Bond Performance of Reinforcing Bars in Thin Concrete Panels with the Presence of Innovative Void Formers Under Tensile Loading

This paper investigates the bond performance of reinforcing bars in thin concrete elements incorporating an innovative, patented ‘ROBOVOID’ void-former solution. A series of full-scale experiments, representing sub-assemblies of larger structures, were conducted using various bar sizes and configurations, bond length, concrete and reinforcing details. The results from the experiments were compared with results from the Australian Standard, European Code and American concrete design methods. The suitability of both standards was investigated and a design recommendation for ROBOVOID panels is presented. The bond length required to achieve full development of the reinforcing bar strength for ROBOVOID slabs can safely be ensured via the proper application of concrete design standards, and because of the thinner concrete panels and shallow internal concrete cover where the bars are placed directly on the plastic void forming components.