Incorporation of untreated rice husk ash and water treatment sludge in masonry unit production

Abstract

Conventional masonry units are made of clay with high temperature kiln firing or Ordinary Portland Cement (OPC) concrete mix. However, these conventional masonry unit production methods require intensive energy inputs and abundant raw materials. This predicament has led the researchers to look for sustainable methods of producing masonry units. Subsequently a research has been carried out to develop cement masonry unit incorporating Untreated Rice Husk Ash (URHA) and Water Treatment Sludge (WTS). Especially an attempted has been made to partially replace OPC and Quarry Dust (QD) by URHA and WTS, respectively. Totally nine different mix proportions of OPC, URHA, WTS and QD were used. The mechanical and durability characteristics of those masonry unit specimens were investigated to verify the suitability of the proportions. No significant changes in the mechanical and durability properties were noted in replacing OPC by URHA up to 15%. However, replacement of QD by WTS considerably deteriorated the mechanical and durability properties. Therefore, it was proposed to incorporate maximum of 15% URHA and WTS for the production of masonry unit as it complies with the strength requirements of EN 1996-1-1:2005 and EN 1998–1:2005 for masonry structures.