Fly-ash

Today's world is facing challenging and unsolved environmental problem such as global warming, forest destruction and lack of resources. In order to solve these environmental problems, resources recycling have to be done in environmentally safer methods. As there is a vast scarcity the production of aggregates for concrete the recycled materials have great demand. The present study mainly focuses on investigating the effect of using copper slag as a replacement of fine aggregate on the strength properties. In this report, M25 grade concrete was used and tests were conducted for various proportions of copper slag replacement with sand of 40%, 80% and 100% in concrete. In the first case along with replacement of copper slag with sand there is an attempt is made to replace the cement with 50% flyash similarly in second case for 30% replacement of cement with flyash replacement and in the third case with no replacement of cement with flyash. The obtained results were compared with those of nominal concrete made with ordinary Portland cement and sand. Further split tensile strength and flexural strength studies were also performed to check its durability aspects.

In this study, fly-ash is used as a stabilizing material to stabilize the expansive soil dealing with engineering characteristics as the parameter for it. Present paper describes a study carried out to check the improvement in the properties of expansive soil with fly-ash in varying percentages. Fly-ash is added in 10%, 20%, 30%, 40%, 50% and the change in index properties and engineering characteristics is examined. It has been found that significant variation in liquid limit, plasticity index, and swelling index. In expansive soil, liquid limit decreased from 55.2% to 36.3% and plasticity index decreased from 27.1% to 18.1% , differential free swell (DFS) also reduced from 52% to 14% respectively .the compaction test results showed increase in optimum moisture content (OMC) from 19% to 23% and decrease in maximum dry density (MDD) from 1.63g/cc to 1.52g/cc. Test result indicates that fly-ash has a potential to improve the properties of black cotton soil.

A composite material and method are described where in melted Waste, chemically unmodified plastic powder and fly ash particles are mixed in a vessel to disperse fly ash particles in the plastic powder material. The resulting mixture then is cooled to solidify the melted plastic powder material to form a composite material having a matrix comprising plastic powder and dispersions distributed in the matrix and comprising fly ash particles. The fresh and hardened properties of waste virgin plastic mix concrete have been studied (CUR Report 1991). A number of concrete mixes were prepared in which sand was partially replaced by waste plastic flakes in varying percentages by volume. Waste plastic mix concrete with and without superplasticizer was tested at room temperature. Forty-eight cube samples were moulded for compressive strength tests at three, seven, and twenty-eight days. Eight beams were also cast to study the flexural strength characteristic of waste plastic mix concrete. It was found that the reduction in workability and consideration, such as heavy mass of concreting in PCC in pavements. If plastic wastes can be mixed in the concrete mass in some form, without significant effect on its other properties or slight compromise in strength, we can consume large quantities of plastic waste by mixing it in the concrete mass. Plastic is one component of municipal solid waste (MSW) which is becoming a major research issue for its possible use in concrete especially in self-compacting concrete and light weight concrete. Although some of these materials can be beneficially incorporated in concrete, both as part of the cementitious binder phase or as aggregates, it is important to realize that not all waste materials are suitable for such use. In Bangladesh about 0.6 million tons fly ash is produced annually and its production is likely to increase significantly due to future power plants. Globally around 20% fly ash is used as concrete related applications. In India, the quantity of waste plastic is increasing day by day this is because increase in population. Plastic is harmful if not properly decomposed, decomposing is a tedious work. It takes too many years to decompose plastic waste and its impact on the environment is very harmful if it burnt cause air pollution. Reuse of waste plastic in construction materials can reduce the risk of disposal and pollution caused due to burning of plastic. Our project, waste plastics of small proportion with fly ash is used to manufacture plate and its mechanical behavior is investigated.

To build environmentally sustainable structures, especially in developing countries, the possibility of using some agricultural wastes and industrial by-products from different industries as construction materials will be highly desirable and has several practical and economic advantages. Oil palm shell (OPS) is a form of agricultural solid waste in the tropical regimes. Research over the last two decades shows that OPS can be used as a lightweight aggregate for producing structural lightweight aggregate concrete. The density of OPS concrete is around 20 - 25% lower than normal weight concrete. Generally, mechanical properties of OPS concrete are slightly lower than the other types of lightweight aggregate concrete. It seems that from the summary and analysis of the existing information concerning OPS concrete and comparing it with other lightweight aggregate concrete it appears that significant achievements can be attained. ©2010 Academic Journals.

http://eprints.um.edu.my/5989/

As using Fly ash (FA) as an additive in cement stabilization of soft soil layers makes it possible to improve soil strength, it makes this application become more economical by using FA as a replacement material by Portland Cement (PC). In this study PC and FA classed as F according to ASTM standarts had been used. This study presents the influence of stabilization in this way on the mechanical and geotechnical properties of clayey soil of Harran region. For this purpose, three different mixtures were prepared. For all mixtures, the amount of soil, dosage of binder material and water/binder material (W/B) ratio were held constant and FA was used at different ratios as a replacement material by cement. For all mixtures, the amount of cement was taken as 500 dosage and the ratio of W/B was adopted as 1.00. Mixtures contain 10%, 30% and 50% FA. The properties of mixtures were investigated for the ages of 28 days. The study concluded that mixtures with %10 FA have a more positive effect on the performance. Increase in the FA content decreases the positive effect on compressive strength, splitting tensile strength, unconfined compressive strength and sorptivity at the age of 28 days.

In India, silty soil are available in many states and have poor supporting capacity. Main objective of this research is to utilize the industrial waste like fly-ash to improve the engineering characteristics of the silty soil. Soil samples blended with the fly-ash from 0% to 50% of dry weight of the soil. Samples were prepared and results showed a significant increase in soaked California Bearing Ratio (CBR) value. Liquid limit decreased from 30.66% to 23.31% and plasticity index decreased from 10.21% to 6.29%. DFS of silty soil reduced from (31%) to (5%). From the compaction tests result decreased in maximum dry density (MDD) from 1.71 gm/cc to 1.55gm/cc and increased in optimum moisture content (OMC) from 20.4% to 24.31%. In this investigation it can be seen that fly-ash has a potential to improve the engineering characteristics of silty soil.

This study is carried out for stabilization of soil using rice husk ash and fly ash with black cotton soil. The admixtures were varied by 5%, 10%, 15% for fly ash and for rice husk ash it is 4%, 8% and 12%. Different tests will be performed to check the properties of soil like swelling pressure, Plasticity index, liquid limit, specific gravity etc. for improved pavement works. It is concluded that the properties were enhanced with stabilized soil.

The use of clay as a landfill cover system is a choice of alternative materials that are widely used in almost all the existing landfill system in Indodonesia and in the world. In addition to the relatively low cost of procurement is also available in almost all regions in Indonesia. However, alternative reliable overburden landfills has not been much discussed and researched. The purpose of this study is to design an ideal final cover layer landfill technically and mechanically. The results showed that the addition of fly ash and palm oil fiber (POF) between 10% of fly ash and 0.5% of POF can enhance the mechanical value of soils. the compressive strength of soils increase from 39.4 kPa to 89.0 kPa or rose by 129%, decreasing the value of soil hydraulic conductivity is to be 1,2x10-7 from the initial value of 1,17x10-6 or decreased by 850.4%, increase in soil friction angle of 8.55° to 24 °, and lowering the soil liquid limit of 33.48% to 24.5%, decreasing of swelling potential of 8 % to only 1.5% at the end of the wetting cycle, reduce the cracking intensity factor (CIF) from 1.96% to zero cracks. Mechanical behavior is heavily influenced by the nature of fly ash which has of a small water absorption and change the water in the soil for the pozzolanic reaction and produce calcium hydrate silica (CSH), in which the reaction is to form granules (binder) in the soil so that the soil becomes dense and hard, while palm oil fiber have cellulose and lignin as dominant compounds that tend to have high water absorption but serves to strengthen the fiber tensile force between the fibers and the soils surface due to adhesion forces so that the soil is not easily collapse and reduce the potential shrinkages and cracking of the soils.. I. INTRODUCTION Cracks behavior of natural clay used as Compacted clay liners (CCL) is the main problem of the structure of clay. because it will lead to cracks in the overburden landfills. and consequently will reduce the sealing function of the cover layer dramatically. From the standpoint of engineering, landfill cover materials must have sufficient technical properties, such as low hydraulic conductivity, sufficient compressive strength, high tensile strength, and flexibility. The drying process will lead to the behavior of cracks in clay soil will cause the surface of the liquid migrating into landfills causing increased liquid and gaseous waste. In the end the potential for contamination of soil and ground water will increase [14]. Currently there are several possibilities in the use of other materials to improve the performance of the clay as a hydraulic barrier in landfills. Research to design a cover liners that is ideal in landfills, which is to analyze the mechanical behavior of soft soil, the behavior and development of shrinkage and cracking of soft soil, stabilized fly ash and reinforcement fibers whether it can increase the capacity of soft soils as final cover landfill, it also makes models of laboratory hydraulic conductivity of soil stabilization fly ash and fiber in its effectiveness to retain surface run on and leachate from the landfill.