Durability performance of Portland limestone cement mortar containing butyl and zinc stearate admixtures

Abstract

The benefits of partial replacement of Portland cement by limestone are well established. This study investigates the impact of zinc and butyl stearates, as water-repellent additives, on the compressive strength, flexural strength, water penetration, absorption, chloride migration, density, drying shrinkage, and thermal expansion of Portland Limestone Cement mortars. The contents of stearates in this work are 1%, 2%, 3%, 4%, 5% by mass of binder content. Spectroscopic analyses using scanning electron microscopy and X-ray diffraction revealed discrete changes in the derived cement composite microstructure. The results of hardened mortar evaluation showed a negligible effect of zinc stearate on durability performance. In contrast to that, incorporation of butyl stearate in the mixtures enhanced resistivity to water permeability and chloride migration.