Production Lightweight Concrete and its comparison with normal density concrete

Abstract

For reducing the weight of concrete, while maintaining its strength, Lightweight concrete is increasingly finding its use in construction industry worldwide. However, its use in Pakistan is limited due to lesser production units. The high initial cost of lightweight concrete is due to the various processes in the production of aggregates, but if overall cost of the project is calculated its result is lower cost of lightweight concrete as compared to normal density concrete. This research work was designed to develop Lightweight concrete, using shale as a lightweight aggregate and compare its strength, durability and economy with the normal weight concrete. The research was conducted in two phases. In first stage, four mixes were prepared. The concrete specimens were tested at 1, 3,7,28 and 56 days for strength and durability. In the second phase, various tests were conducted on the concrete prepared with design mixes finalized in phase one and a comparison of these tests were drawn. The comparison of test results revealed, that concrete prepared with lightweight aggregate has its strength although less than normal weight concrete but can be used as structural lightweight concrete. Comparative cost analysis indicated that concrete prepared with lightweight aggregate although has high initial cost but if overall project cost is calculated its cost is comparable with the normal weight concrete