Rubber Additions into Concrete and Gamma Radiation Effects on Mechanical Properties and Microwave Absorption Capacity

Rubber is the indispensable raw material for the manufacture of tires; it is obtained from plants, trees and currently can be produced synthetically. The tire rubber is mixed with compounds such as carbon black, sulfur, cement, paints, antioxidants, oils and fats, steel wire, almost etc., making impossible to recycle the tires itself. In this work, we investigate, the effects of the incorporation of ground rubber in concrete, mixture designed to establish the possibility of being used in the construction industry. The samples of concrete were addition with, 5 vol. %., 15 vol. % and 25 vol. % of rubber. Samples with different rubber addition were irradiated by a cobalt 60 gamma source to study the effect on their mechanical compression properties and microwave absorption capacity. Likewise, the microwave absorption capacity was studied for both irradiated and the non-irradiated. It was found that between 5 vol. % and 15 vol. % of rubber addition change the mechanical properties approximately 25 %, higher rubber additions result in a decrease in a 75 % of its mechanical properties. The fracture behavior is not the expected one due to as the curves of stress vs. strain show a double slope, which is associated with the concrete porosity and rubber content. The aging with the gamma rays generates loss of mechanical properties, especially at lower rubber addition, since at content greater than 15 Vol % the radiation effect is less. These rubber additions allow moderate deformations in compression, thus contributing to the care and preservation of the environment.