Comprehensive modification of emulsified asphalt on improving mechanical properties of crumb rubber concrete

The surface modification of crumb rubber concrete (CRC) by the emulsified asphalt (EA) is presented in this paper. The effect of different EA contents on the mechanical properties of CRC (the fine aggregate was replaced with 5%, 10% and 15% rubber by volume) was studied. Several tests, including the static mechanical experi-ments of compression, bending, splitting tensile and three-point bending, the dynamic mechanical experiments of the split Hopkinson pressure bar (SHPB) and the micro-analysis of the digital image correlation (DIC) test and SEM image, were carried out to compare with CRC modified by NaOH. The tests depict that CRC modified by EA demonstrates better mechanical properties, such as the higher compressive strength, the higher splitting tensile strength, the more significant strain rate sensitivity at high strain rates, the lower the elastic modulus (Ec) and the bending modulus (Eb). The better modified effects can be attributed to the better interfacial bonding surface between the cement matrix and the rubber particles and the fewer stress concentrations than that of NaOH modification. The modification of CRC by EA can be regarded as a better synergistic method to bring advantages of CRC into full play.