AGRO-WASTES AS SUBSTITUENT OF FINE AGGREGATES IN CONCRETE

Abstract

- The mining of construction grade sand, which is used as fine aggregates in concrete, is the most disastrous activity that threatens the very existence of the river ecosystems. The aim of this research is to partially replace fine aggregates in concrete by various agricultural wastes. In this study, corncob ash, groundnut shell and sugarcane bagasse ash are used as the replacing fillers. These agro wastes are utilized as 0%, 5%, 10%, 15% and 20% as fine aggregates in concrete. Different properties of fresh concrete are investigated for these agro-waste fillers and various tests such as slump, shrinkage and density are carried out. In the hardened state of agro – waste concrete, various tests such as compressive strength, flexural strength, ultrasonic pulse velocity tests were determined at the age of 7 days, 28 days, 56 days and 90 days. With increasing percentage of replacement of rice husk ash, groundnut shell and sugarcane bagasse ash with fine aggregate, the slump value decreased while slump value increased with increase in corncob ash as a replacement material. Till optimal replacement of 20% of fine aggregate with sugarcane bagasse, the minimum compressive strength was achieved while maximum compressive strength was achieved for 5% replacement of groundnut shell with fine aggregate. Corncob ash as a replacement of 10% with fine aggregate showed maximum strength and ultrasonic pulse velocity showed decreased strength with increase in corncob content in concrete. Thus the utilization of agro – wastes proves to be very sustainable and eco – friendly in construction.