EXPERIMENTAL INVESTIGATION ON CONCRETE USING PARTIAL REPLACEMENT OF FINE AGGREGATE WITH QUARRY DUST

Urbanization has led to an increase in demand for concrete and river sand as well as to increased processing of river sand.Excessive mining of river sand has caused ecological imbalances, riverbank instability and depletion of groundwater resources.Quarry dust (QD) is a by-product of mining and processing rock, creating disposal issues, while having properties similar to fine aggregates.In this study, an experimental investigation is performed to determine the mechanical properties of concrete that include QD as a replacement for natural sand.Concrete mixes were developed using five different percentages (0%, 10%, 20%, 30%, and 40%) of QD replacement at a constant water-cement ratio of 0.45 and tested for compressive, splitting tensile and flexural strength at 7 and28 days of curing.The results showed concrete strength improved until 30% QD replacement due to additives contributing to improved packing density and reduced porosity, but excess replacement of QD resulted in reduced strength due to increased water requirement for breaking through to aggregate particles and weak bonding between the aggregate and cement paste; this remains consistent with theoretical particle packing and interfacial transition zone (ITZ) analysis.In conclusion, QD has the potential to be a sustainable alternative to sand for use in structural concrete.