Improvement of chloride ion penetration resistance in cement mortars modified with rubber from worn automobile tires

Disposal of worn tires poses a major problem worldwide. In Greece more than 50,000 tons of worn automobile tires are stockpiled annually. This paper presents the results of laboratory research that examines the incorporation of tire rubber granules as a partial replacement for the sand in cement mortars. Physical and mechanical properties of these rubber mixtures are studied while, for the first time, resistance to chloride ion penetration is measured. Results showed a decrease in mechanical properties, whereas an increase in chloride ion penetration resistance has been observed. This implies that cement-based mortar and concrete products, modified with tire rubber granules as a partial replacement for the sand, can be used in applications where mechanical properties are not of prime importance but where high resistance to chloride ion penetration is demanded.