PHYSICAL PROPERTIES OF LIGHT WEIGHT AGGREGATE CONCRETE

Abstract

The use of lightweight aggregate concrete for load bearing purposes had started in the developed countries after the second world war. Considerable study has been done on the properties of lightweight aggregate concrete in these countries. Both naturally occurring and manufactured lightweight aggregates are widely used in the developed countries. Even lightweight fine aggregates are manufactured. Structural lightweight concrete has been found to be economical for prefabricated construction and for highrise buildings. There has been very little research and application of lightweight aggregates in India. Construction of high-rise buildings and prefabrication are gaining popularity. Hence there is an urgent need to study and apply lightweight aggregate concrete here also. Hence the reason to take up this dissertation which is an experimental investigation on the physical properties of lightweight aggregate concrete using bloated clay aggregates. Properties like compressive strength, split tensile strength, flexural strength, modulus of elasticity, drying shrinkage, moisture movement and coefficient of thermal expansion have been examined. A total of five mixes were cast to investigate the properties of lightweight aggregate concrete. Three mixes were cast using lightweight aggregate, one using lightweight aggregate and superplaticizer and the last one using normal weight aggregate; other contents were fine sand and cement. Comparison between the properties of lightweight aggregate concrete and normal weight concrete has been made. The weight reduction achieved by using lightweight aggregate was upto 30%. So it has been possible to produce structural grade concrete of lightweight. Detailed results of the various properties are given in the main text. This study has been useful and enlightening for the author who hopes that it will be useful to others and will make some contribution to the application of lightweight aggregate concrete in this country. iii