Compressive Strength of Cellular Lightweight Concrete

Abstract

This paper presents a study of compressive strength of cellular lightweight concrete adding superplasticizer for standard cylinder and cube specimens at dry unit weights 1600 - 1800 kg/m³ using water to cement ratios of 0.30, 0.35, 0.45 and 0.55, sand to cement ratios of 2:1 and 3:1 and adding superplasticizer dose of 0.0, 0.5 and 1.0 percent of cement weight in air-curing condition at the ages of 7, 14, 28 and 56 days, 24 designed mixes in total. From the study, it was found as the following. (1) The compressive strength of standard cube samples at the dry unit weight of 1600 kg/m³ found in between 58-185 ksc and the maximum compressive strength shown at the mix with sand to cement ratio of 2:1, water to cement ratio of 0.35 and using superplasticizer dose of 0.5 percent of cement weight. (2) At the designed unit weight of 1800 kg/m³, the compressive strength found in between 88-223 ksc and the maximum compressive strength shown at the mix with sand to cement ratio of 2:1, water to cement ratio of 0.30 and using superplasticizer dose of 1.0 percent of cement weight. (3) The development of compressive strength of both cylinder and cube samples seems to be faster than the conventional concrete. The compressive strength at the age of 7 and 14 days are approximately 90 percent of the strength at 28 days and at the age of 56 days the compressive strength is higher than the strength at 28 day-age approximately 20 percent. (4) the increase of superplasticizer dose from 0.5 to 1.0 percent at the water to cement ratio 0.3 increased the compressive strength between 10-70 percent however at the water to cement ratio 0.35, the compressive strength decreased approximately 30 percent. Finally, (5) the maximum compressive strength of cellular lightweight concrete adding superplasticizer is higher than the normal cellular lightweight concrete approximately 90 percent.