旋转与静压成型对水泥稳定碎石性能的影响

Impact on performance of cement stabilized macadam mixtures between gyratory compaction and static compaction methods

为探讨采用旋转成型法(gyratory compation,GCM)进行水泥稳定碎石组成设计的可行性,分析旋转与静压成型方法(static compaction method,SCM)对水泥稳定碎石(cement stabilizedmacadam mixtures,CSMM)性能的影响,采用旋转压实、静压方法成型3种不同结构类型的水泥稳定碎石混合料试件,测试、比较不同成型方法所得混合料试件的物理力学指标,并与振动成型、现场取芯所得结果进行比较。研究结果表明:成型方法是影响水泥稳定碎石混合料性能的关键因素,采用旋转成型法能够得到混合料的干密度-含水率单峰曲线,从而确定最佳含水率和最大干密度;与重型击实相比,旋转成型试件的最佳含水率平均低6.7%,最大干密度平均高2.0%;与静压成型相比,旋转成型试件的7d无侧限抗压强度、28d劈裂强度平均高出117%、106%;旋转成型试件粗集料形成的骨架结构具有更高的抗荷载能力,且破碎程度低,粗细集料在成型过程中能够达到更好的嵌挤状态;旋转成型骨架密实结构水泥稳定碎石与其他结构类型相比具有最佳的物理力学性能;旋转成型试件的物理力学指标与静压成型试件存在线性关系。室内旋转成型混合料试件的7d无侧限抗压强度强度、集料分布破碎情况与振动成型和试验路更为接近;采用旋转成型法进行水泥稳定碎石混合料组成设计是合理可行的。

In order to explore the feasibility of using gyratory compaction method（GCM）to design the cement stabilized macadam mixtures（CSMM）,the influence of performance between GCM and static compaction method（SCM）was analyzed,and three different kinds of CSMM specimens were prepared by GCM and SCM.Physical and mechanical indexes of specimens were measured to analyze the performance of different methods.Besides they were also compared with vibration compaction and test road results.The results show that the compaction method is the key factor affecting the performance of CSMM.Dry density-moisture curve of CSMM can be obtained by GCM,so that the optimum moisture content and maximum dry density can bedetermined.Compared with heavy compaction,optimum moisture content of GCM decreases by6.7% on average,and maximum dry density increases by 2.0% on average.Compared with SCM,unconfined compressive strength at 7th day of GCM increases by 117% and splitting strength at 28 th day increases by 106% on average.Framework structure has better anti-load capacity and lower fragmentation degree.The coarse and fine aggregates can achieve a better embedding state in compaction process and specimens of dense-skeleton structure prepared by GCM have best performance.Physical and mechanical indexes of CSMM between GCM and SCM have linear relationship.7 d unconfined compressive strength of GCM,distribution and fragmentation of aggregates are closer to the vibration compaction method and test road.Using GCM to design the cement stabilized macadam mixtures is reasonable and feasible.