3.

The curing time of wet joint and wet joint concrete shall not be less than 14d.

2.

(8) reinforcement, prestressed reinforcement, formwork, concrete, etc.

(6) pay attention to the accurate positioning of embedded parts.

The foundation at both ends of the post tensioning pedestal and within the appropriate range shall be specially reinforced.

Key points for construction of cast beam bridges 1.

(3) reinforcement, prestressed reinforcement, formwork and concrete shall be constructed in accordance with the relevant provisions of this guide.

(4) during beam installation, pedestrians, vehicles or ships are strictly prohibited from passing in the operation area, and enclosure facilities, safe passage and eye-catching warning signs are set.

(2) the pretensioning pedestal shall be specially designed with calculation sheet.

The remaining concrete, slurry and waste water generated by cleaning concrete equipment shall be properly treated, and it is strictly prohibited to stack or discharge at will.

(2) the pretensioning pedestal shall be specially designed with calculation sheet.

Quality control (1) the foundation of precast and beam storage pedestal shall be reinforced to prevent subsidence and damage to the beam body.

(5) the beam concrete shall be poured continuously in layers, and effective vibration method shall be adopted to avoid unconsolidated or hollow concrete.

(7) the Prefabrication Yard shall be reasonably arranged and hardened.

For high-altitude operation, safety rope, safety belt, guardrail and safety net shall be pulled.

2) storage of beam body (L) the beam storage pedestal shall be specially calculated, and waterproof and drainage facilities shall be set to ensure that the beam body will not be damaged due to the settlement of fulcrum during storage.

(4) effective measures shall be taken to prevent the beam from tipping during storage, transportation and installation.

(4) concrete vibration shall be strengthened to ensure the compactness of concrete.

– General Provisions (1) this section is applicable to precast and installed concrete (prestressed concrete) beams and slab bridges.

5) wet joint and wet joint construction (1) the concrete contact surface at the wet joint and wet joint shall be roughened according to the requirements of the construction joint.

(3) the beam body shall be set with appropriate camber.

Foot Mounted Anchor

(3) the direction and size of pre camber of post tensioning pedestal shall be determined according to previous construction experience or field test.

(7) the formwork removal time of each part shall be determined according to the concrete strength on site and the tensioning of prestressed reinforcement.

3) beam transportation (L) the beam transportation road shall be flat.

(3) after the prestressed duct grouting material at the wet joint reaches the specified strength, the temporary support shall be removed immediately and the system conversion shall be completed in the order specified in the design.

The beam body should be stacked in 2 layers, no more than 3 layers.

(4) the shaped steel formwork should be used for the convenience of dismantling the shaped steel formwork, and the shaped steel formwork should be used for the convenience of dismantling the shaped steel formwork.

(4) when the beam body is stacked in multiple layers, the layers shall be separated by skids.

4) beam body installation (1) the beam body should be installed by guide beam, gantry, bridge erecting machine or crane, and the derrick should not be used.

4.

(2) during the transportation of beam body, special fixing frame should be used to fix the beam body to prevent the beam body from toppling during transportation.

(5) trial hoisting shall be carried out for gantry and bridge erecting machine before formal use.

(2) the installation of beam body shall be accurately positioned, and the installation of support shall be checked in time to ensure uniform stress of support.

(2) the concrete at wet joints and wet joints should be poured in the period with the lowest temperature and relatively stable temperature field, and all wet joints in one joint should be poured at one time.

The maintenance and safety inspection of crane, gantry, bridge erecting machine and other equipment shall be strengthened.

(2) the layout of the Prefabrication Yard shall meet the requirements of prefabrication, transportation, storage and other construction operations.

(3) the beam body should be transported by flat trailer.

Key points of Construction: (1) beam prefabrication (1) the Prefabrication Yard shall be flat and equipped with waterproof and drainage facilities.

The formwork, reinforcement, prestressed reinforcement, beam body, etc.

Construction procedure: the construction procedure of cast beam bridge is generally as follows: construction preparation → Prefabrication Yard construction → beam prefabrication → beam storage → beam transportation → beam installation → wet joint and wet joint construction → acceptance.

(5) take effective measures to ensure the quality of concrete curing.

(3) the storage time of prestressed beams should not exceed 3 months, and under special circumstances should not exceed 5 months.

Operators of cranes, gantry frames, bridge erecting machines and other equipment must work with certificates.

(3) after the beam is installed in place, the adjacent beams shall be temporarily connected and fixed in time to prevent the beam from toppling.

(8) Take effective measures to ensure the concrete curing quality, especially the concrete curing quality in the box.

shall be stacked neatly by classification and the signs shall be standardized.

(4) the transportation speed of beam body shall be strictly controlled.

shall be accepted…

(7) timely check the bearing stress.

The hoisting operation shall be under unified command, and the hoisting rope and hook shall be carefully checked to ensure the safety of hoisting.

(6) beam transportation, installation and other operations should be carried out in the daytime.

(6) during the concrete pouring of beam body, effective measures shall be taken to avoid the floating up or deviation of internal formwork.

(9) In case of abnormal tensioning reverse arch of prestressed beam, the cause shall be found out and effective measures shall be taken before continuing the construction.

(2) the beam body shall be numbered and stored according to the installation sequence.