Deterioration of Bridge Deck Element Based on Neutral Axis Analysis

This study investigates the use of the neutral axis as a damage-sensitive feature for structural health monitoring in composite bridge sections. A methodology was developed to calculate the position of the neutral axis and evaluate its changes over time, involving strain measurements from sensors installed along the cross-section of a bridge specimen tested at The BEAST® (Bridge Evaluation and Accelerated Structural Testing lab) at Rutgers, The State University of New Jersey. The BEAST® laboratory is the first full-scale facility designed for accelerated bridge testing under controlled conditions. It applies repeated vehicle loading and environmental cycles, such as freeze-thaw and de-icing, to simulate decades of deterioration in just a few months. This unique setup provides continuous monitoring data to support the evaluation of structural performance over time. The results reported herein demonstrate that increasing neutral axis-centroid deviations correlate with bridge deck degradation. The findings validate the feasibility of neutral axis-based damage detection, highlighting its applicability in structural health monitoring applications.