Briefly describe the meaning, advantages and disadvantages of precast construction and cast-in-place construction, and their respective application scope?

Precast: Advantages: the superstructure and substructure can be constructed at the same time, and prefabricated in the beam yard, with less interference, high precision, assembly line operation and time saving.

Disadvantages: Building a beam yard and buying templates will generate certain expenses, and the bigger the project, the more economical it will be.

Cast-in-place: Advantages: It is suitable for the situations that the terrain is complex and it is impossible to hoist the variable cross-section cantilever and Gao Qiao pier of precast beams.

Disadvantages: working at high altitude, the accuracy is not as high as prefabrication, the safety requirements are high, the upper and lower structures cannot be constructed at the same time, and the speed is slow.