Feasibility of Quarry Dust to Replace River Sand as Fine Aggregate of Concrete

High cost and scarcity of river sand is one of the main problem faced by construction industry today. Use of substitutions like offshore sand in particular to replace river sand is on the rise. Quarry dust is another alternative for river sand. However, full replacement of river sand with quarry dust is viewed with scepticism. Possible loss of workability and increase shrinkage is sighted against use of quarry dust as fine aggregate in concrete. In this study the properties of concrete with quarry dust as fine aggregate is studied to find out its suitability to replace river sand in structural concrete. Furthermore, use of fly ash with 30% of cement replaced by fly ash is explored as means of increasing the performance of the quarry dust mixes. Quarry dust concrete at the tested water cement ratio is found to have higher compressive strength compared to sand mixes. However, use of quarry has increased the required amount of water in the mix to achieve the design slump. It is also found that the quarry dust mixes has higher shrinkage strain compared to sand mixes. Use of fly ash in quarry dust mixes is found helpful in reducing the shrinkage of quarry dust concrete. Results indicate that quarry dust can be effectively used to replace sand and fly ash can improve the performance of concrete with quarry dust as fine aggregate.