1. Box girder steam method: After concrete pouring, seal the beam with a curing cover, and input steam to control the humidity and temperature around the beam. During steam curing, the temperature should be measured regularly and recorded. The pressure thermometer is arranged in the inner box span, 4 meters near the beam end and outside the side formwork. Temperature shall be measured every 2 hours at constant temperature, and every 1 hour when temperature rises and falls to prevent concrete cracks;

2. Natural curing: During the curing period of formwork concrete, measures such as formwork wrapping, watering, spraying and sprinkling should be taken to keep moisture and moisture, so as to ensure that formwork joints are not dehydrated and dry. In order to ensure the smooth form removal, the formwork can be loosened slightly after 24 ~ 48 hours of concrete pouring, and then the formwork can be watered and maintained until the form removal, and then the formwork can be kept moist to the specified age;

3. Curing solution method: the film spraying curing solution is suitable for special-shaped or large-area concrete structures that are not easy to be cured by water spraying. In this method, the perchloroethylene resin solution is sprayed on the concrete surface with a spray gun, and a plastic film is formed on the concrete surface after the solution volatilizes, so that the concrete is isolated from the air, the water in it is prevented from evaporating, and the normal hydration is ensured. Some films will age and fall off after curing, otherwise they are not suitable for spraying on the concrete surface to be painted in the future. In summer, the film should be protected from the sun after forming, otherwise it will crack easily. When curing concrete with spraying curing liquid, no leakage shall be ensured.