论文部分内容阅读
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、180d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,120d后力学强度可提高约20%。
In order to reveal the formation mechanism and influential factors of lime-fly ash gravel strength, the mechanical vibration strength and the mechanical strength of solid engineering core were compared between the vertical vibration test method (VVTM) The reliability of the test method of vertical vibration of limestone was studied. The influence of forming method, age, lime-mortar content and grading type on the mechanical properties of lime-fly ash gravel was studied by VVTM. The results show that the unconfined compressive strength and splitting strength of the lime-fly ash-fractured VVTM specimens are 91.3% and 90.2% on average, respectively, while the unconfined compressive strength , And the average splitting strength is 46.5% and 51.9% of that of the solid engineering core, which indicates that the VVTM forming specimen can accurately reflect the engineering characteristics of lime-fly ash gravel. The mechanical strength (anti- Compressive strength and splitting strength are respectively about 13%, 60%, 70% and 80% of the ultimate strength, and the resilience modulus is respectively about 10%, 50%, 60% and 70% of the ultimate resilience modulus %. With the increase of the content of lime-fly ash mortar, the compressive strength and the rebound modulus of lime-fly ash first increase and then decrease, while the splitting strength first increases sharply and then tends to be gentle or even decreases; When the content of gray mortar is 32%, the compressive strength and compressive resilience modulus of lime-fly ash reached the maximum, and the splitting strength of lime-fly ash mortar did not increase obviously or even decrease, It is recommended that the content of the two mortars should be 32%. Compared with the graded lime-fly ash graded according to the Technical Specifications for Construction of Roads and Pavements (JTJ 034-2000), the mortar with dense graded lime-fly ash Mechanical strength and modulus of resilience can be increased to about 1.15 times, the mechanical strength can be increased by about 20% 120d.