1. Low-strength grade mortar, such as cement mortar, due to poor cement mortar workability.which is difficult to squeeze the mortar during masonry.
2. Use dry bricks to make the wall dehydrate early which reduce the strength of the mortar. which weakens the adhesion between the bricks and the mortar layer.
3.The masonry speed cannot keep up because the masonry is too long. The water in the mortar is absorbed by the bottom brick, o that the brick layer and the mortar lose their adhesion.
1.Improving the workability of the mortar is the key,to ensuring the fullness of the joint mortar and improving the bond strength. Then choose the suit mortar raw materials is important. Sand cement should be within the shelf life, thickener cellulose ether and redispersible powder are necessary to improve the adhesion.
2.Improve masonry methods,the “three-one bricklaying method” should be promoted,using a large shovel, a brick, a shovel and a squeeze method.
3.Control he length of the grouting. In general temperature,it should not exceed 750mm;when the temperature exceeds 30 ° C,then not exceed 500mm.
4.Never use it on brick walls. The bricks should be wet 1 to 2 days before masonry, so that the moisture content of sintered ordinary bricks and porous bricks can reach 10% to 15% during masonry; the moisture content of lime sand bricks and fly ash bricks can reach 8% to 12%.
5.During winter construction, the brick surface should be properly wet under positive temperature conditions before laying.