Comprehensive Risk-Based Evaluation of Existing Structures Using Rebound Hammer Testing and Multi-Criteria Decision-Making Approaches

This study presents an integrated framework for evaluating the structural condition of existing reinforced concrete buildings using a combination of rebound hammer testing, the Hybrid Risk Assessment Method (RAM), and the Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS). Four buildings of varying ages and usage types were selected to capture diverse structural conditions and exposure environments. Rebound hammer tests, conducted in accordance with IS 13311 (Part 2): 1992, provided in-situ compressive strength estimates, while RAM quantified the severity, probability, and detectability of potential failures to derive a Risk Priority Number (RPN) for each structure. These risk scores, along with building age and rebound values, were incorporated into the TOPSIS multi-criteria decision-making framework to rank the buildings by their proximity to an ideal condition. Results indicated that Building 3 exhibited the highest relative closeness to the ideal solution (RCi = 1.0), followed by Building 2, Building 1, and Building 4, the latter having the highest risk and lowest performance. The integrated RAM–TOPSIS approach demonstrated its effectiveness in combining qualitative expert judgment with quantitative field data, enabling a robust, data-driven prioritization of maintenance interventions. This methodology enhances the reliability of non-destructive testing outcomes and supports cost-effective, safety-focused asset management for existing structures.