The shear behavior and drainage characteristics of coal-fouled ballast when treated with elastomeric polyurethane are assessed by means of large-scale direct shear and permeability tests. The results from direct shear tests confirmed that the shear strength of both stabilized and unstabilized coal-fouled ballast was highly influenced by the extent of fouling (VCI: void contamination index). The performance index (PI) of elastomer-stabilized coal-fouled ballast (ESFB), determined as the fraction of shear strength of fouled ballast to the shear strength of fresh and unstabilized ballast, lies in the range of 1.23 to 0.84. Moreover, the performance of ESFB having VCI ≥30% was found to be either similar to or poorer than that of clean ballast without any treatment, thus indicating that the elastomer treatment may be provided only to ballast with VCI ≤30%. The results from constant head permeability tests indicate that the hydraulic conductivity of ballast (k) is highly influenced by the presence of fouling materials but is only slightly reduced as a result of the elastomer stabilization. The k of ballast decreased from 43 to 0.18 mm/s as the VCI increased from 0 to 75%. For VCI ≥ 45% the k of ballast was found to be lower than that recommended for sub-ballast. On the other hand, the k of ballast reduced slightly from 43 to 37 mm/s because of the elastomer stabilization. Furthermore, an empirical relationship is established between k and e to determine the k of both stabilized and unstabilized fouled ballast.

用弹性聚氨酯处理的煤垢压载物的剪切行为和排水特性通过大规模直接剪切和渗透性测试进行评估。直接剪切试验的结果证实，稳定和不稳定的煤垢压载物的剪切强度受污垢程度（VCI：空隙污染指数）的影响很大。弹性体稳定煤污道碴 (ESFB) 的性能指数 (PI)，确定为污染道碴剪切强度与新鲜和未稳定道碴剪切强度的分数，在 1.23 至 0.84 的范围内。此外，发现 VCI ≥ 30% 的 ESFB 的性能与未经任何处理的清洁镇流器的性能相似或更差，因此表明弹性体处理可能只提供给 VCI ≤ 30% 的镇流器。恒水头渗透率试验结果表明，压载水的导水率（k ) 受结垢材料存在的影响很大，但由于弹性体的稳定作用仅略微降低。随着 VCI 从 0 增加到 75%，镇流器的k从 43 减少到 0.18 毫米/秒。对于 VCI ≥ 45%，发现镇流器的k低于推荐的子镇流器。另一方面，由于弹性体的稳定性，镇流器的k从 43 毫米/秒略微降低到 37 毫米/秒。此外，在k和e之间建立了经验关系，以确定稳定和不稳定的污染压载物的k。