ABSTRACT
Utilization of used tires or other vulcanized rubber waste is an important ecological problem for all countries. Rubber waste has long-term decay in natural conditions due to high durability for lot of climate or soil exposure and biological attacks. Used tires or other vulcanized rubber waste in most countries are burned up, but this has negative effect on environment. The aim of investigation was to study the possibilities to use granulated rubber waste as elastic additive for Portland-cement concrete.
Used tires or other vulcanized rubber waste were crumbed into different sizes fractions 0/0.5 mm, 0/1 mm and 0/3 mm. The rubber additive was used as fine aggregate replacement in concrete mixtures by 3.2 per cent of aggregates mass. Previous results indicate that using elastic additives from rubber waste increase freezing and thawing resistance of concrete. This additive works as damping agent reducing the stresses inside the concrete. The influence of different fractions granulated tires rubber waste on the properties of fresh and hardened concrete was tested in this investigation. The effect of this additive on technological properties, air content in fresh concrete, density, compressive strength, porosity, abrasive resistance and deformation properties of concrete was investigated.
The experimental results indicate the reduction of compressive strength and modulus of elasticity of concrete for all fractions of rubber waste. Rubber waste has no influence on capillary porosity of hardened concrete but increases air content and closed porosity of concrete and has positive effect on freezing and thawing resistance of concrete
The results of investigation showed that crumbed rubber waste additive could be used for modification of Portland-cement concrete properties and utilization of used tires or other vulcanised rubber waste.
