Use of Unground Rice Husk Ash in Concrete Block Production

Abstract

This research was aimed to utilize unground rice husk ash for producing hollow non-load bearingconcrete block. The tested properties included unit weight, water absorption, compressive strength, dryingshrinkage, durability on wetting and drying process, and weight loss due to acid attack. Two types of rice huskash, black rice husk ash from an electrical generating power plant using rice husk as a fuel and black rice huskash from a rice mill, were used. The replacement percentages of rice husk ash in aggregate (crushed limestone)by weight were 0%, 10%, 15%, and 20%. Water to cement ratio (w/c) was controlled in the range of 0.53% to0.64% by weight, depending on the formation of concrete block. Sulfuric, acetic, nitric, and hydrochloric acidswith a concentration in pH value equal to 1.0 were used to study acid attack concrete blocks.

The tested results showed that the compressive strength of rice husk ash concrete block increased whenthe replacement percentages of rice husk ash in aggregate increased and was also higher than the minimumspecified value from TIS 58-2530 standards whereas the unit weight of rice husk ash concrete block decreased.Furthermore, when the replacement percentage of rice husk ash increased, the resistance against acid attack,water absoption value, and drying shrinkage also increased.