基于振动法的抗疲劳断裂水泥稳定碎石强度标准

Strength Standard of Anti Fatigue-Fracture Cement Stabilized Macadam Based on Vibration Testing Method

以水泥稳定碎石基层施工期和运营期在荷载作用下不发生疲劳破坏所需材料最小强度为准则,研究了水泥稳定碎石力学强度特性、疲劳特性及施工期与运营期水泥稳定碎石基层荷载响应,提出了抗疲劳断裂的水泥稳定碎石强度标准.结果表明:为防止基层在施工车辆荷载作用下发生极限断裂破坏,水泥稳定石灰岩碎石基层必须养护7d后,且其劈裂强度达到0.55MPa以上,方可进行下结构层施工;为防止设计年限内基层在施工车辆和运营车辆反复作用下产生疲劳断裂,水泥稳定石灰岩碎石7d劈裂强度不应小于0.70MPa.为了便于应用,结合抗压强度和劈裂强度的关系,提出水泥稳定石灰岩碎石7d抗压强度不应小于7.0MPa.

Cement stabilized limestone macadam is taken as object, researches on the mechanical strength characteristics and fatigue property, the load response of cement stabilized macadam during the construction and operation period are conducted. The standard of strength for fatigue fracture of the cement stabilized macadam was proposed. The researches show that in order to prevent the ultimate damage caused by construction vehicle load, the con- struction of next structure layer should be conducted until the curing age of cement stabilized limestone macadam is no less ＂than 7 d and the splitting strength is no less than 0. 55 MPa; to prevent the fatigue damage under repeated load effect of the construction and operation vehicle during the designed usage, the 7 d splitting strength should be no less than 0.70 MPa. In order to facilitate application, in consideration of the relationship between compressive strength and splitting strength, it is proposed that the 7 d compressive strength of cement stabilized limestone macadam should be no less than 7.0 MPa.