Study on Preparation of High Rubber Composite Emulsified Asphalt and Its Mixture Application

Waste rubber powder can improve the high and low temperature performance of asphalt, but with the traditional hot mixing process, the wide application of modified asphalt is restricted due to its unstable performance and odor problems. The traditional emulsified asphalt mixtures have poor cohesiveness, low high-temperature strength, poor resistance to water damage, and have problems with the operability of mixing construction. The styrene-butadiene-styrene copolymer composited with waste rubber powder (composite with high content of rubber, CHR) modified asphalt was hydrated and applied to OGFC-13 graded permeable pavement. Firstly, a composite high latex emulsified asphalt was prepared, and its softening point, viscosity, mechanical properties and micro morphology were analyzed. The high and low temperature performance and water stability performance of OGFC-13 mixture were studied. The test results show that the emulsified asphalt prepared with a non-ionic emulsifier and an emulsification time of 15 minutes has good cohesiveness, high softening point, uniform dispersion and good mechanical properties. The performance test of the mixture shows that when the ratio of asphalt to stone is 6.5%, the CHR emulsified asphalt mixture exhibits good high and low temperature performance, the dynamic stability reaches 5842 times·mm^–1, the bending failure strain reaches 3024 μm/m, and the maximum failure load is 1256 N, the freeze-thaw splitting strength ratio reaches 80.2%, and it has good resistance to water damage. The research results are beneficial to the comprehensive utilization of waste rubber powder in environmental protection and resources, and will promote the high-value application of waterborne asphalt, which has broad application prospects in road paving, maintenance, and building waterproofing.