The Effect of Natural Resin on Thermo-physical Properties of Expanded Vermiculite–Cement Composites

Abstract

This study focuses on production of lightweight concrete that presents thermal insulation property. Lightweight concretes were produced using resin-added cement and expanded vermiculite. The rates of expanded vermiculite were determined as 20%, 40%, 60%, and 80% of the total volume in the mixture. The amount of tragacanth resin in the mixture was detected as 0%, 0.5% and 1% of the total weight of cement and expanded vermiculite. Thermal, mechanical and microstructure properties of the samples produced were determined. Porosity ratio increased by 15.01% to 55.22%, 0.5% and 1% in samples without resin and by 18.97% to 57.88% and 19.64% to 60.73% in resin-added samples, respectively. As the resin increased, density, thermal conductivity, compressive strength decreased and porosity, abrasion loss and water absorption rates increased. Similarly, when expanded vermiculite rate of the samples without resin in the mixture was increased from 20% to 80%, density, thermal conductivity, and compressive strength decreased at the rates of 14.13% to 21.29%, 14.32% to 24.36%, and 31.37% to 39.82%, respectively, compared to 0.5% resin samples and the rates of 12.34% to 13.05%, 12.37% to 19.59%, and 17.65% to 35.29% compared to 0.1% resin samples. Also, the water absorption rates of the samples were found to be lower than 30%, which is the critical value. It was shown that expanded vermiculite and tragacanth resin-added lightweight concrete samples would provide a good performance in non-load bearing places in the buildings, in the partitions instead of bricks, in the ceiling and floor covering, and as plaster and gypsum.