Parametric Study on Effects of Water-Cement Ratio to Compressive Strength of RHA Mortar

The main objective of this research is to investigate the effects of using Rice Husk Ash (RHA) as a
partial cement replacement material in mortar mixes. Water to cement ratio (w/c) were varied namely
0.50 and 0.55 while RHA content were differed from 0% to 45% at increment of 5%. The studied
binder:sand ratio (b:s) was varied at 1:3 and 1:4. Compressive strengths of the mixes were
determined at 7, 28 and 60 days. In addition, the water absorption and initial water suction rate of
mix samples were also investigated. The obtained results show that most of the mortar mixes up to
20% of RHA replacement level achieved higher strength compared to other mixes with RHA
replacement level exceeding of 20%. Furthermore, this study showed that mixes with w/c of 0.55
possesses higher strength.