沥青搅拌站回收碱性废粉对沥青混合料水稳定性影响研究

Study on Effect of Recycled Alkaline Waste Powder from Asphalt Mixing Plant to Water Stability of Asphalt Mixture

采用沥青搅拌站回收的碱性废粉掺入沥青混合料,代替部分矿粉,会降低沥青与集料的黏附性,不利于沥青混合料的水稳定性。为了利用碱性废粉且不降低沥青混合料的水稳定性,试验研究在沥青混合料中分别加入一定比例的水泥、消石灰、PA-1型沥青抗剥落剂,通过浸水马歇尔稳定度试验、飞散试验、冻融劈裂试验,对比水泥、消石灰、PA-1型沥青抗剥落剂对沥青混合料水稳定性的影响规律。试验结果表明:水泥、消石灰、PA-1型沥青抗剥落剂加入有碱性回收废粉的沥青混合料,可以提高沥青混合料的残留稳定度、冻融劈裂强度比、减小飞散损失,可有效改善有碱性回收废粉的沥青混合料的水稳定性。相同含量的消石灰比水泥对于沥青混合料的水稳定的提高更有效。相比于水泥、消石灰,加有PA-1型抗剥落剂的沥青混合料的浸水残留稳定度、冻融劈裂强度比是最大的,且飞散损失最小,表明PA-1型抗剥落剂对于掺有回收废粉的沥青混合料的水稳定性改善效果最佳。

The alkaline waste powder recycled from asphalt mixing plant was mixed into asphalt mixture to replace part of mineral powder,which would reduce the adhesion between asphalt and aggregate.It was not conducive to the water stability of asphalt mixture.In order to take advantage of the alkaline waste powder,but the water stability of asphalt mixture would not be reduced,a certain proportion of cement,slaked lime,PA-1 type asphalt anti-stripping agent were added into asphalt mixture respectively.Through the submerged Marshall stability test,flying immersion test,freeze-thaw splitting test,compared the effect of cement,slaked lime,PA-1 type asphalt anti-stripping agent on water stability of asphalt mixture.The experimental results show that:Cement,slaked lime and PA-1 asphalt anti-stripping agent could effectively improve the water stability of asphalt mixture added with alkaline recycled waste powder.The tests results showed that:adding cement,slaked lime and PA-1 asphalt anti-striping agent into the asphalt mixture with alkali recycled waste powder could improve the residual stability,freeze-thaw splitting strength ratio,reduce the flying loss,and effectively improve the water stability of asphalt mixture with alkali recycled waste powder.The same amount of lime slaked lime is more effective than cement in improving the water stability of the asphalt mixture.Compared with cement and slaked lime,the asphalt mixture with PA-1 anti-stripping agent has the highest stability of submerged Marshall stability,the highest ratio of freeze-thaw splitting strength and the lowest loss of flying,it indicated that PA-1 anti-stripping agent had the best effect on improving the water stability of asphalt mixture mixed with recycled waste powder.