Yang Guangqing, Bi Yanlei, Wang Zhiqiang, Si Chundi, Li Ting, Pu Changyu, Huo Erjin
School of Civil Engineering, Shijiazhuang Tiedao University, Shijiazhuang, 050043, China.
School of Traffic and Transportation, Shijiazhuang Tiedao University, Shijiazhuang, 050043, China.
Environ Res. 2025 Jul 5;285(Pt 1):122293. doi: 10.1016/j.envres.2025.122293.
Although cement-stabilized macadam (CSM) base is widely used in highway construction for its excellent mechanical properties, but its poor shrinkage resistance leads to thermal and drying shrinkage cracks, which remains a critical challenge. This study used four distinct particle sizes of waste tire rubber particles (RP) to replace fine aggregates through equivalent volumetric and particle size. The strength of rubber cement-stabilized macadam (RCSM) was assessed through unconfined compressive strength (UCS) testing. Following strength validation, systematic investigations into the synergistic effects of RP size (RPS) and RP replacement rate (RPRR) on shrinkage characteristics were conducted through drying shrinkage and thermal shrinkage tests. A dual-index mathematical model (strength retention rate vs. crack resistance coefficient) was established to optimize RCSM mix proportion design, coupled with mechanistic analysis of shrinkage mechanisms and environmental benefits. The results indicate that the shrinkage performance of RCSM exhibits an inverse correlation with RPS and a positive correlation with RPRR. RPRR emerges as the dominant factor governing shrinkage behavior, while RPS predominantly determines the compressive strength. To reconcile mechanical performance with crack resistance, an equilibrium optimization scheme is proposed: RPS = 0.6-1.18 mm and RPRR = 75 %. Mechanism analysis reveals that the high elasticity of RP mitigates shrinkage stresses through energy buffering effects, while its hydrophobic nature contribute to reduced shrinkage coefficients. Notably, the 4.75-RC-100 formulation achieves negative carbon emissions. This research provides methodological references for performance optimization of pavement base materials while establishing an innovative pathway for resource utilization of waste tires.
尽管水泥稳定碎石基层因其优异的力学性能在公路建设中被广泛应用，但其抗收缩性能较差，会导致温缩和干缩裂缝，这仍然是一个关键挑战。本研究使用四种不同粒径的废旧轮胎橡胶颗粒（RP）通过等效体积和粒径来替代细集料。通过无侧限抗压强度（UCS）试验评估橡胶水泥稳定碎石（RCSM）的强度。在强度验证之后，通过干缩和温缩试验对RP粒径（RPS）和RP替代率（RPRR）对收缩特性的协同效应进行了系统研究。建立了双指标数学模型（强度保留率与抗裂系数）来优化RCSM混合料配合比设计，并对收缩机理和环境效益进行了机理分析。结果表明，RCSM的收缩性能与RPS呈负相关，与RPRR呈正相关。RPRR是控制收缩行为的主导因素，而RPS主要决定抗压强度。为了兼顾力学性能和抗裂性能，提出了一种平衡优化方案：RPS = 0.6 - 1.18毫米，RPRR = 75%。机理分析表明，RP的高弹性通过能量缓冲效应减轻了收缩应力，而其疏水性有助于降低收缩系数。值得注意的是，4.75-RC-100配方实现了负碳排放。本研究为路面基层材料性能优化提供了方法参考，同时为废旧轮胎资源利用开辟了创新途径。
