Reduction of expansion in concrete road pavement by using perlite

In concrete road pavement, tensile stresses due to expansions caused by the effect of temperature loads exceed the tensile strength of the concrete, causing expansion cracks. In this study, it was aimed to reduce the expansion amounts and prevent cracks by using expanded perlite and raw perlite aggregate in the concrete content. Perlite was used at the rate of 0, 5, 10, 15, and 30% of the total volume of the concrete. While the compressive and tensile strengths of the concrete decreased with the use of expanded perlite, there was no change with the use of raw perlite. In the temperature tests carried out by heating the concrete samples, the temperature change with thermocouple and the elongation values with LVDT and straingauge sensors were determined. The mixture with the least measured difference between the upper and lower surface temperatures of the concrete samples was HP30. While the place where the concrete samples elongated the most during the heating process was the upper part close to the heat source, the least elongation was in the lower part. While the minimum elongation was 0.02 mm in the GP30 sample, the maximum elongation was 0.05 mm in all other raw and expanded perlite samples. The elongation amounts in the temperature tests of the perlite samples were less than the 0.06 mm elongation that would cause cracking in the beam sample, and no crack formation was observed in any sample. When the mechanical and thermal properties of the perlite samples were evaluated, it can be said that GP5, GP10, HP5, HP10, HP15 and HP30 mixtures can be used in concrete road pavement.