Concrete patch repairs under propped and unpropped implementation

A summary of published research on the implementation of concrete patch repair, especially in relation to propping or not of a structure before excavation of the deteriorated concrete, is presented. For completeness, other major considerations for implementing patch repair are mentioned. A dearth of information is observed with respect to repairs of plates and shells. It is argued that the available recommendations are not universally applicable. This is because various researchers have usually considered different problems or only a limited number of influencing parameters in their studies. It is asked whether risk (or cost–benefit)-based methodology can be the means for rationally evaluating various methods of patch repair and their implementation.