盐冻融与干湿作用下沥青混凝土的高低温力学性能分析

制备了沥青混凝土样品,并进行了不同次数的盐冻融干湿循环试验。在此基础上,测试了沥青混凝土的高温车辙深度、动稳定度和低温抗弯拉强度,得到了车辙深度、动稳定度和抗弯拉强度随盐冻融干湿循环次和盐浓度的变化规律,研究了盐冻融与干湿作用下沥青混凝土的高低温力学性能。研究结果表明:(1)沥青混凝土60min车辙深度随盐浓度的增加和冻融循环次数的增多而呈线性增长的趋势;(2)沥青混凝土的抗高温变形能力随盐冻融干湿循环次数的增多而逐渐弱化;(3)沥青混凝土的抗弯拉强度经历9次和15次盐冻融干湿循环后分别下降22%~26.4%和42.6%~51.5%;(4)冻融干湿循环次数一定时,沥青混凝土的抗弯拉强度随盐浓度的增加而缓慢下降,并且当盐浓度达到12%时,沥青混凝土的抗弯拉强度减小就很不明显。

Analysis of High and Low Temperature Mechanical Properties of Asphalt Concrete under the Action of Salt Freeze-thaw and Dry and Wet Conditions

The asphalt concrete samples were prepared and the salt freeze-thaw dry and wet cycle tests were carried at different times.On this basis,the high temperature rut depth,dynamic stability and low temperature flexural strength of asphalt concrete were tested.The changes of rut depth,dynamic stability and flexural strength with the cycles of salt freeze-thawing and dry-wet and several salt concentrations were obtained.The high and low temperature mechanical properties of asphalt concrete under the action of salt freeze-thawing and dry-wet were studied.The research results show that:(1)The rut depth of asphalt concrete for 60min increases linearly with the increase of salt concentration and freezethaw cycle.(2)The high temperature deformation resistance of asphalt concrete gradually weakens with the increase of the number of freeze-thaw dry and wet cycles.(3)The flexural tensile strength of asphalt concrete decreased by 22%~26.4%and 42.6%~51.5%respectively after 9 and 15 cycles of salt freeze-thaw,dry and wet cycles.(4)When the number of freeze-thaw cycles is constant,the flexural tensile strength of asphalt concrete decreases slowly with increasing salt concentration.And when the salt concentration reaches 12%,the reduction of the flexural tensile strength of asphalt concrete is not obvious.