ABSTRACT

The deteriorating condition of infrastructure, combined with fiscal limitations experienced by many agencies, necessitates increased service life of bridges. Maintenance and preservation methods such as overlays and sealers have been known to protect bridge decks from deterioration, while also extending a bridge’s service life. It is important to understand the characteristics of various overlay types to make informed maintenance decisions, thus assessing and comparing the performance of thin epoxy overlays and low slump dense concrete (LSDC) overlays is desirable. To evaluate the performance of these two overlay types, the chloride resistance and long-term bond strength of the overlays were assessed. Three bridges were chosen to install each overlay type, with corresponding field and laboratory evaluations performed.

The above tests results indicated that the initial bond strength of both overlays is good, but that the thin epoxy overlays showed decreased performance after 300 F/T cycles. The bond performance of the LSDC remain unchanged for the duration of the freeze–thaw testing, indicating superior long-term performance. As expected, the epoxy overlay performed much better than the LSDC overlay with respect to chloride resistance. These performance metrics are important to keep in mind when selecting maintenance and rehabilitation methods for bridges.

摘要

基础设施状况的恶化，加上许多机构的财政限制，需要增加桥梁的使用寿命。众所周知，诸如覆盖层和密封剂之类的维护和保存方法可以保护桥面免受损坏，同时还可以延长桥梁的使用寿命。了解各种覆盖层类型的特性以做出明智的维护决策非常重要，因此需要评估和比较薄环氧树脂覆盖层和低坍落度致密混凝土 (LSDC) 覆盖层的性能。为了评估这两种覆盖层类型的性能，评估了覆盖层的耐氯化物性和长期粘合强度。选择了三座桥来安装每种覆盖类型，并进行了相应的现场和实验室评估。

上述测试结果表明，两种覆盖层的初始粘合强度都很好，但薄的环氧树脂覆盖层在 300 F/T 循环后表现出性能下降。LSDC 的粘合性能在冻融测试期间保持不变，表明其具有优异的长期性能。正如预期的那样，环氧树脂覆盖层在耐氯化物方面的表现比 LSDC 覆盖层要好得多。在选择桥梁的维护和修复方法时，要牢记这些性能指标很重要。