It really depends on what foundation your foundation concrete is. Generally speaking, the foundation concrete of bridge type has strength requirements, but it cannot be specified by curing time. For example, if the concrete test block is retained in summer, the superstructure construction shall be carried out according to the general strength requirements, and the test block can be sampled in 7 days. For the construction with high strength requirements, such as pier concrete construction, it is required that the strength test of pile foundation concrete test block be carried out 28 days later.

Generally, it is enough to maintain the foundation concrete of highway engineering for 5 ~ 7 days in summer. If it is necessary to backfill earthwork backfill material or pipeline foundation concrete for 3 days in summer, it should be enough. Winter is hard to say. It depends on your winter maintenance measures and the ambient temperature. When the air temperature is within the range of 5- 10, it will take more than 10 days to dismantle the formwork.