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1
Jin, Na. "Fly Ash Applicability in Pervious Concrete." The Ohio State University, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=osu1279136103.
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Yousef, Shebani A. "Durability of Incinerator Fly Ash Concrete." Thesis, Coventry University, 2015. http://curve.coventry.ac.uk/open/items/72f1ced3-5b19-470d-a0a8-06ebadc81d08/1.
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The main theme of this research was to investigate the durability of concrete made using waste materials as a cement replacement. This is a method to produce green sustainable concrete. The objective was to use locally available wastes to produce a concrete that could be used by the local authority. The mechanical, physical and chemical properties of concrete made predominantly with IFA as a partial cement replacement have been tested. The IFA was won locally from the domestic waste incinerator at Coventry, UK. The other materials used in the mixes included Ground Granulated Blast Furnace Slag (GGBS), silica fume and by-pass dust, which was used as an activator and was also won locally from the Rugby cement plant. Compressive strength and tensile strength, workability, corrosion of embedded steel, shrinkage and expansion, freeze and thaw, corrosion and chloride ingress were studied. Water permeability was studied by the author on mortar samples during one year and on concrete samples during the following. Carbonation was studied on concrete samples and finally mechanical experiments were carried out on concrete beams and slabs. Two further experiments were carried out to complete the study of durability of concrete made with waste materials being, the ASR (Alkaline Silica Reaction) and sulphate attack experiments. One main physical experiment, in the form of a trial mix, was carried out in one of the waste recycling sites of Warwickshire in September 2013. Subsequent to observations during the site trial, the author compared results of setting time, heat of hydration and strength of the trial mix and control mixes. The outcome of this research was a novel mix that had more than 30 percent waste material and a further 40 percent of secondary materials, making it as sustainable as possible. Both laboratory and site trial results have achieved compressive strength which are higher than 30 MPa, indicating that the novel mix concrete could be used for structural purposes. Most of the durability results of the novel mix were comparable with the control OPC mix and the novel mix concrete, in terms of transport properties, induced less electrical current seepage. Furthermore the tensile strength of the novel mix concrete was higher than the control OPC concrete and this is due to the higher ductility index of the novel mix.
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Bortz, Brandon Stallone. "Salt-scaling durability of fly ash concrete." Thesis, Manhattan, Kan. : Kansas State University, 2010. http://hdl.handle.net/2097/3878.
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Hung, Hsien-Hsin. "Properties of high volume fly ash concrete." Thesis, University of Sheffield, 1997. http://etheses.whiterose.ac.uk/14441/.
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This thesis presents a detailed investigation on the engineering properties and microstructural characteristics of concrete containing a high volume of fly ash (HVF A). The purpose of the project is to evaluate the concept of using relatively large volumes of fly ash in normal portland cement concrete, and hence enhance the beneficial use of fly ash in value-added products and construction. A total of eight concrete mixtures with and without fly ash was investigated. The proportion of fly ash in all the HVF A concrete mixtures varied from 50 to 80 % by weight of the cementitious materials, with a constant water-to-cementitious ratio of 0.40 for all the mixtures. A high degree of workability was maintained by the use of a superplasticizer. To optimize the pozzolanic activity in the HVF A concrete, silica fume was used in some of the mixes. The total cementitious materials content was kept constant at 350 kg/m3 and 450 kg/m3 respectively. The influence of the different replacement materials and two curing regimes was studied. The study consisted of two parts. The first part is an extensive study of the engineering properties such as strength development, modulus of elasticity, ultrasonic pulse velocity, swelling, and drying shrinkage at various ages up to 18 months. The depth of carbonation of HVF A concrete under different curing regimes was also investigated. A study of the microstructure of HVF A concretes forms the second part of the investigation. Pore structure, air permeability and water absorption of HVF A concretes with different replacement mixtures were studied. A detailed discussion dealing with the change of the morphological phase under different curing regimes is also presented. The results show that HVF A concretes exhibit excellent mechanical properties with good long-term strength development. Compressive strength in the range of 40 to 60 MPa "as achieved for all the HVF A concretes at the age of 90 days. The dynamic modulus of elasticity reached values of the order of 55 GPa at 90 days. Under similar conditions, concretes made with both fly ash and silica fume had engineering properties which were as good as those made with cement replaced by fly ash alone. The use of fly ash to replace both cement and sand has the advantage of mobilizing and combining the benefits and effects of both separate replacements. The HVF A concretes also have low permeability and exhibit good potential characteristics to resist water penetration. Reduction in the volume of large pores was observed with the progress of the pozzolanic reaction. Higher HVF A concrete strength was generally associated with a lower volume of large pores in the concrete. A decrease in the levels of calcium hydroxide was seen with progressive water curing and age in all the HVF A concretes, providing evidence of continued pozzolanic reactivity of the fly ashes. Various empirical relationships and design equations are presented and conclusions are drawn at the end of each part. It is recommended that further research is required to determine the influence on HVF A concretes of extreme curing conditions such as high or low temperature and low moisture availability, and to improve the early strength properties of the HVF A concretes.
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Hardjito, Djwantoro. "Studies of fly ash-based geopolymer concrete." Thesis, Curtin University, 2005. http://hdl.handle.net/20.500.11937/634.
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The use of Portland cement in concrete construction is under critical review due to high amount of carbon dioxide gas released to the atmosphere during the production of cement. In recent years, attempts to increase the utilization of fly ash to partially replace the use of Portland cement in concrete are gathering momentum. Most of this by-product material is currently dumped in landfills, creating a threat to the environment. Geopolymer concrete is a ‘new’ material that does not need the presence of Portland cement as a binder. Instead, the source of materials such as fly ash, that are rich in Silicon (Si) and Aluminium (Al), are activated by alkaline liquids to produce the binder. Hence concrete with no Portland cement. This thesis reports the details of development of the process of making fly ash-based geopolymer concrete. Due to the lack of knowledge and know-how of making of fly ashbased geopolymer concrete in the published literature, this study adopted a rigorous trial and error process to develop the technology of making, and to identify the salient parameters affecting the properties of fresh and hardened concrete. As far as possible, the technology that is currently in use to manufacture and testing of ordinary Portland cement concrete were used. Fly ash was chosen as the basic material to be activated by the geopolimerization process to be the concrete binder, to totally replace the use of Portland cement. The binder is the only difference to the ordinary Portland cement concrete. To activate the Silicon and Aluminium content in fly ash, a combination of sodium hydroxide solution and sodium silicate solution was used. Manufacturing process comprising material preparation, mixing, placing, compaction and curing is reported in the thesis.Napthalene-based superplasticiser was found to be ii useful to improve the workability of fresh fly ash-based geopolymer concrete, as well as the addition of extra water. The main parameters affecting the compressive strength of hardened fly ash-based geopolymer concrete are the curing temperature and curing time, the molar H2O-to-Na2O ratio, and mixing time. Fresh fly ash-based geopolymer concrete has been able to remain workable up to at least 120 minutes without any sign of setting and without any degradation in the compressive strength. Providing a rest period for fresh concrete after casting before the start of curing up to five days increased the compressive strength of hardened concrete. The elastic properties of hardened fly ash-based geopolymer concrete, i,e. the modulus of elasticity, the Poisson’s ratio, and the indirect tensile strength, are similar to those of ordinary Portland cement concrete. The stress-strain relations of fly ash-based geopolymer concrete fit well with the expression developed for ordinary Portland cement concrete.
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Hardjito, Djwantoro. "Studies of fly ash-based geopolymer concrete." Curtin University of Technology, Dept. of Civil Engineering, 2005. http://espace.library.curtin.edu.au:80/R/?func=dbin-jump-full&object_id=18580.
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The use of Portland cement in concrete construction is under critical review due to high amount of carbon dioxide gas released to the atmosphere during the production of cement. In recent years, attempts to increase the utilization of fly ash to partially replace the use of Portland cement in concrete are gathering momentum. Most of this by-product material is currently dumped in landfills, creating a threat to the environment. Geopolymer concrete is a ‘new’ material that does not need the presence of Portland cement as a binder. Instead, the source of materials such as fly ash, that are rich in Silicon (Si) and Aluminium (Al), are activated by alkaline liquids to produce the binder. Hence concrete with no Portland cement. This thesis reports the details of development of the process of making fly ash-based geopolymer concrete. Due to the lack of knowledge and know-how of making of fly ashbased geopolymer concrete in the published literature, this study adopted a rigorous trial and error process to develop the technology of making, and to identify the salient parameters affecting the properties of fresh and hardened concrete. As far as possible, the technology that is currently in use to manufacture and testing of ordinary Portland cement concrete were used. Fly ash was chosen as the basic material to be activated by the geopolimerization process to be the concrete binder, to totally replace the use of Portland cement. The binder is the only difference to the ordinary Portland cement concrete. To activate the Silicon and Aluminium content in fly ash, a combination of sodium hydroxide solution and sodium silicate solution was used. Manufacturing process comprising material preparation, mixing, placing, compaction and curing is reported in the thesis.Napthalene-based superplasticiser was found to be ii useful to improve the workability of fresh fly ash-based geopolymer concrete, as well as the addition of extra water. The main parameters affecting the compressive strength of hardened fly ash-based geopolymer concrete are the curing temperature and curing time, the molar H2O-to-Na2O ratio, and mixing time. Fresh fly ash-based geopolymer concrete has been able to remain workable up to at least 120 minutes without any sign of setting and without any degradation in the compressive strength. Providing a rest period for fresh concrete after casting before the start of curing up to five days increased the compressive strength of hardened concrete. The elastic properties of hardened fly ash-based geopolymer concrete, i,e. the modulus of elasticity, the Poisson’s ratio, and the indirect tensile strength, are similar to those of ordinary Portland cement concrete. The stress-strain relations of fly ash-based geopolymer concrete fit well with the expression developed for ordinary Portland cement concrete.
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Deb, Partha Sarathi. "Durability of fly ash based geopolymer concrete." Thesis, Curtin University, 2013. http://hdl.handle.net/20.500.11937/2126.
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Inclusion of ground granulated blast furnace slag (GGBFS) together with fly-ash can have significant effects on the development of mechanical and durability properties of geopolymer concrete when cured at normal temperature. The slag blended geopolymer concretes showed durability properties comparable to those of the control OPC concrete. In general, the results show that it is possible to design fly ash and slag blended geopolymer concrete suitable for ambient curing with similar or better durability properties of conventional OPC concrete.
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Chelberg, Matthew. "The Effect of Fly Ash Chemical Composition on Compressive Strength of Fly Ash Portland Cement Concrete." The Ohio State University, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=osu1555611247091087.
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Matenda, Amanda Zaina. "GEOPOLYMER CONCRETE PRODUCTION USING COAL ASH." OpenSIUC, 2015. https://opensiuc.lib.siu.edu/theses/1654.
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Coal powered power plants account for more than 40 percent of the electricity production of the United States. The combustion of coal results in a large number of solid waste materials, or coal combustion byproducts (CCBs). These waste materials are stored in landfill or ponds. The construction industry is heavily reliant on concrete which is used to make the building blocks for any type of structures, bricks. Concrete is a composite material made of a binder and coarse and fine aggregate. The most widely used binder in concrete production is Ordinary Portland Cement (OPC). Since cement manufacture is costly and environmentally damaging, research has increased in recent years to find a more readily available binder. This study aims at investigating the properties of Illinois fly ash as a binder in the production of geopolymer concrete. Geopolymer concrete is an innovative material made by using Alumina and Silica rich materials of geological origins as a binder as well as an alkali activated solution. Sodium Silicate and Sodium Hydroxide were used to make the activator solution of two different ratios. Geopolymer Concrete with a ratio of 1:1 of Sodium Silicate to Sodium Hydroxide reached a compressive strength above 6000 psi while samples made with a ratio of 1:2 reached a compressive strength above 4000 psi. This environmentally-friendly, green concrete was also found to have a cost comparable to conventional concrete.
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Sahmaran, Mustafa. "Self-compacting Concrete With High Volumes Of Fly Ash." Phd thesis, METU, 2006. http://etd.lib.metu.edu.tr/upload/2/12606896/index.pdf.
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In this investigation, SCCs were prepared by keeping the total mass of cementitious materials (cement and fly ash) constant at 500 kg/m3, in which 30, 40, 50, 60, and 70% of cement, by weight, was replaced by the high-lime and low-lime fly ash. For comparison, a control SCC mixture without any fly ash
was also produced. The fresh properties of the SCCs were observed through, slump flow time and diameter, V-funnel flow time, L-box height ratio, U-box height difference, segregation ratio and the rheological parameters (relative
yield stress and relative plastic viscosity). Relations between workability and rheological parameters were sought. Setting times and temperature rise of the SCC were also determined. The hardened properties included the compressive strength, split tensile strength, drying shrinkage and permeation properties (absorption, sorptivity and rapid chloride permeability tests) up to 360 days.
The results obtained indicated that it is possible to produce SCC with a 70% of cement replacement by both types of fly ash. The use of high volumes of fly ash in SCC not only improved the workability and permeability properties but
also made it possible to produce concretes between 33-40 MPa compressive strength at 28 days.
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Simms, Scott A. "Use of coal fly ash in asphalt concrete mixes." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk2/tape17/PQDD_0024/MQ31639.pdf.
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Abdalhmid, Jamila M. A. "Drying shrinkage of self-compacting concrete incorporating fly ash." Thesis, University of Bradford, 2019. http://hdl.handle.net/10454/17455.
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The present research is conducted to investigate long term (more than two years) free and confined drying shrinkage magnitude and behaviour of self-compacting concrete (SCC) and compare with normal concrete (NC). For all SCCs mixes, Portland cement was replaced with 0-60% of fly ash (FA), fine and coarse aggregates were kept constant at 890 kg/m3 and 780 kg/m3, respectively. Two different water binder ratios of 0.44 and 0.33 were examined for both SCCs and NCs. Fresh properties of SCCs such as filling ability, passing ability, viscosity and resistance to segregation and hardened properties such as compressive and flexural strengths, water absorption and density of SCCs and NCs were also determined. Experimental results of free drying shrinkage obtained from this study together with collected comprehensive database from different sources available in the literature were compared to five existing models, namely the ACI 209R-92 model, BSEN-92 model, ACI 209R-92 (Huo) model, B3 model, and GL2000 model. To assess the quality of predictive models, the influence of various parameters (compressive strength, cement content, water content and relative humidity) on the drying shrinkage strain are studied. An artificial neural network models (ANNM) for prediction of drying shrinkage strains of SCC was developed using the same data used in the existing models. Two ANNM sets namely ANNM1 and ANNM2 with different numbers of hidden layer neurones were constructed. Comparison between the results given by the ANNM1 model and the results obtained by the five existing predicted models were presented.
The results showed that, using up to 60% of FA as cement replacement can produce SCC with a compressive strength as high as 30 MPa and low drying shrinkage strain. SCCs long-term drying shrinkage from 356 to 1000 days was higher than NCs. Concrete filled elliptical tubes (CFET) with self-compacting concrete containing FA up to 60% are recommended for use in construction in order to prevent confined drying strain.
ACI 209R-92 model provided a better prediction of drying shrinkage compared with the other four models. However, a very high predictability with high accuracy was achieved with the ANNM1 model with a mean of 1.004. Moreover, by using ANNM models, it is easy to insert any of factors effecting drying shrinkage to the input parameters to predict drying shrinkage strain of SCC.Ministry of Higher Education, Libya
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Mackechnie, James Ronald. "The durability of fly ash concrete in marine and softwater environments." Master's thesis, University of Cape Town, 1989. http://hdl.handle.net/11427/18788.
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Concrete is attacked by aggressive agents in the marine and softwater environments which reduce the durability of concrete. To help lessen the effect of this aggressive attack, fly ash concrete has been recommended for use in these environments. The lower permeability, increased chemical resistance and higher long-term strength of fly ash concrete are expected to improve the concrete durability. In this research the effect of fly ash was investigated with regard, initially to general concrete properties such as bleeding, early set, workability, mortar excess and compressive strength. Lethabo field 2 fly ash and Western Cape materials were used for this work. Having developed a wide range of concrete mixes, further investigation was done into specific concrete properties such as the effect of different curing regimes, water absorption, permeability and freeze-thaw resistance. These properties are considered to have an influence on concrete durability. Comparisons were made between the concrete properties of Lethabo field 2, Lethabo classified and Matla classified fly ash concrete. The three types of concrete were tested for compressive strength, sorptivity (rate of water absorption) and density. At the same time, fly ash and OPC concrete samples were exposed to the marine and softwater environment for up to 10 months. Marine exposure was done in the submerged, tidal and spray zones in Table Bay. Softwater exposure was done at Constantia Nek and Steenbras Water Treatment Plants. The performance of concrete in the various exposure conditions was measured by compressive strength, sorptivity and density tests. Fly ash improved many of the properties of concrete, with fly ash concrete having better workability, higher long-term strength, reduced bleeding, lower sorptivity and reduced permeability than similar OPC concrete. Some of the properties of concrete were however worsened by using fly ash. Fly ash concrete had longer setting times, reduced resistance to freezing and thawing and was more adversely affected by dry curing than similar OPC concrete. Lethabo field 2 fly ash concrete had higher compressive strength and lower sorptivity than either Lethabo classified or Matla classified fly ash concrete. The long-term performance of Lethabo classified and Matla classified fly ash concrete was better than that of Lethabo field 2 fly ash concrete, with regard to compressive strength development and sorptivity reduction. Fly ash concrete performed well in both the marine and softwater environments. After 10 months of exposure in either marine or softwater conditions, fly ash concrete had higher compressive strength and lower sorptivity than similar OPC concrete. The good performance of fly ash concrete in the marine and softwater environment confirmed the ability of fly ash to improve many of the important durability properties of concrete. From this medium-term durability investigation it was found that Lethabo field 2 fly ash improved the performance of concrete in marine and softwater environments while fly ash, in general, improved many of the durability properties of concrete.
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Mukheibir, Pierre Victor. "The deformation properties of concrete with classified Lethabo fly ash." Master's thesis, University of Cape Town, 1990. http://hdl.handle.net/11427/15944.
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Bibliography: pages 71-74.It has become necessary to determine the magnitude of creep, shrinkage, elastic and thermal deformations of concrete as these characteristics determine the loss of prestressing in prestressed concrete and affect the deflections with time of large concrete sections. Much of the literature available on this topic has conflicting conclusions. In this research, the effect of fly ash was first investigated with regard to general concrete properties such as bleeding, early set, workability, mortar excess and compressive strength. Classified Lethabo fly ash and local Western Cape materials were used for this work. With the increase in the percentage fly ash present in the concrete mix, the water requirement was reduced in order to get the same workability. This characteristic reduced the amount of water available for bleeding. For a given C/W ratio the inclusion of fly ash in a concrete mix had no effect on the mortar excess. The early setting time was retarded for mixes with increasing percentages of fly ash. Higher cementitious material to water ratios were required for concrete with classified Lethabo fly ash than Ordinary Portland Cement mixes, to obtain the same 28 day compressive strength. The fly ash mixes had higher strength developments with time i.e. they have lower early strengths and higher long term strengths than OPC mixes for the same 28 day compressive strengths. Having developed a wide range of concrete mixes, the main investigation was done on specific deformation properties of concrete such as the elasticity, shrinkage, creep and thermal movement. The effect of different wet curing durations and testing ages on these properties were investigated. The elastic modulus was determined by both static and dynamic test methods. A relationship was established between the two methods to estimate the static modulus from the dynamic modulus, which was quicker to perform. In this thesis, the elastic modulus was not affected by the presence of fly ash. The elastic properties of the fly ash mixes was found to be similar to that of the OPC mixes of the same compressive strength. Similarly, the drying shrinkage and thermal movement were not affected noticeably by the presence of fly ash. The volume of aggregate was not a variable as it did not change when fly ash was added to the mix. An attempt was made to develop a test to determine the plastic shrinkage of an unrestrained sample. The effect of fly ash on the plastic shrinkage was not investigated fully. For the creep of concrete, it was established that mixes containing fly ash have lower creep factors than OPC concretes, although no clear trends were apparent for increasing percentages of fly ash. The effect of fly ash in pump mixes was also investigated and the same trends were apparent, although in general, the pump mixes had higher creep factors than the normal mixes. The curing of concrete is critical if good quality concrete is to be obtained. For all deformation properties, the longer a specimen was wet cured, the lower were the deformations. With longer wet curing, a larger volume of hydrated gel developed which gave higher compressive strengths and more rigidity within the matrix. The conclusion reached in this thesis was that the presence of classified Lethabo fly ash did not noticeably affect the deformation properties of the concrete for equivalent compressive strengths. Where some effects were noticed, the fly ash concretes displayed somewhat lower deformations.
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Burden, Donald. "The durability of concrete containing high levels of fly ash." Skokie, Ill. : Portland Cement Association, 2006. http://www.cement.org/bookstore/profile.asp?itemid=SN2989.
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Gogol, Volker R. "The compressive strength of fly ash concrete and its mineralogy." Master's thesis, University of Cape Town, 1994. http://hdl.handle.net/11427/8457.
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Includes bibliographical references.The use of fly ash as a cement extender in portland cement concrete is well established. Strict requirements are set for the fly ash on its physical properties and chemical composition to ensme its successful application as a partial replacement material for cement. An investigation was undertaken into the effectiveness and properties of a high carbon clinker ash when used as a cement extender at a 30 direct mass to mass substitution for portland cement. The clinker ash came from the Van Eck power station in Windhoek, Namibia and was milled to pass a 63micron sieve. For comparison fly ashes from the Escom power stations of Lethabo, Duvha and Matla were used. Both concrete and pure paste specimens were prepared for the evaluations.
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Deb, Partha Sarathi. "Properties of Geopolymer Concrete Using Ultrafine Fly Ash and Nanosilica." Thesis, Curtin University, 2018. http://hdl.handle.net/20.500.11937/75529.
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This study investigated the effects of ultrafine fly ash and nanosilica in geopolymers cured at room temperature. It was found that the optimum percentages of ultrafine fly ash and nanosilica with fly ash alone or that blended with 15% GGBFS or 10% OPC significantly improved strength and durability of geopolymers. The properties of geopolymer improved by enhancement of the hydrated phases and microstructure that reduced porosity.
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Jerban, Majid. "Performance of concrete incorporating amorphous silica residue and biomass fly ash." Mémoire, Université de Sherbrooke, 2016. http://hdl.handle.net/11143/9807.
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L'industrie du ciment est l'une des principales sources d'émission de dioxyde de carbone. L'industrie mondiale du ciment contribue à environ 7% des émissions de gaz à effet de serre dans l'atmosphère. Afin d'aborder les effets environnementaux associés à la fabrication de ciment exploitant en permanence les ressources naturelles, il est nécessaire de développer des liants alternatifs pour fabriquer du béton durable. Ainsi, de nombreux sous-produits industriels ont été utilisés pour remplacer partiellement le ciment dans le béton afin de générer plus d'économie et de durabilité. La performance d'un additif de ciment est dans la cinétique d'hydratation et de la synergie entre les additions et de ciment Portland. Dans ce projet, deux sous-produits industriels sont étudiés comme des matériaux cimentaires alternatifs: le résidu de silice amorphe (RSA) et les cendres des boues de désencrage. Le RSA est un sous-produit de la production de magnésium provenant de l'Alliance Magnésium des villes d'Asbestos et Thedford Mines, et les cendres des boues de désencrage est un sous-produit de la combustion des boues de désencrage, l'écorce et les résidus de bois dans le système à lit fluidisé de l'usine de Brompton située près de Sherbrooke, Québec, Canada. Récemment, les cendres des boues de désencrage ont été utilisées comme des matériaux cimentaires alternatifs. L'utilisation de ces cendres comme matériau cimentaire dans la fabrication du béton conduit à réduire la qualité des bétons. Ces problèmes sont causés par des produits d'hydratation perturbateurs des cendres volantes de la biomasse quand ces cendres sont partiellement mélangées avec du ciment dans la fabrication du béton. Le processus de pré-mouillage de la cendre de boue de désencrage avant la fabrication du béton réduit les produits d'hydratation perturbateurs et par conséquent les propriétés mécaniques du béton sont améliorées. Les approches pour étudier la cendre de boue de désencrage dans ce projet sont : 1) caractérisation de cette cendre volante régulière et pré-humidifiée, 2) l'étude de la performance du mortier et du béton incorporant cette cendre volante régulière et pré-humidifiée. Le RSA est un nouveau sous-produit industriel. La haute teneur en silice amorphe en RSA est un excellent potentiel en tant que matériau cimentaire dans le béton. Dans ce projet, l'évaluation des RSA comme matériaux cimentaires alternatifs compose trois étapes. Tout d'abord, la caractérisation par la détermination des propriétés minéralogiques, physiques et chimiques des RSA, ensuite, l'optimisation du taux de remplacement du ciment par le RSA dans le mortier, et enfin l'évaluation du RSA en remplacement partiel du ciment dans différents types de béton dans le système binaire et ternaire. Cette étude a révélé que le béton de haute performance (BHP) incorporant le RSA a montré des propriétés mécaniques et la durabilité, similaire du contrôle. Le RSA a amélioré les propriétés des mécaniques et la durabilité du béton ordinaire (BO). Le béton autoplaçant (BAP) incorporant le RSA est stable, homogène et a montré de bonnes propriétés mécaniques et la durabilité. Le RSA avait une bonne synergie en combinaison de liant ternaire avec d'autres matériaux cimentaires supplémentaires. Cette étude a montré que le RSA peut être utilisé comme nouveaux matériaux cimentaires dans le béton.Abstract : Cement manufacturing industry is one of the carbon dioxide emitting sources. The global cement industry contributes about 7% of greenhouse gas emission to the earth’s atmosphere. In order to address environmental effects associated with cement manufacturing and constantly depleting natural resources, there is necessity to develop alternative binders to make sustainable concrete. Thus, many industrial by-products have been used to partially substitute cement in order to generate more economic and durable concrete. The performance of a cement additive depends on kinetics hydration and synergy between additions and Portland cement. In this project, two industrial by-products are investigated as alternative supplementary cementitious materials (ASCMs), non-toxic amorphous silica residue (AmSR) and wastepaper sludge ash (WSA). AmSR is by-product of production of magnesium from Alliance Magnesium near of Asbestos and Thetford Mines Cities, and wastepaper sludge ash is by-product of combustion of de-inking sludge, bark and residues of woods in fluidized-bed system from Brompton mill located near Sherbrooke, Quebec, Canada. The AmSR is new industrial by-products. Recently, wastepaper sludge ash has been used as cementitious materials. Utilization of these ashes as cementitious material in concrete manufacturing leads to reduce the mechanical properties of concretes. These problems are caused by disruptive hydration products of biomass fly ash once these ashes partially blended with cement in concrete manufacturing. The pre-wetting process of WSA before concrete manufacturing reduced disruptive hydration products and consequently improved concrete mechanical properties. Approaches for investigation of WSA in this project consist on characterizing regular and pre-wetted WSA, the effect of regular and pre-wetted WSA on performance of mortar and concrete. The high content of amorphous silica in AmSR is excellent potential as cementitious material in concrete. In this project, evaluation of AmSR as cementitious materials consists of three steps. Characterizing and determining physical, chemical and mineralogical properties of AmSR. Then, effect of different rates of replacement of cement by AmSR in mortar. Finally, study of effect of AmSR as partial replacement of cement in different concrete types with binary and ternary binder combinations. This study revealed that high performance concrete (HPC) incorporating AmSR showed similar mechanical properties and durability, compared to control mixture. AmSR improved mechanical properties and durability of ordinary concrete. Self-consolidating (SCC) concrete incorporating AmSR was stable, homogenous and showed good mechanical properties and durability. AmSR had good synergy in ternary binder combination with other supplementary cementitious materials (SCMs). This study showed AmSR can be use as new cementitious materials in concrete.
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Nath, Pradip. "Study of fly ash based geopolymer concrete cured in ambient condition." Thesis, Curtin University, 2014. http://hdl.handle.net/20.500.11937/190.
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This research studied the properties of concrete using fly ash geopolymer as a low-emission alternative of Portland cement. Inclusion of small quantity of additives enabled curing in normal ambience eliminating the need for elevated heat. Mixtures suitable for curing in ambient condition were found that provided the setting time, workability and strength comparable to those of traditional cement concrete. Blending of additives with fly ash resulted in enhanced engineering and durability properties of geopolymer concrete.
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Olivia, Monita. "Durability related properties of low calcium fly ash based geopolymer concrete." Thesis, Curtin University, 2011. http://hdl.handle.net/20.500.11937/506.
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Geopolymer material using by-products can lead to a significant reduction of the carbon footprint and have positive impact on the environment. Geopolymer is recognized as an alternative construction material for the Ordinary Portland Cement (OPC) concrete. The mechanical properties of geopolymer concrete are superior for normal exposure environments. In terms of durability in the seawater, a limited number of publications were available. The seawater environment contains chloride ions and microorganisms that are harmful for reinforced concrete structures. Hence, a study of the durability of fly ash geopolymer concrete is essential when this material is to be used in a real application. The present study aims to investigate the durability of fly ash geopolymer concrete mixture in a seawater environment such as seawater resistance and corrosion of steel reinforcement bars. The development of mixtures and their mechanical properties were also presented.The concrete mixtures were developed using the Taguchi optimization method. Three mixtures, labelled T4, T7, T10 and a control mix were investigated further. Mechanical properties such as compressive strength, tensile strength, flexural strength, Young’s Modulus of Elasticity were determined for each mix. In addition the water absorption/AVPV and drying shrinkage were also measured. The seawater resistance study comprises chloride ion penetration, change in strength, change in mass, change in Young’s Modulus of Elasticity, change in effective porosity and change in length. The corrosion performance of steel reinforcement bars in fly ash geopolymer concrete was determined by measuring the corrosion potential by half-cell potential, accelerated corrosion test by impressed voltage method and microbiologically influenced corrosion incorporating algae. The microstructure of the samples was also investigated using SEM and microscope.It can be summarized that the fly ash geopolymer concrete has an equivalent or higher strength than the OPC concrete. The seawater resistance revealed a high chloride ion penetration into the fly ash geopolymer concrete due to lack of a chloride binding ability and continuous hydration under aqueous medium. The geopolymer concrete had a higher strength and small expansion following exposure to wetting-drying cycles. There was a rapid depassivation of steel reinforcement bars in fly ash geopolymer concrete, although it has a smaller corrosion rate than the OPC concrete. This could delay the pressure in generating cracks in the concrete cover which is not favourable in the long term, due to a sudden loss of load carrying capacity. A novel study on the corrosion performance in algae medium demonstrated a risk of steel bar corrosion in fly ash geopolymer concrete due to the low alkalinity of this concrete. It can be concluded that the low calcium fly ash geopolymer offers some advantages in durability for reinforced concrete in seawater environments.
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Cheema, Didar Singh. "Low calcium fly ash based geopolymer concrete: Long term durability properties." Thesis, Curtin University, 2014. http://hdl.handle.net/20.500.11937/2146.
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Alkaline activated low-calcium fly ash geopolymer (LCFG) was investigated for durability compared to conventional concrete. The investigation involved simulated laboratory testing mimicking the severe field environments and in-situ field observations of commercially produced culverts. Laboratory test data: pore structure, porosity, chloride diffusion, scaling, strength and electrochemical testing supported and explained the observed field data. Research investigated the impact of slag and reinforcing pre-treatment. Geopolymer binder being non-cement one using by-products, can be significantly sustainable.
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Fizette, Hobson H. "Development of concrete composites by synergistically using Illinois PCC Bottom Ash and Class F Fly Ash /." Available to subscribers only, 2007. http://proquest.umi.com/pqdweb?did=1328063751&sid=8&Fmt=2&clientId=1509&RQT=309&VName=PQD.
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Ryno, Barnard. "Mechanical properties of fly ash/slag based geopolymer concrete with the addition of macro fibres." Thesis, Stellenbosch : Stellenbosch University, 2014. http://hdl.handle.net/10019.1/95866.
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Thesis (MEng) -- Stellenbosch University, 2014.ENGLISH ABSTRACT: Geopolymer concrete is an alternative construction material that has comparable mechanical properties to that of ordinary Portland cement concrete, consisting of an aluminosilicate and an alkali solution. Fly ash based geopolymer concrete hardens through a process called geopolymerisation. This hardening process requires heat activation of temperatures above ambient. Thus, fly ash based geopolymer concrete will be an inadequate construction material for in-situ casting, as heat curing will be uneconomical. The study investigated fly ash/slag based geopolymer concrete. When slag is added to the matrix, curing at ambient temperatures is possible due to calcium silicate hydrates that form in conjunction with the geopolymeric gel. The main goal of the study is to obtain a better understanding of the mechanical properties of geopolymer concrete, cured at ambient temperatures. A significant number of mix variations were carried out to investigate the influence that the various parameters, present in the matrix, have on the compressive strength of fly ash/slag based geopolymer concrete. Promising results were found, as strengths as high as 72 MPa were obtained. The sodium hydroxide solution, the slag content and the amount of additional water in the matrix had the biggest influence on the compressive strength of the fly ash/slag based geopolymer concrete. The modulus of the elasticity of fly ash/slag based geopolymer concrete did not yield promising results as the majority of the specimens, regardless of the compressive strength, yielded a stiffness of less than 20 GPa. This is problematic from a structural point of view as this will result in large deflections of elements. The sodium hydroxide solution had the most significant influence on the elastic modulus of the geopolymer concrete. Steel and polypropylene fibres were added to a high- and low strength geopolymer concrete matrix to investigate the ductility improvement. The limit of proportionality mainly depended on the compressive strength of the geopolymer concrete, while the amount of fibres increased the energy absorption of the concrete. A similar strength OPC concrete mix was compared to the low strength geopolymer concrete and it was found that the OPC concrete specimen yielded slightly better flexural behaviour. Fibre pull-out tests were also conducted to investigate the fibre-matrix interface. From the knowledge gained during this study, it can be concluded that the use of fly ash/slag based geopolymer concrete, as an alternative binder material, is still some time away as there are many complications that need to be dealt with, especially the low modulus of elasticity. However, fly ash/slag based geopolymer concrete does have potential if these complications can be addressed.
AFRIKAANSE OPSOMMING: Geopolimeerbeton is ‘n alternatiewe konstruksiemateriaal wat vergelykbare meganiese eienskappe met beton waar OPC die binder is, en wat bestaan uit ‘n aluminosilikaat en ‘n alkaliese oplossing. Vliegas-gebaseerde geopolimeerbeton verhard tydens ‘n proses wat geopolimerisasie genoem word. Hierdie verhardingsproses benodig hitte-aktivering van temperature hoër as dié van die onmiddellike omgewing. Gevolglik sal vliegas-gebaseerde geopolimeerbeton ‘n ontoereikende konstruksiemateriaal vir in situ gietvorming wees, aangesien hitte-nabehandeling onekonomies sal wees. Die studie het vliegas/slagmentgebaseerde geopolimeerbeton ondersoek. Wanneer slagment by die bindmiddel gevoeg word, is nabehandeling by omliggende temperature moontlik as gevolg van kalsiumsilikaathidroksiede wat in verbinding met die geopolimeriese jel vorm. Die hoofdoel van die studie was om ‘n beter begrip te kry van die meganiese eienskappe van geopolimeerbeton, wat nabehandeling by omliggende temperature ontvang het. ‘n Aansienlike aantal meng variasies is uitgevoer om die invloed te ondersoek wat die verskeie parameters, aanwesig in die bindmiddel, op die druksterkte van die vliegas/slagmentgebaseerde geopolimeerbeton het. Belowende resultate is verkry en sterktes van tot so hoog as 72 MPa is opgelewer. Daar is gevind dat die sodiumhidroksiedoplossing, die slagmentinhoud en die hoeveelheid water in die bindmiddel die grootste invloed op die druksterkte van die vliegas/slagmentgebaseerde geopolimeerbeton gehad het. Die styfheid van die vliegas/slagmentgebaseerde geopolimeerbeton het nie belowende resultate opgelewer nie. Die meeste van die monsters, ongeag die druksterkte, het ‘n styfheid van minder as 20 GPa opgelewer. Vanuit ‘n strukturele oogpunt is dit problematies, omdat groot defleksies in elemente sal voorkom. Die sodiumhidroksiedoplossing het die grootste invloed op die styfheid van die vliegas/slagmentgebaseerde geopolimeerbeton gehad. Staal en polipropileenvesels is by ‘n hoë en lae sterke geopolimeer beton gevoeg om die buigbaarheid te ondersoek. Die die maksimum buigbaarheid het hoofsaaklik afgehang van die beton se druksterkte terwyl die hoeveelheid vesels die beton se energie-opname verhoog het. ‘n OPC beton mengsel van soortgelyke sterkte is vergelyk met die lae sterkte geopolimeerbeton en daar is gevind dat die OPC beton ietwat beter buigbaarheid opgelewer het. Veseluittrektoetse is uitgevoer om die veselbindmiddel se skeidingsvlak te ondersoek. Daar kan tot die gevolgtrekking gekom word dat, alhoewel belowende resultate verkry is, daar steeds sommige aspekte is wat ondersoek en verbeter moet word, in besonder die styfheid, voordat geopolimeerbeton as ‘n alternatiewe bindmiddel kan optree. Volgens die kennis opgedoen tydens hierdie studie, kan dit afgelei word dat die gebruik van vliegas/slagmentgebaseerde geopolimeerbeton, as 'n alternatiewe bindmiddel, nog 'n geruime tyd weg is, as gevolg van baie komplikasies wat gehandel moet word, veral die lae elastisiteitsmodulus. Tog het vliegas/slagmentgebaseerde geopolimeerbeton potensiaal as hierdie komplikasies verbeter kan word.
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Islam, G. "Evaluating reactivity and sorptivity of fly ash for use in concrete construction." Thesis, University of Dundee, 2012. https://discovery.dundee.ac.uk/en/studentTheses/94122abd-aa82-4c91-85ea-079505e14489.
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This thesis describes research carried out to investigate techniques for (i) rapidly assessing the reactivity of fly ash; and (ii) evaluating its interaction with air-entraining admixtures (AEAs), both with regard to use in concrete. The materials considered for the project included, 54 fly ashes from 8 UK sources, and an additional three materials from Bangladesh, covering a range of fineness, loss-on-ignition (LOI) and production conditions (run-of-station, carbon removed, air-classified, co-combustion, oxy-fuel technology); Portland Cements (PCs) from five UK sources with various properties (strength classes 32.5 R, 42.5 N and 52.5 N); laboratory grade hydrated and quick limes; and three commercial AEAs and a standard laboratory grade reagent (surfactant). The research examining fly ash reactivity considered activity index tests to BS EN 450 (BSI, 2005c) as the reference and investigated tests covering fly ash properties/providing measures of fly ash behaviour to rapidly assess this. These included (i) fly ash fineness (45 µm sieve residue, or LASER particle size distribution (PSD) parameters), LOI and flow properties; (ii) accelerated curing of PC and lime-based mortars (iii) lime consumption by fly ash when combined with PC in paste or suspension (Frattini) or from a saturated lime solution; (iv) various measures of fly ash chemical composition (based on oxide/mineralogical analysis); and (v) a quicklime slaking test. The test results were validated by strength tests with 100 mm concrete cube. Results of the above indicated good correlations between fly ash fineness, mortar flow/water requirement and (pozzolanic) activity index (standard or accelerated curing). However, fly ash reactivity and fresh properties appeared to be influenced by the properties of the test PC (e.g. chemical composition and fineness) and there is a need to take this into account during assessment. Generally, finer fly ashes gave better flow; however, there is an optimum fineness (d90 ~40 µm) for best performance, and which is similar to the fineness of the test PC. Strong correlations between the accelerated and standard cured PC-based mortar indicate the latter can be used to estimate the former taking account of the fly ash properties. In view of eliminating the effect of PC properties on reactivity, mortar tests with laboratory grade hydrated lime suggested potential for this. However, for better assessment, this approach requires further work to address issues relating to slower rates of strength gain and increased time requirements, although high temperature conditions were used for curing. Measuring Ca(OH)2 consumption from fly ash/PC paste or suspension agreed with the behaviour in mortar, but needs special instruments (e.g. TGA or XRF). A similar approach with saturated lime did not work well, despite several measures being taken to try and improve this. The oxide and mineralogical analysis results of fly ash did not give good correlations with activity index, but improved when a factor combining them with fineness was considered. The test results were validated in concrete and with air-classified fly ashes from single sources which gave clear trend/behaviour. The lime slaking test was found to be ineffective for identifying fly ash reactivity. The reactivity assessment results were validated by carrying out concrete strength tests. In general, more consistent trends were obtained for fly ash from single source as noted with mortar earlier. Methods adopted/developed to assess the interaction of fly ash with AEA included (i) the foam index test; (ii) acid blue 80 (AB80) dye adsorption test (spectroscopic method); and (iii) methylene blue test. High variability in foam index test results between different operators were noted, which reflected differences in the degree of shaking applied and difficulties in identification of the test end point. Adoption of an automatic shaker and determination of suitable test conditions reduced this by more than 50%. Reliable test procedures were also established for the AB80 dye adsorption method. The results obtained from these tests gave very good correlations with fly ash specific surface area and the AEA dose required (both with commercial AEAs and standard reagent) for achieving target air contents in mortar and concrete. The methylene blue dye test also gave good correlations with these parameters, but was less effective for low LOI fly ashes. Between laboratory tests were carried out at three UKQAA members and considered, LOI, fineness (45 µm sieve and LASER PSD), and activity index. The results gave good agreement with those obtained at the Concrete Technology Unit for this work and again emphasized the role of fly ash fineness on its reactivity. Overall, fly ash fineness was found to be the best means of rapidly assessing its reactivity. Some of the other methods considered gave promising behaviour but require further refinements. Therefore, it is suggested that in addition to 45 µm sieve residue, other types of fineness measurement (e.g. sub 10 µm quantities, d50 and d90) can be considered suitable alternatives to activity index. Similarly, foam index tests with the automatic shaker or the AB80 test method could both be used as fly ash physical requirement tests, or in production control for air-entrained concrete.
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Kothari, Ankit. "Effects of Fly Ash on the properties of Alkali Activated Slag Concrete." Thesis, Luleå tekniska universitet, Geoteknologi, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-63534.
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This master thesis presents the effects of fly ash on the properties of alkali activated slag concrete, commonly referred as Geopolymer concrete (GPC). Cement manufacturer are major producers of CO2 which negatively affects the environment. Due to the increased construction activities and environmental concern, it is necessary to introduce alternative and eco-friendly binders for concrete. Slag and fly ash based concrete, which is by-product from industrial waste, is probably the best replacement for OPC concrete due to less or nil environmental issue. Most of the researchers have already concluded that slag and fly ash can be used as binders in concrete by activating them with alkali activator solution (e.g. by sodium silicate or sodium carbonate). In the present work concretes were produced by varying the proportion of slag to fly ash (40:60, 50:50, 60:40 & 80:20); amount of alkali activators (5, 10 & 14) and chemical modulus of sodium silicate (Ms) (0.25, 0.5 & 1). Setting times and compressive strength values were evaluated. Results showed that decrease in fly ash content irrespective of % of alkali activators and alkali modulus (Ms), the compressive strength was increasing and setting time was getting shorter. The produced concretes showed increasing compressive strength with increase in % of alkali activator for Ms 0.5 and 1, while for Ms=0.25 the strength was decreasing with increase in % of alkali activators. From this it can be concluded that, Ms=0.5 was the optimum point below which the reaction got slower. Based on the initial investigations, mix S8:F2-SS10(1) and S8:F2-SS10(0.5) showed most promising results in terms of fresh and hardened concrete properties and were easy to handle. Consequently, the above mentioned mixture was chosen to be studied in more detail. The experimental program for these mixes included determination of slump flow, compressive strength (7, 14, 28 days) and shrinkage (drying and autogenous). The results shows that, strength increased with time and comparatively mix with Ms=0.5 showed higher compressive strength than mix with Ms=1, due to higher alkalinity of the pore solution. Mix with Ms=1 showed higher drying shrinkage compared to mix with Ms=0.5, which was explained by higher alkalinity of the solutions (Ms=0.5) leading to rapid formation of aluminosilicate gel. Autogenous shrinkage appeared to be higher for mix with Ms=0.5. This was associated with lower modulus which leads to densification of concrete microstructure at early ages. Pore diameter decrease and the water trapped in the pores exerted increasing tensile stress resulting for higher autogenous shrinkage.
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Chang, Ee Hui. "Shear and bond behaviour of reinforced fly ash-based geopolymer concrete beams." Thesis, Curtin University, 2009. http://hdl.handle.net/20.500.11937/468.
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Concrete is by far the most widely used construction material worldwide in terms of volume, and so has a huge impact on the environment, with consequences for sustainable development. Portland cement is one of the most energy-intensive materials of construction, and is responsible for some emissions of carbon dioxide — the main greenhouse gas causing global warming. Efforts are being made in the construction industry to address these by utilising supplementary materials and developing alternative binders in concrete; the application of geopolymer technology is one such alternative. Indeed, geopolymers have emerged as novel engineering materials with considerable promise as binders in the manufacture of concrete. Apart from their known technical attributes, such as superior chemical and mechanical properties, geopolymers also have a smaller greenhouse footprint than Portland cement binders.Research on the development, manufacture, behaviour and applications of low calcium fly ash-based geopolymer concrete has been carried out at Curtin University of Technology since 2001. Past studies of the structural behaviour of reinforced fly ash-based geopolymer concrete members have covered the flexural behaviour of members. Further studies are needed to investigate other aspects of the structural behaviour of geopolymer concrete. Design for both shear and bond are important in reinforced concrete structures. Adequate shear resistance in reinforced concrete members is essential to prevent shear failures which are brittle in nature. The performance of reinforced concrete structures depends on sufficient bond between concrete and reinforcing steel. The present research therefore focuses on the shear and bond behaviour of reinforced low calcium fly ash-based geopolymer concrete beams.For the study of shear behaviour of geopolymer concrete beams, a total of nine beam specimens were cast. The beams were 200 mm x 300 mm in cross section with an effective length of 1680 mm. The longitudinal tensile reinforcement ratios were 1.74%, 2.32% and 3.14%. The behaviour of reinforced geopolymer concrete beams failing in shear, including the failure modes and crack patterns, were found to be similar to those observed in reinforced Portland cement concrete beams. Good correlation of test-to-prediction value was obtained using VecTor2 Program incorporating the Disturbed Stress Field Model proposed by Vecchio (2000). An average test-to-prediction ratio of 1.08 and a coefficient of variation of 8.3% were obtained using this model. It was also found that the methods of calculations, including code provisions, used in the case of reinforced Portland cement concrete beams are applicable for predicting the shear strength of reinforced geopolymer concrete beams.For the study of bond behaviour of geopolymer concrete beams, the experimental program included manufacturing and testing twelve tensile lap-spliced beam specimens. No transverse reinforcement was provided in the splice region. The beams were 200 mm wide, 300 mm deep and 2500 mm long. The effect of concrete cover, bar diameter, splice length and concrete compressive strength on bond strength were studied. The failure mode and crack patterns observed for reinforced geopolymer concrete beams were similar to those reported in the literature for reinforced Portland cement beams. The bond strength of geopolymer concrete was observed to be closely related to the tensile strength of geopolymer concrete. Good correlation of test bond strength with predictions from the analytical model proposed by Canbay and Frosch (2005) were obtained when using the actual tensile strength of geopolymer concrete. The average ratio of test bond strength to predicted bond strength was 1.0 with a coefficient of variation of 15.21%. It was found that the design provision and analytical models used for predicting bond strength of lapsplices in reinforced Portland cement concrete are applicable to reinforced geopolymer concrete beams.
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Chang, Ee Hui. "Shear and bond behaviour of reinforced fly ash-based geopolymer concrete beams." Curtin University of Technology, Department of Civil Engineering, 2009. http://espace.library.curtin.edu.au:80/R/?func=dbin-jump-full&object_id=120482.
Full textAbstract:
Concrete is by far the most widely used construction material worldwide in terms of volume, and so has a huge impact on the environment, with consequences for sustainable development. Portland cement is one of the most energy-intensive materials of construction, and is responsible for some emissions of carbon dioxide — the main greenhouse gas causing global warming. Efforts are being made in the construction industry to address these by utilising supplementary materials and developing alternative binders in concrete; the application of geopolymer technology is one such alternative. Indeed, geopolymers have emerged as novel engineering materials with considerable promise as binders in the manufacture of concrete. Apart from their known technical attributes, such as superior chemical and mechanical properties, geopolymers also have a smaller greenhouse footprint than Portland cement binders.Research on the development, manufacture, behaviour and applications of low calcium fly ash-based geopolymer concrete has been carried out at Curtin University of Technology since 2001. Past studies of the structural behaviour of reinforced fly ash-based geopolymer concrete members have covered the flexural behaviour of members. Further studies are needed to investigate other aspects of the structural behaviour of geopolymer concrete. Design for both shear and bond are important in reinforced concrete structures. Adequate shear resistance in reinforced concrete members is essential to prevent shear failures which are brittle in nature. The performance of reinforced concrete structures depends on sufficient bond between concrete and reinforcing steel. The present research therefore focuses on the shear and bond behaviour of reinforced low calcium fly ash-based geopolymer concrete beams.
For the study of shear behaviour of geopolymer concrete beams, a total of nine beam specimens were cast. The beams were 200 mm x 300 mm in cross section with an effective length of 1680 mm. The longitudinal tensile reinforcement ratios were 1.74%, 2.32% and 3.14%. The behaviour of reinforced geopolymer concrete beams failing in shear, including the failure modes and crack patterns, were found to be similar to those observed in reinforced Portland cement concrete beams. Good correlation of test-to-prediction value was obtained using VecTor2 Program incorporating the Disturbed Stress Field Model proposed by Vecchio (2000). An average test-to-prediction ratio of 1.08 and a coefficient of variation of 8.3% were obtained using this model. It was also found that the methods of calculations, including code provisions, used in the case of reinforced Portland cement concrete beams are applicable for predicting the shear strength of reinforced geopolymer concrete beams.
For the study of bond behaviour of geopolymer concrete beams, the experimental program included manufacturing and testing twelve tensile lap-spliced beam specimens. No transverse reinforcement was provided in the splice region. The beams were 200 mm wide, 300 mm deep and 2500 mm long. The effect of concrete cover, bar diameter, splice length and concrete compressive strength on bond strength were studied. The failure mode and crack patterns observed for reinforced geopolymer concrete beams were similar to those reported in the literature for reinforced Portland cement beams. The bond strength of geopolymer concrete was observed to be closely related to the tensile strength of geopolymer concrete. Good correlation of test bond strength with predictions from the analytical model proposed by Canbay and Frosch (2005) were obtained when using the actual tensile strength of geopolymer concrete. The average ratio of test bond strength to predicted bond strength was 1.0 with a coefficient of variation of 15.21%. It was found that the design provision and analytical models used for predicting bond strength of lapsplices in reinforced Portland cement concrete are applicable to reinforced geopolymer concrete beams.
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Lee, William K. "Solid-gel interactions in geopolymers." Connect to thesis, 2002. http://repository.unimelb.edu.au/10187/1071.
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This is partly because the requirements for such an ultimate material change with people’s perception about its properties as well as its environmental impact. Thus, the once-believed ultimate Portland cement binder is now becoming unacceptable for a number of reasons including poor durability as well as severe environmental impact during production. Thus, an improved mineral binder is required by modern society to serve the same purposes as the existing Portland cement binder, as well as to reduce the current environmental impact caused by Portland cement production.Geopolymerisation is such a ‘green’ technology capable of turning both natural ‘virginal’ aluminosilicates and industrial aluminosilicate wastes, such as fly ash and blast furnace slag, into mechanically strong and chemically durable construction materials. However, the source materials for geopolymer synthesis are less reactive than Portland cement clinkers and the chemical compositions of these source materials can vary significantly. Consequently, product quality control is a major engineering challenge for the commercialisation of geopolymers.
This thesis is therefore devoted to the mechanistic understanding of the interfacial chemical interactions between a number of natural and industrial aluminosilicates and the various activating solutions, which govern the reactivity of the aluminosilicate source materials. The effects of activating solution alkalinity, soluble silicate dosage and anionic contamination on the reactivity of the aluminosilicate source materials to produce geopolymeric binders, as well as their bonding properties to natural siliceous aggregates for concrete making, are examined. In particular, a new set of novel ‘realistic’ reaction models has been developed for such purposes. These reaction models have been further utilised to develop a novel analytical procedure, which is capable of studying geopolymerisation on ‘real’ geopolymers in situ and in real time. This novel procedure is invaluable for the total understanding of geopolymerisation, which is in turn vital for effective geopolymer mix designs.
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Bleszynski, Roland F. "Study of the effects of fly ash on alkali-silica reaction in concrete." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape11/PQDD_0024/MQ51606.pdf.
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Abu, Bakar Asif. "Effects of Nano Silica and Basalt Fibers on Fly Ash Based Geopolymer Concrete." Thesis, North Dakota State University, 2018. https://hdl.handle.net/10365/31729.
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Emission of carbon dioxide gas has been a source of major concern for the construction industry. To curb this emission, geopolymer concrete has been deemed as a potential alternative in the recent studies. Previous research also indicates that silica and fibers provide strength benefits to ordinary Portland cement concrete OPC. This study was undertaken to recognize the benefits of adding silica and basalt fibers in Class F fly ash based geopolymer concrete and comparing it with OPC concrete. One OPC and four Geopolymer mixtures were prepared. The results show a tremendous potential of using geopolymer concrete in place of OPC concrete with Nano silica proving to be the most advantageous. Nano silica provided 28% increase in compressive strength, 8% increase in resistivity when compared with normal Fly ash based geopolymer concrete. The SEM analysis of geopolymer concrete indicates that nano silica improved the compactness of concrete providing a dense microstructure.
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Upadhyaya, Sushant. "Early age strength prediction for high volume fly ash concrete using maturity modeling." College Park, Md.: University of Maryland, 2008. http://hdl.handle.net/1903/8868.
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Thesis (Ph. D.) -- University of Maryland, College Park, 2008.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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Williams, Franklin. "The formation of geopolymer concrete from bauxite-refining residue and fly ash: Application in sustainable concrete production." Thesis, Williams, Franklin (2021) The formation of geopolymer concrete from bauxite-refining residue and fly ash: Application in sustainable concrete production. Honours thesis, Murdoch University, 2021. https://researchrepository.murdoch.edu.au/id/eprint/63765/.
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Bauxite-refining residue is generated in the processing of bauxite into alumina using the Bayer process, and fly ash is a by-product of burning pulverized coal in an electricity generating. Bauxite-refining residue (red mud) and its’ concentrated sodium aluminate solution (Spent Liquor) are known to have properties of high alkalinity and fly ash consisting of fine powder are easily dispersed into the surrounding environment, such as aquatic, air and soil which may lead to ecological problems. This research synergistically incorporates red mud, fly ash, and the Spent Liquor from the Bayer process along with sodium-silicate solution to produce a geopolymer based material which can be used as building materials. This research focused on the sustainable use of red mud as an additive material with fly ash to form concrete. A series of three laboratory trials using of 10 – 30% dried and crushed red mud addition on the geopolymer formation reaction, and 70% red mud as combined with Spent Liquor was carried out.
An improvement in setting time and compressive strength was observed with red mud addition at all trial conditions for 7, 14, and 28 days. The structural characterization revealed that the rate of reaction of red mud was dependent on the caustic soda (NaOH) concentration. However, the development of mechanical properties was related to the collaborative effect of NaOH concentration, solubility of silicates and the iron oxides presence. Based on standards for concrete, the compressive strength achieved in all series is suitable for paving blocks, slabs, driveway, backfill, retaining blocks etc. The production of these concrete materials and compressive strength test meets the requirements of the Australian Standards’: AS 1012.1- 2014, AS 1012.3.1, AS 1012.8.1-2014, and AS 1012.9-2014 respectively. Leaching of toxic metals were within permissible limits, but further research should be carried out for the identification of ongoing reactions.
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Puri, Rajnish. "Development of High performance Concrete Composites Using Class F Fly Ash and PCC Bottom Ash, and a Statistical Model to Predict Compressive Strength of Similar Concrete Composites." OpenSIUC, 2015. https://opensiuc.lib.siu.edu/dissertations/1123.
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AN ABSTRACT OF THE DISSERTATION OF RAJNISH PURI, for the Doctorate of Philosophy Degree in ENGINEERING SCIENCE WITH CONCENTRATION IN CIVIL AND ENVIRONMENTAL ENGINEERING, presented on APRIL 15, 2015 at Southern Illinois University Carbondale TITLE: DEVELOPMENT OF HIGH PERFORMANCE CONCRETE COMPOSITES USING CLASS F FLY ASH AND PCC BOTTOM ASH, AND A STATISTICAL MODEL TO PREDICT COMPRESSIVE STRENGTH OF SIMILAR CONCRETE COMPOSITES ADVISOR: Dr. Sanjeev Kumar It is a common knowledge that the use of concrete is as old as the evolution of human civilization. People have always dreamed beyond the dotted lines and so does the usage of concrete. With the rapid industrialization and globalization, the journey from ordinary concrete to high performance concrete (HPC) has been swift and remarkable. The diversification and utilization of high performance concrete has given the tool in the hands of engineers and architects who can now design and execute buildings of any shape and size deemed impractical a few decades ago. The aim of this research was to develop high performance concrete composites having different percentages of Illinois Class “F” fly ash and bottom ash by replacing the appropriate proportions of Type 1 portland cement and fine aggregate, respectively. The target was to develop high performance concrete composites that have compressive strength of 8,000 psi (55 Mpa) after 28 days of curing in water with a slump of 4±½” (102mm ± 13mm) and air content between 4 and 6 percent. In order to achieve the targeted air content, an air entraining agent DARAVAIR 1400 was used. The water-cement ratio of 0.3 was maintained throughout the research and to achieve the targeted slump, high-range water reducer ADVA 140M was used. The engineering parameters of the high performance concrete composites and an equivalent control mix were evaluated by conducting a detailed laboratory study which included several tests, e.g., slump, fresh air content, compressive strength, splitting-tensile strength, flexural strength, resistance to rapid freezing and thawing, sealed shrinkage and free swelling, and rapid chloride permeability. The results presented show that all high performance concrete composites developed in this study achieved the targeted compressive strength of 8,000 psi (55 MPa) after 28 days of curing in water. The results of the durability tests show that the concrete composites developed in this study have trends similar to that of an equivalent conventional concrete. Based, on the results of this study, it was concluded that the concrete composites have potential to be used on real world projects and thus help the environment by substantially reducing the amount of fly ash and bottom ash going to ash ponds or landfills. Based on the experimental test result data, a detailed statistical analysis was conducted to develop an empirical model to predict compressive strength of similar concrete composites for a given amount of fly ash, bottom ash, and curing period. Additional laboratory tests were performed to validate the mathematical model.
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Tackett, Paul M. "Evaluation of concrete strength and permeability with time." Thesis, Kansas State University, 2013. http://hdl.handle.net/2097/15733.
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Master of ScienceDepartment of Civil Engineering
Kyle Riding
The relationship between in-place concrete strength and permeability with concrete cylinder strength and permeability with time is of interest - especially when supplementary cementitious materials (SCMs) are used. A joint research project between The University of Kansas was undergone to quantify these relationships. The permeability of concrete is directly tied to its ability to mitigate certain failure mechanisms such as corrosion and sulfate attack. The three concrete mixtures being tested by Kansas State University (KSU) vary in cementitious content as follows: (1) 100% ordinary portland cement (OPC), (2) 25% Class F fly ash (F-ash) and 75% OPC, (3) 25% Class C fly ash (C-Ash) and 75% OPC. The mixtures were also placed in three different seasons to present differing curing environmental effects. The summer slabs were cast during July and August. The fall slabs were cast in October and November. The final set of slabs were cast in March and April. Three sets of concrete specimens (lab cured, field cured and in-situ core specimens) were tested at 28, 56, 90, 180, and 360 days for strength and permeability properties. The permeability performance tests being utilized are ASTM C1202 and ASTM C642. The results have shown very desirable permeability and strength data for the mixes using blended fly ash cements. The F-ash exhibited the best high early strength and low permeability data for the summer placement season and slower strength and permeability performance at cold weather. The C-ash performed the best overall for all seasons and had the least environmental effects. The OPC performed the worst in regards to permeability and did not reach as high long term strength.
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Sharma, Rohit Kumar. "High Volume Fly Ash Concrete." Thesis, 2018. http://ethesis.nitrkl.ac.in/9550/1/2018_MT_216CE3074_RKShrama_High.pdf.
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India is still a developing country and for development of any country electricity is considered as a major source. For production of electricity in India mostly coal is used, and as a waste product of coal based thermal power plants mostly tapped,a huge amount of fly ash results. Fly ash is a fine and waste material resulting from combustion of coal. Disposal of fly ash is a big problem; requires millions of acres land for its dumping. Because of this environment is also highly polluted.Fortunately, the fly ash has certain important advantages such as cementitious products,which can pave way for its utilisation in bulk for replacement of cement in concrete pavement, which can be a more sustainable and economical means of disposing and utilising for a better cause. Thus, the use of fly ash in concrete is promoted not only from environmental consideration but also from economizing construction cost.
Now-a-days, because of increase in construction activities, the demand for cement also increase. So to avoid production of greenhouse gases and to produce environment friendly concrete, certain percentage of cement in concrete mix is replaced by fly ash without sacrificing strength and achieving durability and economy in construction work. However, fly ashes from different sources have different properties, thus affecting the performance of concrete. Hence it is quite necessary to understand the behaviour of concrete with fly ashes collected from different sources to get an overall idea of application of fly ash in concrete pavement. It is therefore necessary to develop the mix design for the Pavement quality concrete made with different fly ashes and study their performance characteristics such as compressive strength,workability, flexural strength,fatigue characteristics etc. The optimum quantity of fly ash is to be determined based on the above basic characteristics.
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Khuito, Murumi. "Enhancing fly ash utlisation in concrete." Thesis, 2017. http://localhost:8080/iit/handle/2074/7328.
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Lin, Sih-Ming, and 林思明. "Chlorid Transport Behavior in Fly Ash Concrete." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/21825321722733020398.
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碩士國立臺灣海洋大學
材料工程研究所
103
The RCPT(Rapid chloride permeability test) usually used to estimate the concrete's durability . If we use fly ash to replace cement mix with concrete,the total electricity will drop significantly in RCPT. The reason result in this situation is the fly ash's granular structure is smaller than cement,it will change the structure in concrete and consume the Hydroxide ions in concrete simultaneously. To evaluate the criteria of total charge and adjust the method of total charge in the Fly ash concrete by using Rapid Chloride Permeability Test (RCPT) in this study.There are four tests in this study which are the test of compressive strength, test of rapid chloride ion penetration (Rapid chloride penetration test :RCPT ) , test of chloride non-steady-state migration coefficient (Chloride migration coefficient from non-steady-state migration experiments :RCM ),test of chloride ion penetration speed (Accelerated chloride migration test :ACMT ),and test of salt storage (Ponding test ). There are some results below showed that in this study , fly ash concrete in the amount of fly ash to replace 40% of the transmission coefficient, diffusion coefficient and compressive strength without adding fly ash concrete than good, to resist chloride ion invasion have good benefits. Though “RCPT total charge and RCPT transmission coefficient diagram ˮ, “RCPT total charge and RCM non-steady-state migration coefficient diagram ˮ, “RCPT total charge and Ponding test diffusion coefficient diagram ˮ, “RCPT total charge and Ponding test permeation depth diagram ˮwe design four kinds of methods to adjust total charge. Among all, The results of the "RCPT total charge and RCPT transmission coefficient diagram assessment methods" and "RCPT total charge and RCM non-steady-state migration coefficient diagram assessment methods"are similar. If using both of the ways at the same time to assess the fly ash concrete, it could effectively determine the durability of fly ash concrete than using only one way.
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Liu, Yen-Chih, and 劉彥志. "Chloride transport bebavior in Fly Ash Concrete." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/54295729791233436149.
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碩士國立臺灣海洋大學
材料工程研究所
99
In this study, Taichung, Taiwan power Co. plant in Class F fly ash, The percentage of fly ash to replace cement by weight of 0%, 20%, 30%, 40%, 50%, 60% and 70%, Used in water-cement ratio 0.35,0.45,0.55 and 0.65 of the concrete, to explore the impact of transport behavior of concrete. Assessment project using the rapid chloride ion penetration test (Rapid chloride penetration test; RCPT), chloride ion transport speed test (Accelerated chloride migration test; ACMT), salt storage test (Ponding test) and compressive strength. Comprehensive test results of concrete specimens 91 days after the curing period, fly ash concrete in the amount of fly ash to replace 40% of the transmission coefficient, diffusion coefficient, power and compressive strength without adding fly ash concrete than good, to resist chloride ion invasion have good benefits. However, instead of cement, fly ash concrete at 70% fly ash can not stop the chloride ion diffusion and transport behavior. Finally, instead of cement, fly ash concrete at 70% fly ash, the use of RCPT test can not effectively assess the chloride ion penetration.
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KUMAR, VIVEK. "PREDICTION OF STRENGTH OF FLY ASH CONCRETE." Thesis, 2017. http://dspace.dtu.ac.in:8080/jspui/handle/repository/15957.
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Concrete, being widely used, is the most important building material in civil engineering. Concrete is a highly complex material, which makes modeling its behavior a very difficult task. Many attempts were taken earlier to develop suitable mathematical models for the prediction of compressive strength of different concretes, but not for flyash concrete. Those traditional methods have failed to map non-linear behavior of concrete ingredients. The present study has used artificial neural networks (ANN) to predict the compressive strength of fly ash concrete. The ANN model has been developed and validated in this research using the mix proportioning and experimental strength data of 6 different mixes. The artificial neural networks (ANN) model is constructed trained and tested (in MATLAB) using the previous researches data. A total of 149 different fly ash concrete mix design were collected from technical literature. For comparative study, 4 models were developed. Strength was modeled in ANN-1 model as a function of three input variables: w/b, cement, water. ANN-2 model was presented with 4 input parameters: w/b (water-binder ratio), cement, water and fly ash%. ANN-3 model consist of 6 input variables: w/b (water-binder ratio), cement, water, fly ash%, coarse and fine aggregates. In this study, an attempt was also made to develop a multiple regression model for predicting strength (in EXCEL) as it is being used largely by researches in prediction. Finally, these four models were compared using coefficient of determination and RMSE values, and resulted in the fact that ANNs models have performed better than MLR model in predicting compressive strength of flyash concrete. Also, ANN model presented with more description of system (with more input variables that affect strength) yield more accurate results showing better correlation with observed/ experimented/actual strength.
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Lin, Feng-li, and 林峰立. "The Study of Subbituminous Coal Fly Ash (Class C Fly Ash) Application in Plain concrete." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/61304872994430124989.
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碩士東南科技大學
防災科技研究所
97
This resesarcl by subbituminous (Class C Fly Ash) substitution part cement as concrete binder,march different water-to-binder ratio (W/B) with fly ash substitution quantity concrete fresh and hardened and microscopic correlation experiment discussion it’s plain concrete influence. Findings demonstration mixing class c fly ash in concrete may increase flowing property promotes the good workability compressive strength at age 91 days being higher than has not mixed uses fly ash concrete increase class c fly ash regarding concrete setting time has the phenomenon which slow congeals superficial resistance value, Chloride ion electroosmosis and crack sensitivity gauging result demonstration class c fly ash conduciving toward favor therefore class c fly ash applies in the concrete regarding concrete fresh and hardened property has good being of help but increases the ratio must discretely for it excessively many class c fly ash possibly causes the property produces the buckle phenomenon.
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Len, Yun-Chen, and 林耘丞. "Properties of Concrete using Circulating Fluidized Bed Combustion Fly Ash and Coal-fired Fly Ash." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/16020627200273360796.
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碩士國立臺灣海洋大學
河海工程學系
101
The effects of coal-fired fly ash and coal-fired ground granulated blast-furnace slag as the replacement of cement on improving the strength and durability of concrete have been clarified in construction engineering. Circulating fluidized bed combustion (CFBC) is an advanced and promising combustion technology for power generation, which has been installed in Taiwan recently. After the combustion process, the coals turn into the combustion solid wastes - CFBC fly ashes, which have the potential instead of cementing materials due to their cementitious characteristics. The purpose of this study is to investigate the fresh properties, physical mechanics properties and durability of cement-based composites with CFBC fly ash and coal-fired fly ash. Tests results show for fresh mixes, specimens with CFBC fly ash and coal-fire fly ash lead to an increase of setting time and slump. For hardened concrete, specimens with CFBC fly ash and coal-fired fly ash result in a decreasing compressive strength and a volume expansion. In addition, the adding of CFBC fly ash and coal-fired fly ash can reduce the penetration of water and chloride ions and increase the sulphate attack resistance, but an increase in carbonization depth. There exists a negative relationship between compressive strength and carbonization rate. CFBC fly ashes used in this study cannot meet the requirements on physical properties and chemical compositions in ASTM C821-09 (Standard specification for lime for use with pozzolans), but suit the requirements of ASTM C593-06 (Standard specification for fly ash and other pozzolans for use with lime for soil stabilization). Based on the test results, CFBC fly ash and coal-fired fly ash can be considered as cement replacement materials and employed in concrete, however, the contents are limited and further study is needed.
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Huang, Yu-Chen, and 黃玉珍. "Mechanical properties of high-volume fly ash concrete." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/18790431912068658732.
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碩士國立中興大學
土木工程學系所
104
The purpose of this study is to explore the impact of fly ash content concrete strength development and the applicability of High-Volume Fly Ash concrete, according to the result of compressive strength test based on the concrete specimens with different fly ash content (0%, 20%, 40%, 60%) and appropriate concrete mixtures. The fly ash used in this study includes the power plant product of Taiwan Power Company (Tai-power) and Formosa Plastics Company (FPC). It complies with the level of CNS 3036 Grade-F fly ash specifications. The result of compressive strength tests indicated that the amount of cement substituted by fly ash inversely proportional to the concrete compressive strength in early strength (age less than 28 days), regardless of using the product of either Tai-power or FPC. It illustrates that the more amount of fly ash substitution, the lower early strength will be resulted, which is due to the Pozzolanit reaction has not been effectively developed under the age of 28 days in fly ash concrete. On the other hand, the late strength (age more than 91 days) of fly ash concrete with different fly ash content of 20%, 40% and 60% is higher than the compressive strength of concrete without adding fly ash, regardless of using the product of either Tai-power or FPC. The effect of fly ash concrete in late strength is significant. Furthermore, the more amount of fly ash substitution, the higher late strength on the trend. It concludes that the applicability of High-Volume Fly Ash concrete is feasible. In addition to the exploration of different substitution amounts of fly ash content concrete on the development of compressive strength, this study intends to investigate the variable of major domestic sources of fly ash supplier, in order to confirm the stability and quality of fly ash. The study intends to promote the use of fly ash pozzolan materials on either public or civil construction and to enhance the effectiveness of concrete mixture. Thereby, the recycling of waste materials, environmental protection as well as the sustainability of the earth may be achieved.
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Wei, Rui-Jun, and 魏睿君. "Properties of alkali-activated slag-fly ash concrete." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/2d6p5e.
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Zulu, Sabelo N. F. "Optimizing the usage of fly ash in concrete mixes." Thesis, 2017. http://hdl.handle.net/10321/2673.
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Improving on our construction practices to promote sustainable development in engineering and to promote eco-friendly living is vital in the fight against global warming and associated problems. This study looked at one of the ways in which engineering can contribute to this fight through promoting the recycling of waste by-products such as fly ash (FA), on a larger scale in the cement and concrete industry, by utilizing the FA to the optimum.
In this study concrete mixes of 25 MPa, 35 MPa and 50 MPa with FA partially substituting the cement at 30%, 40%, 50% and 60% were produced and numerous tests were performed to determine the optimum amount of FA that can be used and still obtain better or comparable concrete to ordinary concrete. Testing for concrete properties was conducted under laboratory conditions over a period of one year. In addition, a cost comparison between ordinary concrete and FA concrete was undertaken.
The results obtained show that the increase in FA content influenced the rheological properties of fresh concrete favorable. The recorded slump increased with the increase of FA content. Increasing the FA content prolonged the setting of concrete, with the ordinary concrete taking 1 hour 45 min to set, compared to more than 2 hours for FA mixes. The FA increase had negligible effects on the air content of the concrete mixes. The drying shrinkage of concrete increased with the increase of FA content, with the strain ranging from 0,045% to 0,56%.
The compressive strength results show that the control mixes with 30% FA content attained the highest compressive strength over a year. In some cases, the 40% FA strength was compatible to the 30% FA strength. The durability index results showed the control mix of 30% FA attaining better results for Oxygen Permeability Index and Sorptivity Index, with the 40% FA mix following closely. The higher FA content mixes (50% and 60%) attained better Chloride Conductivity results than the lower FA content mixes.
Increasing the FA content does affect the performance of the concrete at early stages, however concrete with acceptable strength and good durability qualities can be produced even with 50% FA volume. Increasing the FA content can also significantly reduce the cost of producing and working with concrete. The practice of utilizing higher FA content in concrete can be beneficial for the South African cement and concrete industry without compromising the quality of the cement products concrete structures.M
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葉文德. "Shear friction strength of high-strength fly-ash concrete." Thesis, 1990. http://ndltd.ncl.edu.tw/handle/60288242750624104997.
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Wnag, Yu-He, and 王郁賀. "Study for Transport Behavior of Slag-Fly Ash Concrete." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/53001781534744354335.
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碩士國立臺灣海洋大學
材料工程研究所
103
In this study, concrete containing different slag-fly ash ratios (30%,40%,50% and 60%) of mineral admixtures with different water-to-binder ratios (0.45, 0.55 and 0.65) are made and test with the rapid chloride permeability test (RCPT), accelerated chloride ion transport test (ACMT) and Chloride migration coefficient from non-steady-state migration experiments (RCM) etc. After the test got total charge, penetration depth, steady-state migration coefficient (MS) and non- steady-state migration coefficient (MR 、Mn) to evaluate the durability and the correlation among each test. Compressive results show strength decrease with increasing W/B, but there is no rise or declining trend with increasing slag-fly ash amount of cement replacement, only with the W/B=0.45 substitution ratio 30% and 40% ,higher than the control group (group C); RCPT results show that the total charge decrease with increases W/B,that it increases with slag-fly ash amount of cement replacement less,and penetration depth,and the total content of chloride ion are also the same result. ACMT results showed that in 91 days of curing age, steady state and non-steady state migration coefficient increases due to W/B rises, and they become less with an increases with slag-fly ash amount of cement replacement less; RCM test results show that the migration coefficient with non-steady falls with slag-fly ash amount of cement replacement increasing.When the slag-fly ash amount replace 60%, non-steady-state migration coefficient is higher than 50%. The test about RCPT penetration depth and the total charge showed that, because slag-fly ash replace part of the cement, hydration reaction at 28 days of age than control group (Group C) and produce intercept difference. It may need to adjust the charge.The test also show that at the age of 91 days compared to 28 days, the hydration reaction more complete and the two groups showed a good linear relationship (R2=0.93), which does not need to adjust charge. RCM non-steady state migration coefficient and ACMT steady migration coefficient show that in the age of 28 days showed a linear relationship (R2=0.97);Both MR,MS and RCPT penetration depth show that the deeper RCPT penetration depth, the higher and MR,MS.They show a linear relationship.
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huang, Yung-Kuang, and 黃永光. "Fly-Ash Concrete for Erosion Prevention to Offshore Structure." Thesis, 1993. http://ndltd.ncl.edu.tw/handle/66425026915803553191.
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Chen, Yi-Ting, and 陳怡廷. "Shear strength of high strength fly ash concrete beams." Thesis, 1993. http://ndltd.ncl.edu.tw/handle/51644285773797386204.
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CHAUDHARY, SHASHANK. "STUDY OF PROPERTIES OF FLY ASH BASED GEOPOLYMER CONCRETE." Thesis, 2019. http://dspace.dtu.ac.in:8080/jspui/handle/repository/16986.
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The serious issue the world is confronting today is the natural contamination. In the construction industry basically the creation of Portland cement will causes the emanation of toxins brings about natural contamination, like emission of CO2 gas. By using the industrial by products in construction industry we can reduce effect of pollution on environment. . Geopolymer concrete is such a one and in the present study, to produce the geo-polymer concrete the Portland cement is fully replaced with fly ash and the fine aggregate is replaced with quarry dust and alkaline liquids are used for the binding of materials. The alkaline liquids used in this study for the polymerization are the solutions of Sodium hydroxide (NaOH) and sodium silicate (Na2Sio3). 13M, molarity sodium hydroxide is used in this work. The cube specimens are taken of size 150mm x 150mm x 150mm.The Geopolymer concrete specimens are tested for their compressive strength at the age of 28 days. Cylindrical concrete specimen are prepared of test of modulus of elasticity and possion’s ratio of Geopolymer concrete. Ambient and oven curing are used for it, and compare the result of both. Varying fly ash/ slag ratio are used and results are compared.
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Singh, G. V. P. B. "Investigation of Activation in High Volume Fly Ash Concrete." Thesis, 2013. http://raiith.iith.ac.in/589/1/CE11M1004.pdf.
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Supplementary cementitious materials (SCMs) like fly ash are increasingly being used as cement replacement in concrete due to environmental, economical, and concrete quality-related concerns. With demonstrated enhancement to overall durability while improving workability and reducing the water demand, the use of lower priced fly ash results in economical production of high performance concrete. The use of fly ash in concrete is currently restricted to low volumes of cement replacement.