掺外加剂沥青砂浆的力学性能

应用压缩试验应力-应变数据, 分析了常规条件与冻融条件下, 70^#沥青砂浆、90^#沥青砂浆、橡胶沥青砂浆及其对应掺外加剂砂浆的应力响应规律、强度损失指数与影响砂浆力学性能的物理化学原因, 并基于能量转化原理与能量指标, 研究了压缩过程中沥青砂浆的破坏本质与力学耐久性能。分析结果表明: 在常规条件下, 加入外加剂KS的橡胶沥青砂浆、70^#沥青砂浆与90^#沥青砂浆的最大应力分别为1.345、1.218、1.186 MPa, 分别为对应未掺外加剂沥青砂浆最大应力的1.12、1.18、1.30倍, 加入外加剂沥青砂浆的能量释放系数增量分别为0.152、0.067、0.054 MPa^-1·J^-1, 分别为对应未掺外加剂沥青砂浆能量释放系数增量的68.8%、78.8%、41.9%, 因此, 加入外加剂提高了沥青砂浆的抗压强度, 改善了沥青砂浆的力学耐久性能; 在冻融条件下, 加入外加剂的橡胶沥青砂浆、70#沥青砂浆与90#沥青砂浆的最大应力分别为1.311、1.170、1.083 MPa, 分别为对应未掺外加剂沥青砂浆最大应力的1.22、1.11、1.06倍, 加入外加剂沥青砂浆的能量释放系数增量分别为0.221、0.070、0.073 MPa^-1·J^-1, 分别为对应未掺外加剂沥青砂浆能量释放系数增量的61.7%、72.9%、65.2%, 能量释放系数越小, 抗疲劳性能越好, 因此, 加入外加剂能够改善沥青砂浆的水稳定性, 减少冻融损伤, 确保冻融后沥青砂浆的力学耐久性能。

Mechanical property of asphalt mortar with additive

By the stress-strain data of compression test, the laws of stress response, the loss indices of strength and the chemicophysical causes for influencing the mechanical properties of 70# asphalt mortar, 90# asphalt mortar, rubber asphalt mortar and their corresponding mortars with additive were studied under the normal and freezing-thawing conditions, and the physical essences of material damage and the durabilities of six kinds of mortars during the compression process were analyzed based on the principle of energy conversion and the energy index.Analysis result indicates that the maximum stresses of rubber asphalt mortar, 70# asphalt mortar and 90# asphalt mortar with additive are 1.345, 1.218 and 1.186 MPa respectively, and they are 1.12, 1.18 and 1.30 times bigger than the values of corresponding mortars without additiverespectively.The increments of energy release coefficients of rubber asphalt mortar, 70# asphalt mortar and 90# asphalt mortar with additive are 0.152, 0.067 and 0.054 MPa-1· J-1respectively, they are 68.8%, 78.8% and 41.9% of the values of corresponding mortars without additive respectively.So adding additive can improve the compressive strength and mechanical durability of asphalt mortar under the normal condition.Under freezing-thawing condition, the maximum stresses of rubber asphalt mortar, 70# asphalt mortar and 90# asphalt mortar with additive are 1.311, 1.170 and 1.083 MPa respectively, and they are 1.22, 1.11 and 1.06 times bigger than the values of corresponding mortars without additive respectively.The increments of energy release coefficients of rubber asphalt mortar, 70# asphalt mortar and 90# asphalt mortar with additive are 0.221, 0.070 and 0.073 MPa-1·J-1 respectively, and they are 61.7%, 72.9% and 65.2% of the values of corresponding mortars without additive respectively.The smaller the energy releasing coefficient is, the better the fatigue performance is.Therefore, adding additive improves the water stability, reduces the freezing-thawing damage, and ensures the mechanical properties and durability of asphalt mortar after freezing-thawing.