Sand in concrete significance

Sand or fine aggregates form an important component of concrete. It helps to increase the bulk or volume of concrete, which in turn reduces the cost. It helps to adjust the strength of concrete by varying its ratio with cement. It also increases resistance to crushing. Aggregates reduce shrinkage and affect economy. Previously, aggregates were considered as inert materials but now it is recognized that some aggregates are chemically active and also that some aggregates exhibit chemical bonds at the interface of aggregate and paste. Sand combined with coarse aggregate constitutes 70-80% of the volume of concrete. Fine aggregate also helps to fill the voids created by coarse aggregates.