Research on the properties of rubber concrete containing surface-modified rubber powders

Abstract The use of rubber powders in rubber concrete mixtures are gaining importance. In this study, the effect of the modified rubbers on the surface characteristics of rubber concrete is investigated, together with their engineering practicability by different rubber modification methods. The surface changes of rubber modified by sodium hydroxide, sulfonation, and urea were studied by contact angle and infrared spectroscopy. The basic mechanical properties and impact resistance of modified rubber concrete were studied and related by Scanning Electron Microscope image analysis. The results show that the selected rubber modification can improve the interaction between cement paste and rubber and improve the adhesion between them. Compared with ordinary rubber concrete, the compressive strength of rubber concrete treated with sodium hydroxide was only slightly improved, but its flexural strength, tensile splitting strength, and impact resistance were greatly improved. After the rubber was modified by urea or sulfonation, a variety of polar groups were introduced on the rubber surface. That led to an increase in the mutual attraction between rubber particles and cement paste, and improved the compressive strength, the tensile splitting strength, the flexural strength, and the impact resistance of rubber concrete. Furthermore, the strength loss of rubber concrete was greatly reduced. Rubber modification improves the performance of rubber concrete, showing good application potential.