粉胶比对煤直接液化残渣复合改性沥青胶浆及混合料低温性能的影响

Effect of Filler to Asphalt Ratio on Low-temperature Performance of Direct Coal Liquefaction Residue Composite Modified Asphalt Mortar and Mixture

本工作旨在探究粉胶比对煤直接液化残渣(Direct coal liquefaction residue,DCLR)复合改性沥青胶浆及混合料低温性能的影响。设计了四种粉胶比(0.6、0.8、1.0、1.2)下三种沥青胶浆及混合料(SK-90沥青胶浆及混合料、DCLR改性沥青胶浆及混合料、DCLR复合改性沥青胶浆及混合料),采用弯曲蠕变劲度(BBR)试验、低温小梁试验、半圆弯曲(SCB)试验、接触角试验进行性能评价。试验结果表明:相比于DCLR改性沥青胶浆及混合料,DCLR复合改性沥青胶浆临界破坏温度显著降低,混合料破坏应变提升较大,基本上达到SK-90沥青胶浆及混合料的低温性能水平。综合各种试验结果,三种混合料粉胶比为1.0时的低温性能最优。尤其是DCLR复合改性沥青混合料在粉胶比为1.0时,表现出更好的低温应力松弛能力,较强的抗开裂能力与抗裂缝发展能力。但其受粉胶比变化敏感性较强,当粉胶比增加到1.2时,混合料低温抗开裂能力与抗裂缝发展能力显著降低。

The objective of this paper is to investigate the low-temperature performance of direct coal liquefaction residue(DCLR)composite modified asphalt mortar and mixtures with different filler to asphalt ratios.Evaluation of the performance of three types of asphalt mortar and mixtures(SK-90 asphalt mastics and mixtures,DCLR modified asphalt mastics and mixtures,DCLR composite modified asphalt mastics and mixtures)with four types of filler to asphalt ratio(0.6,0.8,1.0,1.2)using the BBR test,the low-temperature trabecular beam test,the SCB test,and the contact angle test.The test results show that:DCLR composite modified asphalt mortar critical damage temperature is significantly reduced,the damage strain of the mixture is significantly improved,compared with the DCLR modified asphalt mortar and mixture,the low-temperature performance has been significantly improved,basically reaching the SK-90 asphalt mortar and mixture of the low-temperature performance level.Comprehensive results of various tests,three kinds of mixtures filler to asphalt ratio of 1.0 when the low-temperature performance is optimal.DCLR composite modified asphalt mixtures show better low-temperature stress relaxation ability,resistance to cracking ability and crack development ability is stronger.However,it is more sensitive to the change of filler to asphalt ratio and is not easy to resist the expansion of low-temperature cracks.When the filler to asphalt ratio is increased to 1.2,the low-temperature cracking resistance of the mixture and the crack development resistance is significantly reduced.