Effects of using pulverized termite mound (PTM) as partial replacement of fine aggregate on the durability properties and microstructure of concrete

Abstract

Unrestrained use of non-renewable natural resources employed in the production of structural concrete is raising sustainability concerns the over the world. The use of suitable waste materials and non-conventional materials are being encouraged to address some of these concerns. Understanding the relationship between durability properties and microstructure of such material will enhance innovativeness in its application and will mitigate some of the environmental issues associated with concrete production. This paper presents the results of investigation conducted to evaluate the durability and study the microstructure of concrete with fine aggregate partly replaced with pulverized termite mound (PTM). The durability assessment was through sorptivity and coefficient of water absorption tests. The scanning electron microscopy (SEM) was used to study the microstructure of the concrete samples at 28 days of curing. The results show (i) that durability of PTM concrete specimens measured through coefficient of absorption, improves progressively with PTM content, (ii) that durability of PTM specimens assessed through sorptivity improves up to 70% PTM content and (iii) the microstructure of the shows smaller pores in relation to the control up following the trend of sorptivity results. Thus, for practical purpose, the use of pulverized termite mound as replacement of fine aggregate in the production of structural concrete should be limited to 70%.