冻融循环对沥青混合料低温弯曲特性的影响研究

The Effect of Freeze-Thaw Cycles on Low Temperature Bending Properties of Asphalt Mixture

为了探究冻融循环作用后沥青混合料的低温弯曲特性,论文采用小梁低温弯曲试验,研究了油石比、冻融循环次数和级配对抗弯拉强度、弯曲劲度模量和弯拉应变的影响。试验结果表明,冻融循环初期,抗弯拉强度、弯曲劲度模量和弯拉应变急剧降低,而当冻融循环次数大于15次时,三者均趋于稳定;随着油石比的增大,抗弯拉强度和弯曲劲度模量出现先增大后减小的变化趋势,当油石比为5%时,两者有最大值,而弯拉应变一直增大;当冻融循环次数相同时,抗弯拉强度和弯曲劲度模量的大小顺序是:AC 13>AC 16>AC 10,而弯拉应变的大小顺序为:AC 13>AC 10>AC 16。综合来看,AC-13混合料的低温弯曲特性最好。

In order to study the low bending properties of asphalt mixture after thawing, this parper through the trabecular bending test at low temperature to study the effect of asphalt aggregate ratio, freeze-thaw cycles and graded on tensile strength, flexural bending stiffness modulus and flexural strain effect. The results showed that ,the initial freeze-thaw cycles, flexural strength, flexural stiffness modulus and flexural tensile strain drastically reduced, and when the freeze-thaw cycles more than 15 times, three caught stabilized; with asphalt aggregate ratio increase Great, flexural strength and flexural stiffness modulus trend appears then decreases when aggregate ratio is 5%, both have maximum bending tensile strain and has increased; When the freeze-thaw cycles are the same, flexural strength and flexural stiffness modulus of the order is： AC-13〉 AC-16〉 AC-10, while bending tensile strain in the order of： AC-13〉 AC- 10〉 AC-16, the whole, AC-13 mixture of the best low-temperature bending properties.