Assessing the strength and durability behaviour of concrete enhanced with kaolin clay and Shea nut shell particles

Abstract

The aim of this study was to investigate the individual and combined effect of kaolin clay (KC) and shea nut shell particles (SSP) on the physical, strength, and durability properties of concrete. The cement content was replaced with up to 20% KC, and the fine aggregate con tent was replaced with up to 40% SSP. The concrete samples were cured for 7, 14, 28, and 90days, and tested. The total SiO2þAl2O3þFe2O3 content of the KC studied was 88.23%; hence, it possesses pozzolanic properties. Initial and final setting times of the KC pastes steadily increased to 154min and 325min at the 20% KC representing 37.5% and 14.4% increase over the control. The control mix obtained a workability value of 102mm, and decreased steadily to 68mm at the 20% KC and 40% SSP concrete mix, representing 50% reduction. Maximum compressive and split tensile strength values of 25.97N/mm2 and 4.14N/mm2 were obtained at the 15% KC and 30% SSP concrete, representing 9% and 5% increase over the control concrete respectively in 90days curing. Furthermore, concrete with 15% KC and 30% SSP recorded 61.5% and 22.1% decrease in water absorption and sulfate attack, over the control concrete respectively in 90days curing. It is concluded that the add ition of KC and SSP positively influenced the physical, strength and durability of concrete, and therefore recommend 15% KC and 30% SSP replacements of cement and fine aggregate respectively for concrete production.