Experimental Investigations on the Durability of Concrete Blended with Pozzolanic Materials

Abstract

The replacement of cement with supplementary cementitious materials such as industrial and agricultural waste, without sacrificing the mechanical and durability properties of concrete has been gaining momentum for the past few years. Replacement by such materials is found to be an environmentally friendly method of disposal of those materials. However, the use of these pozzolanic materials warrants the assessment of their performance when blended with concrete in terms of mechanical and durability properties of concrete. Experimental investigations carried out as a part of research work to evaluate the feasibility of using Rice Husk Ash (RHA), Fly Ash (FA) and Ground Granulated Blast Furnace Slag (GGBS) as pozzolanic materials are presented in this paper. Experiments were conducted on M30 grade concrete prepared with 53-grade ordinary Portland cement with partial replacement of cement by 24% RHA, FA and GGBS. The performance was measured concerning loss in compressive strength over the periods of exposure time. The resistance to chemical attacks viz 5% MgCl₂, 2% Na₂SO₄ and MgSO₄, H₂SO₄(pH 2and 3) and 5% NaOH were tried. The blended concretes exhibited better resistance to chemical exposure measured in terms of strength compared to control concrete. A comparison of these properties further revealed that the blended concretes exhibited varied resistance to the chemicals they were exposed.