Influence of organic addition on strength and durability of lime mortar prepared with clay aggregate

Abstract

Lime mortar is used for restoration of heritage building and for recreating those using traditional methods. This paper deals with the study of mechanical and physico-chemical properties of organic treated lime mortar prepared with clay aggregate. Lime to clay ratio was taken as 1:1, 1:2, and 1:3, with kaolinite and bentonite as two different clay aggregates. Zante currant (Vitis vinifera) was added as the organic admixture with concentrations of 0%, 2%, 4% and 6% for casting of the specimen. Water absorption, bulk density and porosity tests were performed to find the physical properties. Compressive strength test was done to measure the mechanical resistance. Chemical analysis such as XRD and FTIR were carried out to understand the mineralogical transformations in the specimen. Capillary rise test was conducted to interpret the durability properties of lime mortar. It was observed that on the 90th day lime mortar prepared with kaolinite and 4% organic showed higher strength. The physico-chemical and mechanical results show improvement in the hydration and carbonation phases of the lime mortar due to increased calcite formation on organic addition. The organic addition also reduces intake of water, which reduces the pore size distribution, increasing the durability and strength of lime mortar.