The effects of different cement dosages, slumps, and pumice aggregate ratios on the thermal conductivity and density of concrete

Thermal conductivity coefficients of concretes made up of mixtures of pumice aggregate (PA) and normal aggregate were measured. To determine the effect of PA ratio, different cement dosage, and slumps on the thermal conductivity of concrete, 25%, 50%, 75%, and 100% pumice ratios were used in place of normal aggregate by volume, 200-, 250-, 350-, 400-, and 500-kg/m(3) cement dosages, and 3 +/- 1-, 5 +/- 1-, and 7 +/- 1-cm slumps were used in this study. The analysis of the test results leads to the conclusion that PA decreased the density and thermal conductivity of concretes up to 40% and 46%, respectively. Increasing the cement dosage in the mixtures caused both density and thermal conductivity of the concrete to increase. The effect of slump on the density and thermal conductivity fluctuated. (C) 2004 Elsevier Ltd. All rights reserved.