Building Research Establishment Ceram Building Technology

The freeze/thaw resistance of 14 brick types during ten winters’ exposure at a severe climate site in the UK has been compared to results from a laboratory test. This test was developed in the UK and forms the basis of the draft European standard for assessment of clay brick freeze/thaw durability. The test is widely recognised as a reliable accelerated method for assessing the durability of brickwork in severe conditions. However, it is important that results can be demonstrated to relate to those from a severe natural exposure environment. The exposure site testing was clearly able to illustrate the difference in durability between bricks classed as F-category (fully frost resistant) and M-category (moderately frost resistant). In general terms, each winter of the conditions represented by the severe exposure site was equivalent to about 20 laboratory freeze/thaw cycles in terms of the stresses produced within bricks susceptible to frost damage.