Effects of Mix Composition on Rice Hnsk Ash (RHA) Mortar

The research is done to investigate the effects of mix composition on Rice Husk Ash
(RHA) mortar. The properties of RHA mortar are analyzed by varying the mixture
compositions which are water-cement ratio (w/c) of 0.60 and 0.65, binder to sand ratio
of 1:3 and 1:4, and varied RHA replacement (5%, 10%, 15%,20%, 25% & 30%). This
experimental research is intended to further analyze the results that have been found out
by previous researcher which used the same methodology but with w/c of 0.50 and 0.55.
The use of waste materials from paddy industry which is RHA saves the environment
from the dumping activity ofRHA which polluted our Mother Nature. It also reduces the
content of cement in mortar or concrete mixtures and thus, helps save the environment
by lessening the cement production. RHA was obtained from uncontrolled combustion
of rice husks at BERNAS's factory at Sungai Ranggam, Perak and grinded using Los
Angeles Abrasion Machine. RHA that is used in this research has coarser grain size than
cement and finer than sand. The properties of RHA mortar with different composition
are analyzed by conducting three tests. The compressive strength test is conducted at 7,
28 and 60 days of curing period. The initial rate of suction (IRS) test and water
absorption test are conducted after 60 days of curing. The results show that the addition
ofRHA at 5% with 0.65 w/c and 1:4 binder to sand ratio resulted in highest compressive
strength than respective control and RHA mortars. This research also found out that
incorporation of RHA in the mortar with 1:3 binder to sand ratio did not give any
significant contribution towards the properties of the mortar.