Showing papers on "Fly ash published in 2009"
693 citations
TL;DR: In this paper, an overview of the use of metakaolin as partial replacement of cement in mortar and concrete is presented, and properties reported in this paper are the fresh mortar/concrete properties, mechanical and durability properties.
623 citations
TL;DR: Addition of calcium compounds as a fly ash substitute improved mechanical properties for the ambient temperature cured samples while decreasing Properties for the 70 degrees C cured samples.
597 citations
TL;DR: The results show that both fly ash and bottom ash can be utilized as source materials for the production of geopolymers and the moderate NaOH concentration of 10 M is found to be suitable and gives fly ashand bottom ash geopolymer mortars with compressive strengths of 35 and 18 MPa.
541 citations
TL;DR: In this article, the suitability of using more sustainable concrete for wind turbine foundations and other applications involving large quantities of concrete was investigated, which was accomplished by partial replacement of cement with large volumes of fly ash or blast furnace slag and by using recycled concrete aggregate.
470 citations
TL;DR: In this paper, the fresh and hardened properties of self-compacting concrete (SCC) using recycled concrete aggregate as both coarse and fine aggregates were evaluated, and the results indicate that the properties of the SCCs made from river sand and crushed fine recycled aggregates showed only slight differences.
Abstract: In this study, the fresh and hardened properties of self-compacting concrete (SCC) using recycled concrete aggregate as both coarse and fine aggregates were evaluated. Three series of SCC mixtures were prepared with 100% coarse recycled aggregates, and different levels of fine recycled aggregates were used to replace river sand. The cement content was kept constant for all concrete mixtures. The SCC mixtures were prepared with 0, 25, 50, 75 and 100% fine recycled aggregates, the corresponding water-to-binder ratios (W/B) were 0.53 and 0.44 for the SCC mixtures in Series I and II, respectively. The SCC mixtures in Series III were prepared with 100% recycled concrete aggregates (both coarse and fine) but three different W/B ratios of 0.44, 0.40 and 0.35 were used. Different tests covering fresh, hardened and durability properties of these SCC mixtures were executed. The results indicate that the properties of the SCCs made from river sand and crushed fine recycled aggregates showed only slight differences. The feasibility of utilizing fine and coarse recycled aggregates with rejected fly ash and Class F fly ash for self-compacting concrete has been demonstrated.
414 citations
TL;DR: In this article, the effect of fly ash activation on the properties of the geopolymers cured at ambient temperature has been studied and after 28 days, compressive strength of the room temperature cured samples was 16 (2) and 45 (8) MPa for unmilled and mechanically activated fly ash based samples, respectively.
378 citations
TL;DR: The fly ashes contained significant levels of chloride and sulphate and it is suggested that the performance of fly ash-cement binders could be improved by the removal or control of these chemical species.
368 citations
TL;DR: The results of the study demonstrated that the fly ash could be used as an effective low cost adsorbent for the removal of heavy metal ions from municipal solid waste leachate.
367 citations
TL;DR: Fly ash was added as a seed material to enhance lime precipitation and the suspension was exposed to CO2 gas, which increased the particle size of the precipitate and significantly improved sedimentation of sludge and the efficiency of heavy metal removal.
346 citations
TL;DR: This experimental study demonstrates that 1 ton of fly-ash could sequester up to 26 kg of CO(2), i.e. 38.18 ton ofFly-ash per ton ofCO(2) sequestered, and confirms the possibility to use this alkaline residue for CO( 2) mitigation.
TL;DR: In this paper, a durability-based multi-objective optimization of the mixtures were performed to achieve an optimal concrete mixture proportioning, and the results indicated that when the durability properties of the concretes were taken into account, the ternary use of S and SF provided the best performance.
TL;DR: In this article, the physical properties of concrete containing ground bagasse ash (BA) including compressive strength, water permeability, and heat evolution, were investigated, and it was shown that concrete samples containing 10-30% ground basse ash by weight of binder had greater compressive strengths than the control concrete.
TL;DR: The effects of ash weathering and organic matter accumulation over time on the chemical, physical and biological properties of the developing ash-derived soil are not well understood and require further study.
TL;DR: Kinetic studies reveals that blast furnace slag was not effective for lead and zinc removal, and the bentonite and fly ash were effective for Lead and zinc Removal.
TL;DR: A new type of steel slag-fly ash-phosphogypsum solidified material totally composed with solid wastes to be utilized as road base material that has higher early strength and long-term strength is much higher than cement stabilized granular materials.
TL;DR: In this article, an artificial neural network (ANN) was used to predict the 28-day compressive strength of self compacting concrete (SCC) and high performance concrete (HPC) with high volume fly ash.
TL;DR: Experimental results showed that immobilization effect of cement on MSWI fly ash is good, and the leaching toxicity is still in a safety range, and reusing of MSWIFly ash as partial replacement for cement in concrete mixes is potentially feasible.
TL;DR: In this paper, the use of municipal solid waste incinerator (MSWI) fly ash as a partial replacement of fine aggregate or mineral filler in stone matrix asphalt (SMA) mixture is discussed.
TL;DR: The study shows that the unconfined compressive strength of specimens with the ISSA/cement addition was improved to approximately 3-7 times better than that of the untreated soil; furthermore, the swelling behavior was also effectively reduced as much as 10-60% for those samples.
TL;DR: In this article, a comprehensive study on the properties of concrete containing fly ash and steel fibers was conducted, and the results showed that steel fiber addition, either into Portland cement concrete or fly ash concrete, improved the tensile strength properties, drying shrinkage and freeze-thaw resistance of hardened concrete.
TL;DR: These composite materials containing 10% Portland cement, 70% and 60% fly ash and 20% and 30% tire rubber particles have sufficient strength for masonry applications.
TL;DR: The analysis of raw fly ash identified a number of different morphologies, unequal distribution of elements, Fe-rich rim, high internal porosity, and minor crystalline phases of mullite and quartz, while excellent immobilization of Zn(2+), Cu( 2+), Cd(2-), and Cr(3+) are reported.
TL;DR: In this paper, the transport and mechanical properties of self-consolidating concrete that contain high percentages of low-lime and high-lime fly ash (FA) were examined, and it was shown that high volumes of FA in SCC not only improved the workability and transport properties but also made it possible to produce concretes between 33 and 40 MPa compressive strength at 28 days.
Abstract: This paper presents the transport and mechanical properties of self consolidating concrete that contain high percentages of low-lime and high-lime fly ash (FA). Self consolidating concretes (SCC) containing five different contents of high-lime FA and low-lime FA as a replacement of cement (30, 40, 50, 60 and 70 by weight of total cementitious material) are examined. For comparison, a control SCC mixture without any FA 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, and segregation ratio. The hardened properties included the compressive strength, split tensile strength, drying shrinkage and transport properties (absorption, sorptivity and rapid chloride permeability tests) up to 365 days. Test results confirm that it is possible to produce SCC with a 70% of cement replacement by both types of FA. The use of high volumes of FA in SCC not only improved the workability and transport properties but also made it possible to produce concretes between 33 and 40 MPa compressive strength at 28 days, which exceeds the nominal compressive strength for normal concrete (30 MPa).
TL;DR: In this paper, the correlation between mechanical and dilatometric properties of aluminosilicate geopolymer binders is highlighted by analysis of a set of samples synthesised from a single ash source using different activating solution compositions and liquid/solid ratios.
TL;DR: In this paper, the authors present the results of an experimental investigation on the properties of fly ash concrete incorporating either hydrated lime or silica fume to improve the early strength of concrete.
TL;DR: The experimental results obtained after casting concrete formulated with different mix proportions of municipal solid waste incineration by-products, bottom ash (BA) and air pollution control fly ash (APCFA), as aggregates, can be concluded that these concrete mix proportions are suitable for use as non-structural concrete.
TL;DR: Fly ash-based geopolymers were found to immobilize a number of trace pollutants, but the leachable levels of elements occurring in their oxyanionic form were increased after geopolymerization, suggesting that an optimal dosage, synthesis and curing conditions are essential in order to obtain a long-term stable final product that ensures an efficient physical encapsulation.
TL;DR: In this article, the role of fly ash on strength and microstructure development in blended cement stabilized silty clay was examined by unconfined compression test and its micro-structure (fabric and cementation bond) by a scanning electron microscope (SEM), MIP, and thermal gravity (TG) analysis.
TL;DR: The use of fly ash could be a promising solution to the removal of phosphate in the wastewater treatment and pollution control because of its role in the adsorption and precipitation of phosphate.