According to 7.4.7.5's Code for Acceptance of Construction Quality of Concrete Structure Engineering (GB 50204). : Before the concrete strength reaches 1.2n/mm2, it is forbidden to trample on it or install templates and supports.

When it reaches 70%, the formwork can be removed. Generally, it is best to wait until the maintenance is completed and the strength of 100% is completed before going to work.

East China can go up and pay off in three or four hours after work in summer, and it needs to go up for construction every other day in winter; Some projects rushed blindly, and the surface of concrete was not dried. .