Effect of MK and SF on the concrete mechanical properties

Abstract

This paper inspects the impact of MK and SF on the mechanical properties of concrete. In this study the replacement percentage of cement with Meta-kaolin was ranged from (7–8%) and the addition of silica fume by (15%). The results showed that the obtained compressive strengths, split tensile strengths and flexural strengths for the concrete have been determined that all results of the tests have been increased while increasing the meta kaolin ratio up to 7%. later there is a little decreasing in the strength for overflowing use of meta kaolin up to 7.5% and 8% which decreases the ratio of w/c and postponement the activity of a pozzolan. The maximum value of strength with the 7% ratio of meta kaolin addition is sufficient because the meta kaolin amount reacts with the calcium hydroxide which speeds up the hydration of cement and creates gel of C-SH. From the results the best percentage of Meta-kaolin can be replaced with cement is (7%) with addition of silica fume by (15%).