Volume :

2

Issue :

1

Abstract :

The research addresses the mitigation of Sulphate attack on concrete as it is considered one of the major degradation-causing phenomenons in the durability of concrete. The primary variable in the research was the introduction of Silica Fume as a 12% replacement by weight of cement. Super-plasticizer was also used in order to attain high strength and make the concrete more workable in the presence of silica fume. A concrete batch, with a proper mix design was prepared, aiming at a high strength of 6000psi. Part of the batch was tested for 28 days Strength and part of it was subjected to cyclic wetting and drying exposure to Sulphate-rich environment, the solution being 50 g/l of Na2SO4. The quality of concrete was measured by Non-Destructive Testing which showed an appreciable improvement in the resistance of concrete to Sulphate attack due to addition of Silica fume whereas the Normal concrete cylinders were affected severely in the Sulphate environment. The same concrete cylinders were tested afterwards for compressive strength under the Universal Testing Machine and the results showed an alarming reduction in strength of the normal concrete cylinders whereas the Silica fume made concrete cylinders showed small reduction in strength. The main conclusions derived from this study are that the use of Silica fume leads to a better performance of concrete in Sulphate rich environments although the strength may not be altered as desirable.