Experimental Study on Strength Characteristics of Lightweight Concrete with Fly Ash Aggregate

Abstract

Fly ash is left as a by-product after burning of coal in thermal power plant and need suitable dumping system so that it does not become menacing and harmful to human life and
environment. Most of the research works done previously were done by using orthodox fine and coarse aggregates in concrete. In this research work, the coarse aggregates is replaced entirely by fly ash aggregates in concrete mix.
Mix design was done for M20 grade concrete conforming to the IS 10262-1982. The design of fly ash aggregate's concrete mix based on the extensive experimental investigations at
the Building Research Station UK was followed to design the mix proportions for fly ash aggregate concrete. PortlandSlag Cement grade was selected and fly ash aggregates were arranged by mixing fly ash with Bentonite Clay. The fly ash aggregates were sieved, and 10mm to 20mm aggregates were taken as the fly ash coarse aggregate. The properties of fly ash angular coarse aggregates were determined. The aggregate crushing strength value and aggregate impact strength value of fly ash coarse aggregates were also
determined. The Bentonite Clay and fly ash proportions of 10:90, 15:85 and 20:80 were adopted with a appropriate water flyash ratio 0.27 to prepare the Briquettes, which when crushed gives flyash aggregates. The concrete cubes, cylinders, and prisms were cast with the fly ash aggregates obtained from the above three cement fly ash proportions. Then the cube compressive strength test, split tensile strength test, and flexural strength test were conducted at different ages and compared with conventional control concrete.From the studies conducted, it was detected that fly ash aggregates play a vital role in improving the strength and sustainability aspects of concrete.