Monitoring method of waveguide rod induced acoustic emission for prestressed steel strands damage in post-tensioned double hollow slabs

Prestressed tendons play a critical role in the stability of small- and medium-span bridges. This study presents a new method for continuous, real-time acoustic emission (AE) monitoring and damage localisation in prestressed tendons of post-tensioned prestressed hollow slab bridges. The method utilises a waveguide rod to direct AE waves from damaged double-plate prestressed tendons and incorporates a test platform based on practical engineering scenarios, where double-plate anchorage reinforcement is achieved through welded bending and connection. To simulate AE damage sources, a technique involving the hammering and breaking of waveguide rods was applied. This approach successfully simulated significant damage to steel strands over 16 m in length in prestressed hollow slabs and was effective in identifying various types of damage within the prestressed steel strands. The AE monitoring method for dual-plate prestressed tendons relies on waveguide rod technology with only two sensors. This method allows for accurate localisation of damaged prestressed tendons within the hollow slab, effective detection of concrete damage, and precise identification of its location. Additionally, it enables efficient monitoring and precise localisation of broken wires within the prestressed tendons. This method reduces operational costs and simplifies procedures, contributing to the maintenance and assessment of in-service small- and medium-span bridges.