NDT Methods Applicable to Health Monitoring of ABC Closure Joints

In Accelerated Bridge Construction (ABC), prefabricated bridge deck elements are connected using “Closure Joints.” Because of cast-in-place nature of closure joints that are expected to go into service and field observations, there have been some concerns about their long-term durability. This has necessitated the need for health monitoring of ABC closure joints using Non-Destructive Testing (NDT) methods. Closure joints contain unique features that sets them apart from conventional deck panels. They require a special treatment when it comes to selecting the appropriate NDT technique. However, a clear guideline for selection of the most applicable NDT method for various types of closure joints has not been developed yet. To address this, a research project was carried out at ABC-UTC at FIU. This report describes this investigation that includes review of all relevant NDT methods and efforts for categorizing closure joints based on features affecting the use of NDT. Since the applicability of NDT methods heavily depend on the type of expected anomaly to be detected and its root causes, all potential defects and damages were identified and investigated using a Damage Sequence Tree (DST). Consequently, damage etiology for closure joints were established using Fault Tree Analysis (FTA). Finally, a quantitative statistical analysis was performed to substantiate the selection of the most applicable NDT methods. The guide and process presented in Section 8 of this report can be readily used by bridge owners and consultants as a practical guide for selection of NDT methods for health monitoring of ABC bridges with closure joints. The proposed guide will be validated in upcoming projects to further support their implementation.