Robustness of Shrinkage-Compensating Repair Concretes
Drying shrinkage is one of the least desirable properties of repair concrete, because in restrained conditions, it may lead to shrinkage cracking and thus adversely affect its durability. Shrinkage compensating concretes (ShCCs) made with expansive mineral admixture represent an attractive alternative to prevent shrinkage cracking. This paper outlines a project devoted to the study of ShCC repair material robustness as a function of selected parameters. Two types of expansive agents were used, a calcium sulfoaluminate-based admixture (Type K) and a calcium oxide-based (Type G) one. The assessment of robustness addressed the influence of both 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 expansive behavior, the bond between ShCC repairs and concrete substrates, and ShCC frost durability. Overall, the results yielded in this study demonstrate interesting potential of ShCCs as crack-resistant and durable repair materials.
KeywordsTensile Splitting Strength Mixture Design Repair Material Stress Balance Concrete Substrate
This project has been financially supported by the Natural Sciences and Engineering Research Council of Canada (NSERC), the Québec FQRNT Research Fund and the industrial partners of the Industrial Chair on Durable Repair and Optimized Maintenance of Concrete Infrastructures at Laval University (BASF Building Systems, City of Montreal, City of Québec, Euclid, Holcim, Hydro-Québec, Kerneos, King Packaged Materials, Lafarge, Ministry of Transportation of Québec, W.R. Grace & Co.).
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