1
European standard superimposed shear wall cross-section and reinforcement construction practice
European superimposed shear wall construction requirements:
- 1) The thickness of the blade of the superimposed shear wall should be calculated according to the diameter of the horizontal steel bar and vertical steel bar and truss rebar of the shear wall and add the protective layer of the steel bar.
- 2) According to the fireproof and non-fire protection requirements, the thickness of the protective layer is different, and the thickness of the superimposed shear wall blade with fire protection requirements should be increased.
- 3) The thickness of the single-sided blade of the general European superimposed shear wall is 60~70mm.
- 4) The minimum specification of truss reinforcement of The European superimposed shear wall is 8/5/5, that is, the upper string reinforcement is Φ8, the lower string reinforcement is Φ5, and the abdominal rod reinforcement is Φ5.
- 5) The maximum spacing of truss reinforcement bars for Superimposed Shear Walls in Europe is 625mm.
Comparison of construction practices and advantages and disadvantages of European standard, national standard and landmark superimposed shear wall node
Design requirements for superimposed shear wall nodes for high-rise buildings in the European Seismic Zone:
- 1) The structural requirements of the superimposed shear wall of high-rise buildings in the European seismic zone are similar to the domestic norms: the shear wall is strengthened by increasing the vertical reinforcement and stirrup of the edge components, and the ductility of the shear wall is guaranteed to resist the seismic force.
- 2) The European code also has requirements for the bottom reinforcement area for high-rise buildings, and the reinforcement and thickness of the shear wall in the bottom strengthening area are higher than those in the non-reinforced area; the twenty-story buildings under construction in Berlin that we examined are cast-in-place in the bottom reinforcement area, and in the non-reinforced area, the external wall shear wall adopts a solid insulation wall, the inner wall shear wall adopts a superimposed shear wall, and the shear wall in the elevator room adopts cast-in-place, which is very flexible.
Superimposed shear wall (german project construction site)
Software application and automation control system
Factory produced
Product display
02
Overview of domestic superimposed shear wall standards (superimposed shear wall)
03
Domestic superimposed shear wall application project
Shanghai Huinan Town Baoye. Wanhua City 23# Building
Basement retaining wall of hefei Hewu mussel project
Yuhui Heilongjiang Harbin Labor Technical School project application
Application of public rental housing project in Xiaogan, Hubei Province
Wuhan Meimei Group construction and residential project application
Double-sided stacked shear wall residential design
Double-sided superimposed shear wall structure system
The superimposed shear wall is divided into three layers from the thickness direction, prefabricated on the inside and outside sides, connected by truss reinforcement, with a cavity in the middle, poured on site from dense concrete. After on-site installation, the vertical reinforcement of the upper and lower components and the horizontal reinforcement of the left and right components are arranged and overlapped in the cavity, and then the concrete is poured to form a solid wall.
The superimposed shear wall does not require a sleeve or a pulp anchor connection, and has the characteristics of good integrity and smoothness on both sides of the plate. The superimposed shear wall combines the advantages of the fast construction progress of the prefabricated structure and the good integrity of the cast-in-place structure, and the prefabricated part not only replaces the formwork of the cast-in-place part in a wide range, but also provides a certain structural strength for the shear wall structure, and can also provide an operating platform for structural construction and reduce the pressure on the support system.
Double-sided stacked shear wall
Superimposed shear wall insulation system
The outer wall adopts prefabricated single-sided superimposed insulation exterior wall panels, and the shear wall is divided into four layers from the thickness direction, outer leaf plate, insulation layer, cavity and inner leaf plate. The outer blade is not load-bearing, and the outer blade and insulation are connected to the inner blade by means of a pull-knot. The rebar on one side of the shear wall is embedded in the inner leaf plate, and the reinforcement on the other side is exposed in the cavity, connected to the inner leaf plate by truss reinforcement. After on-site installation, the vertical reinforcement of the upper and lower components and the horizontal reinforcement of the left and right components are arranged and overlapped in the cavity, and then the concrete is poured to form a solid wall. Double-sided superimposed insulation shear wall does not require sleeve or pulp anchor connection, has the characteristics of good integrity, good thermal insulation performance, good fire performance, and smooth on both sides of the wall panel.
The applicable height of the double-sided superimposed shear wall
National Standard: Appendix A of the Technical Standard for Prefabricated Concrete Buildings (GB/T 51231-2016).
04
Range of prefabricated layers for double-sided superimposed shear wall structures
05
Stacked shear wall split design
Advantages of double-sided superimposed shear walls
- (1) The prefabricated solid shear wall is self-important, and the requirements for production, transportation and hoisting equipment and facilities are high;
- (2) When prefabricating solid shear wall, it is necessary to reserve the end of the steel bar and the assembly connection of adjacent components, and when producing, it is necessary to customize the opening of the mold, the production process is complex, the mold reuse rate and production efficiency are low;
- (3) When the prefabricated solid shear wall is produced, there will be reserved steel bars at the end, which is not convenient for late hoisting, transportation and storage, and the reserved steel bars are susceptible to disturbance and deformation, resulting in difficulties in installation and construction positioning;
- (4) When the prefabricated solid shear wall is connected up and down, the sleeve grouting connection is mostly used, and the precise alignment of the steel bar of the upper and lower shear wall has high requirements for design and construction, but due to various reasons in the actual engineering project, the positioning of the upper and lower steel bars is inaccurate and difficult to locate, and the construction quality is difficult to guarantee;
- (5) When connecting up and down the prefabricated solid shear wall, the sleeve grouting connection is adopted, and the connection of steel bars is numerous, and the price of the sleeve and special grouting material is expensive.
- (6) The self-weight of prefabricated components is reduced by up to 50%, which is convenient for production, construction and transportation, and reduces the production, construction and transportation costs of components;
- (7) There is no reserved expenditure on the four ends of the prefabricated components, the mold reuse rate is high, the production process is simple, which effectively reduces the production cost and improves the production efficiency; there is no defect that the steel bar is susceptible to disturbance and deformation such as production, transportation and storage;
- (8) The superimposed shear wall up and down, left and right connections are the use of cast-in-place layer and cast-in-place edge components, etc., using rib connection, convenient construction, no difficulty in precise positioning of steel bars and sleeves, construction quality is easy to ensure; but also avoids the high cost of special sleeves and grouting materials;
- (9) The double-sided superimposed shear wall can carry out one-time prefabricated composite of the insulation system, which can realize the integration of thermal insulation and energy saving and the integration of external wall decoration.
- (10) Sandwich insulation superimposed shear wall wall is poured 150mm thick self-dense concrete, and the waterproof performance is better.
Editor: Cao Xiaoran
Review: MaBinya
Source: Green Prefabricated Building Industry Alliance
(Welcome to reprint, please indicate the source, the copyright of the picture and text belongs to the original author)