纤维与BRA岩沥青复合改性剂组成优化及混合料性能评价

为了优化木质素纤维、聚酯纤维、BRA岩沥青复合添加剂材料组成,以峰值剪切强度为评价指标,通过极差、方差分析了木质素纤维、聚酯纤维、BRA岩沥青对基质沥青抗剪切强度的影响,优选了纤维的最佳掺配比例及BRA岩沥青的最佳掺量。通过车辙试验、低温弯曲试验、浸水马歇尔和冻融劈裂强度试验研究了纤维与BRA岩沥青复合改性沥青混合料的路用性能。结果表明,当复合添加剂中m(木质素纤维)∶m(聚酯纤维)=1∶2,纤维总掺量为基质沥青质量的7%,BRA掺量为沥青质量的15%时,复合改性沥青具有最优的抗剪切性能。复合改性剂可以同时发挥BRA岩沥青的高温改性优势以及聚酯纤维的低温性能。

Composition optimization of fiber and BRA rock asphalt composite additives and mixtures performance evaluation

In order to optimize the composition of lignin fiber,polyester fiber and BRA rock asphalt composite additive,the peak shear strength was used as the evaluation index,and the effect of lignin fiber,polyester fiber and BRA rock asphalt on the shear strength of the matrix asphalt was analyzed by the range and variance analysis.The blending ratio of fiber and the blending amount of BRA rock asphalt are optimized.The road performance of fiber BRA rock asphalt modified composite additive is studied by rutting test,low temperature bending test,water immersion Marshall and freeze-thaw splitting strength test.The results show that when the m(lignin fiber)∶m(polyester fiber)=1∶2 in the composite additive,the total fiber content is 7%of the mass of the matrix asphalt,and the blending additive is 15%of the mass of the asphalt,modified asphalt has the best shear resistance.The composite additive can fully utilize the high temperature modification advantage of BRA rock asphalt while taking into consideration the low temperature performance of the polyester fiber.