Fly Ash

Fire is one of the most severe environmental conditions that concrete structures might be subjected to, especially in closed conduct structures, such as tunnels. Concrete in general can withstand fire but its properties degrade when exposed to fire at high temperatures. The effect of heating duration, at a high temperature, on the performance of fly ash-based geopolymer concrete is presented. Cubes of low, medium and high strength grades of geopolymer concrete that had been cured for 28 days, were exposed to a fire flame at 1000 °C for 30, 60, 90, 120, 150 and 180 min. After the fire exposure, the cubes were cooled to the ambient temperature before further testing. A visual observation was performed on the cubes to detect any colour change, cracking and spalling. The losses of mass and residual compressive strength of the cubes were recorded. The results showed that as the heating duration increased from 30 to 90 min, the compressive strength of the cubes also increased. Contrarily, the compressive strength decreased as the heating duration increased beyond 90 min indicating that the extended heating duration induced the loss of free water and decomposition of aluminosilicate products in geopolymer concrete. The evaporation of water by virtue of the heating for the extended duration, at high temperature, led to a loss in the mass of concrete. The findings suggest that geopolymer concrete was able to sustain its structural integrity without any noticeable spalling and hence, it can be classified as a fire-resistant material.

Swelling mica exhibits unique characteristics for purification of drinking water contaminated by heavy metals and for selective removal of Sr2+ and Ba2+ ions from nuclear waste solution. As a new approach to recycle fly ash, conversion of fly ash to swelling mica has been attempted and ion-exchange properties of fly ash-derived swelling mica (referred to hereinafter as FA-swelling mica) were

Concrete in farm buildings is subjected to severe corrosion if manure is stored below slatted floors. Many chemicals associated with manure are identified as having a detrimental effect on concrete and the reinforcing steel embedded in the concrete. Of these, hydrogen sulfide is the most corrosive agent that leads to the rapid deterioration of concrete in barns. As well, manure has high concentrations of sulfates. In the present study, 48 concrete cylinders, 100 mm diameter and 100 mm high, were made with Portland cement, and various combinations of slag, fly ash and silica fume. Each has a reinforcing steel bar embedded in it. 24 cylinders are half immersed in sodium sulfate (20,000 ppm SO4 2- ) and also subjected to hydrogen sulfide gas (1,000 ppm H2S). The second set of 24 is subjected only to hydrogen sulfide gas. In each set, there are 8 different treatments. The specimens results indicate that after 16 cycles (each cycle is about five weeks long) of testing over 28 months, spe...

Waste foundry sand (WFS) and fly ash D-Optimal mixture design/response surface methodology/design of experiments Statistical optimization Geopolymer concrete (GPC) Compressive strength A B S T R A C T This work examines the partial replacement of fine aggregates with waste foundry sand (WFS) and fly ash, process by-products, to synthesize geopolymer concrete (GPC). D-optimal mixture design of experiments was adopted to guide the proportion of mixture constituents (fine aggregates, WFS, and fly ash) to obtain desired responses (high compressive strengths). The experimentally measured responses/compressive strengths were successfully fitted to Scheffe polynomial model to obtain cubic models which represent compressive strengths of solidified GPC at 7 th day curing time (CS 7) and at 28 th day curing time (CS 28). The models were statistically evaluated by the standard error of design estimation and experimentally verified by comparing their predicted responses to the independently performed experiments. The models were subjected to analysis of variance (ANOVA) and residuals (diagnostics) for statistical significance and validation, respectively. The established models, hence obtained, were used to assess the impacts of relative proportions of mixture constituents at CS 7 and CS 28. It was observed that, although the highest compressive strength requires a high proportion of fine aggregates, yet, some mixture compositions could be proposed for better utilization of waste materials. Finally, the optimization was performed to maximize the usage of WFS and fly ash. A recipe was identified which yielded 18.9 N/mm² CS 7 and 22.3 N/mm² CS 28 by mere 32 wt. % contribution of fine aggregates in a (fine aggregates + WFS + fly ash) mixture. This study can be helpful in designing experiments and optimizing the utilization of similar waste materials into useful products.

In our recent study, BABA has been tested to manage Meloidogyne incognita under stress conditions due to fly ash. The reduction in the growth of pathogen under abiotic stress is being intensified by DL-β-amino butyric acid (BABA). The combination of abiotic and biotic stress can have a positive effect on the yield of plants by reducing the sensitivity to biotic tension and limiting the crop yield and more priority has been given on the surface of the research table now a days. Therefore this study was carried out observe the effect in combination of Fly ash and BABA in resistance to Root knot nematodes. Results indicate that 30% fly ash in combination with BABA (125 μg/ml) undoubtedly reduced the gall Index by 50% when compared with the control. The interesting thing is that the lower dose of BABA when combined with the abiotic stress was similar to the high dose of BABA efficacy (250 μg / ml).

The Indonesian Government's decision to remove Fly Ash and Bottom Ash (FABA) coal waste from the hazardous and toxic materials (B3) list has generated pros and cons in various circles. The waste that comes from burning coal is known to have harmful side effects for health and damage to the environment and the living biota in it. However, according to the test results of the Indonesian Ministry of Environment, FABA waste does not meet the characteristics of B3, and it has high economic benefits in several countries that have succeeded in managing this type of waste, such as China, Japan, the United States and others. If the Government can create good regulations, this waste will be a vast potential, both environmentally and economically. Learning from European countries that have succeeded in managing this waste by forming a particular association that deals with coal waste, Indonesia needs to apply international standards so that this potential does not impact environmental health through related international cooperation. Using the literature study method, this research will be qualitative, and environmental theory and international cooperation will describe and analyze Indonesia's opportunities in accelerating the use of FABA-type coal waste through international cooperation. The target achievement of this research is a policy recommendation for the Government on issues related to the handling of coal waste types of FABA.

The bagasse fly ash, an industrial solid waste of sugar industry, was used for the removal of cadmium and nickel from wastewater. As much as 90% removal of cadmium and nickel is possible in about 60 and 80 min, respectively, under the batch test conditions. Effect of various operating ...

Fly Ash (FA) from South African power stations was successfully used to treat Acid Mine Drainage (AMD) and the insoluble residual solids that were obtained as a result of the reaction between FA and AMD proved suitable as a backfill material for mine stabilization. Particle Size Distribution (PSD) of FA varies from time to time depending on the coal burning conditions in the power station. Such variability in PSD of FA could influence its capability to neutralize AMD as well as the flow behaviour of residual solids that have to be transported hydraulically to the backfill site. The objective of this paper is to study the influence of variability of PSD on the above mentioned properties. The FA from Arnot power station in South Africa was used for this study. PSD analysis showed that the FA particle size distribution was <25 m (38%), 25-75 m (42%) and 75-150 m (14%). The % of fine and coarse particles (in the context of this study) could influence the neutralization capacity of FA...

Coal fly ash (CFA) is a waste product produced from the electrical power plant and hazardous towards the environment. However, the high composition of silica and alumina in the CFA makes it useful as raw materials in the zeolite synthesis. However, the presence of silica in the form of quartz in the CFA does not facilitate the transformation of CFA to zeolite at 100oC and autogeneous pressure. In this study, CFA was converted to zeolites in various NaOH concentrations by microwave heating at various heating time. All synthesized product were characterized by X-ray diffraction(XRD), and gravimetric analysis. XRD has shown that quite pure sodalite in nanosize has been formed as early as 15 minutes and increase with time. Prolong heating up to 45 minutes has reduced the content of quartz to ca 20%. Gravimetric analysis performed on the liquor of the reaction showed that the dissolved silica decrease with increase of heating time indicating that most of the dissolved quartz is used up to form sodalite framework. Hence, quartz of CFA did help in enhancing the crystallinity of the formed sodalite after prolong heating.

The potential problems and their consequences due to fly ash disposal have been well studied around the world. Ash pond is a common available disposal facility for thermal power plants. The pond ash is subjected to weathering and the ions present in ash migrate to the soil ...

Fly ash is generated in large measures, especially by thermal power plants. A great batch of inquiry has been channeled out for efficient utilization of fly ash in the structure industry. Use of fly ash in manufacturing brick is one such thing which is being studied by many research scholars and engineers. The aim of the present study is to investigate the durability and water absorption features of fly ash bricks made up with different percentage of lime (L), local soil (S) and fly ash (FA). The experiments were conducted by both Pressure molded fly ash bricks. It was found that none of the L-S-FA bricks satisfy all the demands of standard codes. While some of the bricks satisfy the provisions in respect of intensity level only the L-S-FA (40-0- 60) bricks satisfy the demand of Indian Standard Code in respect of intensity as easily as water absorption features.

Self- Compacting Concrete is a special type of concrete that is able to flow and compact under its own weight and can occupy all the spaces in the form without any vibration and at the same time it is cohesive enough to be handled without bleeding or segregation. In recent years, self-compacting concrete has been gaining wide range of application for placement in congested reinforced concrete structures with difficult casting conditions. For such applications, the fresh concrete must possess high fluidity and good cohesiveness. The use of additive materials such as industrial wastes as mineral admixtures can ensure the required concrete properties. The initial experimental study aims at producing and evaluating SCC for ternary blends incorporating fly ash, GGBS, sugarcane bagasse ash and alccofine as partial replacement of cement. Five number of SCC mixes were investigated in this study. The self-compacting mixes have cement replacement with different percentages of mineral admixtur...

The demand of using local fly ash is growing rapidly in Indonesian cement industries. The quality of fly ash plays an important role to ensure since the quality of coal used is not uniform. Basically, good and fewer qualities of coal are mixed together in the field. Twelve representative samples of fly ash produced by five Indonesian power plants were collected from site and cement industries. All samples are class F fly ashes with good pozzolanic characteristics according to the standard. The samples were examined for their physical, mechanical and chemical properties with compression test. Mortar samples were made from each fly ash sample according to ASTM C 311. Their strength activity was examined at 7 and 28 days. The results showed that both physical and chemical properties of fly ash influenced the mechanical properties of mortars containing fly ash.

This study examines an attempt to produce self-compacting concrete (SCC) containing fly ash (FA), ground granulated blast furnace slag (S) and both (FA+S). The effects of these materials on the rheological properties of the SCC mixes were studied experimentally. The study began with three groups of SCCs, each with 25% water binder (w/b) and 550 kg/m3 total binder content. Instead of superplasticizers (SP), the chemical admixtures were lignosulphonates (LS), which replaced Portland cement (PC) at levels by weight of 10%, 20%, 30% 40%, 50%, and 60%. The fresh properties of the mixtures were examined experimentally for slump flow diameter, T50 time, V-funnel time, and L-box height ratio. In the mixtures with FA alone, a continuous decrease was observed in compressive strength. Increases in strength ended at 40% in the case of FA alone, and 30% for both the S and FA+S mixes. Statistical analysis was carried out to assess the effect of  experimentally substituted materials FA and S, with results showing
that S had a greater influence than FA on T50 time, V-funnel, L-box height ratio, and compressive strength, while FA had more effect than S on the slump flow diameter test.

Electronic waste is an emerging issue posing serious pollution problems to the human and the environment. The Disposal of electronic waste in an environment is considered to be a big problem due to its very low biodegradability and presence in large quantities. To rectify this environmental problem of disposing the E-waste, reuse of E-waste in concrete industry is considered as the most feasible application. This study focuses on the possibility of re-using E-waste that is now produced in large quantities in the formulation of concrete as a partial replacement of coarse aggregate along with the substitution of cement by fly ash. The work was conducted on M25 grade mix. Various cube specimens were casted with 5% replacement of coarse aggregate by e waste with fly ash ranging from 0-30% by weight of cement. Compressive strength test was conducted on the specimens after 7, 14 and 28 days of curing and the strength was recorded and compared with the strength of standard mix. The-E-waste is suitable to replace the coarse aggregate but not suitable as fine aggregate.

Главной целью данной работы является выявление влияния сдвига «сомбреро» от оси на показатель эффективности установки. Эта работа важна для реализации промышленной модели инерционно-вакуумного золоуловителя. Лучшая эффективность достигается при корректных размерах, пропорциях и отношениях одних элементов к другим, что очень сложно спроектировать в жизни. Ниже просчитаны различные варианты для проверки выявления отклонения эффективности улавливания от первичных результатов при вибрациях «сомбреро» из-за больших расходов потока уходящих газов. Разработка аппарата ИВЗ выполняется по заданию фонда «Энергия без границ».