橡胶粉与岩沥青复合干法改性高模量沥青混合料试验研究

Experimental Study on High Modulus Asphalt Mixture Modified by Dry Method of Rubber Powder and Rock Asphalt

为探明不同粒度特征的橡胶粉等量替换布敦岩沥青(BRA)对改性沥青混合料路用性能的影响,采用干法改性工艺拌制Sup-13型沥青混合料,开展了残留稳定度试验、冻融劈裂试验、车辙试验、低温劈裂试验和小梁弯曲试验。结果表明:采用较细粒度的橡胶粉相对较粗粒度的橡胶粉,可减小橡胶粉等量替换部分BRA对沥青混合料残留稳定度和动稳定度的不利影响,并能明显提升改性沥青混合料的劈裂抗拉强度、冻融劈裂抗拉强度比和低温劈裂压缩模量,而低温劈裂压缩变形量有所降低;100目的橡胶粉等量替换BRA,使改性沥青混合料的动稳定度提升了21.2%,小梁低温弯曲的弯拉强度和弯曲劲度模量分别提高了71.8%和87.5%。

In order to find out the effect of rubber powder with different particle size characteristics to replace Burton rock asphalt(BRA)in the same amount on the road performance of modified asphalt mixture,Sup-13 type asphalt mixture was mixed by dry modification process.The residual stability test,freeze-thaw splitting test,rutting test,low temperature splitting test and trabecular bending test were carried out.The adverse effect of partial replacement of BRA in the same amount with rubber powder on the residual stability and dynamic stability of asphalt mixture can be reduced by using fine rubber powder compared with coarse rubber powder.It can obviously improve the splitting tensile strength,freeze-thaw splitting tensile strength ratio and low-temperature splitting compression modulus of the modified asphalt mixture,while the low-temperature splitting compression deformation decreases.100 mesh rubber powder replaced BRA in the same amount,which increased the dynamic stability of the modified asphalt mixture by 21.2%.The bending tensile strength and bending stiffness modulus of trabecular at low temperature bending increased by 71.8%and 87.5%respectively.