Effect of guinea corn husk ash as partial cement replacement in cement-admixed clay

Abstract

Soil stabilization involves the incorporation of cement into the soil component of a road pavement to increase its strength. However, the production of cement emits carbon dioxide into the atmosphere leading to greenhouse effect, a major health hazard. A way out is the replacement of some portion of cement with agro-based pozzolanic materials. This study was carried out to find the consequence of using Guinea Corn Husk Ash (GCHA) as a cement replacement in cement admixed clay. The design mix was done with replacement of cement from 10 % - 30 % by weight and GCHA was varied from 5% - 35 % by weight of the cement replacement. X-ray Fluorescence (XRF) was used in obtaining the oxide components of GCHA while a Universal Testing Machine (UTM) was used in determining the Unconfined Compressive Strength (UCS) of the clay. The XRF results reveal that the sum of the oxides of silicon, Aluminium and Iron in the GCHA is 76.92 %. This is greater than the specification by ASTM C-618. The UCS test results indicate that 5 % by weight of GCHA, 20 % by weight of cement incorporation with 200 % by volume of water content had the optimal strength of 7.56 MPa for GCHA incorporation in the admixed clay samples. This strength is higher than the limits specified in IRC: SP 72-2015 for sub-base and base courses for pavement construction. Therefore, GCHA can be incorporated into admixed clay for road construction.