The weathering resistance of paving tiles is one of the important signs of durability of sintered tiles. The requirements for the weathering resistance of bricks should be determined according to the weathering degree of each region (for the regional division of weathering degree, see GB / T5101-1998). The weathering resistance of bricks is usually divided into three goals: frost resistance, water absorption and fullness coefficient. Freezing resistance means that after 15 freeze-thaw cycles, no frost damage such as cracks, delamination, peeling, chipping, and corner loss occurs; and the weight loss rate is less than 2%, and the strength loss rate is less than the regular value. Water absorption refers to the weight water absorption for 24 hours of soaking at room temperature. The fullness coefficient refers to the ratio of the water absorption rate at room temperature to 24h and the boiling water absorption rate at 5h.
Generally, the anti-weathering function of the brick is judged by the goals of frost resistance, water absorption and fullness coefficient. National standard (GB5101-2003) rules, according to the province where the project is located, put forward different requirements on the weathering resistance of the brick (water absorption, fullness coefficient and frost resistance). The provinces of Northeast, Northwest, and North China are classified as severely weathered areas. Henan Province and areas south of the Yellow River are classified as non-severely weathered areas. Bricks in Northeast, Inner Mongolia, and Xinjiang (particularly severely weathered areas) must be subjected to freeze-thaw experiments. The weathering resistance of bricks in other provinces and regions is identified by water absorption and fullness coefficient. When the rules of the table are met, the freeze-thaw experiment may be omitted and the weathering-resistant function is qualified. Otherwise, the above-mentioned freeze-thaw experiment must be performed. Sintered bricks are mainly used for load-bearing walls, columns, arches, chimneys, trenches, foundations, etc. of masonry construction projects, and sometimes for small water conservancy projects, such as gate piers, culverts, aqueducts, retaining walls, etc. The effect of mortar properties on the strength of brickwork. Before masonry, the bricks must be wetted with water in advance. The reason is that the water absorption of the bricks is large, generally 15% to 20%.