Microstructure Study for Effect of Local Admixture in Concrete Durability

Abstract

Concrete permeability plays the main role in concrete durability because of the entry of harmful substances such as chlorides, sulfates, carbon dioxide (CO2), oxygen (O2). Concrete permeability is affected by factors such as size and proportion of aggregate, type, and quantity of cement, water-cement ratio, type and dose of admixture used, which help concrete have a high life. This research aims to investigate the effect of local admixture prepared to improve concrete properties, especially reducing the permeability of concrete using its proven effectiveness in salt attack. This research studies the effect of this admixture on concrete microstructure for several concrete specimens. This chemical admixture, which contains calcium oxide (CaO), chloride (Cl), and others, helps obtain a good performance of concrete. Adding calcium oxide (CaO) plays an important role in improving the physicochemical properties of concrete. An increase in the compressive strength was observed for all specimens. Incorporating additives without CaO to concrete has been shown to decrease its strength. In the present study, concrete showed higher compressive strength than other concrete, which has not contain this admixture which may be explained by the larger quantity of CaO in the cement.