Production of Lightweight and Heat-Insulating Concrete Using Minced Tires

Abstract

The main objective of the research was to study the effect of crushed rubber tires, which were used as a substitute for coarse aggregate (gravel) in production of lightweight and heat-Iinsulating concrete. The volume ratios of the mixtures used were as follows: First was 2 gravel, 1.5 sand, and 1 cement. The second was 2 minced tires, 1.5 sand, and 1 cement, while the third mixture was 1 minced tires, 1 spring gravel, 1.5 sand, and 1 cement. Concrete cubes were produced and the results were compared with ordinary concrete. The following tests were carried out: compressive, resistance, water absorption, porosity, volumetric density, specific weight, treatment with alkaline solutions -KOH NaOH, and thermal conductivity. The results of the tests proved that the addition of minced tires negatively affected the compressive strength compared to the reference concrete at the ages of 7, 14, and 28 days. As an alternative to Al-Naba gravel, it was also shown that there was an increase in water absorption with an increase in the proportion of minced tires relative to the water absorption in the reference mixture. Also, the density values of lightweight concrete decreased compared to the regular reference concrete, which leads to a reduction in the weight of the dead loads and therefore the foundations and their quality. Because of the high temperatures in the summer as these types of concrete do not react with alkaline solutions such as NaoH and KOH, and this is one of the advantages for concrete work.