What should be paid attention to in the construction of glass curtain wall?

Quality management of glass curtain wall installation project

1, according to the standard:

Unified standard for construction quality acceptance of building engineering (GB50300-200 1)

Code for Acceptance of Construction Quality of Building Decoration Engineering (GB502 10-200 1)

Technical specification for glass curtain wall engineering JGJ 102-96

2, construction preparation

Glass curtain wall has developed rapidly in recent years. It not only has a unique artistic effect, but also needs to consider the performance requirements of architectural modeling and building structure, such as mechanics (strength, stiffness and stability), waterproof, heat insulation, air tightness, fire prevention, earthquake resistance and lightning protection. These performances are closely related to the use function and personal safety. Therefore, the Ministry of Construction and the Beijing Municipal Construction Committee stipulate that all enterprises engaged in the design, manufacture and installation of glass curtain walls must therefore review the qualifications of design, production and installation units before construction.

2. 1 Materials and main machines:

2. 1. 1 aluminum alloy profile: the surface shall be anodized. The variety, grade, specification, color, cross-sectional shape and thickness of anodic oxide film on the surface of aluminum profile must meet the design requirements, and its alloy composition and mechanical properties should be qualified by the manufacturer and should meet the current national standards. Appearance inspection should be carried out when entering the site; To be straight and square, the surface is free from pollution, pits, scratches, warping and other defects, and the specifications and models are packaged separately on indoor wooden mats.

2. 1.2 glass: the appearance quality and optical performance shall conform to the current national standards.

2. 1.2. 1 by structure:

A. Single glass: float glass or tempered glass (generally 6mm or 8mm thick).

B. Double-layer insulating glass: the thickness is 6+ 12+6(mm) or 8+9+8(mm), and the middle value is the gas trap layer between the two layers of glass.

2. 1.2.2 Classification by function:

A. Heat-absorbing glass: A very small amount of metal chloride is added to transparent glass to form colored glass, which is characterized by allowing visible light to pass through and limiting infrared light with heat.

B. Mirror glass: one or both sides of single-layer or double-layer glass are plated with a metal film to reflect the thermal radiation of sunlight and achieve the purpose of heat insulation.

Choose the glass type according to the design requirements, the manufacturer calculates the wind pressure of the glass curtain wall, and provides the factory certificate and necessary test data; After the glass comes into play, it should be sampled out of the box to check the appearance quality. The glass has the same color, smooth surface, no pollution and warping, even coating, no scratches and peeling. There should be a special steel shelf to allow the whole container to enter the site. If it is unpacked, it should be stored vertically on a shelf made of wooden square nails indoors.

2. 1.3 rubber strip and rubber pad: they shall have the factory certificate of aging resistance and flame retardant performance test, and the dimensions shall meet the design requirements without fracture.

2. 1.4 aluminum alloy decorative battens and fasteners: the colors are consistent, without distortion, scratches and damage, and the dimensions meet the design requirements.

2. 1.5 connectors for connecting keels: galvanized connectors between vertical keels and transverse keels, special inner sleeves, connectors between vertical keels, etc. , should be prefabricated in the factory, materials and specifications should meet the design requirements.

2. 1.6 Bearing fasteners: the vertical keel is connected with the main structure by bearing fasteners. The specifications and dimensions of fasteners shall meet the design requirements. In order to prevent corrosion, the surface of fasteners should be galvanized. When fasteners are fixed with embedded parts embedded in concrete beams, columns and walls, stainless steel or galvanized bolts should be used.

2. 1.7 Fasteners such as bolts, nuts and steel nails are made of stainless steel or galvanized parts, with specifications and dimensions meeting the design requirements and factory certificates.

2. 1.8 sealant: joint sealant is the key to ensure the waterproof, airtight and seismic performance of curtain wall. Its materials must have good impermeability, aging resistance and corrosion resistance, and have elasticity that can adapt to structural deformation and temperature expansion and contraction, so they should have factory certificates and waterproof test records.

2. 1.9 thermal insulation material: thermal conductivity, waterproof performance and thickness shall meet the design requirements.

2. 1. 10 main machines and tools: elevator for vertical transportation, electric welding machine, nail welding gun, electric screwdriver, pistol drill, ring spanner, adjustable wrench, theodolite (or laser theodolite), level gauge, steel tape measure, molten iron level, steel ruler and steel square.

2.2 Operating conditions:

2.2. 1 The main structure of reinforced concrete (or steel structure) has been completed, and the quality acceptance formalities have been completed.

2.2.2 In the main structure construction stage, the construction unit shall make and embed the glass curtain wall according to the design, embedded parts layout and embedded parts details provided by the production unit, and the embedded parts shall be firm and accurate. Before the vertical keel of curtain wall is installed, the built-in parts should be removed in advance. If the elevation and position exceed the allowable deviation, the design negotiation should be handled in time.

2.2.3 measuring unreeling in advance:

2.2.3. 1 according to the vertical axis of each column of the main structure and the wheelbase size of the original structure, after verification with theodolite, the center line of vertical keel will pop up at the edge of each layer, and at the same time, check whether the center line of each embedded part is consistent with the center line of vertical keel. If there is any error, make a good treatment plan in advance.

2.2.3.2 verifies whether the actual total elevation of the main structure is consistent with the design total elevation, and marks the floor elevation of each floor on the floor edge at the same time, and then checks it when installing the curtain wall.

According to the plane column spacing of the main structure, 2.2.3.3 used theodolite to find out the outermost line size of the glass curtain wall. It should be noted that it echoes the construction method of other exterior wall decoration materials connecting nodes. (The above content is to find the dimension line of X-axis, Y-axis and Z-axis).

2.2.4 The external shelf (or electric hanging basket) for operation has been erected, and it has been checked and accepted by the safety officer.

2.2.5 The temporary power supply of all kinds of electric tools has been connected in advance, and the safety trial operation has been carried out.

2.2.6 The vertical keel, horizontal keel and all kinds of accessories have been counted in advance, and classification code has been stored in the designated location on the floor, and there are modes.

2.2.7 The lightning protection and grounding design scheme of glass curtain wall has been completed.

3, the operation process

3. 1 process flow:

Install fastening iron pieces on each floor → install vertical main keel → install horizontal secondary keel → install galvanized steel plate → install thermal insulation and fireproof mineral wool → install glass → install cover plate and decorative strip.

3.2 Installation of fastening iron parts on each floor: The embedded form of embedded parts and the connection method between fastening iron parts and embedded parts during the construction of the main structure shall be operated according to the requirements of design drawings. Generally, there are two ways:

3.2. 1 In each layer of cast-in-place concrete floor slab or beam of the main structure, iron pieces are embedded, angle steel connectors are welded with embedded parts, and then connected with vertical keel by bolts (galvanized), as shown in Figure 9- 17.

3. 2. 2T-groove embedded parts are embedded in each layer of cast-in-place concrete floor slab or beam of the main structure, and angle steel connectors are connected with the T-groove through galvanized bolts, that is, bolts are inserted into the T-groove in advance and then connected with angle steel connectors, as shown in Figure 9- 18.

The installation of fasteners is the main link in the installation process of glass curtain wall, which directly affects the firm and safe connection between curtain wall and structural main body. Fig. 9- 18 During installation, align the center lines of fastening iron pieces in vertical and horizontal directions, initially tighten the bolts, and then tighten the bolts after correcting the positions of fasteners. Figure 9- 17 When installing fasteners, align the vertical and horizontal center lines first, and then conduct electric welding. The length, height and quality of covered electrode meet the requirements of structural welds.

3.3 Assembly of horizontal and vertical keels: Before the keels are installed in place, assemble the following connectors in advance:

3.3. 1 galvanized steel plate inner sleeve connector is used to connect vertical main keels, as shown in figure 9- 19.

3.3.2 Connecting piece between vertical main keel and fastener.

3.3.3 Connector of transverse secondary keel.

The connection mode of each node connector should meet the requirements of design drawings, and the connection must be firm, horizontal and vertical.

3.4 Installation of vertical main keel: The main keel is generally installed from bottom to top, and every two floors are a whole root, and each floor is connected with the floor by connecting and fastening iron pieces.

3.4. 1 First, erect the main keel, align the connectors at the upper and lower ends with the bolt holes of the fastening iron pieces, and initially tighten the bolts.

3.4.2 The main keel can be adjusted up, down, left and right by fastening the long bolt holes of iron parts and fittings. The left and right horizontal direction should be consistent with the position line of the floor, and the top and bottom should be aligned with the floor elevation, and the front and back (that is, the Z-axis direction) should not exceed the control line, so as to ensure that the top and bottom are vertical and the spacing meets the design requirements.

3.4.3 The main keel vertically passes through the inner casing. In order to prevent aluminum from being deformed due to temperature, expansion holes with appropriate width should be provided at the joint. The specific dimensions should meet the design requirements, and the center lines of the upper and lower keels at the joints should be aligned.

3.4.4 After being installed on the top floor, the verticality shall be corrected and checked with a fine weft tester. All bolts, nuts and washers connecting the vertical keel with the structure shall be fastened and welded firmly. All welds shall be re-welded to the design requirements, and the welding coating shall be broken. After cleaning and inspection, two coats of antirust paint should be applied.

3.5 Installation of horizontal keel: After installing vertical keel, check verticality = levelness and spacing, and then install horizontal keel if it meets the requirements.

3.5. 1 Before installation, put waterproof rubber pads on both ends of the horizontal keel.

3.5.2 Temporary laying of main keel with wood support, then installation of transverse keel, and then pressing rubber pads at both ends after the removal of wood support, which has good waterproof effect.

3.5.3 After it is approximately horizontal, start to tighten the bolt of the connector, and then level it with a level meter. After the horizontal keel is leveled, tighten the bolts.

3.5.4 During installation, the center distance and verticality between horizontal keels should be strictly controlled, and at the same time, whether the glass size can be correctly inlaid should be checked.

3.6 Install galvanized steel plates between floors: As the curtain wall is hung on the external wall of the building, the holes between the vertical keels lead to the floors. For sound insulation and fire prevention, mineral wool fire insulation layer should be laid on galvanized steel plate to seal the floor. In order to make the joint between steel plate and keel tight, firstly, put rubber sealing strips around the steel plate, insert the steel plate into the ceiling keel (or nail it on the concrete floor with expansion bolts), and then paste asphalt sealant tape at the joint between steel plate and keel and smear it evenly. Finally, weld steel nails on the steel plate. The steel nails should be welded firmly, and the nail spacing and specifications meet the design requirements, as shown in Figure 9-20.

3.7 Installation of thermal insulation and fireproof mineral wool: After installation of galvanized steel plate, install thermal insulation and fireproof mineral wool.

Glue the mineral wool insulation layer to the steel plate with adhesive, and fix the insulation layer with welded steel nails and stainless steel sheets. Mineral wool should be laid flat, leaving no gap at flat-fell seam.

3.8 Glass installation: Single-layer and double-layer glass shall be installed from top to bottom and continuously from one direction. The glass is transported to the designated place on each floor in advance by the external elevator, stored vertically and watched by special personnel.

3.8. 1 Clean the dirt in the frame, and pad the rubber locating block in the lower frame. The pad supports the total weight of the glass, which requires certain hardness and durability. See figure 9-2 1 for the location.

3.8.2 Insert the inner rubber strip into the frame groove (note the model). The method of inserting rubber strip is to insert it at intervals first, and then insert it at different sides, as shown in Figure 9-22.

3.8.3 When handling glass (large glass is handled by mechanical vacuum sucker), the dust and dirt on the glass surface shall be wiped clean first. When installing in the frame, pay attention to correctly judge the inside and outside, and embed the glass into the frame groove, and the embedding depth should be consistent around.

3.8.4 Put rubber pads on both sides of the mullion, then fix the glass, and embed the outer sealing strip (also can be sealed with sealant). The inlay should be smooth and dense. Fig. 9-23 is a cross-sectional view of the main keel and the horizontal transverse keel, and a schematic diagram of the outer sealing strip of the mosaic frame.

3.9 Cover strips and decorative layering:

3.9. 1 Installation of cover strip: After installing the rubber strip (or sealing paste) on the outside of the glass, cover the joint between the glass and the cross frame, install the outer corner brace on the outdoor side, and install the batten (all aluminum alloy) on the indoor side. Specifications and types should be determined according to the design requirements of curtain wall. See Figure 9-23.

3.9.2 The junction of curtain wall and roof parapet should have aluminum alloy coping, and waterproof structural measures should be taken to prevent rainwater from flowing in along the gap between curtain wall and parapet. According to the curtain wall design when operating. Figure 9-24 is the structural schematic diagram of the rear top of the parapet.

3. 10 Scrubbing glass: After the curtain wall glass assembly is installed, before the completion acceptance, the glass should be scrubbed with a window cleaner (or other spreader) to make its surface clean and bright.

4, quality standards

See the detailed rules for specific standards.

5, finished product protection

5. 1 aluminum alloy frame materials and various accessories shall be placed in the rain-proof warehouse according to the specifications and classification code after entering the site, and no heavy objects shall be placed on the ground. Handle materials with care to prevent damage and scratches. The glass should be stored in the warehouse to prevent the sun exposure, put on special wooden frames with different specifications, and be kept and transported by designated personnel to prevent the surface coating from being damaged and scratched.

5.2 During the installation of aluminum alloy frame, pay attention to protect the outer membrane of aluminum frame from scratches. When installing the outer shelf, pay attention to protect the glass to prevent it from breaking.

5.3 Bolt holes used in combination of aluminum alloy horizontal and vertical keels and accessories shall be drilled by machinery in advance, and holes shall not be burned by electric welding.

5.4 During installation, components shall be prevented from falling, so a safety net shall be erected.

5.5 For each working procedure near the glass curtain wall, the glass shall be temporarily protected before construction, such as covered with fiberboard.

6. Quality problems that should be paid attention to

6. 1 glass cannot be installed: when installing longitudinal and transverse keels, the center line and verticality were not carefully checked, and the glass size was not checked. Therefore, verticality and centerline position must be strictly controlled when installing longitudinal and transverse keels.

6.2 Decorative layering is not vertical or horizontal: when installing decorative layering, it should be controlled by hanging the thread and pulling the horizontal line, and it should be horizontal and vertical after installation.

6.3 There is a serious phenomenon of "image distortion" in the glass, which is caused by the warping of the glass itself, uneven installation of the adhesive tape, and cement pollution on one side of the glass coating. Therefore, when the glass comes into play, it should be unpacked for inspection. If warpage is found before installation, it should be removed. In the installation process, each working procedure should be strictly operated, the sealing strip should be inlaid flat, and the half surface after gluing should be wiped clean.

6.4 The surface pollution of aluminum alloy components is serious: the protective film on the surface is torn off prematurely during transportation and installation, or the surface is polluted when gluing.

6.5 Water seepage of glass curtain wall: rainwater seeps in due to loose rubber strip plugs around the glass or gaps at the interface. Therefore, when installing the adhesive tape, the specifications of the adhesive tape should match, the size should not be too large or too small, the plug should be flat and dense, and the joint must be filled with sealant to ensure water tightness.

6.6 The fastener connecting the vertical keel is not welded firmly with the embedded parts: this fastener should be a load-bearing part, which is related to the safety and firmness of the connection between the curtain wall frame and the main structure. Therefore, the welding quality of connecting fasteners and embedded parts must be strictly controlled, and welders with welder's license are allowed to weld. The height and length of weld should be welded according to the requirements of structural weld.

6.7 Some parts of curtain wall glass have black marks, which are mainly caused by unqualified coating of some glasses. Every piece of glass should be inspected before installation, and then installed after it is qualified.

7, quality records

7. 1 Qualification certificate of curtain wall design, manufacture and installation manufacturer and business license of the Municipal Construction Committee.

7.2 aluminum alloy skeleton mechanical performance test certificate, mineral wool, rubber strip, sealing paste, glass, etc. Must have a factory certificate.

7.3 Fastener installation inspection records (including lightning protection grounding wire installation inspection records).

7.4 curtain wall installation quality inspection and evaluation records.