The effects of different cement dosages, slumps and pumice aggregate ratios on the compressive strength and densities of concrete

Compressive strengths 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 compressive strength of concrete, (1) 25%, 50%, 75% and 100% pumice ratios were used instead of normal aggregate by volume, (2) 200, 250, 350, 400 and 500 kg/m³ cement dosages were used and (3) 3±1, 5±1 and 7±1 cm slumps were also used in this study.The analysis of the test results leads to the conclusion that PA decreased the density of concretes up to 41.5% and reductions occurred due to the increase of the PA ratio in the mixes. With the increase of cement dosage in the mixes, both density and compressive strength of concretes increased up to 3.2% and 265%, respectively, when compared to the control sample that contain 200 kg/m³ cement dosage. The effect of the slump on the density and compressive strength was varied. Elasticity moduli were decreased with an increase of PA ratio and increased with an increase of cement dosage. Water absorption improved with an increase of cement content.