Basic requirements for beam making of moving formwork
1. The bottom mold of the movable formwork bridge building machine should be set with pre-camber. This pre-camber is responsible for the elastic deformation of the main girder under the load of the artificial bridge. This elastic deformation should be calculated based on the actual weight (weight) of the concrete and corrected with the relevant experimental data.
2. The beam concrete should be continuously poured by pumping concrete and completed once in the initial setting time.
3. The requirements for inspection of raw materials, steel bar processing and erection, hole making, prestressing rib production, vacuum assisted grouting, demoulding, etc. shall be in accordance with the “Trains and Bridges of Passenger Dedicated Lines”. Relevant provisions of the Engineering Construction Technical Guide.
4. Whether the inverse camber degree is consistent with the design, the super-pull stress of the upper flange of the concrete beam body shall not be caused by the rebound of the main beam of the bridge machine. If necessary, the elevation of the bottom mold should be lowered with the tension of the prestressing tension.
5. The main factors affecting the deflection of the suspended cast beam are: concrete bulk density, elastic modulus, shrinkage and creep, sunshine and temperature changes, prestressing, structural system conversion, construction load and bridge pier displacement.