The effect of stearates on mechanical and durability of concrete

water transfer to concrete can be considered as the main threat to the durability of concrete structures. calcium stearate and zink stearate as the most available materials deriving from fatty acids provide a water repellent layer among capillary pores and consequently increase the surface tension between water and capillary pores. as a result water transfer in non-hydrostatic condition in concrete will be restricted. Accordingly effect of calcium and zink stearate as damp-proofing admixtures on mechanical and durability aspects of ordinary concretes have been studied. To this end, these materials were added to concretes and cement pastes and properties of fresh paste and concrete in addition to mechanical and durability aspects of the hardened concrete have been investigated. Results show that mentioned materials do not change normal consistency, setting time of the paste and percentage of entrapped air. In hardened concrete, chloride difusivity and electrical resistivity were not affected by the use of damp-proof admixtures. in contrast, damp-proof admixtures remarkably decreased the rate and percentage of water absorption.