Portland limestone cement for reduced shrinkage and enhanced durability of concrete

Abstract

In this work, different cementitious systems were used to investigate the shrinkage of concrete under plastic and drying conditions. Emphasis was placed on Portland limestone cement (type IL) with replacement amounts of 10% of Portland cement. Comparisons were made with a cement type with low Blaine fineness (i.e. coarse ground cement). The results indicated that type IL cement has good shrinkage results without adversely affecting other engineering properties of concrete such as strength, resistivity, degree of hydration and setting time. This is probably due to improved particle packing, access to more nucleation sites for the hydration products and the formation of calcium carbo-aluminate hydrates. Scanning electron micrographs of coarse ground cement paste also indicate a retarded degree of hydration compared to type I/II Portland cement paste.