道路透水沥青混合料改性试验研究

Experimental study on modification of road permeable asphalt mixture

为了有效解决城市热岛和内涝问题,配制了一种PAC-13透水沥青混合料,并利用消石灰和木质纤维对其进行改性试验。结果表明:PAC-13透水沥青混合料的最佳油石比为4.5%,在基本配合比下,空隙率可达25%,连通空隙率可达18.9%;随着消石灰掺量增大,PAC-13透水沥青混合料各项性能逐渐得到优化,消石灰对冻融劈裂强度比(水稳定性能)的改善效果最好,消石灰替代率每增加1%,冻融劈裂强度比将提升约2%;木质纤维对PAC-13透水沥青混合料也有一定的改良作用,但效果不及消石灰,木质纤维掺量不宜过高,当掺量过高时,需要根据析漏损失和飞散损失重新确定沥青混合料的最佳油石比。

In order to effectively solve the problems of urban heat island and waterlogging,a PAC-13 permeable asphalt mixture was prepared and modified by hydrated lime and wood fiber.The results show that the optimum asphalt aggregate ratio of PAC-13 permeable asphalt mixture is 4.5%.Under the basic mix proportion,the void ratio can reach 25%and the connected void ratio can reach 18.9%.With the increase of hydrated lime content,the properties of PAC-13 permeable asphalt mixture are gradually optimized.Hydrated lime has the best effect on the improvement of freeze-thaw splitting strength ratio(water stability).With the increase of hydrated lime substitution rate of 1%,the freeze-thaw splitting strength ratio will increase by about 2%.Wood fiber can also improve PAC-13 permeable asphalt mixture,but the effect is not as good as hydrated lime.The content of wood fiber should not be too high.When the content is too high,it is necessary to re determine the best asphalt aggregate ratio of asphalt mixture according to leakage loss and dispersion loss.