According to the description of the topic, it is most likely that the settlement cracks develop vertically or at an angle of 30~45 degrees to the ground. Large through settlement cracks often have a certain deviation from top to bottom. The contraction joint of this pavement is a little shallow. Although it has little to do with this concrete crack, it should be at least 1/3 deep.
Solution: If the road surface is painted black, no subsequent treatment is required. If it is not painted black, it will be cut into rectangles, and the treated subgrade will be poured again. Asphalt can also be injected to reduce possible water damage to the subgrade.
Extended data:
Pavement construction
The general process of concrete pavement construction is:
① Install side formwork, joint fillet, dowel bar, steel mesh, etc.
(2) mixing the concrete mixture and transporting it to the construction site;
③ Paving and vibrating of concrete mixture;
(4) Leveling the concrete surface, brushing or engraving small scratch-proof grooves;
⑤ Curing and caulking. In addition, vacuum water absorption and vibration rolling are tried in concrete pavement construction.
In early years, rail formwork was used in the construction of concrete pavement. On the one hand, it is used as a side formwork, and on the other hand, it can be used for the driving operation of steel wheel concrete mixers, trucks, pavers and vibrators.
In the 1940s, the concrete pavement construction in some industrialized countries was fully mechanized. From foundation forming, track formwork installation and disassembly, concrete mixing, paving, tamping and finishing, to joint cutting, joint filling and maintenance, assembly line operation is carried out by special machinery.
1960 A slipform cement concrete pavement paver appeared (see cement concrete pavement paver). Formwork is installed on both sides of the tail to move forward randomly, paving, vibrating, finishing and grooving are completed in turn, and the formed road surface extends out from the back of the machine.
In addition, there is a combined paver for concrete pavement, which can form the subgrade at one time, spread and compact the base, and then lay concrete slabs on it.
Strengthen and add stories
When the concrete pavement is damaged, an asphalt concrete layer with a thickness of at least 15 ~ 20cm can be added to prevent cracks and joints from being reflected on the asphalt layer. If new concrete is added, there are three forms:
1. Combined adding layer: roughen the old pavement, coat it with cement slurry or epoxy resin, and then lay a new concrete layer to make it well combined with the old pavement.
2. Adding layer by local combination: clean the old pavement first, and then lay a new concrete layer, which is poorly combined with the old pavement.
3. Isolation and adding layer: first lay a layer of linoleum or 2 ~ 3 cm thick coarse sand or asphalt sand on the old pavement, and then lay a new concrete layer.
Concrete pavement is durable, can meet the requirements of modern high-speed, heavy-duty and dense automobile transportation, and has low maintenance cost, so it is widely used in airport runways, expressway, trunk highways, urban roads, factory roads, parking lots and so on. It is also especially suitable for the pavement of tunnels and water roads.
Baidu encyclopedia-cement concrete pavement
Baidu Encyclopedia-Code for Construction and Acceptance of Cement Concrete Pavement