Study of the correlation between the compressive strength of rice husk ash mortar

Abstract

Several studies in the scientific community have investigated the possibility of using rice husk ash in construction materials. Most of these studies looked at the possibility of using ground or unground rice husk ash. The aim of this work is to study the correlation between the compressive strength of ground rice husk ash mortar (GRHA) and the compressive strength of unground rice husk ash mortar (URHA), for the same cement replacement rates. To do this, we formulated cementitious mortars in which a mass fraction of cement is replaced by rice husk ash. The two types of mortar obtained are GRHA and URHA. The mass fractions of cement substitution by rice husk ash are: 0%, 2.5%, 5%, 7.5%, 10%, 12.5%. The different formulations obtained are Ref, GRHA2.5%, GRHA5%, GRHA7.5%, GRHA10%, GRHA12.5%, for ground rice husk ash and Ref, URHA2.5%, URHA5%, URHA7.5%, URHA10%, URHA12.5%, for unground rice husk ash. Density, porosity, and compression tests were carried out on the prepared specimens after 28 days of curing. The compressive strengths were analyzed in Excel Office to determine the correlation between the compressive strengths of GRHA mortars and URHA mortars. The results of this work show that, for low rates, an increase in the compressive strength of GRHA mortars is associated with an increase in that of URHA mortars. However, there is a weak link between the compressive strengths of the two materials for high levels of rice husk ash (RHA). The results of this work make it possible to estimate the compressive strength of URHA from that of GRHA.