Modified sand brick with partial cement replacement using rice husk ash (RHA)

Abstract

The increasing demand of cement in construction industries makes many researchers find other alternatives to reduce the cost and uses of cement. The material that can be replaced by cement must a pozzolanic material as it can enhance the strength properties of concrete mixes. Rice Husk Ash (RHA) is one of the by-product wastes that can be used as cement replacement as it have higher pozzolanic properties. The chemical composition of RHA has been determined through X-Ray Fluorescence Test (XRF) and the main composition of RHA is silica. In this research, the main objective is to investigate the performance of RHA as a partial cement replacement in the brick and determining the compressive strength of the sand brick with different percentage of modified RHA. The percentages of RHA used as partial cement replacement were 0%, 5%, 10% and 20% at 95°C burning degree of RHA. 0% is the control sample. The sample sizes were 215 mm x 65 mm x 102.5 mm. The brick sample then was left for ambient air cured and tested for 7, 14 and 28 days. The test that was conducted is compression strength and water absorption. The result shows the strength of the brick containing RHA is lower than brick sample without RHA. However, the higher sample containing RHA is 25.47 at 5% for 28 days of curing. The result also shows the strength increase with the increment of air curing whereas the water absorption was increase with the percentage of RHA replace.