Fly ash from coal and biomass for use in concrete : Origin, properties and performance (original) (raw)

A Study on Low Quality Fly Ash as an Opportunity for Sustainable and Economical Concrete

International Journal of Scientific Research, 2012

As concrete usually has been produced by using high quality fly ash and without fly ash (standard concrete). By using high quality fly ash constituents, increase drastically the initial cost of concrete. The objectives of this research work were to intend to study the possibility of producing low cost concrete. To verify the impact of carbon content on fly ash on the strength and durability of concrete. For this purpose it was decided to enhance the 'as received' fly ash by eliminating particles coarser than 75μm, thus reducing the carbon content by 50%. It was also observed that the carbon content did have little impact on the strength and durability of concrete. Applications of fly ash, which is technically, sound, environmentally safe for sustainable development. Use of fly ash in various engineering applications can solve the problem of disposal of fly ash and other purposes. The major constituents of most of the fly ashes are Silica (SiO2), alumina (Al2O3), ferric oxide (Fe2O3) and calcium oxide (CaO). The other minor constituent of the fly ash are MgO, Na2O, K2O, SO3, MnO, TiO2 and unburnt carbon. This paper is study on low quality fly ash as an opportunity for sustainable and economical concrete for a new millennium.

Influence of modern coal-fired power technologies on fly ash properties and its use in concrete

Advances in Cement Research

The Paper investigates the properties and use of fly ash produced from technologies developed to reduce environmental impact/improve efficiency of the coal-fired power generation process. These include, NOx reduction, co-combustion, supercritical steam technology and oxy-fuel combustion. The nine samples examined were characterized physically, chemically and in terms of their reactivity. Tests were also carried out for consistence and compressive strength of concrete. Comparisons were made with (i) a selection of reference fly ashes, (ii) the requirements of EN 450-1 and (iii) fly ash studies from the 1980s and 1990s. The results indicate that for some processes, fly ash tended to be coarser and of higher loss-on-ignition (co-combustion and incombustion NOx reduction), while for others lower carbon contents were found (supercritical steam), or there was little obvious effect. Fly ash chemistry was slightly affected in some cases, but mainly as expected for the coal being used. There was general agreement between water requirement and activity index with fly ash fineness. Similar effects were noted with concrete in terms of superplasticizing admixture dose for a target slump and compressive strength. The behaviour of the materials was similar to that from the earlier studies and suggests suitability for use in concrete construction.

Utility assessment of biomass fly-ash for production of concrete products

Czasopismo Techniczne

International agreements oblige our state to develop ecological sources of energy, one of which is biomass. During its combustion fly-ashes are produced. Several studies have shown that they might be useful in concrete production. The article presents a comparison of biomass fly-ash and coal fly-ash influence on the properties of cement composites. The replacement levels of cement by fly-ash (FA) were 20%, 40% and 60%. Biomass fly-ash FA(B) have replaced coal fly-ash by 0%, 50% and 100%. The compressive strength tests showed similarities in strength development of coal and biomass fly-ashes concretes. Specimens with biomass fly-ash presented similar or better abrasion resistance comparing to coal fly-ash samples.

Biomass fly ash in concrete: Mixture proportioning and mechanical properties

Fuel, 2008

ASTM C 618 prohibits use of biomass fly ashes in concrete. This document compares the properties of biomass fly ashes from cofired (herbaceous with coal), pure wood combustion and blended (pure wood fly ash blended with coal fly ash) to those of coal fly ash in concrete. The results illustrate that with 25% replacement (wt%) of cement by fly ash, the compressive strength (one day to one year) and the flexure strength (at 56th day curing) of cofired and blended biomass fly ash concrete is statistically equal to that of two coal fly ash concrete in this investigation (at 95% confidence interval). This implies that biomass fly ash with co-firing concentration within the concentration interest to commercial coal-biomass co-firing operations at power plants and blended biomass fly ash within a certain blending ratio should be considered in concrete.

Characterisation and Use of Biomass Fly Ash In Cement-Based Materials

Journal of hazardous …, 2009

This paper presents results about the characterisation of the biomass fly ashes sourced from a thermal power plant and from a co-generation power plant located in Portugal, and the study of new cement formulations incorporated with the biomass fly ashes. The study includes a ...

BIOMASS AND COAL FLY ASH IN CONCRETE -STRENGTH

International Journal of Scientific Research and Review, 2019

From previous years, it has been observed that waste products are producing from industry while fabrication of equipment etc. These waste materials can be solid waste, biological waste, construction and demolition waste. Biomass is one such type of waste material. Globally, 140 billion metric tons of biomass is generated every year from agriculture. Biomass wastes includes agricultural wastes, such as corn stalks, straw, sugarcane bagasse, mustard husk, rice husk, nutshells and manure from cattle, poultry, and hogs; forestry residues, such as wood chips, bark, sawdust, timber slash, and mill scrap; municipal waste, such as waste paper and yard clippings. These waste materials are thrown into open environment, or dumped on the land and into water. In this research work, the M25 and M30 grade of concrete were designed for different percentage of biomass ash and coal fly ash. The biomass ash and coal fly ash were used at percentage of 15%, 20%, 25% and 7.5%, 10.0%, 12.5% by partial replacement of cement in M25 and M30 grade of concrete respectively. The specimen of similar percentage of biomass and coal fly ash were also casted and results investigated.

Fly Ash as a Concrete Ingredient-A Review Introduction

2016

This paper is written to access the use of fly ash, a waste product by thermal power plant, as an ingredient of concrete used for various engineering purposes such as production of pozzolana Portland cement, geopolymer concrete, lightweight concrete, precast concrete industry, manufacture of precast Poly Vinyl Chloride (PVC) pipes and paver blocks, Self compacting concrete (SCC) and mass concrete etc. The area is of much importance in Indian context as about 145 million tones of fly ash is being produced in India annually from electricity generation plants and this figure is increasing with the growth of demand for energy. The disposal of high volume of fly ash is posing a threat to the environment and requires immediate attention. In present scenario the cement industry alone is responsible for 7% of all the CO2 being produced in the world. Using fly ash as an ingredient in concrete, the problem of safe disposal of fly ash can be addressed considerably. Moreover the use of fly ash ...

Physico-Chemical Characterization of Fly Ash

ASEM13 Jeju Korea, 2013

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.

Study of Utilization of Fly Ash as a Partial Replacement for Cement in Concrete

International Journal of Current Engineering and Scientific Research, 2019

Mining industry produces a large quantity of waste every year resulting in severe damage to the environment. The wastes that are produced during mining should be efficiently disposed or effectively reused for any other productive purposes. Coal and lignite mining results in considerable dust pollutions very specifically the coal beneficiation process produces extensive amount of ashes. These ashes can be utilized in construction materials rather than dumping as landfill. When dumped as landfills, these ashes have the tendency to be carried away by the wind resulting in massive damage to the surrounding environment. This study is made to investigate whether this fly ash can be used as an ingredient in concrete preparation as a partial replacement for cement by studying the strength properties of fly ash mixed concrete. The strength properties of concrete when certain percentage of cement in the concrete is replaced with fly ash are studied. The replacement percentage of cement is maintained at 10%, 20%, 30%, 40% and 50% and the samples are tested in the laboratory after the curing period of 21 days. The workability, tensile strength, compressive strength and shear strength of the fly ash mixed concrete sample are determined. Similar tests are conducted on concrete with no fly ash content and both results are compared to find the optimum amount of fly ash that can be replaced without compromising the quality of the concrete. By utilizing fly ash as partial replacement to cement the percentage of CO2 emitted due to cement manufacturing can also be considerable reduced.