Production of lightweight aggregate from fly ash and clay

Abstract

The main objective of this study is to determine whether fly ash and clay can be used to produce lightweight aggregate, study the durability of lightweight aggregate from fly ash and clay and to make comparison between lightweight aggregate and normal aggregate. In this study, lightweight aggregate produced is spherical in shape and size of 10 mm. Forty samples are produced using different mixtures which is 40%, 50%, 60%, 70% and 80% of fly ash. Each mixture was heated in a furnace using different temperatures which is 850°C, 900°C, 950°C, 1000°C, 1050°C, 1100°C, 1150°C and 1200°C. The first test done on to the lightweight aggregate is specific gravity which is to choose a optimum lightweight aggregate to produced concrete cubes 50 mm x 50 mm x 50 mm. Besides that, 50 mm x 50 mm x 50 mm cube using normal aggregates are also produced to compare the compressive strength, water absorption and surface hardness. All samples were introduced into a different curing period of 7, 14 and 21 days. Each sample weighed after curing period to get water absorption and then followed by compressive strength and surface hardness test. This study was found that for 50% fly ash mixture and heated at a temperature of 1200°C is the most optimum lightweight aggregate. 50 mm x 50 mm x 50 mm cube were produced by using the 1:2:4 ratio of 1 cement 2 sand and 4 aggregate lightweight. This ratio is based on volume.