Improvement of chloride ion penetration resistance in cement mortars modified with rubber from worn automobile tires,”Cement & Concrete Composites
- N.Oikonomou, S. Mavridou
In this study, 0%, 5%, 10%, 15% and 20% of waste rubber powder and 10% of sand was used to made crumb rubber cement mortar specimens in order to investigate the physical and chemical properties of the resulting cement. The examine the resulting materials the following tests were used: normal consistency water of fresh properties, compressive strength, and flexural strength, splitting strength, shrinkage test and durability. The materials were cured for ages of 1, 3, 7, 28, 56 and 91 days. Optical microscope, X-Ray Diffract meter, and scanning electron microscopy observations of the rubber powder and cement paste were made to evaluate the interface characteristics, to verify the engineering properties of rubber concrete and to evaluate the development of the strength and durability of the materials. The aim of the study was to provide a basis for the use of waste rubber tires and to provide a reference for the future. The results showed that the setting time of crumb rubber cement mortar increases as the amount of replacement waste rubber powder increased. The higher the substitution in the mixture, the more water was necessary to achieve consistency. Compressive strength, flexural strength and splitting strength decreased, as the substitution of rubber powder increased; at the same time, the higher the amount of replacement, the lower the strength was. This result may be due to the lower viscosity of the rubber particles as compared to the cement particles. OM, X-ray, SEM observations confirmed these results and showed that the cement paste and rubber particles bond less. Thus, with more replacement material in the concrete, the material interfacial transition zone between the interfaces will become more vulnerable.