Effect of Rice Husk Reinforcement on Strength of Earth Blocks

Abstract

The high deficit of housing in Africa occasioned by poverty, high inflation rates, high population growth rate and soaring costs of construction materials, makes quality housing out of the reach of low-income earners who make up the bulk of Africa’s population. This has led to research efforts in developing quality low-cost building materials such as enhanced earth blocks. This study evaluated the performance of rice husk-reinforced compressed earth blocks. Compressed earth blocks measuring 200 mm x 100 mm x 100 mm reinforced with rice husk (0-1.5%) by weight of laterite were produced and tested for their densities and compressive strengths after 28 days of curing. The results obtained revealed that the addition of rice husk to the matrix led to an increase in the compressive strength of the blocks.  The addition of 0.5%, 1.0% and 1.5% of rice husk resulted in a 1.34%, 3.49% and 6.28% decrease in density and a 15.46%, 10.31% and 5.15% increase in the compressive strength respectively when compared with the control. The blocks may be used for non-load bearing applications as their compressive strengths fall below the minimum requirements specified for load-bearing walls by the Nigeria Building and Road Research Institute. An optimum reinforcement of the blocks with 0.5% rice husk is recommended.