Reason:
1. Assembling small steel molds, not set up according to regulations, resulting in poor overall performance of the building
2. The foundation where the formwork is placed is not firm, no flat plate is placed, and poor waterproof measures cause the foundation to sink
3. Wooden building formwork or plywood is used for construction. After passing the acceptance, the concrete is not poured in time, and the surface is deformed due to long-term sun and rain.
4. The support spacing is too large, and the rigidity of the steel plate is poor
5. The speed of pouring concrete for walls and columns is too fast, the height of one pouring is too high, and the vibration is excessive.
Solution:
1. When the combined small steel formwork is assembled, the connectors should be placed according to the regulations, and the spacing and specifications of the purlins and the tension bolts should be set according to the design requirements.
2. The support spacing at the bottom of the beam should be able to ensure that there is no deformation under the action of concrete weight and construction load. If the support bottom is a soil foundation, it should be compacted first, set up drainage ditches, and lay long skids or section steel to ensure support Do not sink.
3. When using wooden building formwork and plywood building formwork for construction, concrete should be poured in time after acceptance to prevent the wooden building formwork from being deformed due to long-term exposure to the sun and rain
4. When designing building formwork and support systems, full consideration should be given to its own weight, construction load, concrete content and lateral pressure generated during pouring, so as to ensure that building formwork and supports have sufficient bearing capacity, stiffness and stability.
5. For cast-in-place reinforced concrete beams and slabs with a span of not less than 4m, the building formwork should be arched according to the design requirements; when there is no specific requirement in the design, the arching height should be 1/1000-3/1000 of the span.
