Structural and Environmental Characterization of Modern Concrete Masonry for Climate Change Design Adaptation

In 2018, the results of a Climate Change Adaptation Standards Inventory Analysis conducted by the Canadian Standards Association (CSA) indicated cavity-wall design as requiring urgent climate change adaptation provisions. Distress in cavity-walls is often attributed to excessive differential movements due to moisture-induced volumetric variations, producing cracks in outer clay brick veneer and compromising durability, which may increase with climate change—test data are, however, still scarce, and only refer to individual blocks/bricks rather than mortared masonry samples. To address these knowledge gaps and devise climate change-adapted design alternatives for cavity-wall structures, a comprehensive research project has recently been launched at McGill University, co-sponsored by Natural Sciences and Engineering Research Council (NSERC), Mitacs, the Canadian Masonry Design Centre (CMDC) and the Canadian Concrete Masonry Producers Association (CCMPA). The latter focuses on the design challenges and structural implications related to the use of wider cavities (to augment thermal insulation) through mechanical and environmental tests, as well as numerical modelling, vital for identifying potential criticalities and opportunities in such new climate-adapted designs. In this paper, we present preliminary results from structural and environmental laboratory characterization studies on modern concrete masonry assemblies, including uniaxial compression tests on masonry units, doublets, triplets and prisms, but also innovative moisture tests specifically conceived to monitor the volumetric variations of both units alone and masonry specimens under controlled temperature and relative humidity, therefore providing a more accurate overview of drying shrinkage. Produced data, combined with those collected in the next research stages through additional tests also on clay brick veneers and building-scale numerical modelling, will enable us to evaluate the combined effects of climate change and multiple design alternatives to meet more stringent sustainability goals, vital for ensuring the durability of the next generation of masonry constructions.