Effect of Lignite By-products in Plastic Shrinkage Property of Concrete

P. Priyadharshini, G. Mohan Ganesh, A.S. Santhi Abstract— The reduction in moisture of fresh concrete results in plastic shrinkage due to tensile stress induced by capillary pressure. When the tensile strength signs beyond the capacity of concrete, it cracks and this effect in early stage of concrete is termed as plastic shrinkage of concrete. This becomes a serious issue for large surface area members like slabs. The shrinkage of concrete under restrained conditions during early stages can be characterized by experiments. The present study was aimed at studying the plastic shrinkage property of fly ash aggregate concrete incorporated with bottom ash as fine aggregate. Concrete mix with combination of fly ash aggregate with 20% and 40% replacement of fine aggregate with bottom ash has been studied. The 20% replacement of bottom ash gives good results and higher percentages like 40% of bottom ash together with fly ash aggregate makes better combination to avoid plastic shrinkage of concrete. Higher percentage incorporation of bottom ash shows mild surface cracks in concrete due to plastic shrinkage.