The glass curtain wall refers to a building envelope or decorative structure composed of a supporting structure system and glass, which has a certain displacement capacity relative to the main structure and does not share the effect of the main structure. Because it has the advantages of absorbing infrared rays, reducing solar radiation entering the room, and reducing indoor temperature, it is widely used in construction projects in my country. However, due to various reasons in the construction process of installing the glass curtain wall, such as inappropriate glass materials, unreasonable thermal insulation materials and fireproof materials, unreasonable installation of the main firmware structure, poor sealant effect, incorrect anchor point practices, and failures between components Effective installation of gaskets and unsound structure, etc., these construction errors are very likely to cause serious problems in the quality of the glass curtain wall project.

  Therefore, in order to standardize the construction technology of the glass curtain wall and ensure the quality requirements of the project, then the editor of Lizhong Construction will discuss the three main aspects of the composition and advantages of the glass curtain wall, the construction process and method, the protection and acceptance of the finished glass curtain wall. Construction technology of architectural glass curtain wall decoration project.

  1 Composition and advantages of glass curtain wall

  1.1 Constitute

  The glass curtain wall is a building enclosure wall made of aluminum alloy or other metal rolled into a skeleton, made of glass and closed metal hollow-shaped rods. At present, it is basically a double-layer hollow glass wall; the thickness of a single piece of glass is 6~8 mm, and the weight of the wall is about 40~60 kg/m2; the outer glass of the curtain wall is generally colored metal coated glass to reflect the different colors of the building Style characteristics.

  1.2 Advantage

  The advantages of glass curtain wall are: absorb infrared light; reduce the solar radiation entering the room; reduce the indoor temperature; light and beautiful; not easy to pollute; save energy;

  In addition, in the glass curtain wall of modern high-rise buildings, hollow glass is used, which is a combination of coated glass (or low-e coated glass) and ordinary glass, and the compartment is filled with dry air. Insulating glass is a new type of building material with good heat insulation, sound insulation, frost resistance, moisture resistance, strong wind pressure resistance, beautiful appearance, and reduced building weight. It uses two (or three) glass pieces High-strength and high-tightness composite adhesive is used to bond the glass sheet to the aluminum alloy frame containing the desiccant to make a highly efficient sound-insulating and insulating glass.

  According to experimental tests, in winter, when the outdoor temperature is -10℃, the temperature in front of the indoor single-layer glass window is -2℃, and the temperature in front of the hollow glass window is 13℃; while in summer, the double-layer insulating glass can block 90% of the sun’s radiant heat; although sunlight can still pass through the glass curtain wall, it does not feel hot when exposed to the sun. Therefore, rooms with hollow glass curtain walls can be warm in winter and cool in summer, greatly improving the living environment.

  2 Construction technology and method of glass curtain wall

  2.1 Safety factors of glass curtain wall construction

  2.1.1 Strictly control glass materials

  (1)Low-radiation (such as Low-E) glass can reflect infrared rays in the sun in summer, which can save the cost of air conditioning; in winter, it can re-reflect the indoor heat and reduce the heat loss.

  (2)Adiabatic profiles. The heat insulation profile is an effective heat insulation layer formed by inserting a low thermal conductivity spacer between the internal and external metal frames with high thermal conductivity to block the way of dissipating heat through the door window frame or sash profile. The adiabatic profile has a reasonable structure, firm combination, high strength, good rigidity, large thermal resistance, and has excellent sound insulation and energy saving performance, wind resistance performance and air tight water tight performance.

  2.1.2Embedded components

  In order to ensure the firm connection between the curtain wall and the main structure, the embedded parts connected to the curtain wall and the main structure should be buried according to the number, location and method required by the design when the main structure is constructed; The color and performance should meet the design requirements; the embedding should be firm and the position is accurate, and the elevation deviation of the embedded parts should not be greater than 10mm. The deviation between the position of the embedded part and the design position is not more than 20mm.

  2.1.3Measurement pay-off

  It should be combined with the main structure to measure the facade of the main structure, use the theodolite to calibrate the vertical control lines of each area, use the level to calibrate the horizontal control lines of each floor, and then pop up the center line of each detail. Control, allocate, and digest the errors; verify whether the actual total elevation of the main structure is consistent with the design total elevation, and at the same time place the floor elevation of each floor on the side of the floor; the verticality of the main structure should be combined with the details of the curtain wall nodes. Practice, determine the entrance and exit lines of the curtain wall plane; the determined entrance and exit dimensions need to ensure that the construction and installation of the curtain wall does not contradict the main structure.

  2.2 Key points of operation of glass curtain wall construction

  2.2.1 Upright installation

  In the construction of glass curtain wall, the embedded parts should be set according to the grid, and the connecting parts should be connected to the main body embedded parts, and then the uprights should be connected to the connecting parts, using 10~12mm stainless steel bolts; the special aluminum alloy ferrules and ferrules should be used for the butt joints The length is not less than 250~400 mm; the expansion joints should be 15~20 mm when the columns are docked. After the curtain wall frame is adjusted, the expansion joints should be sealed with silicone sealant; The upper end (or lower end) should be fixedly connected to the main structure, and the lower end (or upper end) is a connection that can move up and down; the deviation of the installation elevation of the column should not be greater than 3 mm, the deviation of the front and back of the column axis should not be greater than 2mm, and the deviation of the left and right should not be greater than 3mm; When welding steel connectors, the height of the weld is 5~7 mm. After welding, the welding slag should be cleaned up and coated with two zinc-rich paints to prevent corrosion.

  2.2.2 Crossbeam installation

  When installing the beam. The materials, specifications, varieties, and quantities of connecting pieces and bolts (nails) connected to the fixed beam must meet the design requirements, and the screws should have anti-loosening measures; the number of connecting bolts (nails) at the same connection should not be less than two; According to the requirements of the curtain wall design and construction drawings, determine the position of the connector in combination with the reference line of each layer of the building structure and the building elevation line; the beam connector should use M6 stainless steel bolts to fix the aluminum alloy corner code on the upright (frame steel material corner code Can be welded and fixed), pay attention to the two pads between the two columns and the rubber pads at the two ends of the beam; the connectors and elastic rubber pads at both ends of the beam should be installed at the predetermined position of the column to ensure that it is firm, and the joints Sealed with sealant; the installation order of beams on the same layer should be from bottom to top. When the height of the first floor is installed, it should be inspected, adjusted, corrected and fixed at any time to make it meet the quality requirements of allowable deviation.

  2.2.3 Glass plate installation

  When installing the glass plate, the glass quality, size and specifications of the glass plate should meet the design requirements; the dust and dirt on the glass surface should be wiped clean, and the inspection of the glass coating should be ensured to be free of pollution and peeling; according to the design requirements of the curtain wall, the After the curtain wall frame combination is installed. It should be able to achieve three-dimensional adjustment of the frame (ie, front, back, left, and up) to meet the flatness and verticality requirements of the curtain wall acceptance standard; after the adjustment, the actual grid size of the curtain wall frame is compared with the design and calculation of the glass plate size. And install the position number according to the grid to ensure the consistency of the glass glue seam; the aluminum alloy attached frame on the glass plate is connected and fixed to the vertical beam through the external pressure plate through bolts and nuts; the two sides of the glass plate should be installed with a length of not less than 100 mm Aluminium alloy bracket with 1mm thick rubber pads; all exposed metal parts (pressing plates) of the curtain wall should be flat from any angle, and no small deformation, ripples, recesses or protrusions of fasteners are allowed The surface of the installed glass should be flat without warping; the weather should be selected during installation. Construction should be stopped when the weather is under heavy wind or heavy rain or when the temperature is below -5℃.

  Sealing of curtain wall glass plates: indoor rubber sealing strips, and trichloroethylene propylene rubber sealing strips should be used to ensure the service life. Outdoors are polyethylene foam rods and weather-resistant sealants; curtain wall glass seams should be neat and even The size of the plate should be accurate; there should be a gap of not less than 16 rain on both sides of the curtain wall and the structural opening. The gap is filled with thermal insulation rock wool and then sealed with polyethylene foam rods and weatherproof sealant; sealant Must carry out peel test, anti-aging test and compatibility test.

  2.2.4 Fire protection layer installation

  The installation of the fireproof material of the glass curtain wall should be carried out in strict accordance with the design requirements. The whole block of rock wool is used to fill the fireproof material. The fireproof lining board for fixing the fireproof material should be anchored and firm; the thickness of the galvanized iron sheet used to support the rock wool should not be less than 1.5mm. Glass curtain wall The gap between the surroundings and the main structure. All should be filled with fireproof materials; when filling fireproof materials, they must be filled and filled flat, no gaps are allowed, and they are wrapped with aluminum foil to prevent the insulation and fireproof materials from being damaged by moisture.

  2.2.5 Lightning protection installation

  The lightning protection parts of the glass curtain wall should be constructed according to the design requirements. The pressure equalizing ring of the curtain wall should be connected to the main structure lightning protection system. The embedded parts and the pressure equalizing ring should be connected by round steel or flat steel; round steel or flat steel and the embedded parts 3. The pressure equalizing ring is lap welded. The length of the weld is not less than 75mm. After the inspection of the welding point is correct, it should be painted and anti-corrosion; mm, thickness not less than 2 mm of aluminum strip connection; on the facade of the curtain wall, every 10 m within the column on the floor without pressure ring must be connected to the column fixed on the floor with pressure ring 4 ohms.

  3 Protection and acceptance of finished products of glass curtain wall engineering

  3.1 Finished product protection

  After the installation of the glass curtain wall, attention should be paid to product protection. The protective film on the surface of the profile should be peeled off after the decoration construction is completed, and the pollutants on the surface of the curtain wall should be removed in time; ; When using the cleaning agent, it should be cleaned with a cleaning agent that is not corrosive to the curtain wall.

  3.2 Engineering acceptance

  (1)The glass curtain wall should be scrubbed clean before acceptance.

  (2)During the acceptance of the curtain wall project, the following materials shall be submitted: design drawings, documents, design revisions and material substitution documents; materials and components leave factory quality certificates. Structural silicone sealant compatibility and adhesion test report and wall physical performance inspection report; concealed project acceptance documents; construction and installation self-inspection records.

  (3)During the acceptance of the glass curtain wall project, the concealed acceptance shall be carried out according to the requirements of the concealed project acceptance.

  (4)The quality inspection of the glass curtain wall should be carried out by visual inspection and sampling inspection, and one glass curtain wall should be used as the inspection unit, and each glass curtain wall should be inspected.

On the construction technology of glass curtain wall decoration engineering

Acceptance of glass curtain wall project

  Visual inspection: the surface of the glass curtain wall should be flat and clean; the color of the entire glass should be uniform; there must be no pollution and coating damage; the exposed frame or the bead of the exposed glass curtain wall should be horizontal and vertical, and the color and specifications should meet the design requirements , The installation of the bead should be firm; the unit seam of the unit glass curtain wall or the divided glass seam of the hidden frame glass curtain wall should be horizontal, vertical and uniform; the sealing glue seam, settlement joint, expansion joint and shockproof joint of the glass curtain wall and The lightning protection system should comply with the specifications; the concealment and repair of the hidden nodes of the glass curtain wall should be neat and beautiful; the allowable deviation of the installation of the open-frame glass curtain wall should be checked with theodolite, level, cable and ruler; the curtain wall should not leak.

  Sampling inspection: aluminum alloy material and glass surface should not have aluminum scraps, burrs, oil spots or other dirt; glass should be installed or bonded firmly, rubber strips and sealants should be inlaid densely, filled flat; tempered glass surface should not have scratches; The surface quality of square meters of glass and divided aluminum alloy profiles, the installation quality of aluminum alloy frames and hidden frame glass curtain walls should all meet the design requirements.