Laboratory Investigation of Latvian Historic Brick and Measurements of Water Movement in Historic Masonry Walls

Experimental laboratory tests including density, water absorption, soluble salts, compressive strength and freeze-thaw (FT) resistance have been done on clay, concrete and silicate bricks from 6 masonry buildings in Latvia following CEN standards with adjustments for historic bricks. In addition, in-situ measurements of moisture content in brick masonry walls were done over a 5 month period using Trotec micro-wave apparatus. Laboratory findings include similarities to results of previous research, a surprising lack of quality in newer bricks, a low content of soluble salts and low FT resistance for Soviet-period silicate bricks. Wall measurements reveal the predicted drying in spring, less moisture in greater height and multiple spatial moisture tendencies that require further research.