橡胶粉对水泥稳定级配碎石力学性能与变形特性的影响

Effect of rubber powder on mechanical properties and deformation characteristics of cement-stabilized graded macadam

为了增强水泥稳定碎石的柔韧性,并提高半刚性基层的抗裂性能,将0~4.75 mm小汽车轮胎胶粉等质量替代集料,基于室内试验研究了橡胶粉掺量对橡胶粉-水泥稳定级配碎石混合料力学性能和变形特性的影响规律。结果表明,橡胶粉-水泥稳定碎石的无侧限抗压强度、弯拉强度均随橡胶粉掺量增大而线性关系降低,在4.5%~5.5%水泥剂量范围内,掺加2%~4%橡胶粉能确保水泥稳定碎石有足够的无侧限抗压强度和抗冲刷性能,同时实现了橡胶粉-水泥稳定碎石破坏应变和疲劳寿命显著增大、模量可调节的功能,橡胶粉-水泥稳定碎石可作为路面结构的变形协调功能层。橡胶粉提高了水泥稳定级配碎石混合料的劈裂破坏应变与弯拉破坏应变,在3%橡胶粉掺量时,橡胶粉-水泥稳定碎石混合料的疲劳性能最优,同时疲劳寿命对应力水平的敏感性最低。但是掺加橡胶粉能降低水泥稳定级配碎石混合料温缩性能的不利影响。实体工程跟踪检测结果表明,橡胶粉-水泥稳定级配碎石混合料施工性能和力学性能优良,掺加橡胶粉能提高水泥稳定级配碎石混合料的抗裂性能,对防止半刚性基层沥青路面早发性反射裂缝有着积极的意义。

In order to enhance the flexibility of cement stabilized crushed stone and improve the crack resistance of the semi-rigid base layer,0~4.75 mm car tire rubber powder and other quality are substituted for aggregates.Based on laboratory experiments,the effect of rubber powder content on rubber powder is studied.The influence law of the mechanical properties and deformation characteristics of cement stabilized graded crushed stone mixture.The results show that the unconfined compressive strength and flexural tensile strength of rubber powder-cement stabilized crushed stone decrease linearly with the increase of rubber powder content.In the range of 4.5%~5.5%cement dosage,the addition of 2% ~4% rubber powder can ensure that the cement stabilized crushed stone has sufficient unconfined compressive strength and erosion resistance.At the same time,it realizes the functions of rubber powder-cement stabilized crushed stone to significantly increase the failure strain and fatigue life,and the modulus can be adjusted.The rubber powder-cement stabilized crushed stone can be used as the deformation coordination functional layer of the pavement structure.Rubber powder improves the split failure strain and flexural failure strain of cement stabilized graded crushed stone mixture.When 3% rubber powder is added,the fatigue performance of rubber powder-cement stabilized crushed stone mixture is optimal,and the fatigue life is at the same time The least sensitivity to stress levels.However,the addition of rubber powder can reduce the adverse effect of the temperature shrinkage of cement stabilized graded crushed stone mixture.The physical engineering tracking test results show that the rubber powder-cement stabilized graded crushed stone mixture has excellent construction performance and mechanical properties.The addition of rubber powder can improve the crack resistance of the cement stabilized graded crushed stone mixture and prevent the early development of asphalt pavements.The reflective cracks of the semi-rigid base layer have positive significance.