Rehabilitation strategies and material performance of SCC used for the repair of the Jarry/Querbes underpass in Montreal

摘要

Conventional demolition methods can create major problems for the local population. During the course of the Jarry/Querbes underpass repair project, a process normally used in the mining industry, which also presents the advantage of being less noisy, was used to quickly and efficiently demolish the concrete surface of the retaining walls. A problem often encountered during surface repairs to existing concrete elements is the formation of cracks. Cracks are due to restrained shrinkage of the repair concrete. In such a case, given its very special viscoplastic properties, the use of self-consolidating concrete (SCC) represents a major advantage since it limits the formation of cracks. During this repair project, 420 m~3 of fiber-reinforced self-compacting concrete was used to repair a 1700 m~2 surface (retaining walls, abutments and columns), making this the first major repair project in Quebec using fiber-reinforced SCC. This article presents the state-of-the-art methods used in the repair of the Jarry/Querbes underpass and summarizes the main findings of two SCC mixtures used in this project.