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采用三点弯曲试验,研究橡胶粉掺量和温度对橡胶沥青应力吸收层混合料抗裂性的影响,并对比分析橡胶沥青应力吸收层和SBS改性沥青应力吸收层对路面抗裂性和温度敏感性的改善效果。试验结果显示:随着橡胶粉掺量的增多,最大弯曲力、最大应变和断裂能都呈现先增大后减小的变化规律,当掺量为20%时,抗裂性最好。温度越高,最大弯曲力越小,最大应变越大,而断裂能随温度的升高呈现抛物线规律变化,当温度为0℃时断裂能最大;应力吸收层能显著改善路面的抗裂性,且橡胶沥青应力吸收层对抗裂性的改善效果优于SBS改性沥青应力吸收层;负温时随温度区间的升高,VTS(温度敏感性系数)逐渐减小,混合料温度敏感性逐渐降低,正温时随温度区间的升高,VTS逐渐增大,温度敏感性逐渐增强;橡胶沥青应力吸收层比SBS改性沥青应力吸收层更能降低温度敏感性。
The effect of rubber powder content and temperature on the crack resistance of rubber asphalt mixture was studied by three-point bending test. The influence of rubber asphalt stress absorption layer and SBS modified asphalt stress absorption layer on the crack resistance and temperature Sensitivity improvement effect. The experimental results show that with the increase of the content of rubber powder, the maximum bending force, the maximum strain and the fracture energy increase at first and then decrease, and the crack resistance is the best when the content of rubber powder is 20%. The higher the temperature is, the smaller the maximum bending force is, the larger the maximum strain is, and the fracture energy changes parabolically with increasing temperature. The fracture energy is the largest when the temperature is 0 ℃. The stress absorption layer can significantly improve the crack resistance, And the improvement effect of the rubber asphalt stress absorption layer on the crack resistance is better than that of the SBS modified asphalt stress absorption layer. With the increase of the temperature range, the VTS (temperature sensitivity coefficient) gradually decreases and the temperature sensitivity of the mixture gradually decreases , The VTS increases with increasing temperature in the positive temperature range, and the temperature sensitivity gradually increases. The rubber asphalt stress absorption layer can reduce the temperature sensitivity more than the SBS modified asphalt stress absorption layer.