Precast concrete components are concrete components that are pre-fabricated in a factory or on-site.

Assembled concrete structure is a concrete structure assembled from precast concrete components through reliable connections, i.e. pure PC structure.

Assembled monolithic concrete structure is an assembled concrete structure that consists of precast concrete elements connected in a reliable way and formed into a monolithic structure with on-site post-cast concrete and cementitious grout, i.e., a structure in which PCs and cast-in-place **** exist.

The main types of PC components are: exterior wall panels, interior wall panels, laminated panels, balconies, air-conditioning panels, staircases, prefabricated beams, prefabricated columns.

Prefabrication rate refers to the volume ratio of the material usage of prefabricated component part of the main structure and enclosure structure above the outdoor floor of the assembled concrete building to the total material usage of the corresponding component. Prefabrication rate is the prefabrication index of a single building, such as a house prefabrication rate of 15%, which is the ratio of the volume of prefabricated components of 150 cubic meters to the total volume of concrete of 1,000 cubic meters.

Assembly rate is the ratio of the number (or area) of prefabricated components and building parts in an assembled building to the total number (or area) of similar components or parts. Assembly rate is generally the proportion of assembled buildings in a project. For example, if a project *** has 10 buildings, 5 of them are PC structures, i.e. the assembly rate is 50%.

Advantages of PC structure

1, high seismic performance

C structural calculations are mainly carried out in accordance with the load-bearing capacity of each member itself, which is connected into a whole by appropriate means. Nodes, joints pressure through the backing concrete or grouting or seating slurry directly transfer; tensile force by the connecting bars, pre-embedded weldments transfer. When the bond strength of precast concrete joint interface is higher than the member itself concrete tensile and shear strength, can be regarded as equivalent to cast-in-place concrete.

Connection parts according to the direction and size of the deformation can be made into sliding, articulated or solid support (assembly is difficult to make a rigid connection). When there is an earthquake and other disasters, the PC structure mainly through the strain at the nodes to eliminate the stress, not so much as to allow the stress to continue to be transmitted within the structure, to prevent the structure from collapsing continuously.

2, factory production

PC components due to factory production, you can use dry hard concrete, extrusion molding, high-frequency vibration, high-temperature maintenance, centrifugal molding and other processes, the compressive strength of the concrete can easily do more than 80MPa. While the site cast-in-place structure is limited to the conditions, it is difficult to do. At the same time, due to the different processes, without increasing the cost of the premise is easy to make "clear water concrete" and "decorative concrete" to reduce the cost of subsequent decoration and renovation. pc components due to the scale of automated production of assembly line operation, its finished product production costs The cost of finished product production of PC components is decreasing due to large-scale automated production.

3, PC component productization

Some industrial plants and some civil buildings in the components are highly standardized products, can be produced according to the manufacturing industry batch continuous production, the formation of industrial inventory for procurement and sales.

The advantages of PC are precisely what cast-in-place concrete is difficult to have.

Is PC construction expensive?

The industry's current problem with PC construction is "high cost," which is a fact, or perhaps a falsehood.

PC building cost composition and cast-in-place structure is certainly different, its process and the traditional cast-in-place process is fundamentally different, the construction process is different, building performance and quality will be different, the two "cost" is not comparable. The construction field continues to carry out technical and technological innovation, * the ultimate goal is only two: in the same cost conditions to improve building performance, or in the same building performance conditions to reduce the cost. If a new process can both reduce the cost and improve the quality of the building, of course, better, but not too idealistic.

Put in the macro thinking dimension, the cost is only a factor to consider and a point, from the overall situation, from the whole, from the long-term thinking, the future, in order to green low-carbon and improve building quality, appropriate increase in cost is also acceptable, and with the continuous progress of the PC technology, the cost will gradually decline.

PC standardization, design and production of standardized components, can be common in the assembly of buildings, building industrialization, the first to complete the "modulus coordination principle standard". Only in this way can reduce the cost of PC.