials and RAs. It was also noted that the RAs reduced the overall stiffness in the investigated stages of oxidation. However, differential aging rates and hardening susceptibilities were observed between the RA and RAP/RAS additions to each of the three bases, noting that these differences were not consistent with the type of RAS, i.e. MWAS or TOAS. Additionally, the base binder aging properties due to the addition of the recycled material was highly influenced by the RA dosages within each blend.
Furthermore, the binder blend oxidative aging predictions at binder specific geographical location indicated that using the recycled materials along with the RAs at the optimum dosage, according to the proposed methodology, was able to restore the binder blend properties to the virgin binder.
The influences of the recycled material and RAs on the PG 64-28P base binder were also investigated through the binder PG grading and mortar testing. Consistent directions for the influence of the evaluation materials were observed within both procedures, suggesting the capability of the mortar procedure in characterizing the effects of RAP and RA materials on virgin binder without the use of chemical extraction.
The Uniaxial Thermal Stress and Strain Test (UTSST) was also conducted on the PMFC and RPMLC specimens of the NV field project to investigate the influence of the high recycled material and RAs on the asphalt mixtures. Through consideration of the thermo-viscoelastic properties, marked differences in the binder oxidation were noted between the experimental factors. Typically, decreases in the viscous response of the mixtures as well as increases in both the stiffness and brittle behavior were observed with aging and also inclusion of the recycled material. Although the addition of the RAs to the recycled mixtures indicated some extent of properties restoration, crack initiation and fracture were observed to occur in significantly warmer temperatures compared to the virgin mixture.
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Singh, Pralendra. "RESILIENT MODULUS OF RECYCLED AGGREGATES AS ROAD PAVEMENT MATERIALS." OpenSIUC, 2015. https://opensiuc.lib.siu.edu/theses/1624.
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The sources of natural or virgin coarse aggregates are diminishing in alarming rate and its production is quite expensive, uses a lot of energy, and is not environmental friendly. Hence, utilizing the recycled aggregates like reclaimed or recycled concrete aggregate (RCA) and recycled asphalt pavement (RAP) on road pavement will not only preserve the natural aggregates but also reduce the negative environmental impact. It also helps to conserve the waste landfill sites. The major downside for the use of the recycled aggregate is the quality control during its production. This research characterizes RCA samples obtained from a demolished old foundation and RAP samples from old parking lot and determines their suitability as road pavement materials. Virgin aggregates, recycled aggregates, and several blended mixtures with 20 to 80% replacement of natural coarse aggregate or virgin aggregate (NCA or VA) by weight with RCA and RAP were prepared and tested for resilient modulus (Mr) and California Bearing Ratio (CBR) test. The durability of the virgin aggregate and recycled aggregate were also determined by micro-deval test. The resilient modulus value of 100% RCA and 100% VA was found to be very similar or higher but for 100% RAP the resilient modulus is higher than that of the 100%VA. The Resilient modulus of the RAP blended mixtures increases with the increase in the content of RAP percentage and for the RCA it was not consistent. The CBR values for the blended mixtures decreases with the increase in the percentage of the recycled aggregates. The micro-deval degradation test result for RCA was more than of VA due to presence adhere materials in RCA.
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Fung, Wing-kun, and 馮永根. "The use of recycled concrete in construction." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2005. http://hub.hku.hk/bib/B30517643.
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Sulaiman, Salim J. "Fracture and crack growth in recycled mixes." Thesis, University of Dundee, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.320522.
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Bolden, Johnny J. IV. "Innovative uses of Recycled and Waste Materials in Construction Application." Thesis, North Carolina Agricultural and Technical State University, 2013. http://pqdtopen.proquest.com/#viewpdf?dispub=1545862.
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More production equals more waste, more waste creates environmental concerns of toxic threat. An economical viable solution to this problem should include utilization of waste materials for new products and one that minimizes the heavy burden on the nation's landfills. The importance of recycling is huge because it saves natural resources, saves energy, reduces solid waste, reduces air and water pollutants, and reduces greenhouse gases. The construction industry can start being aware of and take advantage of the benefits of using waste and recycled materials. Studies have investigated the use of acceptable waste, recycled, and reusable materials and methods. The use of swine manure, animal fat, silica fume, roofing shingles, empty palm fruit bunch, citrus peels, cement kiln dust, fly ash, foundry sand, slag, glass, plastic, carpet, tire scraps, asphalt pavement, and concrete aggregate in construction is becoming increasingly popular due to the shortage and increasing cost of raw materials. In this study a survey was conducted to find out the current practices of the uses of waste and recycled materials in the construction industry. The results proved that companies are not aware of what's available to use or the quality of the materials performance or the cost savings or any other benefits including environmental. Based from the results of the survey the following research was conducted to create better documentation for Green Building, connecting researches and contractors with an overview of what recycled materials are available for different construction applications.
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Sotayo, Adeayo. "Development and characterisation of novel structural composites from recycled materials." Thesis, Lancaster University, 2016. http://eprints.lancs.ac.uk/86062/.
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Carpets are composite materials and, like many composite materials, waste carpet is both difficult and expensive to recycle because of the complicated, multi-stage processes involved. In the UK, approximately 400,000 tonnes of carpet waste are sent to landfill annually. However, the landfill option is becoming uneconomic due to increasing landfill charges, the reduction in landfill sites and changes in environmental legislation. This project, in collaboration with ECO2 Enterprises, aimed to avoid the landfill option and develop novel structural composites from carpet waste, which could be used to replace timber and PVC posts and rails in equestrian fencing. The development of these composites is a recycling approach that makes use of carpet waste which would otherwise be sent to landfill thereby increasing environmental pollution. The study encompasses the investigation of relevant material and mechanical properties and processing characteristics of the prototype novel waste carpet composites both as a structural beam and an assembled fencing system. Details of the manufacturing processes of the novel waste carpet structural composites are described. Extensive experimental testing has been carried out to determine and compare the mechanical properties of the novel waste carpet structural composites to timber and PVC materials. In addition, experimental load tests and Finite Element (FE) analysis on typical equestrian timber and PVC post and rail fencing structures (benchmark data) were carried out to evaluate their stiffness characteristics against corresponding characteristics for a similar fencing structure comprised of the novel waste carpet structural composites. Design optimisation via geometric changes and FE analyses showed that a 69 % increase in the depth (from 71 to 120 mm) of the novel waste carpet composite posts resulted in a transverse stiffness similar to that of the timber fence. The results obtained from this study has demonstrated that the mechanical properties of the novel structural composites could potentially serve as an alternative/replacement for some common materials used in structural applications, such as timber and PVC fencing.
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Okeyinka, Oriyomi M. "The applicability of recycled waste paper as lightweight building materials." Thesis, University of Wolverhampton, 2016. http://hdl.handle.net/2436/620495.
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In this era of increasing standard of living and rapid growth of civil engineering construction, environmental issues pertaining to natural resources depletion, global warming, energy crisis, waste pollution and greenhouse gas emission have been major issues of concern throughout the world and most especially in the construction industry. This research was conducted to investigate the applicability of recycled wastepaper as lightweight building materials with focus on contributing to sustainability in the creation of the built environment. The major aim was to develop an eco-friendly lightweight non-loadbearing block from recycled wastepaper without the use of cement as binder. This study specifically addressed the drawback of low strength development that usually occur with increasing wastepaper content in the existing cement-based-wastepaper blocks. It also indirectly addresses; the environmental impacts associated with the construction industry (including; high consumption of natural resources, greenhouse gas emission, high energy consumption and so on), the environmental pollution resulting from unsustainable waste generation, and the generic drawback of high water absorption that plagues wastepaper-based blocks. To achieve this, research methods including; laboratory experimentation and simulation modelling were employed. The research outcome is an eco-friendly block unit designated as Cement-less Wastepaper-based Lightweight Block (CWLB) which contains 75% waste content and exhibiting properties that satisfy the requirements for application as non-loadbearing lightweight blocks in building construction. CWLB displayed compressive strength that far outweighs those recorded for the existing cement-based wastepaper blocks available in the literature. The properties recorded for the optimal CWLB includes; 2.71 MPa average compressive strength, 901.5 kg/m3 average density, 0.19 W/m.k thermal conductivity, 989.9 m/s ultrasonic pulse velocity, 0.0026 g/m2.S0.5 average coefficient of capillary water absorption and 883.38 MPa estimated elastic modulus. The approximate compressive strength of 2.38 MPa and 1.58 MPa were respectively predicted and recorded for the solid and hollow finite element model samples of CWLB. The impressive satisfactory properties of CWLB for the intended application and its eco-friendliness in terms of natural resources conservation and improved compressive strength suggests that CWLB shall indeed serve as a more sustainable alternative to the reigning/existing cement-based-wastepaper blocks and to the conventional masonry blocks of the same category. Amongst other things, future work will address the validation of the approximate compressive strength predicted for the solid and hollow CWLB insitu samples in order to take further the subject matter.
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Cetin, Bora. "Stabilization of recycled base materials with high carbon fly ash." College Park, Md.: University of Maryland, 2009. http://hdl.handle.net/1903/9573.
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Thesis (M.S.) -- University of Maryland, College Park, 2009.Thesis research directed by: Dept. of Civil and Environmental Engineering . Title from t.p. of PDF. Includes bibliographical references. Published by UMI Dissertation Services, Ann Arbor, Mich. Also available in paper.
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Gao, Ya. "Investigation of cracking resistance of recycled Superpave mixtures." Thesis, Kansas State University, 2017. http://hdl.handle.net/2097/38175.
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Master of ScienceDepartment of Civil Engineering
Mustaque A. Hossain
The use of economical and environmentally friendly recycled asphalt materials has become increasingly popular for asphalt pavement construction. Although reclaimed asphalt pavement (RAP) and recycled asphalt shingles (RAS) are typically used in hot-mix asphalt, increasing the amount of RAP and RAS materials increases the potential for premature pavement distresses, especially cracking. This research evaluated four recycled Superpave mixtures with different RAP and RAS contents from Kansas Department of Transportation projects. Two of the mixtures contained 10% RAP and 5% RAS, while the other two mixtures contained 25% RAP but no RAS. Illinois semicircular bending and Florida indirect tension tests were performed to assess mixture cracking and fracture properties. Results showed that mixtures containing 10% RAP and 5% RAS have relatively low fracture energy, creep compliance, energy ratio, and flexibility index but high resilient modulus. These results indicate that mixtures containing 10% RAP and 5% RAS are stiffer, more prone to cracking, and tend to absorb less fracture energy. Mixtures with 25% RAP and no RAS showed the opposite behavior.
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Huang, Yue. "Life cycle assessment of use of recycled materials in asphalt pavements." Thesis, University of Newcastle Upon Tyne, 2007. http://hdl.handle.net/10443/1729.
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The increasing use of recycled materials in asphalt pavements asks for prescriptive environmental assessment on associated impacts such as the energy and CO2 footprint. Accredited by a number of industries already, life cycle assessment (LCA) is being accepted by the road industry to measure and compare the key environmental impacts of its product or process throughout the whole pavement life time, and present the results for communication with stakeholders. This thesis reviews the technical performance of asphalt pavements containing recycled materials; searches for relevant LCA resources worldwide; identifies the gap for the road industry, and the key environmental impacts of recycling in asphalt pavements. It describes the development of a LCA model for pavement construction and maintenance that accommodates recycling practice and up-to-date research findings. Details are provided of both the methodology and data acquisition. 3 real case studies are carried out during the model development, and their findings described in this thesis. This is followed by a discussion of the challenges of applying LCA to road practice, and recommendations for further work. Data in this model come from a mixed source of UK plants, EU standards and relevant LCA results. Methodology follows the ISO14040 norms. Unit processes in asphalt pavement construction are analysed and represented in this LCA model. The most significant variables in the process are identified, followed by data analysis and sensitivity check. This LCA model can be further tested and calibrated as a decision supporting tool for the asphalt industry. In order to achieve sustainable construction however, environmental assessment must be placed alongside the outcome of technical and economic studies.
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Adhikary, Kamal Babu. "Development of Wood Flour-Recycled Polymer Composite Panels As Building Materials." Thesis, University of Canterbury. Chemical and Process Engineering, 2008. http://hdl.handle.net/10092/1795.
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Wood plastic composites (WPCs) were made using matrices of recycled high-density polyethylene (rHDPE) and polypropylene (rPP) with sawdust (Pinus radiata) as filler. Corresponding WPCs were also made using virgin plastics (HDPE and PP) for comparison with the recycled plastic based composites. WPCs were made through melt compounding and hot-press moulding with varying formulations based on the plastic type (HDPE and PP), plastic form (recycled and virgin), wood flour content and addition of coupling agent. The dimensional stability and mechanical properties of WPCs were investigated. Durability performances of these WPCs were studied separately, by exposing to accelerated freeze-thaw (FT) cycles and ultraviolet (UV) radiation. The property degradation and colour changes of the weathered composites were also examined. Dimensional stability and flexural properties of WPCs were further investigated by incorporation of nanoclays in the composite formulation. To understand the changes in WPCs stability and durability performance, microstructure and thermal properties of the composites were examined. Two mathematical models were developed in this work, one model to simulate the moisture movement through the composites in long-term water immersion and the other model to predict the temperature profile in the composites during hot-press moulding.
Both rHDPE and rPP matrix based composites exhibited excellent dimensional stability and mechanical properties, which were comparable to those made from virgin plastics. Incorporation of maleated polypropylene (MAPP) coupling agent in composite formulation improved the stability and the mechanical properties. The incorporation of 3 wt. % MAPP coupling agent to WPCs showed an increase in tensile strength by 60% and 35 %, respectively, for the rHDPE based and rPP based composites with 50 wt. % wood flour. Scanning electron microscopy (SEM) images of the fractured surfaces of WPCs confirmed that the MAPP coupling improved the interfacial bonding between the plastic and the wood filler for both series of composites. Long-term water immersion tests showed that the water transport mechanism within the WPCs follows the kinetics of Fickian diffusion.
Dimensional stability and flexural properties of the WPC were degraded after 12 accelerated FT cycles as well as 2000 h of UV weathering for both recycled and virgin HDPE and PP based composites. However, the MAPP coupled composites had improved stability and flexural property degradation. The surface of the weathered composites experienced a colour change, which increased with the exposure time. The MAPP coupled composites exhibited less colour change as compared to non-coupled composites. Regarding the effect of the plastic type, the PP based composites experienced higher colour change than those based on HDPE. With weathering exposure, flexural strength and stiffness of the WPCs were decreased, but elongation at break was increased regardless of plastic type and wood flour content. MAPP coupled rPP and rHDPE based UV weathered WPCs lowered the degradation of stiffness by 50% and 75%, respectively compared to non-coupled WPCs. SEM images of the fractured surfaces of FT and UV weathered WPCs confirmed a decrease in the interfacial bonding between the wood flour and matrix. Thermal properties of weathered composites changed with weathering, but the extent of the changes depended on WPCs formulation and matrix type.
From the experimental studies on nanoclay-filled rHDPE composites, it is found that stability, flexural properties of WPCs could be improved with an appropriate combination of coupling agent, and nanoclay contents processed by melt blending. Incorporation of 1-5 wt. % nanoclay in the maleated polyethylene (MAPE) coupled wood plastic composite improved the dimensional stability and flexural properties. The thermal properties changed with the addition of nanoclay and MAPE in WPCs. In this work, a hot press-moulding model was proposed based on the one-dimensional transient heat conduction to predict the temperature profile of the WPCs during hot pressing cycle. The results from this work clearly show that rHDPE and rPP can be successfully used to produce stable and strong WPCs, which properties and performances are similar to or comparable to composites made of wood and virgin plastics. Therefore, WPCs based on recycled PP and HDPE matrix could have potential to use as construction materials.
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Cunha, Érica Cristina. "Placas recicladas de embalagens longa vida: caracterização, design e propostas projetuais." Universidade de São Paulo, 2011. http://www.teses.usp.br/teses/disponiveis/18/18141/tde-08052012-093150/.
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Esta tese apresenta o estudo das placas recicladas provenientes de embalagens Longa Vida. São compostas principalmente por polietileno de baixa densidade, alumínio e resíduos de papel. Embora as placas recicladas sejam tratadas como sustentáveis e aplicadas nas edificações com resultados positivos, são poucos os dados publicados que apresentam sua caracterização geral. Outros problemas foram identificados, como a necessidade de melhoria na tecnologia para produção, dificuldade na aceitação estética e pouco design incorporado aos produtos e objetos resultantes. Apesar dos problemas, a observação do uso crescente dessas placas resultou no traçado da hipótese desta pesquisa: as placas podem ser mais eficientes e atrativas para especificação, se utilizadas com design incorporado aos componentes arquitetônicos. A partir disso, o trabalho busca dois objetivos essenciais: traçar um perfil de caracterização técnica e de design relacionados ao material e, a partir desse repertório, apresentar propostas projetuais alternativas para uso na arquitetura. Para tanto, foram estudadas as conceituações sobre materialidade, as abordagens técnicas, estéticas e culturais e a reciclagem e produção das placas, além de ensaios térmicos de condutividade térmica e calor específico, absortância, envelhecimento acelerado em câmera de UV e o ensaio complementar de transição vítrea. A caracterização estética gerou dados sistematizados sobre textura, tamanho, espessura e estudos compositivos com outros materiais. Por fim, foram criadas três propostas projetuais como indicativos de novas possibilidades de uso das placas. Este estudo concluiu que as placas de polietileno-alumínio podem ser utilizadas em várias superfícies arquitetônicas, desde que cuidadosamente incorporadas aos sistemas, prezando-se a qualidade da produção, projeto, design e acabamento.This thesis presents the study of plates from recycled cartoon packaging. They are composed mainly of low density polyethylene, aluminum and paper waste. Although the plates are treated as recycled and sustainable, applied in building with positive results, there are few published data to show their general characterization. Other problems were identified: need for improvement of production technology, difficulty in accepting some design aesthetics and few design incorporated to the products and the resulting objects. Despite the problems, the observation of the growing use of these plates resulted in the design of the hypothesis of this research: the plates can be more efficient and attractive to specification if used with design incorporated into the architectural components. Based on this, the work seeks two essential goals: a profile of technical characterization and design-related material, and from this repertoire, present proposals about design alternatives for use in architecture. To this end, were studied the concepts of materiality, in technical, aesthetics and cultural approaches and the recycling and production of plates, besides the thermal tests of thermal conductivity and specific heat, absorptance, accelerated aging and UV camera and additional test of glass transition. The aesthetic characterizations generated systematic data on texture, size, thickness and compositional studies with other materials. Finally, were created three project proposals as indicative of new possibilities to use the plates. Through this study it can be concluded that the polyethylene-aluminum plates can be used in various architectural surfaces, as long as they are carefully incorporated into the systems, maintaining the quality the quality of production, design and finish.
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Kozlesky, Joel Aden. "Investigation of the Seismic Capacity of a School Built with Recycled Materials." University of Toledo / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1325863280.
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Blankenagel, Brandon J. "Characterization of Recycled Concrete for use as Pavement Base Material." Diss., CLICK HERE for online access, 2005. http://contentdm.lib.byu.edu/ETD/image/etd1001.pdf.
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Nounezi, Thomas. "Light Weight and High Strength Materials Made of Recycled Steel and Aluminum." Thèse, Université d'Ottawa / University of Ottawa, 2012. http://hdl.handle.net/10393/20523.
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Recycling has proven not only to address today’s economical, environmental and social issues, but also to be imperative for the sustainability of human technology. The current thesis has investigated the feasibility of a new philosophy for Recycling (Alloying-Recycling) using steel 1020 and aluminum 6061T6. The study was limited to the metallurgical aspects only and has highlighted the potential of recycled alloys made of recycled aluminum and steel to exhibit substantially increased wear resistance and strength-to-weight ratio as compared to initial primary materials. Three alloy-mixtures are considered: TN3 (5wt% 1020 +95wt% 6061T6); TN5 (0.7wt% 1020 + 99.3wt% 6061T6); and TN4 (10wt% 6061T6 + 90wt% 1020). A Tucker induction power supply system (3kW; 135-400 kHz) is used to melt the alloy mixtures for casting in graphite crucibles. Heat treatment of the cast samples is done using a radiation box furnace. Microscopy, Vickers hardness and pin-on-disc abrasive wear tests are performed.
Casting destroyed the initial microstructures of the alloys leading to a hardness reduction in the as-cast and solution heat-treated aluminum rich samples to 60 Hv from 140 Hv. Ageing slightly increased the hardness of the cast samples and provided a wear resistance two times higher than that of the initial 6061T6 material. On the steel rich side, the hardness of the as-cast TN4 was 480 Hv, which is more than twice as high as the initial hardness of steel 1020 of 202 Hv; this hints to strong internal and residual stress, probably martensite formation during fast cooling following casting. Solution heat treatment lowered the hardness to the original value of steel 1020, but provided about ten (10) times higher wear resistance; this suggests higher ductility and toughness of normalised TN4 as compared to 1020. In addition, TN4 exhibits about 25% weight reduction as compared to 1020.
The actual recycling process and the effect of non-metallic impurities shall be investigated in future works. Also, the casting and heat treatment processes need to be improved.
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Hayles, Meika. "Investigation Into the Mechanical Properties and Structural Behaviour of Recycled Concrete Members." Thesis, Université d'Ottawa / University of Ottawa, 2018. http://hdl.handle.net/10393/37801.
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Recycled concrete aggregates (RCA) are an eco-sustainable alternative to traditional aggregates. The equivalent mortar volume method has been developed to design RCA concrete with comparable mechanical and strength properties to natural aggregate concrete by accounting for the adhered mortar that distinguishes RCA from natural aggregates. This method also presents an opportunity to reduce the cement content of RCA concrete, increasing its cement efficiency. Modifications to mix design procedures were introduced to improve the fresh state properties of RCA concrete with a 19% cement reduction compared to the control mix. Beams cast with the RCA concrete had similar flexural capacity to corresponding control beams, however the shear strength varied as a function of RCA content in the concrete. Polished core samples taken from RCA members showed that crack development and aggregate interlock in RCA members is influenced by the aggregate properties and the spacing of coarse aggregates, indicating that knowing the compressive strength of RCA concrete is not the only parameter required for member design.
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Voth, Christopher Ray. "Lightweight sandwich panels using small-diameter timber wood-strands and recycled newsprint cores." Pullman, Wash. : Washington State University, 2009. http://www.dissertations.wsu.edu/Thesis/Fall2009/c_voth_120609.pdf.
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Thesis (M.S. in civil engineering)--Washington State University, December 2009.Title from PDF title page (viewed on Jan. 26, 2010). "Department of Civil and Environmental Engineering." Includes bibliographical references.
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Williamson, Gregory Scott. "Investigation of Testing Methods to Determine Long-Term Durability of Wisconsin Aggregate Resources Including Natural Materials, Industrial By-Products, and Recycled/Reclaimed Materials." Thesis, Virginia Tech, 2005. http://hdl.handle.net/10919/31822.
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The Wisconsin Department of Transportation (WisDOT) uses approximately 11,000,000 tons of aggregate per year for transportation projects. Being able to select durable aggregates for use in transportation projects is of considerable importance, if the aggregate deteriorates then the constructed facility requires premature repair, rehabilitation or replacement. Realizing the importance and also that deficiencies in the current WisDOT testing protocol may exist, it has been concluded that the durability-testing program for Wisconsin aggregates needs to be updated. For example, WisDOT is currently using the Sodium Sulfate Soundness Test (ASTM C 88) to measure durability, a test that was put in place in 1960. The ability of this test to predict durability performance and simulate field conditions is questionable and it has also been criticized for its lack of precision.
It should also be noted that the use of recycled and reclaimed aggregates has increased in recent years and not all typical durability tests can be used for testing these aggregates. The Sulfate Test in particular cannot be used for testing Recycled Concrete Aggregates (RCA) because the chemical reaction produces erroneous and misleading results.
This project has identified recent advances in the understanding and testing of aggregate durability. An in depth literature review has been conducted and from the compiled information a laboratory testing program was developed. Selection of the tests was based upon the tests' precision, efficiency, and predictive capabilities. In the laboratory-testing phase of this project the proposed durability tests along with current WisDOT durability tests were used to evaluate the full range of Wisconsin aggregates.
From the test results it was found that the WisDOT aggregate testing protocol could be reduced substantially by eliminating many of the testing requirements for aggregates that have a vacuum saturated absorption of less than 2%. Also, the addition of several tests was ruled out due to their lack of correlation with field performance records. The Micro-Deval abrasion test is recommended for inclusion in WisDOT testing protocol as a test to measure the abrasion resistance of aggregate while the L.A. Abrasion test is better suited as a measure of aggregate strength. Additional conclusions were made based on the durability testing conducted and an overall testing protocol has been developed and is recommended for implementation by WisDOT.Master of Science
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Traut, Michelle. "Recycled building materials : the likely impact on affordable housing in the Western Cape." Thesis, Peninsula Technikon, 2001. http://hdl.handle.net/20.500.11838/1057.
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Thesis (MTech (Built Environment))--Peninsula Technikon, 2001The construction industry globally, contributes between 18% and 24% of the GDP, and because of its labour intensive characteristics, contributes handsomely to total employment, forming important backward and forward linkages with the rest of the economy. Nevertheless, the extent and sophistication of these linkages crucially depend on the relative development of the construction industry relative to the overall economy. In the developing countries, these linkages are not very strong because of the use of informal materials, which is not commercialised and whose opportunity costs are often zero, and the huge imports of construction materials used in the modem sector of the economy. However, whether in the developed or developing economies, the construction industry is a major contributor to economic growth and development by providing the necessary infrastructure that facilitates production, consumption and recreational activities. In fulfilling these activities, the construction industry generates huge wastes of which only a tiny proportion are recycled and reused. However, in economies and countries where adequate and functional housing is a problem mainly due to lack of affordability, recycling and reuse of construction waste is a necessary prerequisite to enhancing housing affordability in these countries. This is the current situation that South Africa finds itself "''here because of its past history of 'apartheid', economic opportunities and amenities were denied to the blacks. There is nowhere that this deprivation is more pronounced than in the built environment sector where housing shortages and general disamenities prevail. High levels of unemployment further exacerbate the situation, - - which is a consequence of low skills and high illiteracy-rates. Thus, housing demand and supply by this group of the population are most likely, on the evidence available, to fall predominantly within the low-income housing category. Presently, all households falling into this category rely on financial assistance from the government to facilitate low-cost housing consumption because of pervasive poverty, which itself is due to the very high unemployment rate, illiteracy, lack of skills and general deprivation: a legacy of 'apartheid' policies enforced by previous government. The dilemma however is how to meet the huge housing demand within the limited resources available to the government on the one hand, and on the other, to satisfy such demand without compromising the environmental sustainability of the physical environment. Thus, the thesis aims to determine ways in which the construction industry could contribute to the sustainability of the carrying capacity of the biophysical environment and enhance social sustainability by facilitating affordability through the possible reductions to construction costs through recycling and reuse. By means of questionnaires and detailed interviews, underscored by a qualitative research approach, the potential of construction recycling and the possible contributions to environmental sustainability and housing affordability are determined. At completion, it is expected that this work will not only contribute to existing knowledge but would be of significance in terms of policy formulation to construction industry practitioners, central and local government policy makers, and other governmental and non-governmental organisations operating in the area of housing.
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Obaid, Arkan Khudhayer. "A Comprehensive Study towards Increasing the Use of Recycled Materials in Asphalt Pavements." Ohio University / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1570016926258889.
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Mahasaranon, Sararat. "Acoustic and thermal properties of recycled porous media." Thesis, University of Bradford, 2011. http://hdl.handle.net/10454/5516.
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This thesis is concerned with developing porous materials from tyre shred residue and polyurethane binder for acoustic absorption and thermal insulation applications. The resultant materials contains a high proportion of open, interconnected cells that are able to absorb incident sound waves through viscous friction, inertia effects and thermal energy exchanges. The materials developed are also able to insulate against heat by suppressing the convection of heat and reduced conductivity of the fluid locked in the large proportion of close-cell pores. The acoustic absorption performance of a porous media is controlled by the number of open cells and pore size distribution. Therefore, this work also investigates the use of catalysts and surfactants to modify the pore structure and studies the influence of the various components in the chemical formulations used to produce these porous materials. An optimum type and amounts of catalyst are selected to obtain a high chemical conversion and a short expanding time for the bubble growth phase. The surfactant is used to reduce the surface tension and achieve a homogenous mixing between the solid particulates tyre shred residue, the water, the catalyst and the binder. It is found that all of the components significantly affect the resultant materials structure and its morphology. The results show that the catalyst has a particularly strong effect on the pore structure and the ensuing thermal and acoustical properties. In this research, the properties of the porous materials developed are characterized using standard experimental techniques and the acoustic and thermal insulation performance underpinned using theoretical models. The important observation from this research is that a new class of recycled materials with pore stratification has been developed. It is shown that the pore stratification can have a positive effect on the acoustic absorption in a broadband frequency range. The control of reaction time in the foaming process is a key function that leads to a gradual change in the pore size distribution, porosity, flow resistivity and tortuosity which vary as a function of sample depth. It is shown that the Pade approximation is a suitable model to study the acoustic behaviour of these materials. A good agreement between the measured data and the model was attained.
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Lynch, Alan Gerald. "Trends in back-calculated stiffness of in-situ recycled and stabilised road pavement materials." Thesis, Stellenbosch : Stellenbosch University, 2013. http://hdl.handle.net/10019.1/85857.
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Thesis (MEng)-- Stellenbosch University, 2013.ENGLISH ABSTRACT: Two common methods of road pavement, granular material stabilisation used in road construction throughout South Africa today include Cold in Place Recycling (CIPR) and stabilisation with cement or bitumen and an active filler to create Bitumen Stabilised Materials (BSM). As part of the updating of the South African Pavement Design Method (SAPDM) an experimental section, investigating the structural capacity of cement and lime stabilised and BSM pavement layers, was constructed and will be monitored over a two year period. As part of this study Falling Weight Deflectometer (FWD) measurements were taken on the various experimental stabilised pavement layers constructed. The FWD deflection data, measured at various time intervals over a 360 day period, forms the basis of the study presented here. The objective of this thesis was to identify typical back-calculated layer stiffnesses and their variability over time for the various in-situ recycled and stabilised base layers constructed within the experimental section. Stabiliser type, content and layer thicknesses were varied across experimental sub-sections. Trends in back-calculated stiffness of cement stabilised base layers consistently showed significant reductions in layer stiffness subsequent to construction traffic loading. Subsequent to the initial reduction in stiffness little change in stiffness was noted under normal traffic loads. Observations on the trends in back-calculated stabilised layer stiffness per material type over time indicated that seasonal moisture and temperature fluctuations have an effect on the stiffness of the pavement structure as a whole. BSM materials showed significant variability over time in-line with seasonal variability in the supporting subgrade stiffness in the southbound lane. BSM materials with 1% cement added in the northbound lane show initial stiffness reductions due to direct rainfall application however a significant increase in layer stiffness occurs up to 360 days after construction. BSMs with 2% cement in the northbound lane show significant increases in layer stiffness over the 360 day observation period. No significant difference in stiffness trend was observed between BSM emulsion a BSM foam materials. The BSM emulsion with 0.9% residual bitumen and 1% cement was observed to show rapid reduction in stiffness upon opening to traffic and reverting to stiffness values similar to an unbound material of approximately 350 MPa. Cement and lime stabilised materials showed typical post 28 –day average stiffnesses per sub-section ranging between 600 MPa and 1800 MPa. BSM foam with 1% cement added were observed to have average stiffnesses per sub-section in the range of 400MPa to 2200 MPa and BSM emulsion with 1% cement with stiffnesses between 400 MPa to 1700 MPa over the 360 day period. BSMs with 2% cement added showed stiffness ranges between 900 MPa to 4300 MPa for BSM foam and 900 MPa to 3900 MPa for BSM emulsions over the 360 day period. The spatial variability of back-calculated stiffness per sub-section of a particular stabilisation design was significant and was observed, through the Co-efficient of Variation (COV), to increase over time. The effect of the observed variability when incorporated into a pavement design scenario, requiring a design reliability of 90%, showed 50% of the pavement structure would be overdesigned by a factor of 4. With respect to the current philosophies on the development of stiffness over time of cement and lime stabilised and BSM pavement layers some useful observations were made. Cement stabilised materials correlate well with stiffness development theories predicted by previous studies. Theories relating to the stiffness development of BSMs however did not predict the levels of variability in base layer stiffness observed on the experimental section. The continued observation of the experimental section for another year will give greater insight to the stiffness trends of the stabilised materials discussed above.
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Fahd, Faisal. "Risk Assessment Approach for Evaluating Recycled Materials Use in Road Construction: A Pilot Study." University of Toledo / OhioLINK, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1230027556.
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Cabrera, Alvino Géraldine. "Eco-design and processing of recycled multilayer/multiphase polymer materials : Structure-properties-process relationship." Thesis, Lyon, 2020. http://www.theses.fr/2020LYSEI076.
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Dans un contexte d’économie circulaire, les premiers travaux de la thèse ont été consacrés à l’étude de l’aptitude à la mise en forme de films souples recyclés provenant de déchets agricoles d’enrubannage et d’horticulture. Ces films multicouches contiennent initialement un additif conférant au produit final un caractère collant. Lors de leur recyclage, cet additif est toujours présent et migre à la surface. Un accent particulier a été dédié à la compréhension et l’étude des mécanismes de migration de cet additif en fonction de l’architecture moléculaire des polyéthylènes utilisés ayant des taux de branchements différents. Pour ce faire, des mélanges modèles, avec ou sans charges minérales, ont été élaborés. Outre des études morphologiques et microstructurales, des méthodologies expérimentales originales ont été mises en place pour étudier la cinétique de migration/diffusion avec des dispositifs tribo-rhéométriques et de suivi du "tack" en surface des films. Quant au comportement rhéologique en cisaillement et en élongation, il est influencé par la présence de cet additif. La deuxième partie de cette étude a été consacrée à l’appréhension des réalités de l’activité du recyclage d’autres films mutlicouches souples à base de polypropylène et polyéthylène. Compte tenu de la complexité de ces gisements, nous avons choisi d’étudier des mélanges modèles équivalents en leur associant des compatibilisants de nature physique. L’influence de ces derniers sur les propriétés rhéologiques, morphologiques et mécaniques a été ensuite évaluée. Cette étude a été ensuite transposée à des systèmes multiphasés post usage. Les derniers travaux ont été dédiés à une approche prospective. Il s’agit d’aller de l’éco-design à l’élaboration de multi-micro/nanocouches facilement recyclables. L’originalité de cette étude consiste à limiter le nombre de constituants, à réduire/contrôler les épaisseurs des couches et éviter l’utilisation des couches de liants. Enfin, leurs propriétés rhéologiques, morphologiques et mécaniques ont été évaluées en fonction des cycles de recyclage mécaniqueIn the context of a circular economy, the first works of the thesis were devoted to the study of the processing ability of recycled flexible films from agricultural bale wrapping film's waste. These multilayer films initially contain an additive that gives the final product a sticky character. During recycling, this additive is still present and migrates to the surface. A particular emphasis has been placed on understanding and studying the migration mechanisms of this additive according to the molecular architecture of the polyethylenes used with different branching content. Model blends, with or without mineral fillers, were prepared for this purpose. In addition to morphological and microstructural studies, original experimental methodologies have been set up to study the migration/diffusion kinetics with tribo-rheometry and film surface's "tack" monitoring devices. As for the rheological behaviour in shear and elongation, it is influenced by the presence of this additive. The second part of this study was devoted to understanding the realities of the recycling activity of other polypropylene- and polyethylene-based multilayer films. Given the complexity of these materials, we chose to study equivalent model blends by combining them with physical compatibilizers. The influence of the latter on the rheological, morphological and mechanical properties was then evaluated. This study was then transposed to postconsumption multiphase systems. The last studies were devoted to a future-oriented approach. This involves going from eco-design to the development of easily recyclable multimicro/ nanolayers. The originality of this study consists in limiting the number of constituents, reducing/controlling the thickness of the layers and avoiding the use of tie-layers. Finally, their rheological, morphological and mechanical properties have been evaluated according to number and type of mechanical recycling cycles
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Cinkilic, Emre. "Alloy Design and Precipitation Modeling of High Fe Concentration Recycled Cast Aluminum Alloys for Structural Applications." The Ohio State University, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=osu1555599698005398.
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Bouarroudj, Mohamed ElKarim. "Utilisation de matériaux naturels modèles pour la formulation de mortier contenant des sables et des fines de granulats recyclés." Thesis, Ecole nationale supérieure Mines-Télécom Lille Douai, 2019. http://www.theses.fr/2019MTLD0016.
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Les granulats de béton recyclé (GBR) ne sont pas suffisamment utilisés dans le secteur de la construction, principalement en raison de leur grande capacité d’absorption d’eau. Ces matériaux sont en effet composés de granulats naturels concassés et de pâte de ciment durcie adhérente qui possède une forte porosité. La première partie de ce travail de recherche s’intéresse à la valorisation des GBR de dimensions inférieures à 4 mm (sables recyclés) dans une formulation de mortier. Les comportements à l’état frais et durci de mortiers fabriqués soit avec un sable recyclé soit avec un sable naturel modèle sont comparés. Le sable naturel modèle est conçu dans le but d’obtenir des caractéristiques physiques proches de celles du sable recyclé. Cette démarche permet de mettre en évidence l’influence de la substitution d’un sable naturel par un sable recyclé de caractéristiques voisines. La seconde partie de ce travail consiste à trouver une piste de valorisation pour les particules de GBR inférieures à 125 µm. L’objectif est ici d’utiliser la poudre issue du broyage de GBR comme addition minérale. Un travail de caractérisation de la poudre recyclée permet de mettre en évidence que la fine recyclée reste poreuse après broyage. Un modèle théorique et une méthodologie expérimentale permettant d’estimer cette porosité sont développés. Enfin, des mortiers fabriqués avec un filler calcaire et une fine recyclée sont comparés, les résultats montrent que la fine recyclée peut être utilisée comme addition minéraleRecycled concrete aggregates (RCA) are not enough used in the construction sector, mainly because of their high water absorption capacity. These fine particles are composed of crushed natural aggregate and adherent hardened cement paste. The first part of this work consists in valuing particles smaller than 4 mm of an RCA in a mortar composition. Thus, the fresh and hardened behavior of mortar performed with recycled fine aggregate and model natural aggregate have been compared. The natural model fine aggregate has been performed to have an equivalent physical characteristics with the recycled one. This approach helped to understand the hardened behavior of the mortar made with recycled fine aggregate. The second part of this work consists in finding a recovery track for particles smaller than 125 μm of RCA, the goal is to use them as mineral addition. A characterization work show that the recycled powder is porous, thus a theoretical model and an experimental methodology allowing to estimate this porosity are developed. Finally, a comparison between mortar made with a limestone powder, and a recycled powder are compared. The results show that the recycled powder can be used as mineral additive in mortar composition
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Jamshidi, Mohammadsadegh. "A process for recycling thermosetting foams and the incorporation of recycled foams into structural composite panels." Thesis, Queen Mary, University of London, 2009. http://qmro.qmul.ac.uk/xmlui/handle/123456789/581.
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In Europe, the rapidly growing thermosetting foam insulation products industry comprises over 11,500 companies employing over a third of a million people and is worth about 6 billion Euros in trade. It is currently estimated 4-7 % of total new UK production is scrapped and goes to landfill. Estimated costs of disposing of this waste foam are of the order of £20 million/annum to the producers of foam panels and insulation blocks. A new strategic direction for rigid polymeric foams waste management has been developed converting the scrapped thermosetting foams into high added value material that can be used in various applications such as fire resistant insulating applications. Thus by this new innovative recycling process the waste is not only eliminated but benefits can be gained from the new material that comes out of it as a structural composite panel. The project involves a new concept that mixes fragmented scrap thermosetting foams materials with a proprietary liquid that cures at ambient temperature to form an incombustible material capable of withstanding high temperatures >1000 C. In this research different kind of polymeric foams used for manufacturing of reconstituted recycled samples. Sodium silicate solution has been chosen as the binder to binds shredded foams together. Due to fastening of sodium silicate curing different kind of acidic powders have been tested. For increasing of post properties after curing variety of fillers as an additive have been tried through out this research. Different foam cutting methods have been tested to find the suitable shredding routine. Rationale for selection of generic binder and its hardeners/fillers has been discussed in this project. Also as post properties evaluation compressive strength, thermal resistance, fire resistance and acoustic properties of recycled structural composite panels have been measured. At last a model for thermal conductivity of composite panels is developed.
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Nguyen, Viet Hung. "Effects of laboratory mixing methods and RAP materials on performance of hot recycled asphalt mixtures." Thesis, University of Nottingham, 2009. http://eprints.nottingham.ac.uk/10863/.
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The primary work reported in this thesis is concerned mainly with the effects of different mixing methods and RAP materials on homogeneity and mechanical properties of hot recycled asphalt mixtures. The recycled asphalt mixture conforms to the requirement of BS 4987-1 (2005) for dense bitumen macadam size 10 mm (DBM 10 mm). The proportion of RAP in the recycled mixture is 40%. RAP materials are artificially aged and processed in the laboratory to prevent the variability of RAP gradation, bitumen content, and the origin. Laboratory RAP is also used to assure that every single RAP particle is an agglomerate of RAP aggregate and binder. The mixing procedures include Black Rock (BR), Complete Blending (CB), the SHRP procedure, and a newly developed field simulation method (FS). The primary difference between these methods is the mixing mechanism. The BR case implies the situation in which there is completely no interaction between RAP and virgin binder. On the contrary, RAP and virgin binder are fully interacted in the CB case. The mixing procedures for BR and CB cases conform to those for conventional asphalt mixtures. However, the bitumen for BR case is pure virgin bitumen. In addition, the bitumen for CB is the blend between RAP and virgin binder. The RAP/virgin binder proportion is 4/6. In the SHRP method, RAP is preheated at 110oC for two hours before being mixed with virgin aggregate and binder for 2 minutes at 130oC. In the FS method on the contrary, the mixing procedure duplicates what occurs in the asphalt mixing plant. RAP is mixed with superheated virgin aggregate (215oC) for different durations before this combination is blended with virgin bitumen for 2 minutes at 130oC. The RAP/superheated virgin aggregate mixing duration starts from short mixing time where RAP still exists at approximately original size and gradually increases until the change in RAP lump size is insignificant. Depending on the size of RAP used, RAP/superheated virgin aggregate mixing duration varies from 1 to 8 minutes. The homogeneity of hot recycled asphalt mixture is examined by using virgin binder with a different colour from that of RAP binder. The colour of virgin binder is obtained by mixing clear binder (Shell Mexphalt C 160/220 Pen) with iron oxide pigment. The proportion of pigment is 10% by weight of the binder making this binder red. The use of virgin binder with different colour from that of RAP binder helps to clearly differentiate the locations of RAP and virgin materials. Surfaces of slices cut from compacted recycled specimens are photographed by digital camera. The analysis of these surfaces in vertical order allows the locations of RAP material to be qualitatively identified in a 3D manner. Stiffness modulus values of samples for homogeneity assessment are also determined by indirect tensile stiffness test. The stiffness test is carried out in four directions along the circumference of each specimen with 45o angular increments. The experimental results show that the stiffness measurement in four directions can indicate the heterogeneity of recycled mixture. The variation in stiffness values in different measured directions will be substantial for heterogeneous mixtures and minor in the case where recycled mixtures are homogeneous. The results indicate there are mutual relations between mixing effort, homogeneity, and stiffness values of recycled asphalt mixtures. The longer mixing time will enhance the homogeneity and reduce the variation in stiffness values of recycled mixture. In addition, as more RAP and virgin binder are incorporated, the stiffness values of recycled mixture generally increase once the mixing time is extended. As the clear binder is dyed red by 10% by weight of iron oxide, the proportion of the pigment certainly alters the flow characteristic of binder. This might affect the mixing process and rejuvenating effect between virgin and aged binder. Therefore, the effects of mixing methods and RAP sizes on mechanical performance of hot recycled asphalt mixtures are further investigated using normal straight run bitumen 160/220 Pen as virgin binder. The assessment indicators include stiffness modulus, resistance to fatigue damage, and resistance to permanent deformation. The experimental results indicate that the conventional laboratory mixing method (SHRP) tends to overestimate the mechanical properties of recycled asphalt mixture. The long RAP preheating time that never exists in the industry coincidentally enhances the reaction between RAP and virgin binder. The long RAP preheating time also slightly alters the properties of RAP binder. For the FS method, the increase in mixing duration significantly improves the homogeneity level of recycled mixtures. The homogeneity level is also substantially affected by the size of RAP material. For the same mixing effort, the mixtures comprised of small RAP are generally more homogeneous than those made from larger RAP. The more homogeneous the mixture, the more interaction between RAP and virgin binder. Therefore, recycled mixtures become stiffer and have better resistance to permanent deformation and fatigue failure. A slightly linear increase in stiffness can result in an exponential increase in fatigue life of the recycled mixture. The mechanical properties including stiffness modulus, resistance to fatigue damage, and resistance to permanent deformation of hot recycled asphalt mixtures are not similar to those of the BR or CB mixtures, even at the favourable condition where RAP is preheated for 2 hours at 110oC in the SHRP method and 8 minutes mixing duration in the FS method. This implies that RAP does not act as Black Rock. In addition, the assumption that RAP and virgin binder are fully blended also never exists in the recycled asphalt production process.
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Jayakody, Arachchige Shiran Pradeep. "Investigation on characteristics and performance of recycled concrete aggregates as granular materials for unbound pavements." Thesis, Queensland University of Technology, 2014. https://eprints.qut.edu.au/78131/1/Shiran%20Pradeep_Jayakody%20Arachchige_Thesis.pdf.
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This research was a step forward in investigating the characteristics of recycled concrete aggregates to use as an unbound pavement material. The results present the guidelines for successfully application of recycled concrete aggregates in high traffic volume roads. Outcomes of the research create more economical and environmental benefits through reducing the depletion of natural resources and effectively manage the generated concrete waste before disposal as land fill.
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Fahd, Faisal. "Risk assessment approach for evaluating recycled material use in road construction : a pilot study /." Connect to full text in OhioLINK ETD Center, 2008. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=toledo1230027556.
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Thesis (M.S.C.E.)--University of Toledo, 2008.Typescript. "Submitted as partial fulfillment of the requirements for Masters of Science degree in Civil Engineering." "A thesis entitled"--at head of title. Bibliography: leaves 90-92.
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Delaware, Kamil. "Construction and demolition waste management : assessment of demand and supply of recycled materials in the Western Cape." Bachelor's thesis, University of Cape Town, 2003. http://hdl.handle.net/11427/15416.
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Includes bibliographical references (leaves 96-100).Concern for environmental degradation has been a motivating factor in the efforts to reuse or recycle construction and demolition waste. The intention is not only to reduce environmental desecration, but also to recycle the construction and demolition waste into potential building materials to be reused elsewhere. This study investigated the supply and demand of recycled construction materials in the Western Cape, and aimed to determine the perception held by important stakeholders about these materials. A qualitative analysis of the case study results revealed that poor waste management plans implemented on construction and demolition sites have affected the quality, supply and price of recycled materials. In addition to this it was also revealed that the negative perceptions regarding recycled materials were the major barriers to creating an established secondary market. Inadequate knowledge and experience were major contributors to resistance to change of perceptions. A case study was conducted on Malans Quarries Recyclers in order to determine the supply of raw materials (construction and demolition waste) reaching the recycling plant; the supply of recycled materials to the end user (consumer); and the recycling process that takes place. A sample of fifteen respondents from a variety of large, medium and small construction contractors, as well as consultants and civil engineering companies, completed a questionnaire to determine the demand for and perceptions about these materials. The qualitative analysis of the results of the questionnaires showed that the majority of respondents still preferred to use primary materials over recycled materials. However, it appears that the gap between respondents who prefer to use primary materials, and those who utilize recycled materials, has narrowed in comparison to results obtained in previous studies. It seems that there may be more usage of recycled materials in the future. The results also revealed that tax cuts, could be a good economic incentive to encourage the use of recycled material. The questionnaire results also revealed that the majority of the respondents believed that landfill taxes where not effective in discouraging the illegal dumping of waste, and that the lack advertisements, and difficulties in obtaining recycled materials played a crucial role in the under-use of recycled materials.
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Alvarez, Cabrera Anthony Robert Jingary, and Gonzales Jose Antonio Sosa. "Mejoramiento de las propiedades mecánicas de un suelo arcilloso de alta plasticidad del Caserío Bello Horizonte, distrito de Curimaná, departamento de Ucayali, adicionando pet reciclado." Bachelor's thesis, Universidad Peruana de Ciencias Aplicadas (UPC), 2020. http://hdl.handle.net/10757/653122.
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Ante la problemática que presentan los suelos arcillosos de alta plasticidad, como la vulnerabilidad a variaciones de volumen, produciendo asentamientos diferenciales ocasionando daños en las estructuras, es por factores como este que se decidió buscar una alternativa de mejora para sus parámetros como el incremento de la resistencia, ángulo de fricción y cohesión de un suelo arcilloso de alta plasticidad (CH). En la ejecución de una obra civil, estos parámetros generalmente no se ajustan a los requerimientos del proyecto, por tal razón se debe buscar una solución para la estabilidad del suelo implicado en cualquier construcción. La constante búsqueda del mejoramiento de las condiciones ambientales ha llevado a la utilización de los residuos del plástico para reforzar el suelo y mejorar sus propiedades mecánicas y físicas. Es por ello que de acuerdo con nuestra propuesta se intenta incrementar data para el uso de este material alternativo como propuesta de mejoramiento del suelo, obteniéndose resultados interesantes y distintos a lo hallado en otras investigaciones que utilizaron similares materiales. Se optó por la trituración del tereftalato de polietileno (PET) obteniendo un PET reciclado de 3-5 mm de longitud como material de refuerzo para mejorar las propiedades mecánicas del suelo. De acuerdo con los ensayos de proctor estándar y corte directo, se determinó que el porcentaje óptimo de adición sea de 1% debido a que se observó un mejor comportamiento del material de estudio con respecto a las otras mezclas analizadas con 0.5%, 2.5% y 3.5%.To the problems posed by clay soils of high plasticity, such as vulnerability to variations in volume, producing differential settlements causing damage to structures, it is due to factors such as this it was decided to seek an alternative enhancement to parameters such as increased resistance, friction angle and cohesion of a high plasticity clay soil (CH). In the execution of civil works, these parameters generally do not conform to the requirements of the project, for that reason should seek a solution for the stability of the soil involved in any construction. The constant search for improving environmental conditions has led to the use of waste plastic to reinforce the soil and improve its mechanical and physical properties. That is why according to our proposal we try to increase data for the use of this alternative material as a soil improvement proposal, obtaining interesting and different results to that found in other investigations that used similar materials. We chose crushing polyethylene terephthalate (PET) obtaining a recycled PET 3-5 mm length as a reinforcing material to stabilize and improve the mechanical properties of the soil. According to the standard proctor and direct shear tests, it was determined that the optimal percentage of addition is 1% because a better behavior of the study material was observed with respect to the other mixtures analyzed with 0.5%, 2.5% and 3.5%.
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Nguyen, Vu Nam. "Valorisation de fines et granulats issus de bétons recyclés comme matériaux cimentaires : Enhancement of fine and aggregate issued from recycled concrete as cementitious materials." Thesis, Toulouse 3, 2016. http://www.theses.fr/2016TOU30058/document.
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La consommation de béton devient de plus en plus importante en raison d'une urbanisation accrue nécessitant la réhabilitation et la construction de bâtiments et d'infrastructures. Néanmoins, la production de béton qui doit accompagner le développement urbain entraîne des problèmes environnementaux relatifs à la préservation des ressources naturelles qui ne sont pas inépuisables. Malgré des efforts de recyclage, la plupart des matériaux recyclés sont généralement utilisés pour les travaux routiers ou de remblai. En s'inscrivant dans le Projet National Recybéton (PN), ce travail de thèse a pour objectif d'apprécier la valorisation du recyclage des matériaux issus des bétons déconstruits en les intégrant dans de nouveaux bétons. Deux types de matériaux recyclés sont étudiés, les fines qui sont produites en quantités importantes lors de la phase de concassage du béton d'ouvrage démoli, et les granulats (sable et gravillon) qui sont pour la plus grande part issus des granulats naturels initiaux. Le présent travail a donc pour mission de quantifier des propriétés des matériaux cimentaires aux différents états lors de l'utilisation de : * granulats recyclés dans le squelette granulaire, * fines de sable broyé (SBC) et de fines de dépoussiérage (FBC) en tant qu'additions minérales. La première partie est dédiée à l'étude de l'influence de l'état hydrique des granulats recyclés (sable et gravillon) sur l'évolution de la rhéologie du béton dans le temps, et à l'étude de leur incidence sur la résistance à la compression à 28 jours. Les résultats obtenus dans la limite du contexte expérimental nous permettent de suggérer des recommandations sur l'état hydrique initial des recyclés et sur leur taux d'incorporation dans le mélange de béton. La deuxième partie présente l'évaluation de la faisabilité d'utiliser des sables de bétons concassés et des fines de bétons concassés (récupérées industriellement) comme addition minérale dans les matériaux cimentaires. A partir des résultats obtenus, il est possible d'apprécier dans quelle mesure ces fines sont compatibles avec les matrices cimentaires aux états frais, durcissant et durci. La troisième partie propose une piste pour limiter le problème de la Réaction Alcali-Granulat (RAG) dans le béton de granulats recyclés. La stratégie est basée sur deux volets. La première insiste à vérifier l'applicabilité du fascicule de documentation FD P18-464 lors de l'utilisation de granulats recyclés. Le deuxième examine l'intérêt de l'utilisation des additions minérales pour limiter, voire empêcher la RAGThe concrete consumption has been becoming more and more important due to the increase of urbanization requiring the rehabilitation and the construction of buildings and infrastructure. Nevertheless, the concrete production that accompanies the urban development leads to many environmental problems related to the preservation of natural resources which are not inexhaustible. Despite of recycling efforts, most of recycled materials are typically used for road works or embankment. By participating in the French National Project Recybéton, this thesis aims to assess the enhancement of recycling materials issued from deconstructed concretes by incorporating them in new concrete design. Two types of recycled materials will be studied, the powder produced in large quantities during the crushing phase of demolished concrete, and the aggregates (sand and gravel) whose the most part issued from the initial natural aggregates. Therefore, research study aims to quantify the properties of cementitious materials in various states by the use of: • recycled aggregates in the granular skeleton, grinded recycled concrete sand and powder of dust removal as supplementary cementing materials. The first part is dedicated to the study of the influence of moisture states of recycled aggregates (sand and gravel) on the concrete's rheology evolution in time and the study of their impact on 28 days compressive strength. The results obtained within the limit of experimental context will allow suggesting recommendations on the initial moisture state of recycled aggregates and their incorporation's rate in the concrete mix. The second part presents the evaluation of the feasibility of using grinded recycled concrete sand and crushed concrete powder (industrially recovered) as supplementary cementing materials. From the results, it will be possible to assess the extent that these fines are compatible with cement matrix in the fresh state, hardening state and hardened state. The third part proposes a way to limit the problem of Alkali-Aggregate Reaction (AAR) in recycled concrete. The strategy is based on two methods. The first insists to verify the applicability of the FD P18-464 documentation when using recycled aggregates. The second examines the interest in the use of mineral additives to limit or even prevent the AAR
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Shaheen, Ehab T. "Long Term Performance of Corrugated HDPE Pipes Produced with Post-Consumer Recycled Materials Under Constant Deflection." Ohio University / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1541422245636659.
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Chatzikos, Nikolaos. "Influence of fluxing agent on the quality of recycled Aluminium billets." Thesis, KTH, Materialvetenskap, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-231166.
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The quality of aluminium cast billets is highly dependent on the cleanliness of the material. Hydro Extruded Solutions are casting billets in Sjunnen that are delivered for extrusion within the same company. In order to produce extruded profiles of high quality and also maintain the pressing tools, it is a good method to keep the billets as free from inclusions as possible. A fluxing agent in form of salt compounds is used to purify the material during melting, but also to protect it from further oxidation. Another task of fluxing agents is to minimize the aluminium amount in the dross phase. The purpose of this project was to investigate if the fluxing agent that is used by the cast house is having any impact on the quality of the billets. Therefore, for that purpose, samples with a variating amount of fluxing agent were processed by the cast house in order to be investigated. These samples were investigated with the Optical Microscopy-method in order to determine the area fraction of non-metallic inclusions inside them. The results did not reveal any significant difference in the quality of the different samples since most samples obtained a low OM-index after the investigation. That can be explained by the type of scrap that was used since new scrap is usually very clean and contains smaller amounts of inclusions.Kvaliteten hos aluminiumgöt är starkt beroende av renheten i materialet. Hydro Extruded Solutions gjuter rundgöt i Sjunnen, som sedan levereras för strängpressning inom samma företag. För att producera strängpressade profiler av hög kvalitet och även upprätthålla pressverktygen, är en bra metod att hålla göten så fria från inneslutningar som möjligt. Ett flussmedel, i form av saltföreningar, används för att rena materialet under smältningen, men också för att skydda den från vidare oxidation. En annan uppgift som flussmedel har är att minimera mängden aluminium i slaggfasen. Syftet med detta projekt var att undersöka om flussmedelet som används av omsmältverket har någon inverkan på götkvaliteten. Därför, för detta ändamål har prover med en varierande mängd av flussmedel tillverkats i omsmältverket för att bli undersökta. Dessa prover undersöktes med den Optiskt Mikroskopiska-metoden för att bestämma areafraktionen av icke-metalliska inneslutningar inuti dem. Resultaten avslöjade inte någon signifikant skillnad i kvaliteten hos de olika proverna eftersom de flesta prover erhöll ett lågt OM-index efter undersökningen. Detta kan förklaras av vilken typ av skrot som användes, då process-skrot oftast är väldigt rent och består av mindre mängder innseslutningar.