The implication of using filtered sand in mortar and concrete

Depletion of natural resources and restriction due to environmental considerations leads to scarcity of good quality river sand. Also sand procurement has become a major concern especially in large cities like Bangalore, India. Nearby sources have been exhausted; therefore, it is very essential to optimize the consumption of natural river sand as well as to develop alternative sources. In this paper, an attempt is made to investigate the potential use of filtered sand and its implication as a substitute for river sand in mortar and concrete. Filtered sand is facing the concerns of environmentalist and engineers due to its alleged poor engineering properties, higher clay and silt content, improper or crude methods adopted for filtering the sand etc. If these issues are addressed, then filtered sand may be used as an alternative to river sand, provided the source of filtered sand is from a barren land and not fertile earth. The present investigation deals with the use of filtered sand as an alternative to natural fine aggregates in concrete and cement-mortar. Two types of filtered sand samples (FS-1 and FS-2) available near Bangalore were collected and physical properties of these samples were studied. Natural sand was replaced partially/fully with filtered sand in different percentages of replacement. Specimens of cement mortar in the ratio 1:6 was cast, cured, and tested for determining the density, compressive strength, and modulus of elasticity, while concrete cube specimens with mix proportion 1:1.5:3 were cast to determine its compressive strength, split tensile strength and flexural strength as per the Indian standard code of practice. The results on comparison with those of conventional concrete and cement-mortar specimen indicated that with the usage of filtered sand, the performance of both the concrete and mortar improved.