Investigation of compressive strength of concrete containing rice-husk-ash

The rice husk ash (RHA) is a pozzolanic material that can be blended with the Portland cement in concrete to obtain a better performance of normal concrete. This paper proclaims an experimental investigation on utilization of RHA for the concrete as it is a byproduct of brick-kilns in Sri Lanka. The results of three different replacement percentages of RHA in concrete (10%, 20% and 30% by mass of cement) were compared with the concrete that does not contain RHA. Those samples were tested for compressive strength, tensile strength, surface water absorption and the durability aspects. A comparative study on chemical composition and physical properties was carried out and the experimental results were discussed. A significant improvement on the compressive strength at early stage is identified and optimum strength was achieved at the 20% RHA replacement by mass of cement. The strength of the concrete with different sizes of RHA particles was compared to identify the effects of particle size of RHA. Around 50% of the RHA collected from the brick-kiln can be utilized for the concrete after proper grinding.