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Статті в журналах з теми "Bitumen emulsion cold mixtures"
1
Fang, Xing, Alvaro Garcia-Hernandez, and Pietro Lura. "Overview on cold cement bitumen emulsion asphalt." RILEM Technical Letters 1 (December 29, 2016): 116. http://dx.doi.org/10.21809/rilemtechlett.2016.23.
Повний текст джерелаАнотація:
Cold mix asphalt, a promising substitute for conventional hot mix asphalt, is manufactured at ambient temperature using bitumen emulsion as binder. To improve its strength and durability, cement is often added to the mixture. This review (1) presents an overview about advances in cold mix asphalt modified with cementitious materials, often called CBEA (cement bitumen emulsion asphalt), (2) illustrates advantages and disadvantages of CBEA and (3) gives recommendations to produce homogenous CBEA mixtures
2
Wulandari, P. S., and D. Tjandra. "The effect of crumb rubber in dense graded and open graded cold mixture asphalt." IOP Conference Series: Earth and Environmental Science 907, no. 1 (November 1, 2021): 012008. http://dx.doi.org/10.1088/1755-1315/907/1/012008.
Повний текст джерелаАнотація:
Abstract Recycling tires is one of the eco-friendly way for reducing environmental problems. Incorporating crumb rubber in asphalt mixtures is an alternative way for reusing the end-of-life tires in road construction. The main purpose of this study is to evaluate the cold mix asphalt incorporating crumb rubber as a substitute for a part of fine aggregates. In this study, the aggregate gradations for mix design were selected according to the specification, Dense Graded Emulsion Mixtures (DGEM) Type IV and Open Graded Emulsion Mixtures (OGEM) Type E/20. The design bitumen content in this study was optimized for stability, void in mixture (porosity), and density. Crumb Rubber (CR) emulsion mixtures were made with optimum bitumen content at 8% by mass of total mixture for DGEM and OGEM. In order to incorporate crumb rubber into the cold emulsion mixtures, laboratory testing were performed for 25% and 50% of fine aggregates replaced with an equal volume of crumb rubber. In general, CR emulsion mixtures showed good results in all parameters. The CR emulsion mixtures also had a good comparison to hot mix asphalt specification for medium volume traffic loads with porosity less than 10%. From this study, crumb rubber can be recommended as a substitution material of fine aggregates in cold mix asphalt.
3
Shojaei Baghini, Mojtaba, and Amiruddin Ismail. "Freeze-Thaw Performance and Moisture-Induced Damage Resistance of Base Course Stabilized with Slow Setting Bitumen Emulsion-Portland Cement Additives." Advances in Materials Science and Engineering 2015 (2015): 1–10. http://dx.doi.org/10.1155/2015/348691.
Повний текст джерелаАнотація:
Freeze-thaw (FT) cycles and moisture susceptibility are important factors influencing the geotechnical characteristics of soil-aggregates. Given the lack of published information on the behavior of cement-bitumen emulsion-treated base (CBETB) under environmental conditions, especially freezing and thawing, this study investigated the effects of these additives on the CBETB performance. The primary goal was to evaluate the resistance of CBETB to moisture damage by performing FT, Marshall conditioning, and AASHTO T-283 tests and to evaluate the long-term stripping susceptibility of CBETB while also predicting the liquid antistripping additives to assess the mixture’s durability and workability. Specimens were stabilized with Portland cement (0%–6%), bitumen emulsion (0%–5%), and Portland cement-bitumen emulsion mixtures and cured for 7 days, and their short- and long-term performances were studied. Evaluation results of both the Marshall stability ratio and the tensile strength ratio show that the additions of additives increase the resistance of the mixtures to moisture damage. Results of durability tests performed for determining the resistance of compacted specimens to repeated FT cycles indicate that the specimen with the 4% cement-3% bitumen emulsion mixture significantly improves water absorption, volume changes, and weight losses. This indicates the effectiveness of this additive as a road base stabilizer with excellent engineering properties for cold regions.
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Terrones-Saeta, Juan María, Francisco Javier Iglesias-Godino, Francisco Antonio Corpas-Iglesias, and Carmen Martínez-García. "Study of the Incorporation of Ladle Furnace Slag in the Manufacture of Cold In-Place Recycling with Bitumen Emulsion." Materials 13, no. 21 (October 26, 2020): 4765. http://dx.doi.org/10.3390/ma13214765.
Повний текст джерелаАнотація:
Cold in-place recycling with bitumen emulsion is a good environmental option for road conservation. The technique produces lower CO2 emissions because the product is manufactured and spread in the same location as the previous infrastructure, and its mixing with bitumen emulsion occurs at room temperature. Adding materials with cementitious characteristics gives the final mixture greater resistance and durability, and incorporating an industrial by-product such as ladle furnace slag (of which cementitious characteristics have been corroborated by various authors) enables the creation of sustainable, resistant pavement. This paper describes the incorporation of ladle furnace slag in reclaimed asphalt pavements (RAP) to execute in-place asphalt pavement recycling with bitumen emulsion. Various test groups of samples with increasing percentages of emulsion were created to study both the density of the mixtures obtained, and their dry and post-immersion compressive strength. To determine these characteristics, the physical and chemical properties of the ladle furnace slag and the reclaimed asphalt pavements were analyzed, as well as compatibility with the bitumen emulsion. The aforementioned tests define an optimal combination of RAP (90%), ladle furnace slag (10%), water (2.6%), and emulsion (3.3%), which demonstrated maximum values for compressive strength of the dry and post-immersion bituminous mixture. These tests therefore demonstrate the suitability of ladle furnace slag for cold in-place recycling with bitumen emulsion.
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Konieczna, Katarzyna, Piotr Pokorski, Wojciech Sorociak, Piotr Radziszewski, Dawid Żymełka, and Jan Król. "Study of the Stiffness of the Bitumen Emulsion Based Cold Recycling Mixes for Road Base Courses." Materials 13, no. 23 (December 1, 2020): 5473. http://dx.doi.org/10.3390/ma13235473.
Повний текст джерелаАнотація:
The benefits of the use of cold recycling mixtures (CRMs) in pavement rehabilitation are associated with both the reduction of natural resource consumption by replacing them with recycled materials and the reduction of energy consumption during their production and paving. The evolution of the stiffness of CRMs in road construction and the fatigue life of pavements with CRM base layers are still being investigated. In this paper, CRMs with 1% cement content, called bitumen-stabilized materials with bitumen emulsion (BSM-Es), were examined. Mixtures that were differentiated in terms of Reclaimed Asphalt Pavement (RAP) content, as well as the amount and type of bitumen emulsions, were subjected to indirect tensile stiffness modulus (ITSM) tests at 5 °C, 13 °C, and 20 °C. The thermal sensitivities of the BSM-E mixtures were analyzed. BSM-E mixture stiffness modulus levels at various temperatures were determined using a statistical approach. On the basis of the results obtained, a discussion on the mechanistic-empirical design of flexible pavements with BSM-E base layers is presented. The potential benefits of using BSM-E materials in road construction in certain aspects of pavement life are indicated.
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Chelelgo, Kiplagat, Zachary C. Abiero Gariy, and Stanley Muse Shitote. "Laboratory Mix Design of Cold Bitumen Emulsion Mixtures Incorporating Reclaimed Asphalt and Virgin Aggregates." Buildings 8, no. 12 (December 10, 2018): 177. http://dx.doi.org/10.3390/buildings8120177.
Повний текст джерелаАнотація:
Bitumen emulsion asphalts, especially those incorporating marginal and secondary aggregates, are energy efficient, environment friendly, and sustainable alternatives to hot-mix asphalts. This study set out to compare engineering properties of a bitumen emulsion asphalt composed entirely of virgin aggregates with another composed of 55% reclaimed asphalt and 45% virgin aggregates. The aggregates were bound with a slow setting cationic bitumen emulsion composed of 65% base bitumen and 35% water. Marshall specimens molded at varying pre-mix water and bitumen emulsion contents were cured in molds for 24 h before being de-molded and cured for a further 72 h at 40 °C. Dry densities, porosities, and indirect tensile strengths for the cured specimens were determined in dry and soaked states. Virgin aggregate mix, at an optimum binder content of 6.1%, had a tensile strength ratio of 1.3 with corresponding air voids and moisture absorption values of 10.1% and 0.92%, respectively. Similarly, reclaimed asphalt mix at an optimum binder content of 6.2% had a tensile strength ratio of 1.03, with corresponding air voids and moisture absorption values of 7.9% and 0.38%, respectively. Compared to virgin mix, reclaimed asphalt mix had lower air voids and lower moisture absorption values with the overall benefit of enhanced resistance to moisture damage.
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Buczyński, Przemysław, Marek Iwański, and Jakub Krasowski. "Assessment of the Impact of Hydraulic Binder on the Properties of the Cold Recycled Mixture with Foamed Bitumen and Bitumen Emulsion: Field Tests." Buildings 10, no. 12 (November 30, 2020): 223. http://dx.doi.org/10.3390/buildings10120223.
Повний текст джерелаАнотація:
The paper presents the results of tests of the impact of hydraulic and bituminous binders on the properties of the cold-recycled mixture (CRM). The composition of the cold-recycled mixture includes two types of different binders, i.e., bituminous binder in the form of foamed bitumen and bitumen emulsion, as well as Portland cement (CEM I 32.5R) and hydraulic binder. The hydraulic binder was produced by mixing three base ingredients in the following ratio: 40% CEM I 32.5R; 20% Ca(OH)2 and 40% CBD (cement bypass dust). The cold-recycled mixtures were produced under industrial conditions on a test section. The prepared CRM with bitumen emulsion (MCE) and foamed bitumen (MCAS) was collected from the test section and compacted under laboratory conditions. The impact of the type and kind of the binder was assessed in terms of physical properties, mechanical properties and deformation modulus (bearing capacity of subbase) of the recycled base course after 1, 7 and 28 days. It was found that the use of hydraulic binder in the recycled base course, regardless of the type of bituminous binder, reduced cohesion without reducing the remaining parameters.
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Krasowski, Jakub, Przemysław Buczyński, and Marek Iwański. "The Effect of Polymer Powder on the Cracking of the Subbase Layer Composed of Cold Recycled Bitumen Emulsion Mixtures." Materials 14, no. 19 (October 7, 2021): 5867. http://dx.doi.org/10.3390/ma14195867.
Повний текст джерелаАнотація:
The research was aimed at assessing the effect of the redispersible polymer powder on the fracture resistance of a subbase made of a mineral–cement mixture with a bitumen emulsion. The test was performed at two temperatures, i.e., 0 °C and 20 °C. The prepared mixtures differed in the content of cement, asphalt emulsion, and polymer modifier. Cement and redispersible polymer powder were dosed in 1.5% steps from 0.5% to 3.5% while the amount of bitumen emulsion ranged from 0.0% to 5.0%. The SCB (semi-circular bending) tests carried out in the laboratory showed the dependence of the influence of the amount of binder and polymer modifier on the fracture resistance of the recycled subbase. Mixes containing a polymer modifier in their composition are characterized by a much higher resistance to cracking than traditional mineral–cement–emulsion mixtures. An example is the doubling of the framework’s fracture toughness (KIC) when the amount of the polymer modifier is increased from 0.5% to 2.0% with a constant cement content of 0.5%. The obtained results (KIC) in this case were 2.90 and 5.81. The key is the right ratio of polymer powder and cement in the base composition.
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Marinković, Milan, Edmundas Kazimieras Zavadskas, Bojan Matić, Stanislav Jovanović, Dillip Kumar Das, and Siniša Sremac. "Application of Wasted and Recycled Materials for Production of Stabilized Layers of Road Structures." Buildings 12, no. 5 (April 26, 2022): 552. http://dx.doi.org/10.3390/buildings12050552.
Повний текст джерелаАнотація:
The construction industry, as one of the most complex sectors, depends on using wasted and recycled materials, timely decision-making, and adequate execution of all activities in supply chains. This paper presents tests of mixtures for cold in-place recycling where existing material is used. In this research, we used cement and bitumen emulsion as well as fly ash, zeolite, slag, and Bakelite. A total of seven mixtures were tested in order to increase sustainability. It was tested the indirect tensile strength and dynamic modulus of elasticity after seven and 28 days for dry specimens, after 28 days for water-saturated specimens and for specimens exposed to frost. After completing the tests using the MEREC (MEthod based on the Removal Effects of Criteria) and CoCoSo (Combined Compromise Solution) multi-criteria model, mixtures were evaluated and ranked in terms of mechanical properties, price, and environmental protection. Considering the ranking of mixtures using the CoCoSo method, the highest quality mixtures, for most combinations of weight factors, are mixtures with slag, mixtures with fly ash, and mixtures with 2% of cement and 2% of bitumen emulsion. Sensitivity analysis was also performed with new simulated values of the criteria in order to determine the individual influence of the criteria on the ranking of mixtures. The conclusions are as follows: the use of bitumen emulsion, cement, waste materials, and other materials in cold recycling would reduce the cost of recycling pavement structures, increase environmental protection, while the mechanical properties of the pavement structures are within acceptable limits.
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Marinković, Milan, Edmundas Kazimieras Zavadskas, Bojan Matić, Stanislav Jovanović, Dillip Kumar Das, and Siniša Sremac. "Application of Wasted and Recycled Materials for Production of Stabilized Layers of Road Structures." Buildings 12, no. 5 (April 26, 2022): 552. http://dx.doi.org/10.3390/buildings12050552.
Повний текст джерелаАнотація:
The construction industry, as one of the most complex sectors, depends on using wasted and recycled materials, timely decision-making, and adequate execution of all activities in supply chains. This paper presents tests of mixtures for cold in-place recycling where existing material is used. In this research, we used cement and bitumen emulsion as well as fly ash, zeolite, slag, and Bakelite. A total of seven mixtures were tested in order to increase sustainability. It was tested the indirect tensile strength and dynamic modulus of elasticity after seven and 28 days for dry specimens, after 28 days for water-saturated specimens and for specimens exposed to frost. After completing the tests using the MEREC (MEthod based on the Removal Effects of Criteria) and CoCoSo (Combined Compromise Solution) multi-criteria model, mixtures were evaluated and ranked in terms of mechanical properties, price, and environmental protection. Considering the ranking of mixtures using the CoCoSo method, the highest quality mixtures, for most combinations of weight factors, are mixtures with slag, mixtures with fly ash, and mixtures with 2% of cement and 2% of bitumen emulsion. Sensitivity analysis was also performed with new simulated values of the criteria in order to determine the individual influence of the criteria on the ranking of mixtures. The conclusions are as follows: the use of bitumen emulsion, cement, waste materials, and other materials in cold recycling would reduce the cost of recycling pavement structures, increase environmental protection, while the mechanical properties of the pavement structures are within acceptable limits.
Дисертації з теми "Bitumen emulsion cold mixtures"
1
Zhao, Bin. "Bounding recycled aggregate pavement mixtures using hydraulic binders and cold bitumen emulsion." Thesis, Sheffield Hallam University, 2007. http://shura.shu.ac.uk/20597/.
Повний текст джерелаАнотація:
With the current emphasis on sustainable development, recycling in the construction industry including highway planning, design, construction and maintenance has become a default option. Traditionally, recycled aggregate has been employed as filling or capping materials. However, the need to replace virgin materials in higher grade applications and reduce landfill has stimulated the need to enhance their performance. The requirements of using low energy and low environmental impact binders such as bituminous emulsion and industrial by-products as hydraulic binders whilst maintaining a long shelf life presented a further challenge. The primary aim of this research was to investigate methods by which a mixture of recycled aggregate composed of road planings, concrete demolitions and bricks with proprietary bitumen emulsion as binder could be enhanced to comply with the prevailing specifications and performance requirements for pavement materials, by using novel combinations of bituminous emulsions and latent hydraulic binders. The preliminary investigation focussed upon the establishment of an appropriate method of compaction of bitumen emulsion recycled aggregate mixtures to ensure results were consistent and representative of field performance. The main investigation evaluated the environmental conditions including freeze-thaw, low and high humidities and varying temperatures upon the behaviour and performance of loose pre-compacted and compacted recycled product using a range of novel latent hydraulic binders and bituminous emulsion combinations. Test methods included Indirect Tensile Stiffness Modulus test, Repeated Load Axial test, Indirect Tensile Fatigue test, Compressive Strength test and a novel modification of the Indirect Tensile Strength test was proposed and developed for enhance assessment of performance. The key findings were that whilst bitumen emulsion mixtures could perform adequately, the addition of a latent hydraulic binder enhanced the mixture's performance in terms of mechanical properties and withstanding extreme conditions exemplified by freeze-thaw and high humidity, whilst maintaining shelf life. However, it was deduced that the performance could be heavily influenced by the condition, consistency and composition of the recycled aggregate. It is recommended that further work should focus on rigorously investigating the influence of recycled components on mixture properties to optimise their performance for given applications, and extended to include tar bound material.
2
Shanbara, H. K. "Development of new cold bitumen emulsion mixtures and finite element modelling of predicting permanent deformation." Thesis, Liverpool John Moores University, 2018. http://researchonline.ljmu.ac.uk/9615/.
Повний текст джерелаАнотація:
The increase of road infrastructure around the world involving the traditional hot mix asphalt (HMA) technology and its effects on the environment and health means that serious attention needs to be paid to building more sustainable flexible pavements. Cold bitumen emulsion mixture (CBEM) as an increasingly attractive cold asphalt mixture is therefore becoming an important subject area for study. Despite the efforts applied during the last few decades to enhance and develop CBEM application, certain issues still exist that make it inferior to HMA, resulting in limiting or minimizing its use. However, the enhancement of CBEM for flexible pavements construction, rehabilitation and maintenance is increasingly gaining interest in both pavement engineering industrial and research sectors. Therefore, the main aim of this study is to gain a deep insight and understanding into the impact response of using natural and synthetic fibres as reinforcing materials, on the mechanical properties and water susceptibility of CBEM including indirect tensile stiffness and resistance to rutting, cracking and moisture damage. Four different types of fibres were used: glass as a synthetic fibre, and hemp, jute and coir as natural fibres. Various samples of CBEM, with and without fibres, were fabricated and tested. Traditional hot mix asphalt mixture was also used for comparison. By achieving this aim it is expected that the use of CBEM would increase, allowing such mixtures to be used as structural pavement materials with some confidence. In spite of the quality of an asphalt mix being one of the most important and significant factors that affect the performance of both hot and cold mix flexible pavements, and the high quality mixes are often cost effective as these mixes require less maintenance and increase the service life of the pavements, it is also cost efficient to replace the semi-experimental flexible pavement design methods with fast and powerful software that includes finite element analysis. Several finite element models (FEM) have been developed to simulate the behaviour of hot mix asphalt, but none exists for cold mix asphalt reinforced by natural and synthetic fibres. This study also describes the development of a three-dimensional (3-D), finite element model of flexible pavements made with CBEMs, which has itself been reinforced with natural and synthetic fibres. The 3-D finite element model was employed to predict the viscoelastic and viscoplastic responses of flexible pavements based on CBEM when subjected to different multiple axle loads, bituminous material properties, tyre speeds and temperatures. The pavements were subject to moving and static loading conditions to test for permanent deformation (rutting). The results indicate a significant improvement in the indirect tensile stiffness modulus, for all fibre-reinforced CBEMs, over different curing times. The improved tensile behaviour represents a substantial contribution towards slowing crack propagation in bituminous mixtures, while scanning electron microscopy analysis confirmed the fibre shape and surface roughness characteristics. The improved performance of the reinforced mixtures with both natural and synthetic fibres facilitated a substantially lower permanent deformation than traditional hot and cold mixtures at two different temperatures (45 °C and 60 °C). When using glass and hemp fibres as reinforcing materials, there was a significant improvement in CBEM in terms of water sensitivity. These reinforcing materials can extend the service life of flexible pavements. Finally, the results show that the finite element model can successfully predict rutting of flexible pavements under different temperatures and wheel loading conditions.
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Nassar, Ahmed Izat Mohammed. "Enhancing the performance of cold bitumen emulsion mixture using supplementary cementitious materials." Thesis, University of Nottingham, 2016. http://eprints.nottingham.ac.uk/38473/.
Повний текст джерелаАнотація:
Several benefits are gained from using cold mix asphalt (CMA) instead of hot mix asphalt (HMA). The benefits include conservation of materials and reducing energy consumption, preservation of the environment and reduction in cost. One of the common types of CMA is cold bitumen emulsion mixture (CBEM) which is the mixture produced by mixing mineral aggregate with bitumen emulsion. Despite the efforts applied in the last few decades in order to improve and develop CBEM utilization, certain deficiencies remain that make it inferior to HMA, resulting in restricting or minimizing of its use. However, the development of CBEM for road construction, rehabilitation and maintenance is steadily gaining interest in both pavement engineering industrial and research sectors. The present study was primarily aimed at evaluating the effect of using different cementitious materials on the performance of CBEM. The idea of the research is to provide a sustainable filler from supplementary cementitious materials (SCMs) to be used as fillers to provide enhanced properties of CBEMs. By achieving this aim it is expected that the utilization of CBEM would increase, allowing them to be used as structural pavement materials with some confidence. Research was first undertaken to optimize the mix design of CBEM using a statistical approach known as response surface methodology (RSM), as an alternative approach to achieve acceptable engineering properties. The optimization of CBEM was investigated, to determine optimum proportions to gain suitable levels of both mechanical and volumetric properties. This optimization focussed on the mix design parameters, namely bitumen emulsion content (BEC), pre-wetting water content (PWC) and curing temperature (CT). This work also aimed to investigate the effect of the interaction between these parameters on the mechanical and volumetric properties of CBEMs. The results indicate that the interaction of BEC, PWC and CT influences the mechanical properties of CBEM. However, PWC tends to influence the volumetric properties more significantly than BEC. The individual effects of BEC and PWC are important, rather than simply the TFC which is used in conventional mix design of CBEM. Furthermore, the experimental results for the optimum mix design corresponded well with model predictions. It was concluded that optimization using RSM is an effective approach for mix design of CBEMs. The study also investigated in-depth the performance characteristics of CBEMs using different filler treatments. The study was extended to understand the performance enhancement through mineralogical and microstructural investigations. The research was designed to use cement, binary and ternary blended fillers (BBF and TBF). Fly ash (FA) and ground granulated blast-furnace slag (GGBS) were used as BBF while silica fume (SF) was added to the BBF to obtain TBF. A significant improvement was achieved in mechanical and durability properties of CBEMs due to incorporation of both cement and blended fillers. Also, the results indicated that TBF was more suitable than BBF for the production of CBEMs. The microstructural assessment indicated that the effect of BBF on the internal microstructure of CBEMs was slightly negative and more noticeable in CBEMs containing FA. Mineralogical and microstructural assessments also suggested that the presence of bitumen emulsion might not affect the hydration of the silicates in treated CBEMs. The formation of additional CSH was observed due to the replacement of conventional limestone filler by cement, BBF and TBF. However, it seems that this can cause a delay in the formation of other hydration products (Ettringite) resulting from the hydration of aluminates in cement. Furthermore, it is proposed that the addition of SF to BBF mixtures can eliminate the delay in formation of hydration products caused by the bitumen emulsion. The present work was also aimed at better understanding the curing mechanism of CBEMs and to bridge the gap between laboratory curing and field evolution of these mixtures. This was achieved by evaluating the effect of the curing process on CBEM performance and developing a prediction model to assess in-situ CBEM performance using maturity relationships. Different contributory factors affecting the curing process were investigated such as curing temperature and relative humidity (RH) in addition to the impact of curing time and the presence of cement/active fillers. The results indicated that high curing temperature is responsible for additional stiffness gain by increasing the binder stiffness due to ageing and by increasing the moisture loss by evaporation during the curing process. However, at high curing temperature the moisture loss by evaporation may hinder the hydration of cement/active fillers. Moreover, the results also indicated that the high RH level influences the stiffness modulus of CBEMs negatively. The laboratory results were then used to develop a tool to assess in-situ curing of CBEMs using the maturity approach, which is widely used to estimate in-situ concrete properties. A strong correlation was found between maturity and the stiffness values obtained from the laboratory tests, which resulted in development of maturity-stiffness relationship. The application of this relationship to assess the in-situ stiffness of CBEMs is presented using three hypothetical pavement sections in the United Kingdom, Italy and Qatar; to simulate different curing regimes. A pavement analysis and design study was conducted to evaluate the incorporation of treated CBEMs into a pavement structure. CBEMs are suggested to be used in two scenarios: the first is as a surface course and the second is as a base course. The scope of the study is limited here to design based on the fatigue criterion only. Although, the structural design was based on practical hypothetical layer thicknesses, the results provided useful insight into the structural capabilities of CBEMs.
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Jenkins, Kim Jonathan. "Mix design considerations for cold and half-warm bituminous mixes with emphasis of foamed bitumen." Thesis, Stellenbosch : Stellenbosch University, 2000. http://hdl.handle.net/10019.1/51831.
Повний текст джерелаАнотація:
Dissertation (PhD)--University of Stellenbosch, 2000.ENGLISH ABSTRACT: The use of foamed bitumen and bitumen emulsion as binders for use in road rehabilitation is gaining favour globally. High-level road facilities through to unpaved roads requiring attention are being treated with these binders due to environmental, economic and practical benefits in the use of cold bituminous mixes. In addition, static and mobile plant with the capability of performing stabilisation using bitumenemulsion and foamed bitumen has become commercially available and widely utilised, as a result of development in recycling technology and lapse in patent rights on foam nozzles. An understanding of the behaviour and failure mechanisms of these cold mixes, as well as sound guidelines for the mix design procedures of cold mixes, especially foamed bitumen, and design guidelines for pavements structures incorporating these materials, are lacking however. Mix designs are carried out primarily on the basis of experience and pavement designs are empirically based. The main objective of this dissertation is to address the need for a fundamental understanding of foamed bitumen and foamed bitumen mixes, and in so doing to develop techniques for adjudicating mixes, optimising their composition and rationalising their design both as mixes and as layers in road pavements. At the same time the exploration of new applications for foamed bitumen and the possibilities for progressive related technology, is a priority. To commence, this study includes an appraisal of most of the literature available on foamed bitumen. This is followed by a fundamental investigation of the colloidal mass of foam that is produced when small quantities of cold water are added to hot bitumen. Factors influencing the quality of the foam are identified and a Foam Index is developed for characterisation and optimisation of the foam. The spatial composition of a cold foamed bitumen mix, including Interaction of the foam with moist mineral aggregate, is also addressed in this dissertation. In particular, the stiffening of the filler mastic using foamed bitumen as binder is analysed. Techniques of optimising the sand type and content in the mix are also developed and guidelines for desired aggregate structures for foam treatment are established. The temperature of the mineral aggregate has been shown to have a profound influence on the behaviour and performance of a foamed bitumen mix. This has been selected as a focal area of further investigation and the research has lead to the development of a new process called "The half-warm foamed bitumen treatment process" that can produce mixes with almost the quality of hot mix asphalt with up to 40% less energy consumption. Other processes developed in this research include the use of cold mix asphaltic blocks for construction of road pavements in developing areas. This technology enhances the use of a high labour component in road construction in an economically competitive manner. The dissertation provides details for mix design and construction of the cold mix blocks. Finally, the study includes models for the performance prediction of foamed bitumen mixes. In particular, foamed mixes that exhibit stress-dependent behaviour have been investigated and models established on the basis of triaxial testing and accelerated pavement testing for the prediction of permanent deformation of such layers under repeated loading. Practical applications of the research findings are summarised in Appendix F. This includes: • methods for optimisation of the foamed bitumen properties, • guidelines for the selection of the ideal aggregate structure for cold foamed mixes, • procedures for carrying out cold mix design in the laboratory (including mixing, compaction and curing), • procedures for manufacturing half-warm foamed mixes in the laboratory, • methods for manufacturing cold mix blocks, and • pavement design methods for road structures incorporating foamed mix layers. Appendix G outlines statistical techniques that are relevant to the design of experiments in pavement engineering including examples of applications of these procedures. The techniques are applied selectively in the relevant chapters of the dissertation.
AFRIKAANSE OPSOMMING: Die gebruik van skuim bitumen en bitumen emulsie as bindmidel in pad rehabilitasie begin groter voorkeur wêreldwyd geniet. Van hoë vlak padfasiliteite tot ongeplaveide paaie wat aandag benodig, word met hierdie binders behandel vanweë die omgewings-, ekonomiese en praktiese voordele wat hierdie koue bitumen mengsels inhou. Voorts is statiese en mobiele masjinerie wat die vermoë het om stabilisasie in die gebruik van bitumenemulsie en skuimbitumen te bewerkstellig, in die handel verkrygbaar. Dit word algemeen gebruik as 'n uitvloeisel van ontwikkelings in herwinningstegnologie en die verslapping van patenteregte op skuim sproeikoppe. 'n Leemte bestaan in die begrip van die gedrags- en swigtingsmeganismes van hierdie koue mengsels, asook goeie riglyne vir die mengselontwerp van koue mengsels en in besonder skuimbitumen, en ontwerpriglyne vir plaveisel strukture waar hierdie materiaal geinkorporeer is. Mengselontwerpe word hoofsaaklik uitgevoer op grond van ondervinding, terwyl plaveiselontwerpe empiries gebaseer is. Die hoofdoel van die verhandeling is om die behoefte vir 'n fundamentele begrip van skuim bitumen en skuimbitumen mengsels aan te spreek, en daardeur tegnieke te ontwikkel vir die be-oordeling van mengsels, optimsering van hul samestelling en rasionalisering van hulontwerp vir beide mengsels en plaveisellae. Terselfdertyd is die ondersoek na nuwe toepassings van skuim bitumen en die moontlikhede van nuwe tegnologie 'n prioriteit. As beginpunt sluit hierdie studie 'n waardeskatting van die meeste literatuur beskikbaar op skuim bitumen in. Dit word gevolg deur 'n basiese ondersoek na die kolloidale massa van skuim wat geproduseer word wanneer klein hoeveelhede koue water by warm bitumen gevoeg word. Faktore wat die gehalte van die skuim beinvloed word uitgewys en 'n Skuim Indeks is ontwikkel vir die karakterisering en optimisering van die skuim. Die ruimtelike samestelling van 'n koue bitumen mengsel, wat die interaksie van die skuim met vogtige minerale samevoegings (aggregate) insluit, word ook aangespreek. Besondere aandag word gewy aan die verharding van die vuiler mastiekgom wat gebruik word as bitumen binder. Tegnieke om die sandtipe en inhoud van die mengsel te optimiseer is ontwikkel en riglyne vir die verlangde samevoegingstrukture (aggregate strukture) vir skuimbehandeling is opgestel. Daar is bevind dat die temperatuur van die minerale aggregaat 'n duidelike invloed op die gedrag en verrigting van 'n skuimbitumen mengsel het. Dit is gekies as In fokuspunt vir verdere studie en die navorsingswerk daarop het gelei tot die ontwikkeling van In nuwe proses wat "Die half-warm skuim bitumen behandelings proses" genoem word. Hierdie proses produseer mengsels wat byna gelykstaande is aan die gehalte van warm gemengde asfalt, maar met tot 40% minder energie verbruik. Ander prosesse wat met dié navorsing ontwikkel is, sluit koue gemengde asfaltiese blokke in, wat gebruik word in die konstruksie van padplaveisel in ontwikkelende gebiede. Hierdie tegnologie bevorder die ekonomiese gebruik van 'n hoë arbeidskomponent in padkonstruksie. Die studie stel besonderhede vir die mengselontwerp en konstruksie vir koue gemengde blokke voor. Laastens sluit die studie modelle in vir die werkverrigtingsvoorspelling van skuimbitumen mengsels. Op basis van drie-assige proewe in die laboratorium en versnelde belasting van paaie is modelle ontwikkel vir skuim bitumen mengsels wat spanningsafhanklike gedrag vertoon (die sogenaamde "granulêre" groep) om die permanente deformasie in die lae as gevolg van herhaalde verkeersbelasting te voorspel. 'n Opsomming van al die praktiese toepassings van die ontwikkelings van die navorsing word in Appendix F verskaf. Dit sluit in: • optimesering van die eienskappe van skuimbitumen, • riglyne vir gewenste samestelling van aggregaat in skuimbitumen mengsels, • ontwerp metodes vir koue skuimbitumen mengsels in die laboratorium (meng, verdigting en curing), • produksie metodes vir half-warme mensels in die laboratorium, • produksie metodes vir blokke wat met koue mengsels gemaak word, en • plaveiselontwerp metodes van strukture wat skuimbitumen lae inkorporeer. Appendix G gee 'n oorsig van statistiese tegnieke wat relevant is vir die ontwerp van eksperimente, insluitend voorbeelde van toepassings van die prosedures in plaveiselingenieurswese. Die tegnieke word selektief toegepas in die relevante hoofstukke van die verhandeling.
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Khan, Abdullah. "Fundamental investigation to improve the quality of cold mix asphalt." Licentiate thesis, KTH, Bro- och stålbyggnad, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-191527.
Повний текст джерелаАнотація:
Cold mix asphalt (CMA) emulsion technology could become an attractive option for the road industry as it offers lower startup and equipment installation costs, energy consumption and environmental impact than traditional alternatives. The adhesion between bitumen and aggregates is influenced by diverse parameters, such as changes in surface free energies of the binder and aggregates or the presence of moisture or dust on the surface of aggregates, mixing temperatures, surface textures (including open porosity), nature of the minerals present and their surface chemical composition, as well as additives in the binder phase. The performance of cold asphalt mixtures is strongly influenced by the wetting of bitumen on surfaces of the aggregates, which is governed by breaking and coalescence processes in bitumen emulsions. Better understanding of these processes is required. Thus, in the work this thesis is based upon, the surface free energies of both minerals/aggregates and binders were characterized using two approaches, based on contact angles and vapor sorption methods. The precise specific surface areas of four kinds of aggregates and seven minerals were determined using an approach based on BET (Brunauer, Emmett and Teller) theory, by measuring the physical adsorption of selected gas vapors on their surfaces and calculating the amount of adsorbed vapors corresponding to monolayer occupancy on the surfaces. Interfacial bond strengths between bitumen and aggregates were calculated based on measured surface free energy components of minerals/aggregates and binders, in both dry and wet conditions. In addition, a new experimental method has been developed to study bitumen coalescence by monitoring the shape relaxation of bitumen droplets in an emulsion environment. Using this method, the coalescence of spherical droplets of different bitumen grades has been correlated with neck growth, densification and changes in surface area during the coalescence process. The test protocol was designed to study the coalescence process in varied environmental conditions provided by a climate-controlled chamber. Presented results show that temperature and other variables influence kinetics of the relaxation process. They also show that the developed test procedure is repeatable and suitable for studying larger-scale coalescence processes. However, possible differences in measured parametric relationships between the bitumen emulsion scale and larger scales require further investigation. There are several different research directions that can be explored for the continuation of the research presented in this thesis. For instance, the rationale of the developed method for analyzing coalescence processes in bitumen emulsions rests on the assumption that the results are applicable to large-scale processes, which requires validation. A linear relationship between the scales is not essential, but it is important to be able to determine the scaling function. Even more importantly, qualitative effects of the investigated parameters require further confirmation. To overcome the laboratory limitations and assist in the determination of appropriate scaling functions further research could focus on the development of a three-dimensional multiphase model to study coalescence processes in more detail, including effects of surfactants, pH and other additives such as mineral fillers and salts. Additionally, better understanding of the breaking process and water-push out could help significantly to optimize CMA mix design. Different methods, both numerical and experimental could be explored for this.Cold mix asphalt (CMA) eller kall asfaltbetong med hjälp av emulsionsteknik kan vara ett attraktivt alternativ för vägbyggnadsindustrin då det möjliggör lägre uppstart- och investeringskostnader, lägre energiförbrukning och mindre miljöpåverkan än traditionella alternativ. Adhesionen mellan bindemedel och stenpartiklarna påverkas av ett flertal parametrar, så som förändring i fri ytenergi hos både bindemedel och partiklar i närvaro av fukt eller damm på stenytorna, blandningstemperatur, yttextur (inklusive ytporositet), mineralegenskaper och ytornas kemiska sammansättning lika väl som tillsatsmedel i bindemedlen. Beteendet hos kall asfaltbetong är starkt påverkad av vätningsegenskaperna hos bindemedlet när det kommer i kontakt med stenmaterialet och detta i sin tur är beroende på bitumenemulsionens brytegenskaper och förmåga att blandas. Bättre förståelse av dessa processer är av största vikt. I detta arbete är avhandlingen baserad på fri ytenergi hos både mineraler/aggregat och bindemedel, baserat på kontaktvinkel och på ångabsorptionsmetoder. Den exakta specifika ytan hos fyra typer av aggregat och sju mineraler undersöktes med en metod baserad på BET (Brunauer, Emmett och Teller):s teorier genom att mäta den fysiska adsorptionen av utvalda gaser på ytorna och beräkna mängden adsorberad ånga som korresponderade mot ytlagret. Styrkan hos kontaktytornas bindning mellan bindemedlet och stenaggregaten beräknades baserat på mätningar av den fria ytenergin hos bägge ingående komponenterna, dels i torrhet dels i våta omgivningar. Som tillägg har en ny experimentell metod utvecklats för att studera bitumens blandbarhet genom att studera bitumendroppars relaxation i en emulsionsmiljö. Genom att använda denna metod har korelationen mellan sväriska droppar av bitumen undersökts mot förändringen i ytans area under blandningsprocessen. Testprotokollet utformades för att studera blandningsprocessen i varierande miljöer i en klimatkammare. Presenterade resultat visar att temperatur och andra variabler påverkar de kinetiska förhållandena vid relaxationsprocessen. De visar även att den utvecklade testmetoden är repeterbar och passar för studier av storskaliga blandningsprocesser. Det bör dock påpekas att vidare studier krävs för att påvisa skillnaderna mellan bitumenemulsionsskalan och större skalor. Framtida forskning kommer att koncentreras på utveckling av tredimensionella multifasmodeller för att studera blandningsförlopp på en mer detaljerad nivå, inkluderande effekter på ytaktiva ämnen, pH-värden och andra additativ så som mineralfiller och salt. Som tillägg kommer nyttan av nya karaktäriseringsmetoder att utvärderas, så som lågvikelspridning av neutroner eller kombinationer av röntgen, neutronradiologi och datortomografi, för att studera brytmekanismer hos bitumenemulsioner vid kontakt med mineraler och aggregat.
QC 20160901
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Needham, D. "Developments in bitumen emulsion mixtures for roads." Thesis, University of Nottingham, 1996. http://eprints.nottingham.ac.uk/11101/.
Повний текст джерелаАнотація:
Bitumen emulsion mixtures, or cold mix, offers certain advantages over hot bituminous road mixtures in terms of potential cost savings, environmental factors, energy savings and easing of logistical difficulties inherent with hot mix. For these reasons, they are currently used in a number of regions including the United States of America, Continental Europe, Scandinavia, Southern Africa and Australia. However, cold mix has not been seriously evaluated or utilized in the UK until comparatively recently. This is due to the slow rate at which it builds strength or cures and its susceptibility to rainfall, particularly during this curing period. The overall aim of this research was, therefore, to study the behaviour of cold mix in terms of mechanical properties and the mechanisms involved in emulsion breaking and mixture curing to gain an insight into how performance may be improved. Mechanical properties were shown to be affected by a number of parameters, including binder grade, void content, curing time and additives such as cement. Fatigue tests showed that without cement, the performance in-situ of cold mix would be very poor. Pavement design calculations revealed that, with cement, emulsion mixtures could be expected to perform similarly to equivalent hot mix. Field trials have indicated that cold mix can be manufactured using conventional hot mix plant and laid using similar techniques. However, problems are still to be overcome in terms of the control of mixture composition and laying in adverse weather conditions. Fundamental tests have shown that emulsion droplet coalescence (which is an essential part of the curing process) was affected by pressure, bitumen type, emulsifier level, cement and temperature and that cement can cause emulsion charges to become more positive (or less negative) but other parameters had no effect on charge. It was also proved that cement can cause bitumen emulsion to set completely and that the residual binder has an increased viscosity compared with unmodified binder. This was shown to be due to the formation of a composite bitumen cement binder.
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Zerzouri, Maroua. "Faisabilité d’élaboration des poudres pré-géopolymères par mécanosynthèse : caractérisation physico-chimique et application aux pâtes, mortiers et enrobés bitumineux." Thesis, Université Gustave Eiffel, 2021. http://www.theses.fr/2021UEFL2039.
Повний текст джерелаАнотація:
Les géopolymères sont des matériaux inorganiques fabriqués à partir de composés d’origine naturelle (kaolin, par exemple), ou issus de déchets industriels (cendres volantes, laitiers de hauts fourneaux…). Leurs excellentes propriétés physico-chimiques et mécaniques justifie l’intérêt grandissant qu’ils suscitent dans le domaine de la construction. Toutefois, leur potentiel d’utilisation reste limité en raison de l’emploi, lors de leur préparation, de solutions alcalines fortement concentrées présentant des risques sanitaires importants et d’une difficulté de stockage et transport ; d’où la nécessité d’implémenter des techniques de confection sans solvant. Cette thèse vise à proposer une nouvelle méthode d’élaboration de poudres pré-géopolymères (PGP) par « mécanosynthèse » faciles à transporter et à stocker. Plusieurs matières premières, de différentes natures et compositions chimiques, ont été testées comme précurseurs aluminosilicatés (cendres volantes, métakaolin, laitier de hauts fourneaux et argile) ; elles ont été activées par différents mélanges alcalins (NaOH, KOH, Na2SiO3 et CaO), à des ratios massiques fixés. L’effet de plusieurs paramètres de procédé a été considéré, notamment le temps et la vitesse de broyage. Les poudres pré-géopolymères produites ont été ensuite incorporées dans des formulations de pâtes, de mortiers et d’enrobés bitumineux. Les propriétés physico-chimiques et mécaniques des pâtes produites ont été étudiées. Les résultats obtenus ont été comparés à ceux des pâtes confectionnées par la méthode classique dans les mêmes conditions. La cinétique de la réaction de géopolymérisation des pâtes a été suivie par spectrométrie infrarouge in situ juste après l’hydratation des PGP. Par ailleurs, le procédé de mécanosynthèse indirecte a été utilisé pour améliorer la réactivité de l’argile.Les résultats ont mis en évidence l’efficacité du procédé de mécanosynthèse pour l’élaboration de poudres pré-géopolymères. Celles-ci donnent lieu après hydratation à des pâtes géopolymères avec une structure semblable à celle des géopolymères classiques. Ce procédé a également permis d’améliorer les performances mécaniques des produits géopolymères. Les poudres pré-géopolymères à base d’argile illitique produites par mécanosynthèse indirecte donnent lieu à des pâtes avec une résistance mécanique atteignant 72,5 MPa après 28 jours de cure à 20 °C et 50 % d’humidité relative, contre 12,5 MPa dans le cas classique. Les résultats obtenus sur les mortiers à base de PGP-laitier montrent des résistances mécaniques qui atteignent 38 MPa après 28 jours de cure.Enfin, les résultats préliminaires sur les enrobés bitumineux à base de PGP révèlent une meilleure tenue à l’eau et résistance à l’orniérage, même après 100.000 cycles, que celles des formules de référence sans PGPGeopolymers are inorganic materials made from compounds of natural origin (kaolin, for example), or from industrial waste (fly ash, blast furnace slag, etc.). Their excellent physicochemical and mechanical properties justify the growing interest they arouse in the construction field. However, their potential of employment remains limited due to the use, during their preparation, of highly concentrated alkaline solutions causing significant health risks and transport storage difficulty; hence it is necessary to implement solvent-free manufacturing techniques.This thesis aims to propose a new producing pre-geopolymer powders (PGP) method by “mechanosynthesis” that are easy to transport and store. Several raw materials, of different types and chemical compositions, were tested as aluminosilicate precursors (fly ash, metakaolin, blast furnace slag and clay); they were activated by different alkaline mixtures (NaOH, KOH, Na2SiO3 and CaO), at fixed mass ratios. The effect of several process parameters was considered, including milling time and speed rotation. The produced pre-geopolymer powders were then incorporated into formulations of pastes, mortars and bituminous mixes. The pastes physicochemical and mechanical properties were studied. The obtained results were compared with those of pastes made by the conventional method under the same conditions. The kinetics of pastes geopolymerization reaction were followed by infrared spectrometry in situ just after the hydration of the PGP. In addition, the indirect mechanosynthesis process has been used to improve the reactivity of clay.The results demonstrated the mechanosynthesis process efficiency for producing the pre-geopolymer powders. These give rise after hydration to geopolymer pastes with a similar structure to that of conventional geopolymers. This process has also helped to improve the mechanical performances of geopolymer products. The pre-geopolymer powders based on illitic clay, produced by indirect mechanosynthesis, give rise to pastes with mechanical resistance reaching 72.5 MPa after 28 curing days at 20 ° C and 50% of relative humidity, against 12.5 MPa for the classic case. The results obtained on slag-based mortars show mechanical strengths reaching 38 MPa after 28 curing daysFinally, the preliminary results on slag PGP-based bituminous mixes reveal better water and rutting resistance, even after 100,000 cycles, than those of the reference formulas without PGP
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Ibrahim, Hamdy El-Sayed Mohamed. "Assessment and design of emulsion-aggregate mixtures for use in pavements." Thesis, University of Nottingham, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.243448.
Повний текст джерела
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Ojum, Chibuzor Kingsley. "The design and optimisation of cold asphalt emulsion mixtures." Thesis, University of Nottingham, 2015. http://eprints.nottingham.ac.uk/30812/.
Повний текст джерелаАнотація:
Road structures are important to the survival of nations. As the cost for the rehabilitation and maintenance of highways soars, civil engineers and administrators face the ever present difficulty of meeting current resurfacing and rehabilitation needs. The deterioration of road structures under growing traffic weight and volume is occurring faster than agencies envisaged coupled with increasingly scarce and expensive new materials required. It is now apparent that for planning, design and construction for road structures, the most efficient and cost effective processes, materials and practices available must be appropriately considered. The use of recycled materials as a sustainable alternative is gaining significant worldwide attention. The overall purpose of this research was to conduct an in-depth investigation and analysis into the design and optimisation of Cold Asphalt Emulsion Mixtures (CAEMs) incorporating high contents of Reclaimed Asphalt Pavements (RAP). To achieve the objectives of the research, four proportions of RAP aggregate materials in addition to Virgin Aggregates (VA) were used as categorised below: - Category 1: 0% RAP (no RAP, 100% VA) - Category 2: 50% RAP (50% RAP, 50% VA) - Category 3: 85% RAP (85% RAP, 15% VA) - Category 4: 95% RAP (95% RAP, 5% VA) The effect of mixing and compaction temperatures at 5°C, 20°C and 32°C and how cement at 0%, 1% and 3% OPC influenced the CAEMs was also investigated. This study presents a practical mix design procedure to act as a guideline for CAEMs incorporating high RAP contents by identifying critical parameters for the various categories of CAEMs which stemmed from the fact that currently there is no universally accepted mix design. The proposed mix design guideline is presented in this thesis. The effect of accelerated curing was investigated to study the effects of temperature, curing duration, conditioning and the influence of cement on the CAEMs. The research showed that an increase in curing temperature results in an increase in the stiffness and strength of the CAEMs. The thesis presents results on the mechanical and performance properties which provided vital information on expected performance of CAEMs incorporating high contents of RAP for use as a road base material. The research was able to highlight the purported effects of residual binder in RAP which could contribute positively to the mechanical and performance properties of the CAEMs. This points to the fact that treating RAP as “black rock” is not the right approach. The RAP needs to be evaluated for its inherent properties and suitability for purpose. The stiffness and strength were investigated using the Indirect Tensile Stiffness Modulus (ITSM) and Indirect Tensile Strength (ITS) tests which proved useful in ranking them. The addition of 1% OPC improved the stiffness of Categories 1-3 mixtures by 32% with Category 4 having the highest increase at 89%. The inclusion of 3% OPC, more than doubled the stiffness values. The Indirect Tensile Fatigue Test (ITFT) was used to investigate the fatigue characteristics. Results showed that if the CAEMs with cement at 1% and 3% experienced strains in the region of 200µε, they tend to fail suddenly soon after crack initiation due to reduced flexibility of the CAEMs. This was more pronounced for the CAEMs at 3% OPC. Resistance to permanent deformation was investigated using the Vacuum Repeated Load Axial Test (VRLAT) which showed that the mixing and compaction temperature influenced the permanent deformation characteristics of the CAEMs. Increasing OPC content to 1% for Categories 2 and 3 resulted in a decrease in permanent strains of 47% and at 3% OPC, the decrease in permanent strains was 54%. Wheel Tracking Test (WTT) was conducted to ascertain the susceptibility of the CAEMs to deform under loading, investigate crack propagation and number of cycles to failure. The test showed that the performance of the specimens was affected by the test temperature. Increased test temperatures resulted in an increased rate of rutting and eventual failure of the specimens. The test further highlighted the positive benefits of adding cement to the mixtures which resulted in reduced strains and an increased number of cycles to failure for the CAEMs. Structural design and modelling was conducted using KENLAYER which was able to account for the non-linearity of the CAEMs. This was crucial in having a total overview of these mixture types. Although, the structural design was based on practical hypothetical layer thicknesses, the results provided useful insight into the structural capabilities of the CAEMs. The RAP CAEMs generally had lower horizontal tensile strain values in comparison to the VA CAEMs. The design charts showed that an increase in the thickness of the base course and surfacing layer resulted in an increase in the overall fatigue life of the pavement structure. Overall, evaluating the complete findings of this research, CAEMs produced with high RAP contents especially at 50% and 85% RAP had considerably enhanced mechanical and performance properties and are suitable for inclusion as a base material for reconstruction and rehabilitation.
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Thanaya, I. Nyoman Arya. "Improving the performance of cold bituminous emulsion mixtures (CBEMs) : incorporating waste." Thesis, University of Leeds, 2003. http://etheses.whiterose.ac.uk/386/.
Повний текст джерелаАнотація:
Currently, there exists no universally accepted Cold Bituminous Emulsion Mixtures (CBEMs) design procedure. Three of the most popular design procedures, which in essence were based on AASHTO and the Asphalt Institute design guidelines were studied and tested in detail during the course of this investigation. In general, the design procedures investigated were found to be not user-friendly or simple to implement. The main obstacles that restrict the adoption of CBEMs as the first choice material as opposed to conventional hot asphalts, for all bound pavement layers are: the high compacted mixture porosity, low early life strength and long curing times. CBEMs are more widely accepted in low to medium trafficked pavements. The key aims of this investigation were to improve and simplify the design procedure of CBEMs, and to investigate ways of improving CBEMs volumetric and mechanical properties. The main aggregate materials used in this investigation were carboniferous limestone and quartzitic asphalt sand. But in response to environmental conservation campaigns, a range of selected waste materials were also tested as partial and full replacement to the virgin mineral aggregates, including: pulverized fuel ash (PFA), red porphyry sand, synthetic aggregates, steel slag, crumb rubber, and crushed glass. The aggregate gradations were designed using a modified Fuller's curve. The emulsion used in this investigation was a cationic bitumen emulsion with 60% and 62% binder content composed of 100 pen base bitumen. The mix design procedure initially developed in this investigation was found to be complicated from a practical application point of view, in particular the steps required to determine the optimum total liquid content at compaction, which were unlikely to be practicable for site applications. A more simplified CBEMs design procedure was therefore introduced in this thesis, where the coating test was found to play a very essential role. Improvements in all mixture properties were readily accomplished by increasing the compaction effort to reduce porosity and by incorporating cement. The porosity target of 5-10% and minimum indirect tensile strength (ITSM) value of 2000 MPa at a fully cured condition were more easily achievable. The main emphasis of this modified design procedure was on simplicity and practicality whilst maintaining the key volumetric and mechanical properties of the mixtures. In this investigation, the mechanical Performances of the CBEMs at full curing condition were more comprehensively evaluated in terms of fatigue and creep tests. Attempts to accelerate the curing times of cold asphalt mixtures were made by compacting the CBEM specimens in two layers (two lifts) thus allowing the moisture to escape faster from each layer and hence reducing the overall curing time. The results from these laboratory trials were very encouraging. Additionally, the incorporation of plastic cells was found to significantly reduce shear deformations of CBEMs under loading during their early lives. The inclusion of plastic grids in the upper layer of a two layered cold mixture system appeared to be very promising. It was concluded that the CBEMs design procedure proposed in this investigation was simpler than the initially adopted procedure. The main advantages of this modified design procedure were that whilst it maintained all the key volumetric and mechanical properties of the mixtures it was simpler and more practical than other existing procedures. Heavier compaction effort and the incorporation of I to 2% cementitious materials were found to be essential for improving the performance of CBEMs, and as is well known, CBEMs are most suitable in dry warmer climates. When CBEMs are carefully designed and are allowed to achieve a full curing condition, the performance of CBEMs can be comparable to hot asphalt mixtures with the same penetration grade binder.
Книги з теми "Bitumen emulsion cold mixtures"
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Lee, Hosin. Examination of curing criteria for cold in-place recycling. Ames, Iowa: Iowa Highway Research Board c/o Iowa Dept. of Transportation, 2008.
Знайти повний текст джерелаЧастини книг з теми "Bitumen emulsion cold mixtures"
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Mignini, Chiara, Fabrizio Cardone, and Andrea Graziani. "Mechanical Behaviour of Cold Recycled Asphalt Mixtures for Binder Courses Produced with Bitumen Emulsion and High Strength Cement." In Lecture Notes in Civil Engineering, 365–74. Cham: Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-48679-2_35.
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Raschia, Simone, Tushar Chauhan, Shalu Panwar, Alan Carter, Andrea Graziani, and Daniel Perraton. "Effect of Water and Cement Content on the Mechanical Properties of Cold Recycled Mixtures (CRM) with Bitumen Emulsion." In Lecture Notes in Civil Engineering, 274–82. Cham: Springer International Publishing, 2019. http://dx.doi.org/10.1007/978-3-030-29779-4_27.
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Mignini, Chiara, Fabrizio Cardone, and Andrea Graziani. "Experimental Study on the Grading Distribution of Cold Recycled Asphalt Mixtures Produced with Bitumen Emulsion and High Strength Cement." In RILEM Bookseries, 887–93. Cham: Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-46455-4_113.
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Pasetto, Marco, and Nicola Baldo. "Cold Recycling with Bitumen Emulsion of Marginal Aggregates for Road Pavements." In Lecture Notes in Civil Engineering, 155–63. Cham: Springer International Publishing, 2019. http://dx.doi.org/10.1007/978-3-030-29779-4_15.
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Betti, G., G. Airey, K. Jenkins, A. Marradi, and G. Tebaldi. "Active Filler’s Effect on In Situ Performances of Bitumen Emulsion Recycled Mixtures." In RILEM Bookseries, 799–810. Dordrecht: Springer Netherlands, 2015. http://dx.doi.org/10.1007/978-94-017-7342-3_64.
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Al Nageim, Hassan, Abbas Al-Hdabi, and Shakir Al Busultan. "Indirect Tensile Stiffness and Permanent Deformation of Microwave Treated Cold Bituminous Emulsion Mixtures (CBEMS) Containing Cementitious Activated Waste Fly Ash." In Advances and Challenges in Structural Engineering, 268–76. Cham: Springer International Publishing, 2018. http://dx.doi.org/10.1007/978-3-030-01932-7_21.
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Nassar, Ahmed I., Nicholas H. Thom, and Tony Parry. "Examining the effects of contributory factors on curing of Cold Bitumen Emulsion Mixtures." In Functional Pavement Design, 1037–47. CRC Press, 2016. http://dx.doi.org/10.1201/9781315643274-114.
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Hasaninasab, Shahab. "The Effects of Using Nano-Silica in Cold-In Place Asphalt with Emulsified Bitumen." In Asphalt and Asphalt Mixtures. IntechOpen, 2019. http://dx.doi.org/10.5772/intechopen.86333.
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"Effect of lime on short-term bearing capacity of bitumen emulsion recycled mixtures." In Asphalt Pavements, 1057–66. CRC Press, 2014. http://dx.doi.org/10.1201/b17219-128.
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Zoorob, S. E., and I. N. A. Thanaya. "Improving the performance of cold bituminous emulsion mixtures (CBEMs) incorporating waste materials." In Performance of Bituminous and Hydraulic Materials in Pavements, 237–49. Routledge, 2017. http://dx.doi.org/10.1201/9780203743928-30.
Повний текст джерелаТези доповідей конференцій з теми "Bitumen emulsion cold mixtures"
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Grilli, Vittoria, Sara Spadoni, Francesco Canestrari, and Andrea Graziani. "Influence of specimen geometry on the complex modulus of cold recycled material mixtures." In 7th International Conference on Road and Rail Infrastructure. University of Zagreb Faculty of Civil Engineering, 2022. http://dx.doi.org/10.5592/co/cetra.2022.1450.
Повний текст джерелаАнотація:
Cold recycling of bituminous pavements is becoming increasingly important because it leads to the reduction of costs of pavement maintenance and to lower pollutant emissions with respect to hot recycling. The stiffness characterization of cold recycled material (CRM) mixtures is essential to predict the stress-strain behaviour of the pavement structure. The present paper describes a laboratory experiment for evaluating the effects of specimen geometry on the complex modulus of CRM mixtures manufactured with bitumen emulsion and cement. In particular, the focus was on cylindrical specimens with diameter of 38 mm, adopted to improve the efficiency of laboratory specimen fabrication. Specimens with three different diameters (100 mm, 75 mm and 38 mm) were obtained by coring samples compacted using a gyratory compactor. Their complex modulus was measured by means of cyclic compression tests, using the Asphalt Mixture Performance Tester. The testing temperatures were 5, 15, 25, 35, 45 and 55 °C and the testing frequencies were 20, 10, 5, 1, 0.5, 0.1 Hz. The tests were carried out after long-term curing in a climate chamber. Results showed that the complex modulus measured on 38 mm specimens, although with a greater dispersion, is comparable to that measured on 100 mm and 75 mm specimens, thus it can be used for evaluating the mechanical behaviour of CRM mixture.
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Valentin, Jan, Pavla Vacková, Nadia Maria Jose Tarifa, and Dimitra Giannaka. "Potential substitutions of traditional hydraulic binders in cold recycled mixtures using blast furnace slag." In 6th International Conference on Road and Rail Infrastructure. University of Zagreb Faculty of Civil Engineering, 2021. http://dx.doi.org/10.5592/co/cetra.2020.1246.
Повний текст джерелаАнотація:
Cold recycling techniques are known for decades in pavement engineering as a suitable rehabilitation method mainly for existing asphalt pavements. Traditionally the most common solution is to use bituminous emulsion or foamed bitumen as a binder usually in combination with small amount of cement or lime as active fillers. In some countries cement or hydraulic road binders are preferred instead of bitumen based options since it is believed that hydraulic binders can increase the bearing capacity of cold recycled layer especially for pavements with underestimated structures which were designed >40 years ago. Based on that the Faculty of Civil Engineering, CTU Prague is for more than 10 years evaluating and developing further alternatives for the cement-based approach of cold recycled mixtures. In the past experience with fly-ashes or activated fly-ash based alternative binders were presented. Presently the focus is concentrating on the potentials of using blast furnace slags which are not generally usable for the cement industry (e.g. because of limited content of glassy compounds which are very typical mainly for granulated blast furnace slags). Air-cooled blast furnace slags were selected and activated by high-speed milling to get a material with latent hydraulic properties. This modified slag was applied in several options to cold recycled mixtures and standard strength and deformation tests were performed, including the determination of resistance to water immersion. Separately pastes based on used treated fine-grained slags were tested and evaluated. Data of the pastes are discussed jointly with the results for experimentally tested cold recycled mixtures.
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Krayushkina, Kateryna, Tetiana Khymeryck, and Kyrylo Fedorenko. "Usage of new materials during rehabilitation of road structure using cold recycling technology." In 6th International Conference on Road and Rail Infrastructure. University of Zagreb Faculty of Civil Engineering, 2021. http://dx.doi.org/10.5592/co/cetra.2020.1229.
Повний текст джерелаАнотація:
Until recently, the most common way for recovering of damaged and worn asphalt pavements on Ukrainian roads remains the provision of additional reinforced layers over the old pavement with patching. However, such measures give only a short-term effect because after one or two years, the existing deformations and fractures beneath reinforced layers occur, especially in conditions of insufficient strength of the foundations. But nowadays, recycling technology of different variations became the main method of existing pavement renovation. The economic attractiveness of cold recycling technology is primarily in the reuse of existing road material for arrangement of new pavement layers, so there is no need to arrange special areas for storage and disposal of old asphalt. In addition, the use of such technology helps to minimize the harmful impacts on the environment during road repair works. The essence of cold recycling technology, which is the most widely used in Ukraine for the arrangement of a road foundation layer, is in the fact that the defective and destroyed pavement layers are strengthened directly by complex admixtures of organic (hot bitumen, bituminous emulsion, foamed bitumen) and mineral suspensions, lime) binders. Cold recycling, according to the complications of the work, is divided into several types, depending of the depth of cutting. The choice of a particular type of recovery depends mainly on the condition of the entire pavement structure, which is determined prior to the start of repair works. Optimal mis design of the organic and mineral mixture for the arrangement of the road foundation layer by cold recycling technology is also executed before the beginning of the works. Actually, the main direction of cold recycling technology research in Ukraine is the usage of new materials such as fiber - basalt or polymer, stabilizing additives (ionic or polymeric), industrial waste - slags of various types of production or other by-products. Performed studies have shown that the use of organic and mineral mixtures of optimal design with the insertion of basalt fiber increases crack resistance and durability of the arranged road foundation layer.
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Amal, R., J. Narendra, M. Sivakumar, and M. V. L. R. Anjaneyulu. "Performance Evaluation of Cold Bituminous Mix Reinforced with Coir Fibre." In International Web Conference in Civil Engineering for a Sustainable Planet. AIJR Publisher, 2021. http://dx.doi.org/10.21467/proceedings.112.67.
Повний текст джерелаАнотація:
Cold bituminous mix (CBM), which is a mixture of bitumen emulsion and aggregate that is mixed together at ambient temperature, has several advantages like energy savings, easiness in preparation, environmental benefits, and high production at low investment. But there are certain limitations of CBMs like inferior mechanical properties, high air voids, weak early life strength, long curing time and poor coating that hinder its extensive usage. The possibility of improving mechanical performance of CBMs by the addition of coir fibre is attempted in this study. The objectives of the study are to assess the improvement in performance of CBM due to addition of coir fibre and to identify the optimum length and optimum content of coir fibre for CBMs. Three coir fibre contents and three coir fibre lengths were used in this study. Performance evaluation of CBM modified with coir fibre was done through Retained Marshall Stability (RMS) test and Hamburg wheel tracking test. Coir fibre was added to the aggregates and mixed before the addition of pre-wetting water and emulsion, to achieve uniform distribution and to avoid balling of coir fibres. When coir fibre was added to the mix, Marshall Stability increased up to a certain level of coir fibre content depending on fibre length. Highest Marshall Stability value was obtained at 0.2% content (by weight of total mix) of coir fibre of 15 mm length. Resistance to moisture damage was assessed by RMS test. It was observed that the addition of coir fibre improved the RMS value. From the Hamburg wheel tracking test, it was observed that the addition of coir fibre improved rut resistance. For all fibre lengths, CBM with 0.2 % coir content showed the highest rut resistance, with 10 mm fibre length showed the best performance. Hence, coir fibre is recommended as a feasible additive for mechanical performance improvement of CBMs.
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Arshad, Ahmad Kamil, Noor Azilatom Ali, Ekarizan Shaffie, Wardati Hashim, and Zanariah Abd Rahman. "Rutting performance of cold bituminous emulsion mixtures." In PROCEEDINGS OF THE INTERNATIONAL CONFERENCE OF GLOBAL NETWORK FOR INNOVATIVE TECHNOLOGY AND AWAM INTERNATIONAL CONFERENCE IN CIVIL ENGINEERING (IGNITE-AICCE’17): Sustainable Technology And Practice For Infrastructure and Community Resilience. Author(s), 2017. http://dx.doi.org/10.1063/1.5005711.
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Zoorob, S., and I. Thanaya. "Improving the performance of cold bituminous emulsion mixtures (CBEMs) incorporating waste materials." In Proceedings of the Fourth European Symposium on Performance of Bituminous and Hydraulic Materials in Pavements, Bitmat 4. Taylor & Francis Group, 6000 Broken Sound Parkway NW, Suite 300, Boca Raton, FL 33487-2742: CRC Press, 2017. http://dx.doi.org/10.4324/9780203743928-36.
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Dołżycki, Bohdan, Andrea Grilli, Alex Balzi, Mariusz Jaczewski, and Cezary Szydłowski. "Binder courses using cold recycled mixtures – a novel concept in cold recycling." In 6th International Conference on Road and Rail Infrastructure. University of Zagreb Faculty of Civil Engineering, 2021. http://dx.doi.org/10.5592/co/cetra.2020.1058.
Повний текст джерелаАнотація:
Cold recycling with cement and bituminous emulsion is one of the most environmentally friendly techniques to maximize the reuse of reclaimed asphalt (RA) collected during demolition of roads. Cold recycled mixtures are commonly used for base courses in construction or rehabilitation of flexible and semi-rigid pavements. Current experiences demonstrated that cold recycling with appropriate requirements and technical recommendations allows long-lasting pavements to be designed. Those outcomes stimulated researchers and engineers in the new challenge of using the cold recycled mixtures in binder layers that are generally more often included in maintenance planning. This paper summarizes current San Marino and Polish experiences with cold recycled mixtures designed for binder layers. The first part of the paper presents the design phase of the cold recycled mixtures in both countries. It describes and compares the composition of the mixtures, grading curves of the mineral mixtures, binding agents and requirements. The second part of the paper shows laboratory test results of mechanical properties of cold recycled mixtures for binder courses including test results in full-scale application.
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Suda, Jan, Jan Valentin, and Josef Žák. "Cold bituminous emulsion mixtures - laboratory mix design, trial section job site and monitoring." In 6th Eurasphalt & Eurobitume Congress. Czech Technical University in Prague, 2016. http://dx.doi.org/10.14311/ee.2016.327.
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Vaitkus, Audrius, Judita Gražulytė, Lina Juknevičiūtė-Žilinskienė, and Vitalijus Andrejevas. "Review of Lithuanian Experience in Asphalt Pavements Cold Recycling." In Environmental Engineering. VGTU Technika, 2017. http://dx.doi.org/10.3846/enviro.2017.153.
Повний текст джерелаАнотація:
One of the key goals in the EU White Paper is to reduce carbon emissions in transport by 60% by 2050. Consequently, during the past years an effect on the environment became a decisive factor in selecting materials and technologies for road construction and rehabilitation. Cold recycling is a reasonable solution in asphalt pavement rehabilitation because it is economical and old asphalt pavements can be reused. This technology differs from others by mixing temperature. Besides, cold recycling does not require additional heating. These benefits result in wide application of cold recycling around the world. In Lithuania, cold recycling has been used for more than 15 years. Both technologies, i.e. cold in-plant recycling and cold in-place recycling, were used. In both technologies reclaimed asphalt pavement (RAP) is bound with bituminous binders (foamed bitumen or bitumen emulsion), hydraulic binders (cement) or a combination of bituminous and hydraulic binders depending on the base course specifications. This paper focuses on the Lithuanian experience in cold recycling of asphalt pavements using different types of cold recycling and binders.
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Iwański, Marek, and Anna Chomicz-Kowalska. "Application of recycled aggregates to the road base mixtures with foamed bitumen in the cold recycling technology." In The 9th International Conference "Environmental Engineering 2014". Vilnius, Lithuania: Vilnius Gediminas Technical University Press “Technika” 2014, 2014. http://dx.doi.org/10.3846/enviro.2014.155.
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