Abstract

This paper presents an assessment of mechanical strength of slag-concrete with partially replacing cement with 0, 10, 20, and 30% metakaolin (MK) for a targeted strength of 35MPa at 28-day curing. The compressive, split tensile and flexural strength of the concrete were examined in line with appropriate specifications. The durability was evaluated by exposing the concrete specimens to sodium sulphate and sodium chloride for 7, 28, 56, and 90 days and measure the loss in compressive strength. The mix design with water-cement ratio of 0.5 is 1:1.21:2.89 (cement: sand: coarse slag). The targeted compressive strength was met by all the percentages of metakaolin though the strength decreases with increase in percentage of metakaolin added. The MK10 has the highest value for compressive, split tensile and flexural strength above the control. The slag-concrete showed more resistance to sulphate attack and exposure to chloride than the control. The maximum loss was obtained at MK30 (10.77%) for 28-days and the minimum loss was 5.87% at 90-days. Loss in compressive strength for concrete cured in sodium chloride showed less deterioration compared to sulphate cured concrete. Based on the obtained results 10% of metakaolin and 100% steel sag will produce eco-friendly concrete pavement and preserve the natural resources.