The new French technical guide for aiding the management of structures damaged by concrete expansion

The Laboratoire Central des Ponts et Chaussees (LCPC) has published in 2003 a guide to aid owners, managers and laboratories having to cope with structures damaged by an internal expansion of concrete. In order to prioritise the investigations which have to be carried out on a patrimony of structures, the methodology recommends to proceed in 5 steps and refers to specific investigation techniques such as the monitoring of the cracking pattern, the monitoring of the global expansion of the structure and the analysis in the laboratory of samples taken from the structure, including residual expansion test conducted on cores. Apart from some cases of structures for which all investigation techniques must simultaneously be applied, the methodology prioritises the monitoring of cracking and global deformations. The guide also gives some advices on the calculations based on the use of a chemo-mechanical model in order to assess the load carrying capacity of structures, and on the treatment methods that can be applied to mitigate the effects of the concrete expansion, considering that there is no reliable and durable repair method to stop the expansion of a structure. For the covering abstract see ITRD E126028.