INVESTIGATION OF THE MECHANICAL PROPERTIES OF GEOPOLYMER CONCRETE CONTAINING NATURAL ZEOLITE UNDER THE EFFECT OF HIGH TEMPERATURE

The use of traditional portland cement-based concrete is quite common in today's construction

industry. Geopolymer concrete has been proposed as an alternative to Portland cement

concrete due to the energy consumption caused by cement consumption in the world and

environmental pollution as a result of high greenhouse gas effect. In this study, metakaolin

and ground blast furnace slag were preferred as binder materials. In addition, it is aimed to

determine the ratio of natural zeolite to be replaced at the optimum rate without reducing the

flexural and compressive strengths of the concrete by using natural zeolite in different

proportions instead of ground blast furnace slag used as a binder in geopolymer concrete. In

this direction, in order to examine the effect of natural zeolite on the mechanical properties of

geopolymer concrete, four mixtures were designed by replacing the total amount of binder by

10%, 15% and 20% and with a reference mixture that does not contain natural zeolite. The

mixtures were subjected to thermal curing at 80 degrees for 8 hours. Metakaolin, aggregate

and alkali activator contents as binders in the mixtures were also kept constant. According to

the test results, it was shown that the mixture containing 10% natural zeolite reached 71.31

MPa by increasing the compressive strength by 7.52% compared to the reference mixture, and

reaching 8.38 MPa by increasing the flexural strength by 12.41%. In addition, it has been

observed that the compressive strength of the mixtures containing natural zeolite is decreased

compared to the reference samples when exposed to high temperature. As a result, the use of

10% of natural zeolite had a positive effect on the strength development and mechanical

properties of geopolymer concrete without losing its mechanical properties such as high

flexural and compressive strengths.