Strength appraisal of light weight green concrete made with cold bonded fly ash coarse aggregate

Abstract

This study focusses on the development of fly ash concrete made with water/cement ratio of 0.5.To develop fly ash concrete in this study, 40% of cement is replaced with fly ash, manufactured sand is used as fine aggregate, light weight fly ash aggregate as used coarse aggregate and for mixing concrete instead of tap water 12% lime concentrated water is used. The fly ash concrete compressive strength obtained is equivalent to that of M30 grade concrete made with OPC. Two sets of samples are prepared one set with 40% fly ash concrete made with river sand and natural crushed stone coarse aggregates and another set of sample with 40% fly ash concrete made with manufactured sand and artificial light weight fly ash coarse aggregates. Experimental studies revealed that use of manufactured sand enhanced compressive, tensile and flexural strengths by 6-8% only. Even permeation properties such as water absorbtion and porosity of fly ash concrete made with manufactured sand and artificial light weight fly ash coarse aggregates is almost similar to that of fly ash concrete made with made with river sand and natural crushed stone coarse aggregates. The results concludeIV. that fly ash coarse aggregates can be used for structural applications instead of natural coarse aggregates but not feasible for use in pavement as per IS 2386. Manufactured sand can be used as 100% replacement to river sand in fly ash based concretes with improved properties of concrete.