Effect of Local Additives on Engineering Properties of OkeleleIlorin (Nigeria) Clay

Abstract

Most additives usually used in clay are imported to the country, Nigeria. Meanwhile there are several agricultural bi-products and other materials which are regarded as wastes in the country that are underutilized which could be used as additives to alter/improve clay properties. Previous works had revealed that some properties of many Nigerian clays need to be improved on to be found suitable for many engineering applications. This paper aims at investigating the effects of the locally available additives on properties of a selected clay sample. The clay sample obtained from a popular Okelele clay deposit at Ilorin, Kwara state, Nigeria was purified through the process of picking/sorting, crushing/grinding and sizing (sieving). The sieved clay sample was thoroughly mixed with five (5) different locally available additives (Palm kernel nutshell, Anthill, rice-husk ash, Groug) and Portland cement separately at the ratio of 1:14 by weight. The mixtures were moulded into rectangular shaped brick of 50mm x 50mm x 50mm diameter. The moulded bricks were fired at the temperature of 1200 0 C, which were subjected to series of laboratory tests using British Standard (BS) American Standard of Testing of Materials (ASTM). However, the result revealed that the additive has significant effect on the properties of the clay. The result of this study also revealed that the additives possess the ability to enhance the strengths of the clay, its mouldness and prevent its cracking and rupture during firing. As such, these additives are suitable as replacement for Portland cement (as additive) in clay material for engineering applications. The effects of the additives on the strength of the clay at yield and at failure are geometrically in order arrangement of groug, anthill, palm kernel nutshell and rice husk better than Portland cement as additive to clay.