AN EXPERIMENTAL INVESTIGATION ON STRENGTH PROPERTIES OF CONCRETE BY PARTIAL REPLACEMENT OF NATURAL COARSE AGGREGATE WITH FLY ASH AGGREGATE

Abstract

The present boom in day by day growing buildings is leading to excessive use of concrete, thereby resulting in depletion of natural resources such as sand and natural aggregates. On the other hand, fly ash which is a byproduct from thermal plants creating environmental problems. To overcome such kind of situation it may be better approach to retrieve aggregates from fly ash and use it again in the preparation of concrete in the form of Cold Bonded Fly ash Aggregate. The present work is directed towards the evaluation of concrete using partial replacement of Natural Coarse Aggregates of size 20 mm (NCA) with 25%, 50%, 75% and 100% cold bonded fly ash aggregates (CBFA). The experimental results of strength properties are evaluated and compared with NCA concrete. Compressive Strength, Split Tensile Strength, Modulus of Elasticity and Flexural Strength of M25 grade concrete were obtained using the standard concrete specimens. Based on the experimental test results, it can be observed that with increase in percentage of Cold Bonded Fly ash Aggregates in concrete, the Compressive Strength increases with 100% replacement of Natural Coarse Aggregates(20 mm) with Cold Bonded Fly ash Aggregate. Test results indicates that the use of Cold Bonded Fly ash Aggregates as partial replacement of coarse aggregates improved strength properties compared to controlled concrete.