Experimental study on effect of fly ash content on self-compacting concrete

Abstract

Self-compacting concrete (SCC), concrete flows by its own weight, is a recent innovation in concrete industry. In recent times, the usage of self-compacting concrete was increasing. Self-compacting concrete will be form, if it had sufficient binder content and required water content. The strength of concrete majorly depending on water to powder ratio. However, there were workability problems associated while fixing the water powder ratio as per target mean strength when SCC was made, especially for design mix for low strength and high strength of concrete. Apart from this, binder content and mineral admixture will also responsible for strength of concrete. As mineral admixture content increases the strength will reduce. If a relationship between compressive strength and mineral admixture content was found, mix proportions of SCC can be made easily. In this area more research has to be focused. This research is an attempt to assessing the grade of concrete with respect to fly ash content and relationship was developed between fly ash content and compressive strength of concrete. IS 10262-2019 and EFNARC guidelines are used in mix design. A water content of 200 kg/m3 and water powder ratio = 0.4 is kept as constant. Cement was partially replaced with fly ash at proportions of 10%, 20%, 30%, 40%, and 50%. In this research the fresh properties, mechanical properties, and Sulphate attack test of each proportion were tested. The workability properties are measured under different chemical admixture levels, such as 0.5%, 0.6%, and 0.8%. Strength properties are determined with a chemical admixture dosage of 0.6%. The fresh properties of concrete were measured by slump flow test, L–box test, and V–cone test. Mechanical properties such as compressive strength, flexure strength and split tensile strength were determined. Sulphate attack test also conducted by immersing cube specimens in 5% of H2SO4. Further, correlation study was done between compressive strength & fly ash content and also correlation between compressive strength & flexure strength.