堤顶道路冷再生混合料力学强度影响因素研究

Research on Effect Factors of Cold Regenerated Mixture Mechanical Strength on Levee Crown Road

为深入探讨堤顶道路冷再生基层混合料力学强度不足的问题,通过室内制备试件,研究了旧料掺量、水泥用量、纤维类型及掺量对堤顶道路冷再生基层混合料力学强度的影响。结果表明:当旧料掺量从60%增加到90%,冷再生基层混合料劈裂强度从0.89 MPa降低到0.61 MPa,降低幅度达31%;与未掺水泥堤顶道路冷再生基层混合料相比,掺5%水泥的堤顶道路冷再生基层混合料的马歇尔稳定度、劈裂强度至少可分别提高33%、21%;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10%;根据力学性能最优原则,同时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%,旧料掺量为70%~80%。

In order to deeply discuss the problem of the insufficient mechanical strength of cold regenerated base mixture on levee crown road,the effect of the proportion of old material,the cement content,the fiber type and dosage on the mechanical strength of the cold regenerated base mixture on levee crown road were studied by preparing specimens in the laboratory.The results showed that,when the proportion of old material increased from60%to 90%,the splitting strength of cold regenerated base mixture decreased from 0.89 MPa to 0.61 MPa,with a reduction of 31%.Compared with the cold regenerated base mixture without cement,the Marshall stability and splitting strength of the cold regenerated base mixture with 5%cement can be at least increased by 33%and 21%respectively.Compared with cold regenerated mixture without fiber,the mechanical strength of cold regenerated mixture with 0.4%polyester fiber can be at least increased by 10%.According to the principle of optimal mechanical properties and the economical problems of the material,it is suggested that,in cold regenerated mixture,the cement content should be 1.5%and the proportion of old material should be 70%to 80%.