The embedded parts of the building curtain wall are important components of the curtain wall, and their connection nodes with the main structure are important connection nodes of the curtain wall. Its main function is to effectively and reliably transfer the load and action borne by the curtain wall to the main structure through embedded parts.

The quality of embedded parts, burial quality, and connection quality with adapters in curtain wall construction have a significant impact on the performance and service life of the curtain wall. This article discusses the construction of embedded parts and the problems that exist during construction.

Construction of pre embedded parts for building curtain walls and related issues

One Types of pre embedded components for building curtain walls

At present, there are three common types of embedded parts in building curtain walls: anchor plate construction embedded parts, groove embedded parts, and rear embedded parts.

1. Anchor plate construction embedded parts: Anchor plate construction embedded parts are components formed by welding (arc welding) anchor plates and symmetrically arranged steel bars. It was buried during civil construction.

2. Groove type embedded parts. The groove type embedded parts are components formed by welding special rolled groove steel and special I-shaped steel (or steel bars). It was buried during civil construction.

3. Rear embedded parts: composed of anchor plates and expansion bolts or chemical bolts (instead of steel bars). It is a pre embedded component formed during the installation and construction of curtain wall engineering.

II Construction requirements for embedded parts of building curtain wall

1. The relevant provisions of clause 5.5 of standard JGJ102-2003 require:

The main structure or structural components should be able to withstand the loads and effects transmitted by the curtain wall. The anchorage bearing capacity design value between the connecting piece and the main structure should be greater than the bearing capacity design value of the connecting piece itself;

2. The glass curtain wall columns should be connected to the main concrete structure through embedded parts, which should be buried during the concrete construction of the main structure and positioned accurately; When there is no condition to use embedded connectors, reliable measures should be taken and their bearing capacity should be determined through testing.

3. The load-bearing embedded parts composed of anchor plates and symmetrically arranged anchor steel bars can be designed in accordance with the provisions of Appendix C of this specification.

4. The pre embedded steel plates and other connection measures of groove type pre embedded parts should be designed in accordance with the relevant provisions of the current national standard "Code for Design of Steel Structures" GB 50017, and their bearing capacity should be determined through testing.

When the glass curtain wall frame is connected to the main structure with rear anchor bolts, the following regulations should be followed:

(1) The product should have a certificate of conformity; (There are test reports on the chemical composition and mechanical properties of steel, as well as design method data and factory certificates).

(2) Carbon steel anchor bolts and anti-corrosion treatment;

(3) After adding bolts, individual pull-out tests and node (group) pull-out tests must be conducted on site. The load applied in the test should reach 1.5 times the design load without significant slippage. If necessary, ultimate pull-out tests should be conducted at the testing unit.

(4) At least 2 bolts should be added after each connection point, and the distance between bolts and the edge of the component should not be less than 70mm. It is recommended to design the nodes where bolts are sheared;

(5) The bolt diameter should be determined through bearing capacity calculation and should not be less than 10mm;

(6) It is not advisable to perform welding operations on connectors that come into contact with chemical anchor bolts;

(7) The design value of anchor bolt bearing capacity should not exceed 50% of its ultimate bearing capacity.

When connecting curtain walls to masonry structures, it is advisable to add reinforced concrete or steel structure beams and columns to the main structure at the connection point. The concrete strength grade of the connected main structure should not be lower than C30. Curtain walls should not be connected to masonry or lightweight walls.