Mechanical Properties, Microstructure, Thermal Conductivity and Drying Shrinkage of Cellular Lightweight Concrete Containing Bagasse Ash
Wunchock Kroehong ^* and Apivich Poolsong
Department of Civil Engineering, Faculty of Engineering and Architecture, Uthenthawai Campus, Rajamangala University of Technology Tawan-ok.

Abstract

This paper aimed to study the mechanical properties, microstructure, thermal conductivity and drying shrinkage of cellular lightweight concrete containing bagasse ash. Portland cement type I was replaced by bagasse ash at 10% 20% and 30% by weight of binder. A water to binder ratio of 0.60 was used. The setting time, water absorption, unit weight, compressive strength, thermogravimetric analysis, porosity, scanning electron microscopy, drying shrinkage and thermal conductivity of cellular lightweight concrete were investigated. The results showed that the cellular lightweight concrete containing 20% of bagasse ash had the highest compressive strength. The compressive strength of cellular lightweight concretes containing bagasse ash 10-30% by weight of binder at 28 days were higher than that of lightweight concrete block specified by the Thai Industrial Standard 2601-2013. The increasing replacements of bagasse ash reduce unit weight of cellular lightweight concretes and water absorption was higher than that of control cellular lightweight concretes. The reduction of Ca(OH)2 content produced increased C-S-H, C2A-S-H8, and C4A-H13, which resulted in an increase the compressive strength. The porosity and large capillary pore of cellular lightweight concretes increased with the increased of bagasse ash content. The use of bagasse ash reduces drying shrinkage and thermal conductivity of cellular lightweight concretes.