After the concrete is poured to the corresponding position by the pumping tank truck of the concrete mixing plant, the concrete needs to be cured, which is the responsibility of the construction party. What matters should be paid attention to in the construction and maintenance of mass concrete?
1. The construction party shall formulate the construction technical scheme for high-strength mass concrete, take temperature control measures, reasonably set temperature measuring holes and measure the temperature of concrete. During curing, the concrete curing measures shall be adjusted according to the temperature measurement.
2. When the concrete fails to meet the pouring requirements during pouring, the construction party shall timely contact the on-site dispatcher or technician, and the laboratory technicians and quality inspectors shall be responsible for adjusting the concrete construction ratio. After the concrete arrives at the construction site, no one can add water without authorization. When the slump of the concrete cannot meet the on-site pouring, it shall be adjusted by the on-site technicians.
3. Measures shall be taken to cool the construction site, formwork and reinforcement before concrete pouring by pump truck. Thermal insulation measures shall be taken for formwork. Cover the pump pipe with wet gunny bag, and spray cold water frequently to cool down during pouring.
4. It is suggested to start pouring at night as far as possible, which is conducive to reducing the concrete molding temperature and pouring time during the day. Sun shading measures should be taken for construction during the day.
5. After the concrete is poured to the elevation, the surface of the concrete shall be covered with plastic film after plastering. In order to make the concrete surface harden without damage, it is necessary to cover the grass curtain and fully spray water to keep it wet for at least 24 hours. If water is not sprayed after closed coverage, a large amount of hydration heat will often be generated, drying the surface and producing cracks.
6. After the final setting of concrete, it is required to store water for curing, and the water shall be discharged evenly during water storage to avoid excessive temperature fluctuation on the concrete surface.
7. During curing, it is necessary to prevent sudden change of temperature and avoid exposure to the sun, wind and rainstorm. In the night with large temperature change, it is best to keep warm with thermal insulation materials. When curing is stopped, it should also be dried gradually to avoid cracks.
8. The concrete mixing plant suggests that the construction party should appropriately extend the vibration time when pouring and making concrete test blocks. Because of the large amount of fine concrete powder, it is not easy to vibrate and compact. At the same time, several groups of test blocks can be considered.
