纤维增强超大粒径沥青混合料的抗裂性能试验研究——以新疆大温差环境为例

Experimental Study on Crack Resistance of Fiber-Reinforced Large-Stone Asphalt Mixtures —Under Large Temperature Differences in Xinjiang

摘要: 针对新疆大温差环境(年均昼夜温差 > 15℃，极端低温−30℃)下沥青路面温缩裂缝频发的问题，文章通过半圆弯曲试验(SCB)和低温劈裂试验，系统研究了钢纤维、聚丙烯纤维和玄武岩纤维对公称最大粒径53 mm (NMAS = 53 mm)的ATB-50与ATB-30沥青混合料抗裂性能的增强效果。结果表明：钢纤维(掺量0.1%~0.3%)可显著提升断裂能与低温疲劳破坏应变，其中ATB-50的断裂能从3.70 J/m² (无纤维)增至4.20 J/m² (0.3%钢纤维)，低温破坏应变从2950 με提升至3300 με；聚丙烯纤维与玄武岩纤维分别提升断裂能5.4%和8.1%，但低温性能改善有限。油石比从3.0%增至3.8%时，钢纤维增强的ATB-50低温破坏应变提升6.5% (3100 → 3300 με)。基于性能–经济性平衡，提出“按需选纤”策略：钢纤维适用于北疆高寒区重载道路，玄武岩纤维适配东疆高温干旱区，聚丙烯纤维可满足南疆乡村公路低成本需求。研究为极端温差区沥青路面材料设计提供了理论依据。

Abstract: To address the temperature-induced cracks in asphalt pavements under extreme temperature differences (annual diurnal variation > 15˚C, extreme low temperature −30˚C) in Xinjiang, this study systematically investigated the effects of steel fibers, polypropylene fibers, and basalt fibers on the crack resistance of large-stone asphalt mixtures (NMAS = 53 mm, ATB-50 and ATB-30) through semicircular bending (SCB) and low-temperature splitting tests. Results show that steel fibers (0.1%~0.3% dosage) significantly improve fracture energy and low-temperature fatigue failure strain. For ATB-50, the fracture energy increased from 3.70 J/m² (non-fiber) to 4.20 J/m² (0.3% steel fiber), and the low-temperature failure strain rose from 2950 με to 3300 με. Polypropylene and basalt fibers enhanced fracture energy by 5.4% and 8.1%, respectively, but with limited low-temperature improvements. When the asphalt-aggregate ratio increased from 3.0% to 3.8%, the low-temperature failure strain of steel fiber-reinforced ATB-50 increased by 6.5% (3100 → 3300 με). A “fiber selection based on needs” strategy was proposed: steel fibers for heavy-duty pavements in northern Xinjiang (cold regions), basalt fibers for high-temperature arid areas in eastern Xinjiang, and polypropylene fibers for low-cost rural roads in southern Xinjiang. This study provides a theoretical foundation for designing asphalt mixtures in extreme temperature variation zones.