主动降温型沥青混凝土制备及性能研究

为降低炎热季节沥青路面温度,提高沥青路面的高温稳定性,减少沥青路面高温车辙病害的产生,同时减少有毒的有机沥青改性剂或路面涂料的使用,采用无机矿质粉末负离子粉作为新型环保沥青改性剂,制备了具有主动降温功能的沥青混凝土(active pavement cooling asphalt concrete,APC-AC)。通过室内车辙板温差试验与室外光照试验,研究了不同负离子粉掺量对APC-AC路面降温性能的影响,并以降温性能为参考指标推荐了负离子粉最佳掺量;借助Hot Disk 2500S导热系数仪对APC-AC及普通沥青混凝土的导热系数、比热容及导温系数进行测试,研究了负离子粉对APC-AC的热学参数影响规律;对APC-AC及普通沥青混凝土进行路用性能试验,研究了负离子粉对沥青混合料高温性能、低温性能、水稳定性的影响。结果表明:与普通沥青混合料相比,APC-AC具有较明显的路面降温效果,当负离子粉掺量为沥青质量的16%时,APC-AC车辙板室内温差试验表面降温幅度为5.9℃,室外光照试验表面温度可降低7.4℃;APC-AC的导热系数、导温系数相较于普通沥青混凝土分别降低9%和20%,比热容则提升14%;与普通沥青混凝土相比,APC-AC的动稳定度提高16%~42%,负离子粉对沥青混凝土的水稳定性与抗裂性能基本没有不良影响。

Research on Preparation and Properties of Active Pavement Cooling Asphalt Concrete

To reduce the temperature of asphalt pavement in hot season,improve the high temperature stability of asphalt pavement,reduce the high temperature defects of asphalt pavement and reduce the use of toxic organic asphalt modifier or pavement coating,inorganic mineral tourmaline anion powder is used as a new environment friendly asphalt modifier,asphalt concrete(APC-AC)with active pavement cooling function is prepared.Through the indoor slab temperature difference test and outdoor illumination test,the effects of different tourmaline anion powder dosage on the cooling performance of APC-AC pavement are studied.The optimal dosage of tourmaline anion powder is recommended by the cooling performance as a reference index.The thermal conductivity,specific heat capacity and temperature coefficient of APC-AC and ordinary asphalt concrete are tested by Hot Disk 2500 Sthermal conductivity meter.The influence of tourmaline anion powder on the thermal parameters of APC-AC is studied.The routine road performance test of APC-AC and ordinary asphalt concrete is carried out to study the effect of tourmaline anion powder on high temperature performance,low temperature performance and water stability of asphalt mixture.The results show that:compared with ordinary asphalt mixture,APC-AC has a more obvious pavement cooling effect.When the amount of tourmaline anion powder is about 16%of the mass of asphalt,the surface cooling range of APC-AC rutting indoor temperature difference test is 5.9℃.The surface temperature of outdoor illumination test can be reduced by 7.4℃;the thermal conductivity and temperature coefficient of APC-AC are reduced by 9%and 20%respectively compared to ordinary asphalt concrete,and the specific heat capacity is increased by 14%;compared with ordinary asphalt concrete,the dynamic stability of APC-AC is increased by 16%~42%,and the tourmaline anion powder has no adverse effect on the water stability and crack resistance of asphalt concrete.