Moustafa El-Assaly https://orcid.org/0009-0009-3606-5221

Daniele Malomo https://orcid.org/0000-0002-4518-5841

McGill University, Department of Civil Engineering, Montréal, Canada

ABSTRACT

Old clay bricks represent a significant share of Canada’s masonry building stock, yet their frost durability remains difficult to assess using a testing framework that was originally developed for newly manufactured products. This paper presents a critical review of frost durability evaluation for old clay bricks in Canada through three interconnected layers: the mechanisms governing frost deterioration, the evolution and current acceptance logic embedded in CSA A82, and the interpretive uncertainty that arises when standardized screening and accelerated freeze–thaw procedures are applied to heterogeneous, service-aged brick populations. The review shows that frost deterioration cannot be reduced to an intrinsic pass/fail material property; rather, it emerges from the coupled interaction between pore-network characteristics, moisture transport, degree of saturation at freezing, and the boundary conditions under which freezing propagates. Within this context, current Canadian practice remains useful as a repeatable decision aid, but its interpretation becomes fragile when exposure history, sampling logic, conditioning severity, and within-population variability are not stated explicitly. The review further highlights that the severity and shortcomings of accelerated freeze–thaw protocols depend strongly on exposure configuration, extended test durations and interruption handling. The principal research gaps therefore concern exposure definition, sampling of old bricks, mechanistically grounded interpretation of screening indices, response-based thresholds, and comparability across procedures. The paper concludes by recommending an exposure-informed and uncertainty-aware assessment workflow in which screening metrics, accelerated testing, and response-based indicators are interpreted together to support defensible repair and reuse decisions for older bricks under severe Canadian climatic exposure.

Keywords: frost; durability; clay brick; masonry; CSA A82; Canada