Title: Evaluation of the robustness of shrinkage-compensating concrete repair concretes prepared with expansive components
Author(s): Benoît Bissonnette,1* Marc Jolin, Richard Gagné, Pierre-Vincent Certain, and Fabien Perez
Publication: Symposium Paper
Appears on pages(s): 1-18
Keywords: bond; component; cracking; curing; curling; repair; robustness; shrinkage; shrinkage-compensating concrete; temperature.
In order to be cost-effective, surface repairs carried out on concrete structures have to perform satisfactorily over a sufficient period of time. Among the factors that can affect the durability of concrete repairs, drying shrinkage is certainly one of the most significant. Shrinkage compensating concretes (ShCC’s) represent a very attractive alternative to prevent shrinkage cracking in repairs. This paper summarizes the results of a project devoted to repair ShCC’s made with an expansive component, more specifically their robustness as a function of selected parameters. The investigated expansive systems were either, a calcium sulfoaluminate-based (ASTM Type K cement or Type K component) or calcium oxide-based (ASTM Type G component). The assessment of robustness addressed the influence of the mixture design parameters (cement composition, type and dosage of expansive agent, w/cm ratio) and the curing conditions (moist curing conditions, temperature) upon the ShCC’s expansive behavior, the bond between ShCC repairs and an existing concrete substrate, and the chemical prestress generated through the bond. Overall, the results yielded in this study demonstrate the remarkable potential of ShCC’s as crack-resistant and durable repair materials.