Development of Maintenance Strategies to Mitigate Bridge End Damage from Water Intrusion

Significant amounts of money are spent annually on the rehabilitation of damaged pavements and approach slabs near bridge ends. Investigation of such failures often reveals that saturated base and subgrade materials or the loss of soil material from underneath the approach slab, pavement, or rip-rap slabs have contributed to failure. This paper reports findings from a research study entitled Water Intrusion in Base–Subgrade Materials at Bridge Ends. The objectives of this research project were to identify potential sources of water intrusion at bridge ends and develop maintenance strategies that can be economically implemented in the field to minimize future occurrences of the problem. The study focused on existing, in-service bridges and remedial strategies that have been successfully implemented. A survey questionnaire was developed and sent to all 25 Texas Department of Transportation administrative districts to collect information about the major factors contributing to water intrusion and bridge-end settlement problems. Field evaluations of selected bridges in four Texas DOT districts were conducted, and one bridge site was selected for detailed field study. On the basis of the information collected, the researchers developed a site assessment protocol to evaluate the potential of a particular site to incur water intrusion and methods to develop optimum repair strategies. The paper reports on the commonly observed sources of water intrusion at the bridge sites investigated. It also lists the preventive maintenance steps that must be taken to ensure that bridge approach pavements have adequate service lives.