There is a growing demand for such products in the market。 But at the same time, the problems are becoming more and more obvious, such as the stolen cover, cover damage, cover prices are too high and so on, so in order to solve these problems, composite well cap emerged, the following on the composite well cap base fracture reasons and prevention。
1. The cause of the fracture of the composite manhole cover.
1. Grass-roots problems are mainly serious ground sand, base strength is not high, base cracking, after the occurrence of vacancy, cracks produced by heavy pressure.
2. In the construction of composite well cover, excessive water addition in cement self-leveling, no clean base, excessive surface water loss, drying shrinkage cracks, rapid water loss, cement hydration reaction is not fully carried out, surface powdering will also occur, and improper maintenance will also cause bulging and cracking.
3, the greater the construction thickness, the greater the cumulative stress, and the risk of cracking will increase. Within the thickness of 5.0mm, the internal stress caused by the expansion contraction is not enough to cause the drumming directly.
4. Some composite wellbore caps with self-leveling cement thickness exceeding 5mm have the risk of cracking and bulging, which is caused by self-leveling shrinkage and expansion, and a few workers do not know or care about the harm of shrinkage and expansion.
Two. Prevention of base break of compound well cover
1. In order to keep the appearance of the cover beautiful, clear surface patterns and handwriting, cover the well cover with thin sheet of iron or wood during the construction of asphalt pavement, and the black well cover can also be brushed with waste oil to prevent asphalt from spraying on the well cover.
2。 Brick masonry masonry of the well cover should be built according to the size of the well cover designed by the design institute to determine its internal diameter or length X-wide, square circle, and also can be carried out according to the corresponding reference standards, and cast a 40 cm wide concrete protective ring around the well cover, the maintenance period should be more than 10 days。
3. When installing the well cover on the asphalt pavement, we must pay attention to avoiding the construction machinery to roll the well base directly. When casting the whole pavement, we should reserve the hole slightly larger than the well base on the pavement and place it after the asphalt paving.
4. After concrete pouring or asphalt laying, the well cover should be opened and cleaned in time, so as to avoid mortar or asphalt pouring the inspection well cover into a whole, so as not to affect the future opening.
The above is the reason and prevention of the breakage of the compound manhole cover, and I hope it can help everyone。