The effects of limestone aggregate on concrete properties

The use of limestone in the construction industry has been increasing due to benefits as aggregate. Some of these benefits include good strength, low possibility of alkali-silica reaction and the decrease in drying shrinkage in concrete. This research discusses the consumption and general characteristics of the limestone aggregate in USA and Japan. Then experiments were conducted on mixtures of different proportions of fine limestone and sand at different water/cement (W/C) ratios. The W/C ratios selected were 45%, 55% and 65% with fine limestone replacements of 0%, 30%, 50% and 100%. The water absorption and porosity of fine limestone and sand were measured to find a relation with the water entrapped in the pores of the surface of the rock and the drying shrinkage. The results show the increases in the compressive and flexural strengths and modulus of elasticity when the fine limestone proportion increases in the mixture. The most outstanding results are found on the drying shrinkage, which decreases considerably with the increase in fine limestone proportions. (C) 2010 Elsevier Ltd. All rights reserved.