In recent years, there is a growing interest in the use of crushed sand obtained from limestone quarries in some countries where river sand is not widely available. Besides, the demand for aggregates to produce concrete is still high while natural resources decrease. The fines content in limestone is usually high (particles with a size of 0.15-0.7 mm) which can affect concrete properties in an either positive or negative way. Studies on aggregate containing fine materials are vitally important. However, little work has been done so far on the effect of fines in crushed sand on the properties of concrete.
This paper examines the influence of limestone filler in sand on concrete properties, which include workability of fresh concrete (slump test method), compressive and tensile strength, unit weight, and ultrasonic pulse velocity. Six concrete mixtures containing different ratios of limestone filler (0, 10, 20, 30, 40, 50) % sand replacement were used while maintaining a constant water/cement ratio. The results proved that limestone filler replacing sand up to 20% without adversely affecting concrete strength.