Study of Self-Compacting Fly Ash Concrete Using Silica Fume Admixture

Abstract

Concrete is the key material used in construction of various types, from flooring of a dwelling to multi-storied high rise structures, from pathways to an airport runways, from under ground tunnels and deep sea platforms to high-rise chimneys and towers. The greatest challenge in this millennium, especially in developing country like India, it needs to build concrete structures in quicker time, so as to meet high infrastructural demand. In order to achieve this, concrete construction practices will have to undergo a sea-change in the country. The study was focused on development of self-compacting concrete using high volume fly ash, admixed with quary dust and Silica fume. The objective of the study included evaluation of properties, viz. compressive strength, weight change observations in sulphate environment and resistance to chloride ion penetration. Several trial mixes were tested before optimizing the three Self-Compacting Concrete mixes based on binary and ternary blends. The strength variation of individual cubes in each of the mixes has been observed to be in the range of 28 to 46 MPa. Self-compacting concrete using high volume flyash, admixed with quary dust and Silica fume mixes have performed extremely well in aggressive chloride environments. Samples cured for 90 days and exposed to sulphate environment had reduced strengths compared to those cured in tap water, in all the blends. But the percentage reduction is lower in case of ternary blends as compared to control concrete. Keywords: Self-Compacting Concrete (SCC), Compressive Strength, High volume flyash, Quary dust, Silica fume, Supplementary Cementious Material (SCM).