冷再生混合料力学强度影响因素探究

采用垂直振动成型方法制备试件,研究乳化沥青类型、水泥掺量、纤维类型及掺量对冷再生混合料力学强度的影响。结果表明:与普通中裂乳化沥青冷再生混合料相比,丁苯橡胶(styrene butadiene rubber, SBR)、苯乙烯-丁二烯-苯乙烯嵌段共聚物(styrene butadiene styrene,SBS)改性乳化沥青冷再生混合料力学强度可分别至少提高15%、9%;掺1.5%水泥的冷再生混合料的抗剪强度至少可提高85%;与不掺纤维冷再生混合料相比,掺0.4%聚酯纤维的冷再生混合料力学强度至少可提高8%。因此,根据力学性能最优原则,选取SBR改性乳化沥青作为冷再生混合料的胶结料,考虑材料经济性问题,建议冷再生混合料中水泥掺量为1.5%,建议选用0.4%掺量的聚酯纤维来提升冷再生混合料的力学强度。

Study on Influence Factors of Mechanical Strength of Cold Regenerative Mixture

Specimens were prepared by vertical vibration molding, and the effects of emulsified asphalt, cement and fiber on the mechanical strength of cold recycled mixture were studied. The results show that the mechanical strength of SBR and SBS modified emulsified asphalt cold regenerative mixture can be improved by at least 15% and 9%, respectively, compared with that of normal mid-split emulsified asphalt cold regenerative mixture.The shear strength of cold recycled mixture with 1.5% cement can be increased by at least 85%.Compared with the cold-regenerative mixture without fiber mixing, the mechanical strength of the cold-regenerative mixture mixed with 0.4% polyester fiber can be improved by at least 8%. Therefore, SBR modified emulsified asphalt is selected as the cementing material of cold regenerative mixture according to the principle of optimal mechanical properties. Considering the economy of materials, it is suggested that the cement content in the cold-recycled mixture is 1.5%.It is recommended to use polyester fiber with content of 0.4% to improve the mechanical strength of cold regenerative mixture.