Integrated Condition Rating Model for Reinforced Concrete Bridge Decks

Most commonly used bridge condition rating systems utilize data emanating from visual inspection reports, inevitably associated with considerable uncertainty. This could possibly lead to unnecessary repair actions or overlooking critical problems. Although the advent of nondestructive testing (NDT) technologies has significantly aided more precise assessment of bridge decks, such techniques have not received due attention in the bridge rating process. Therefore, in the present study a systematic integrated condition rating procedure for concrete bridge decks using fuzzy mathematics has been developed. Infrared thermography (IRT), ground-penetrating radar (GPR), and visual inspection are employed to identify and quantify surface and subsurface defects. The fuzzy synthetic evaluation (FSE) approach was utilized to convert the measured defects into fuzzy condition categories, which were then integrated to develop an overall bridge deck condition index (BDCI). The information sought to identify the parameters affecting the integration process were gathered from bridge engineers with extensive experience and intuition. The developed rating procedure and its application are demonstrated through a case study on a full-scale reinforced concrete bridge deck. The results revealed that rating a bridge deck based solely on visual inspection can overestimate or underestimate its condition index, while integrating NDT techniques can provide a more reliable rating. The proposed methodology could provide bridge stakeholders with a rational appraising tool for the condition of bridge decks, allowing better allocation of budgets and more precise maintenance decisions.