STUDY ON RECYCLED AGGREGATE CONCRETE WITH FLY ASH

Use of recycled coarse aggregate concrete can be useful for environmental protection and economical terms. Recycled aggregates are the materials for the future. Fly ash is a group of materials that can vary significantly in composition. It is residue left from burning coal, which is collected in an electrostatic Precipitators or in a bag house. it mixes with flue gases that result hen powdered coal is used to produce electric power. Globally, the concrete industry consumes large quantities of natural resources, which are becoming insufficient to meet the increasing demands. At the same time, large number of old buildings and other structures have reached the end of their service life and are being demolished, resulting in generation of demolished concrete. Recycling concrete by using it as replacement to new aggregate in concrete could reduce concrete waste and conserve natural sources of aggregate. The aim of present investigation is mix design of recycled aggregate concrete. The ACI (211.1-91) mix design procedure is adopted with targeted design strength of concrete for 28days is 26 Mpa. Six concrete proportions were used with 0, 25, 50, 75 and 100% replacement of natural aggregate by recycled aggregate and addition of fly ash with 15%. Total 30 number of cube specimens were caste for cube compression and 30 number of cylinders specimens were caste for split tensile strength of concrete.