Guan Yao, Zhang Yao, Sang Tianyi, Ding Yifeng, Yan Zichao, Kang Aihong
College of Civil Science and Engineering, Yangzhou University, Yangzhou 225127, China.
Research Center for Basalt Fiber Composite Construction Materials, Yangzhou 225127, China.
Materials (Basel). 2024 Nov 27;17(23):5813. doi: 10.3390/ma17235813.
Hot in-place recycling (HIR) is a sustainable pavement rehabilitation method. However, it is susceptible to aging processes that can compromise its mechanical properties and long-term performance. This study investigates the effects of thermo-oxidative (TO) and ultraviolet (UV) aging on HIR mixtures. Basic performance tests were conducted on the aggregate gradation, moisture content, and asphalt content of the reclaimed asphalt pavement (RAP) to assess the aging level. Simulations of long-term and short-term oxidative aging of the HIR mixture, along with 12 months of UV irradiation, were performed to evaluate its high-temperature stability, low-temperature crack resistance, and water stability. The Verhulst model was employed to establish a predictive equation for performance attenuation under UV aging. To quantify the photoaging effect, indicators for UV aging degree were proposed to characterize the road performance of the HIR mixture, including the aging rate and the aging residual index. Results indicate that the improvement in high-temperature performance after aging is limited, but cracking resistance decreases substantially. Notably, the flexural tensile strain was reduced by 129.25 με for 10 years of TO aging compared to 12 months of UV exposure, underscoring the importance of considering environmental factors in performance predictions. This study emphasizes the need for enhanced aging mitigation strategies to improve the sustainability and reliability of HIR mixtures in practical applications.
就地热再生（HIR）是一种可持续的路面修复方法。然而，它易受老化过程影响，这可能会损害其力学性能和长期性能。本研究调查了热氧化（TO）和紫外线（UV）老化对HIR混合料的影响。对再生沥青路面（RAP）的集料级配、含水量和沥青含量进行了基本性能测试，以评估老化程度。对HIR混合料进行了长期和短期氧化老化模拟以及12个月的紫外线照射，以评估其高温稳定性、低温抗裂性和水稳定性。采用Verhulst模型建立了紫外线老化下性能衰减的预测方程。为了量化光老化效应，提出了紫外线老化程度指标来表征HIR混合料的路用性能，包括老化速率和老化残留指数。结果表明，老化后高温性能的改善有限，但抗裂性大幅下降。值得注意的是，与12个月的紫外线照射相比，热氧化老化10年后的弯曲拉伸应变降低了129.25 με，这突出了在性能预测中考虑环境因素的重要性。本研究强调需要加强老化缓解策略，以提高HIR混合料在实际应用中的可持续性和可靠性。
