Study on the properties of cement concrete using manufactured sand

Abstract

Fine and coarse aggregate constitute about 75 % of total volume of concrete The most commonly used fine aggregate is natural river sand. Nowadays the demand for river sand is increasing due to its lesser availability. Sand quarrying has resulted in scarcity and poses environmental problems such as loosing water retaining sand strata, deepening of the river courses and causing bank slides, loss ofvegetation on thebank of rivers, disturbs the aquatic life as well as affects agriculture.So there is an immediate need to control the sand quarrying and provide a sustainable replacementof river sand. Properties of aggregate affect the durability and performance of concrete, so fine aggregate is an essential component of concrete. Manufactured sand inconcrete not only acts as replacement for concrete but also leads to the development of eco-friendly construction as well as reduction in cost of construction. Manufactured sand offers viable alternative to natural sand and it is purposely made fine aggregate produced by crushing and screening or further processing. This experimental investigation was performed to evaluate the grading and strength properties of M20 gradeof concrete mixes, in which natural sand was replaced with manufactured sand. The properties of river sand and manufactured sand such as specific gravity, sieve analysis, fineness modulus and water absorption were determined through test as per IS 383-1970 and compared. Specimens were cast to compare the strength properties of concrete with river sand and manufactured sand as fine aggregate. Specimens for compressive strength, tensile strength and flexural strength were casted and tested up to failure to evaluate the strength properties of concrete at the age of 7 and 28 days. Test results showed that the grading of manufactured sand fall in the Zone II gradation as per the specifications provided in IS 383-1970. Test results showed that there is only a marginal decreasein compressive strength, splitting tensile strength and flexural strength for M20 concrete mixes on ages of 7 and 28 days in comparison to the river sandconcrete.but the strength is more than the target mean strength for which the mix wasdesigned. These studies reveal that the test results are in conformation with the river sand concrete and hence manufactured sand can be used as fine aggregate in concrete.