单掺及复掺纤维的高模量沥青混合料路用性能研究

Study on Road Performance of High Modulus Asphalt Mixture with Single and Composite Fiber

为评价单掺及复掺纤维对BRA改性高模量沥青混合料性能的增强作用,采用半圆针入度试验、直接拉伸试验研究了纤维对高模量沥青柔韧性和剪切性能的影响,基于车辙试验、贯入剪切试验、低温弯曲试验评价了纤维高模量沥青混合料的各项性能。结果表明:单掺及复掺纤维均能显著提高BRA高模量沥青的蠕变柔量和抗剪切强度;纤维的微观形貌差异导致其对高模量沥青及其混合料性能改善效果各有侧重,采用复掺纤维方案可实现不同纤维对BRA改性沥青性能改善效果的叠加作用;复掺纤维对高模量沥青混合料的低温抗裂性能、长期高温稳定性等各项路用性能有较大提升并且效果更加均衡,有较好的技术优越性。

In order to evaluate the strengthening effect of single and compound fiber on the performance of BRA modified high modulus asphalt mixture, the semicircle penetration test and direct tensile test were used to study the influence offiber on the flexibility and shear performance of high modulus asphalt mixture, and the performance offiber high modulus asphalt mixture was evaluated based on rutting test, penetration shear test and low-temperature bending test. The results show that the creep compliance and shear strength of BRA high modulus asphalt can be significantly improved by adding fiber alone or in combination. The difference of micro morphology offibers leads to a certain emphasis on the performance improvement of high modulus asphalt and its mixture. The composite fiber can greatly improve the low temperature crack resistance, long-term high temperature stability and other road performance of high modulus asphalt mixture, and the effect is more balanced, with better technical advantages.