Cost-Effective Methods to Retrofit Metal Culverts Using Composites

One of the current pressing problems for all DOTs is the corrosion-oriented deterioration of existing metal culverts. These metal culverts typically are designed for a life of 50 years. However, corrosion is making them last no longer than 30 years. A Glass Fiber Reinforced Polymers (GFRP) pipe section has been evaluated as a fit-in GFRP profile liner for complete repair and rehabilitation of the corroded metal culvert with an expected life of 75 years. This is mainly because of the corrosion free nature of the GFRP material. A comprehensive rehabilitation methodology and laboratory scale three-point bending test was conducted to test the composite action of the steel-GFRP section. A finite element model was developed to provide inference on the mechanics of the GFRP-CMP section and the effect of corrosion on the mechanics of the retrofitted pipe. The FE model was verified with experimental observations and will be used to design GFRP section for retrofitting an existing culvert in the field. A Life Cycle Cost Analysis model was developed to conduct a cost-benefit analysis of the proposed retrofitting technique and compare it with other existing technologies.各运输管理部门（Department of Transportation, DOT）当前面临的紧迫问题之一，便是既有金属涵洞因腐蚀引发的劣化。此类金属涵洞的设计服役寿命通常为50年，但腐蚀问题使其实际服役时长不足30年。研究人员已将玻璃纤维增强聚合物（Glass Fiber Reinforced Polymers, GFRP）管段作为嵌入式GFRP型材内衬，用于腐蚀金属涵洞的全断面修复与翻新，预计翻新后管道服役寿命可达75年，这主要得益于GFRP材料的抗腐蚀特性。研究人员制定了一套完整的翻新修复方案，并开展了实验室尺度的三点弯曲试验，以检验钢-GFRP组合管段的协同工作性能。同时构建了有限元模型，用以分析GFRP-CMP组合管段的力学行为，以及腐蚀对翻新后管道力学性能的影响。该有限元模型已通过试验观测结果验证，后续将用于设计现场既有涵洞翻新所需的GFRP管段。此外，研究人员还构建了生命周期成本分析（Life Cycle Cost Analysis）模型，对所提出的翻新技术开展成本效益分析，并将其与其他现有修复技术进行对比。