Effect of High Temperature on Mechanical Properties of Cement Samples with Fly Ash Substitution

To achieve a sustainable concrete, environmental factors should also be taken into account while examining the mechanical and physical properties of concrete. High temperature is an effective environmental factor in the design of sustainable concrete, and cause serious losses on the mechanical and physical properties of concrete considering fire situation on the reinforced concrete structures. In this study, the effects of high temperature, which has an important role for environmental factors, on the fly ash substituted cement paste is examined to achieve a sustainable concrete. In the study, 40x40x160 mm cement mortar samples having (5-10 and20%) rates of fly ash substitution were prepared with using reference sand specified in the TS EN 196-1 Standard. The amount of water required in each group is determined by using Flow Table test according to the ASTM C230, C109 and C1437 Standards. The prepared samples were exposed to 100-200-300-400-500 and 600 Celsius degree before the compressive and bending strength experiments according to the TS EN 196-1 Standards, and then the data obtained were statistically evaluated. As a result, improvements were provided on mechanical and physical properties of cement with 5% fly ash substitution. The cement mortars were less damaged from the high temperature up to 10% fly ash substitution. Strength values were decreased parallel to the temperature increase in all fly ash substituted mixtures.