Construction Technology Requirements for Concrete Casting 1) The free height of concrete falling from height should not exceed 2 m. 2) Before pouring concrete for vertical structure, 50100mm thick cement mortar with the same composition of mortar in concrete should be filled at the bottom; when the pouring height exceeds 3M, chute, tandem device should be used to prevent concrete segregation. 3) Pouring should be carried out continuously, and when it must be intermittent, the secondary concrete should be poured before the initial setting of the front layer; otherwise, construction joints should be retained. 4) Layer-by-layer pouring and vibration tamping are suitable.Inserted vibrators should be inserted quickly and pulled slowly. The moving distance should not be greater than 1.5 times of the radius of the vibrator, and the distance from the model should not be greater than 0.5 times. The depth of the vibrator inserted into the lower concrete should not be less than 50 mm. 5) When pouring beams and slabs connected with columns and walls as a whole, they should stop for 1-1.5 hours after pouring the columns and walls, and then continue pouring. 6) Concrete should be poured into beams and slabs at the same time, slabs with primary and secondary beams should be poured along the direction of secondary beams, one-way slabs should be poured along the long side of the slabs, and concrete can be poured separately in arch and beam structures with height greater than 1 m. 7) In the process of concrete pouring, the situation of formwork, bracket, reinforcing bar, embedded parts and reserved holes should be observed frequently; when deformation and displacement occur, timely measures should be taken to deal with them.