Mechanical properties of green concrete

Abstract

The engineering properties inspection of green concrete resulted from using Metakaolin to replace cement and crushed tiles as waste coarse aggregates is the main aim in this work study. Different concrete mixtures were prepared in order to obtain 30 MPa target strength for concrete in compression. The crushed tile as waste aggregates is used to substitute crushed gravel as natural aggregate with ratios of 0 to 100% in the concrete mixtures and the mixture properties were inspected. It is revealed that employing Metakaolin in the replacement of cement and crushed tile to substitute a ratio of crushed gravel affects all concrete properties such as; elastic modulus, tensile strength, and compressive strength. The difference relies on the percentages of Metakaolin and aggregate substituted. The optimum percentages for both Metakaolin and waste aggregate were found to be 20% and 25% respectively which can be used to produce green concrete with acceptable properties and solve a very important environmental problem. The ACI 318 code equations for estimating the spilt cylinder and modulus of elasticity are used and it is revealed that these equations give overestimated values for green concrete having waste aggregate with percentage exceeding 25%.