ABSTRACT
Fast depleting natural resources, huge consumption of energy, and environmental hazards involved in the production of cement has inspired for searching the substitution by other material with similar material, especially in developing countries. Cement is widely noted to be most expensive constituents of concrete. The objective of is study is to investigate the mechanical properties of concrete with different replacement levels of ordinary Portland cement by rice husk ash and silica fume. The cement has been replaced by rice husk ash (RHA) accordingly in the range of 5%, 10%, 15%, 20% and 25% by weight of cement and 10% of silica fume in common for M-20 mix. The compressive strength at 3 days, 7days and 28 days have been obtained with normal curing condition. A maximum increase in compressive strength of 32.2Mpa with 10% of RHA replacement and silica fume of approximately 10% was observed. The compressive strengths of concrete is reduced as the percentage of RHA replacement is increased beyond 10%.
