SMITS, A. and GREGOIRE, Y.
Belgian Building Research Institute (BBRI), Division of Materials
TIRLOCQ, J. and LEFORT, V. and ANDRE, S
Belgian Ceramic Research Center (BCRC), Research Department
In June 2006 a European method for the determination of the frost resistance of clay masonry units was published as CEN/TS 722-22.
In order to evaluate it compared to the Belgian method, considered as suitable for the Belgium climate, BBRI started an experimental research program in collaboration with BCRC. A detailed parametric study (impregnation level, number of cycles, water spraying…) was performed on a dozen brick types.
The temperatures in the bricks were monitored showing fundamental differences. Freeze-thaw effects occurred over the complete thickness for the Belgian method contrary to the European method where underlying masonry remained frozen.
To evaluate the severity, quantitative methods to measure the loss of dynamic elasticity modulus and cohesive strength were applied.
We can conclude that the Belgian method is more severe than the European one. Since the European method shows interesting advantages (masonry walls which allow test mortars or surface treatments, superficial cycling) further work is planned in optimizing on one hand the principles of the test (uniformity of thawing, ease of fabrication and inspection …) and on the other hand parameters related to the severity (impregnation level, number of cycles …) in order to simulate different climatic regions.
masonry units, clay, frost resistance, durability