Mechanical and permeability properties of hybrid fibre reinforced porous concrete

Abstract

Experimental investigation was carried out to determine the enhancement of compressive strength, flexural strength and abrasion resistance along with water permeability of porous concrete introduced with hybrid fibres (consists of equal proportion of steel, polypropylene and glass) and with two different sizes of coarse aggregate. The varying parameters in the preparation of porous concrete mix were coarse aggregate of two sizes, i.e., 6 mm and 12 mm and five different percentages of hybrid fibres (0.25 - 0.65 with an increment of 0.1). Compressive strength and flexural strength were measured at the end of two curing periods (7 and 28 days) whereas water permeability and abrasion test values were measured at the end of 28 days of curing. From the experimental findings, it is observed that compressive strength and flexural strength values increase with decrease in the size of the aggregate for control as well as fibre reinforced porous concrete. However, with respect to the measured values of permeability, it is found that with increase in size of coarse aggregates, permeability values also increases. For 28 days samples it is observed that 0.35% addition of hybrid fibres to porous concrete found to be optimum and it improved the compressive strength values by 20.24% and 19.06% for coarse aggregate sizes of 6mm and 12mm, respectively as compared to porous control concrete (without addition of hybrid fibres). Whereas, maximum flexural strength was obtained at 0.45% of addition of hybrid fibres and 31.6% (6mm coarse aggregate) increment and 24.26% (12mm coarse aggregate) increment were noticed as compared to porous control concrete. The best values for permeability were found at 0.35% of hybrid fibres and 12 mm coarse aggregate combination, whereas for abrasion resistance it was at 0.35% of hybrid fibres and 6mm coarse aggregate combination. 2019 Associated Cement Companies Ltd.. All rights reserved.