REPLACEMENT OF FINE AGGREGATE IN SELF CURING CONCRETE BY QUARRY DUST AND GRANITE FINESM. LOKESHWARI, T. RAGHAVENDRA, S. SUNIL, H. P. VAGEESH AND L. DURGA PRASHANTH
Concrete is one of the most used construction material due to its good compressive strength and durability. As construction sector in India is growing at a higher rate, dependency on concrete is at high; in turn the requirement of conventional materials is increasing. With increase in demand, the availability of conventional construction materials is depleting, over usage of which causes environmental imbalances. Over extraction of natural sand from river bed has affected the characteristics of river bed and also damages the road condition during its transportation from river bed to the construction site, which also increases the cost of construction. On the other hand, Quarry dust and granite fines are the byproducts of quarry and granite industry, which also contributes to disposal problem. These two can be coupled together to have a sustainable waste management system, in which quarry dust and granite fines can be used to replace natural sand, which reduces the dependency on natural river sand. With rising scarcity of water globally, curing of concrete will be difficult in future days, which contributes to reduction in characteristic properties of concrete. Construction industry is one of the maximum water consuming industries in the world. Hence optimal water usage and wastage of water during curing should be nullified. Present study is an attempt to incorporate quarry dust and granite fines as a replacement of fine aggregate with self-curing agent in concrete. Self curing agent PEG-400 eliminates the use of external water for curing purpose. Three concrete mix combinations with PEG-400 as self curing agent were considered. Conventional concrete of grade M40 was considered for comparison. 100% replacement of fine aggregate in which 75% quarry dust and 25% granite fines \ combination achieved 40MPa strength at 28day age. Hence the study concludes over extraction of natural sand from river beds can be reduced by replacing it with quarry dust and granite fines with elimination of curing water by the use of self curing agent PEG 400.