振动压实二灰碎石力学特性及影响因素
Mechanical properties and influencing factors of lime-fly-ash crushed rock base on vertical vibration test method

为了揭示二灰碎石强度形成机理及影响因素，对比研究了垂直振动试验方法（vertical vibration test method,VVTM）及静压法成型试件的力学强度与实体工程芯样的力学强度，论证了二灰碎石垂直振动试验方法的可靠性，并采用VVTM研究试件的成型方式、龄期、二灰砂浆掺量、级配类型对二灰碎石力学特性的影响规律。研究结果表明：二灰碎石VVTM成型试件的无侧限抗压强度、劈裂强度平均为实体工程芯样的91.3%、90.2%，而静压法成型试件的无侧限抗压强度、劈裂强度平均为实体工程芯样的46.5%、51.9%，表明VVTM成型试件更能准确反映二灰碎石的工程特性；二灰碎石7、90、120、180 d的力学强度（抗压强度、劈裂强度）分别约为其极限强度的13%、60%、70%、80%，回弹模量分别约为其极限回弹模量的10%、50%、60%、70%；随着二灰砂浆掺量的增加，二灰碎石抗压强度和回弹模量先增大后减小，而劈裂强度先急剧增大后趋于平缓，甚〖JP2〗至有所降低；二灰砂浆掺量为32%时，二灰碎石抗压强度和抗压回弹模量达到最大，且继续增加二灰砂浆掺量二灰碎石劈裂强度没有明显增加，甚至有所降低，建议二灰砂浆掺量为32%；与《公路路面基层施工技术规范》（JTJ 034―2000）规定的级配二灰碎石相比，骨架密实级配二灰碎石早期力学强度和回弹模量可提高约1.15倍，120 d后力学强度可提高约20%。
In order to reveal the formation mechanism and influencing factors of strength of lime-fly-ash crushed rock, this paper compared the mechanical strength of specimens obtained with vertical vibration test method (VVTM) and static pressure method with that of practical engineering core samples, and proved the reliability of vertical vibration test method (VVTM). VVTM was then used to research the influence law of molding method, age, content of lime-fly ash mortar and gradation types on mechanical properties of lime-fly-ash crushed rock. The results show that the unconfined compressive strength and the splitting strength of lime-fly-ash crushed rock specimen molded with VVTM is 91.3% and 90.2% of site core samples on average, respectively. The unconfined compressive strength and the splitting strength of lime-fly-ash crushed rock specimen molded with static pressure method is 46.5% and 51.9% of site core samples on average, respectively. So specimen molded with VVTM can reflect more accurately the engineering characteristics of lime-fly-ash crushed rock. The mechanical strengths (compressive strength, splitting strength) of lime-fly-ash crushed rock of 7, 90, 120, and 180 d are about 13%, 60%, 70%, 80% of its ultimate strength, respectively, and their moduli of resilience are about 10%,50%, 60%, 70% of its ultimate resilient modulus, respectively. With the increase of lime-fly-ash mortar content, the compressive strength and modulus of lime-fly-ash crushed rock increases first and then decreases, and the splitting strength increases rapidly first and then levels off or even decreases. When lime-fly-ash mortar content is 32%, the compressive strength and compressive resilient modulus of lime-fly-ash crushed rock achieves the maximum. If it continues to increase lime-fly-ash mortar content, splitting strength of lime-fly-ash crushed rock does not increase and even decreases. The suggested lime-fly-ash mortar content should be 32%. Compared with the