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Heavyweight release | introduction to “advanced, mature and applicable new technology” of precast buildings: partially coated steel-concrete

Compared with steel reinforced concrete, it has the advantages of high prefabrication degree of components, convenient joint connection and no formwork.

According to the new technology achievements submitted by enterprises, the construction industry modernization development committee of China Architectural Society, after consulting experts, has launched 21 advanced, mature and applicable new technologies, edited and formed the compilation of “advanced, mature and applicable new technologies” for precast buildings (the first batch), which can be used for reference, promotion and application by member units and enterprises in the industry.

(6) The main steel parts can adopt section steel or welded section.

Technical indicators in production and manufacturing (1) the concrete part of PEC composite structural members should be precast in the factory.

This issue introduces: partially coated steel-concrete composite structure system.

Wire Lifting Loop

3 is further innovated.

Fig.

(3) The internal force analysis method under the combination of non seismic action adopts elastic analysis without considering concrete cracking.

Concrete improves the local stability of open section steel, and improves the overall stability of pure steel members by increasing the flexural and torsional stiffness of the whole section; The external restraint of steel can restrain the early cracking of concrete cracks to a certain extent.

1 Part of the technical content: the clad steel-concrete composite structure system (hereinafter referred to as PEC structure) is a new type of steel-concrete composite structure formed by welding reinforcement or flat steel in the H-shaped steel cavity and pouring concrete, including PEC steel-concrete composite column, PEC steel-concrete composite beam and PEC steel-concrete composite shear wall.

(4) PEC members shall be checked for deflection and crack width.

(7) The development and possible degree of plastic bearing capacity and deformation capacity of PEC members are closely related to the width thickness ratio of main steel parts.

At the same time, the fire prevention and anti-corrosion life is the same as that of the main structure.

2 on-site construction of PEC steel-concrete composite structure on the basis of narrow flange PEC frame structure, PEC shear wall structure as shown in Fig.

This material arrangement forms the stress characteristics different from that of steel reinforced concrete.

(2) The fabrication of steel structure of PEC composite structure members shall comply with the relevant provisions of the current national standards code for construction of steel structures gb50755 and code for acceptance of construction quality of steel structures gb50205, and the fabrication of concrete part shall comply with the current national standards general code for concrete structures gb55008, code for construction of concrete structures gb50666 Code for acceptance of construction quality of concrete structures GB50204.

The plate with large width and thickness can be used for the welding section to save steel; However, the use of section steel is conducive to standardized and modular design, and can also obtain high comprehensive benefits.

2.

Based on the flat design of the original ordinary PEC frame column to adapt to the characteristics of steel structure residence, the PEC shear wall structure system is proposed to increase the height and seismic performance of PEC structure; The tie bar welding, web opening and concrete pouring of PEC shear wall structure are similar to those of PEC narrow flange column.

The section composition of PEC members is similar to that of steel reinforced concrete members, and the bearing mechanism is similar, but the biggest difference between PEC members and steel reinforced concrete members is that the flange of H-shaped steel is located at the outer circumference of the section, and its contribution to the bending stiffness and flexural bearing capacity of members is much higher than that of steel bones in steel reinforced concrete.

The fabrication of the whole component, including concrete pouring, are completed in the factory.

Zhejiang dadongwu Construction Technology Co., Ltd.

(5) Single H steel PEC members shall meet the requirements of steel contribution rate, area ratio of main steel parts to longitudinal reinforcement, section height width ratio, section width thickness ratio, connecting rod structure, etc.

Recommended unit of partially clad steel-concrete composite structure system: Zhejiang Lvzhu Integrated Technology Co., Ltd.

Its bearing capacity, stiffness and ductility are better than pure steel structure or reinforced concrete structure.

At the same time, it effectively solves the thorny problems of precast steel structure residence, such as sound insulation, structural vibration, thermal insulation performance, living comfort, durability and secondary decoration.

Steel-concrete composite structure combines steel and concrete together and works together with each other.

When determining the design principle of beam column components and selecting the calculation method, it shall be based on the width thickness ratio of main steel parts and the relevant section classification.

For the elastic analysis results, the moment amplitude modulation method is adopted, considering the influence of concrete cracking in the negative moment area and the plastic development of the section, and the internal force amplitude modulation coefficient should not exceed 30%.

PEC steel-concrete composite shear wall 2 Technical index 1 Technical indicators in terms of design (1) the design and construction of PEC structure shall comply with the relevant provisions of the current national standard “design standard of steel structures” GB50017, code for seismic design of buildings “GB50011, technical specification for partially clad steel-concrete composite structures” t / cecs719, etc.

The precast concrete is filled in the I-steel abdominal cavity, which plays a combined stress and solves the problem of fire prevention and anti-corrosion of steel structure.

(2) The safety grade and design service life of the structure meet the provisions of the current national standards unified standard for reliability design of engineering structures gb50153 and unified standard for reliability design of building structures gb50068; PEC structure shall be designed for bearing capacity limit state and normal service limit state.

East China Construction Group Co., Ltd.

(3) The precast concrete pouring in PEC composite structural members can be formed by pouring on both sides or multiple sides in several times and by pouring on both sides or multiple sides in one time.

1 Schematic diagram of partially clad steel-concrete composite structure Fig.

At present, 21 new technologies are introduced in detail by stages.

The concrete in the same area of the component shall be poured and vibrated at one time to avoid the formation of cold joints..

Figure 3.

When one-time pouring is adopted, holes shall be opened on the web of the main steel parts, measures shall be taken to ensure that the concrete can be vibrated and compacted, and exhaust holes should be set.

This makes the members have high vertical bearing capacity and good seismic performance.

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