Study of Combined Effect of Metakaolin and Steel Fiber on Mechanical Properties of Concrete

This study reports the results of an experimental study on mechanical properties of plain and metakaolin (MK) concretes with and without steel fiber. To develop the metakaolin reinforced concrete, Ordinary Portland cement was partially replaced with MK 3%, 6%, 9%, 12%, 15%, 18% by weight of the total binder content. Steel fiber with length 50 mm and diameter 0.70 mm was utilized to produce fiber reinforced concrete. Concrete was designed with water to cement (w/b) of 0.464. First water absorption test was investigated then compressive strength and split tensile strength were calculated by replacing metakaolin with cement at the end of 7 days, 28 days, and 56 days of curing period. Again the effectiveness of MK and steel fiber reinforcement with different percentage of steel fiber i.e. 0.25%, 0.5%, 1% of the weight of cement was taken. Then the compressive, split tensile strength of the concretes was investigated. All tests were conducted at the end of 7 days, 28 days, and 56 days of curing period. It was found that for replacement of metakaolin the compressive strength and split tensile strength were increased up to 9% replacement of metakaolin and decreased after that. It gave the maximum value at 9% of replacement of metakaolin. Addition of steel fiber to the different percentage of metakaolin also increased the strength then that of metakaolin reinforced concrete. The results revealed that incorporation of MK and utilization of different types of steel fibers significantly affected the mechanical properties of the concrete.