路用无黏结集料的动载结构性评价方法研究

由松散集料组成的级配碎石在路面结构中具有很强的动载结构性,但目前对材料的结构性描述是定性的。为了探讨级配碎石动载结构性的定量化描述,采用上表面振动方法成型试样,以水为扰动因素,在3种围压下对试样进行的3000次动载试验,并根据松散集料基层沥青路面的典型破坏形式,定义了级配碎石的动载可稳性、可变性和综合结构性。试验表明:结构可稳性反映了填充料水稳定性,结构可变性表征了骨架排列的稳定性能,二者是土结构性的两个方面,围压σ3≧15 0 kPa时,级配碎石的结构性被钝化,结构性参数应在小围压下测定;采用结构性参数定性评价级配碎石的结构性是可行的。

Evaluation methods of dynamic structural characteristics of unbound aggregate materials

The unbound aggregate materials were of very strong dynamic structural characteristics in pavement structure.However,the depiction of structural characteristics was qualitative at present.In order to discuss quantitative parameters of structural properties of the unbound aggregate materials the specimens were adopted by use of the surface vibrating method.Water was regarded as the disarranging factor,and unsaturated and saturated specimens were loaded 3000 times at different stress states.According to the failure modes of the unbound aggregate materials based asphalt pavement,the dynamic structural stabilizability,structural changeability and comprehensive structural parameters of the unbound aggregate materials were defined.It was indicated by the test results that was reflected the water stability of filling material by the dynamic structural stabilizability parameter,and the arrangement stability of skeleton materials was depicted by be structural changeability parameter.These two parameters reflected the two respects of the dynamic structural characteristics,when the confining pressure σ3≧150 kPa,the dynamic structural parameter was not sensitive,and it should be determined under small confining pressure.It was feasible to evaluate the structural characteristics of the unbound aggregate materials dynamic by use of the structural parameters.