(At present, curtain wall decoration has been widely used in high-end office buildings and iconic buildings in large and medium-sized cities. With the rapid development of China's economy, curtain wall decoration will be more widely used. In order to provide strong technical support for curtain wall installation and construction, special This construction method is prepared. The special decorative glass is hung on the outer wall of the building to form a decorative fence like a curtain.

   Construction technology of glass curtain wall

  1, process characteristics

  1.1 The columns, beams, and glass plates are installed one by one on site, which is convenient to install and easy to adjust.

  1.2 The construction site reduces the key process of manufacturing structural glass assembly components, shortening the construction period and reducing the construction equipment.

  1.3 The columns and beams are cut at the manufacturer, with high processing accuracy and less material waste.

  1.4 The structural glass assembly components are produced in a professional production workshop, the quality of the glue injection and the processing accuracy are guaranteed, and the silicone structural sealant is saved.

  1.5 The glass is fixed to the sub-frame with silicone structural sealant, and then the sub-frame is fixed to the main frame (pillar, beam) by mechanical clamping. The structural glass assembly components are completely separated from the main frame, which is one of the biggest features of the hidden frame glass curtain wall component construction.

  1.6 The construction is simple, the process flow is clear and easy to understand, and the operator is easy to master, but the professional skills and overall planning ability of the manager are higher.

  2, process flow

   Construction preparation → Survey pay-off → Treatment of embedded parts → Connection angle installation → Upright installation → Beam installation → Fabrication and installation of structural glass assembly components → Cleaning inspection → Completion acceptance

  3. Construction operation points

  3.1 Construction preparation

  3.1.1 Material preparation: According to the drawings and engineering conditions, prepare a detailed material order supply plan.

  3.1.2 Construction equipment: inspect the equipment used to ensure good performance.

  3.1.3 Personnel preparation: technical training and explanation for skilled workers.

  3.1.4 Technical preparation: Familiar with the drawings, prepare the tables used for the atlas, quality acceptance standards and internal materials.

  3.2 Measuring pay-off

  3.2.1 Measurement basis

   The measurement of pay-off is based on the centerline and elevation points provided by the civil engineering unit. The design of the curtain wall is generally based on the axis of the building, and the layout of the glass curtain wall should have a certain relationship with the axis. Therefore, the completed civil structure must be measured.

  3.2.2 Measuring method

Outer contour measurement of the building: re-evaluate the centerline of the elevation of each embedded part according to the civil elevation reference line, check the deviation of the embedded part elevation according to this line, and make a record; find out the relationship between the curtain wall column and the building axis, according to the civil construction The axis measures the axis of the column, and checks the left and right deviation of the embedded parts based on it, and makes a record. Sort out the above measurement results and determine the adjustment and treatment plan for the separation of curtain wall columns.

  The external plane positioning of the curtain wall column: determine the distance between the external plane axis of the curtain wall column and the external plane axis of the building according to the design drawings and civil structure error, and use the piano line to determine the appropriate position on the top of the wall.

   The outer plane axis of the curtain wall column.

   Axis positioning of curtain wall columns: After the front and rear positions of the curtain wall are determined, combined with the measurement results of the outer contour of the building, the left and right positions of each column are determined with piano lines. The error between each positioning axis is digested between the positioning axes, and the error is divided between each division by less than 2mm.

  Elevation of the elevation of the curtain wall: Determine the relationship between the elevation of the top of each column and the elevation of the floor, and set the elevation line of the top of the pillar along the pop-up ink line along the outside of the floor.

  3.2.3 Measuring tools: theodolite, spirit level (sometimes horizontal tube is also used) and line weight.

  3.3 Repair of excessive deviation of embedded parts

  3.3.1 Installation of embedded parts

  3.3.2 Quality requirements: The position of the embedded parts is accurate and the embedding is firm. The elevation deviation is not greater than 9mm, and the left and right displacement is not greater than 20mm.

3.3.3 The repair method for the deviation of the embedded parts is too large: when the end of the connection corner code cannot be welded outside the steel plate, cut the corner code to increase the length of the weld; when the side of the corner code cannot be welded, cut the edge of the corner code and leave Welding seam; when the deviation of the embedded board in two directions is large, the steel plate is repaired; when the embedded board is recessed or inclined too much, the backing plate is added.

  3.4 Column production and installation

  3.4.1 Column production

   In order to save aluminum materials and reduce on-site processing, when ordering column materials, attach accurate column processing drawings and entrust aluminum manufacturers to process according to the drawings. The post machining drawing is drawn by the on-site technician after the post measurement is completed.

  3.4.2 Post installation

Before installing the upright, insert the core sleeve (for connecting the long upright and the upright, leaving a 20mm or more seam between the upper and lower uprights.) into the upright, and then drill holes in the upright to install the connection angle with stainless steel bolts. On the upright, the two are separated by anti-corrosion gaskets.

  The installation order of the columns is from bottom to top:

The first column installation: two operators transport the column to the installation work surface, so that the center line on the column coincides with the column stand line (piano line) determined during the measurement, the top of the column and the elevation control line determined during the measurement Horizontally, another welder temporarily spot welded the connection angle code to the embedded steel plate, and then adjusted the position of the post. After the first column is correct, put the upper layer of column into the next layer of column core sleeve, place it accurately and spot weld. This cycle completes the installation of a set of uprights.

  After the installation of one curtain wall column, after checking the accurate position and installing firmly, then add welding according to the requirements of the welding seam. The deviation of the installation elevation of the column should not be greater than 3mm, the deviation of the front and back of the axis should not be greater than 2mm, the deviation of the left and right should be greater than 3mm; The distance deviation between the two columns should not be greater than 2mm.

  3.5 Beam production and installation

  3.5.1 The beam is processed by the manufacturer according to the processing drawing and then sent to the site for installation.

  3.5.2 Crossbeam position measurement

   Use the level to lead the floor elevation line to the column. Based on the floor elevation line, mark the position of the beam on the side of the column. Errors in the separation of beams between each floor are digested in this floor and must not accumulate.

  3.5.3 Beam installation

   Install the connectors (aluminum corner codes) at both ends of the beam and the elastic rubber pads at the predetermined position of the column. The installation is required to be firm and the joints are tight. The installation of the beams on the same floor should be carried out from the bottom to the top. When the height of the first floor is installed, it should be inspected, adjusted, corrected and fixed to meet the quality requirements. The horizontal elevation deviation of two adjacent beams should not be greater than 1mm. Elevation deviation of the same layer: when a width is less than or equal to 35m, it should not be greater than 5mm; when a width is greater than 35m, it should not be greater than 7mm.

  3.6 Manufacture of structural glass assembly components

  Structural glass assembly components are produced in a professional production workshop, and the processing technology is as follows:

  3.6.1 Aluminum frame assembly

  After blanking aluminum profiles, they should be assembled on a special workbench. When producing aluminum frames in large quantities, molds should be set on the workbench and assembled according to fixed molds to ensure the uniformity of the aluminum frame assembly. After assembly, the aluminum frame should be inspected for the following items: the difference in length across the aluminum frame; the difference in diagonal length of the aluminum frame; the assembly gap between aluminum materials; the flatness between adjacent aluminum materials.

  3.6.2 Glass production

  The glass is processed by the producer according to the requirements and then sent to the aluminum frame assembly workshop.

  3.6.3 purification

   Purification is the most critical process of structural glass assembly production. Only by carefully purifying the surface of the substrate according to the process requirements can structural glass assembly components with prescribed reliability be manufactured. For oily stains, use xylene; for non-oily stains, use a mixed solvent of half each of isopropyl alcohol and water. The cleaning method uses two rags: pour the solvent on a rag and wipe the substrate surface in one direction in turn. Before the solvent that has dissolved the stain has not evaporated, wipe the solvent that has dissolved the stain with a clean rag Clean (if this rag is dirty, replace it with another clean rag). Do not wipe after the solvent volatilizes, because after the solvent volatilizes, the stain remains on the surface of the substrate, and the dry rag cannot be wiped off.

   Use a non-marking and non-linting cotton cloth for the rag, and pay attention to that the solvent can only be poured onto the rag, and that the rag cannot be dipped in the container to prevent the stained rag from contaminating the solvent. Apply the glue within 30 minutes after purification, because if the residence time after purification is too long, the surface of the substrate will be contaminated with pollutants in the surrounding environment. At this time, it is necessary to re-purify before applying glue.

  3.6.4 Positioning

  Positioning is to fix the glass in the specified position of the aluminum frame. Positioning fixtures are generally used to ensure that the reference lines of the two coincide. On the positioning platform, a baffle with a height of about 100mm is set along a group of adjacent sides of the platform, as a positioning reference for the glass, an aluminum frame positioning fixture is installed on the platform surface, and the aluminum frame is fixed at the predetermined design position of the glass and the aluminum frame. On the platform, stick the double-sided adhesive tape on the aluminum frame according to the design position, so that the glass falls along the stopper to reach the coincidence of the two baselines.

To achieve a successful positioning of the glass, the glass cannot be moved when the positioning is inaccurate, because once the glass comes into contact with the double-sided adhesive tape, the adhesive is adhered to the glass. Applying structural adhesive on this layer of adhesive cannot guarantee its adhesion to the glass Connect securely. After the glass is positioned, an empty stomach is formed with the glass and aluminum frame as the side walls and the cushion strip as the bottom. Its size should be the same as the width and thickness of the glue seam.

  3.6.5 Glue injection

Protect the aluminum profile or glass surface of about 5cm around the glue injection area with non-stick tape to prevent these parts from being contaminated by glue; check the type, brand, and production date of the structural glue; To maintain proper speed, the air in the cavity is discharged to prevent cavitation, and the air when the compressed air is squeezed out is discharged to prevent residual air bubbles in the glue seam and ensure the glue seam is full; a component is filled with glue, and a scraper is used immediately Squeeze and smooth the glue seam. Glue injection is required in a dust-free environment.

  3.6.6 Maintenance

  The board after glue injection should be kept and kept in the static field. The single-component structural glue can be transported after standing for 7 days. The maintenance environment requires a temperature of 23±5°C and a relative humidity of 70%±5%; the glass plate should be flat during curing; the stacking height should not exceed 7 layers when stacked, and each block should be cushioned with 4 equilateral cube foam plastic blocks. In the next layer, the cube size deviation is ≤0.5mm.

  3.6.7 Test

Use a single-component sealant sampled on the glass substrate to pile up 15.3cm × 7.7cm × 0.65cm ~ 1.3cm colloid as the cut test sample; after the glass plate is cured in the specified environment for 7 days, the test sample will be cut Cut in the middle and observe the cut colloid. If it is a shiny surface, the sealant is not fully cured, if it is a flat or dull surface, it is completely cured; if it is not fully cured after 14 days, it means that the quality of the glue is problematic. Put 20cm×1.5cm×1.5cm colloid on the surface of the substrate as the peeling test sample; after 21 days, carry out the peeling test on the peeling test sample, cut a 5cm long incision in the middle of the colloid thickness with a knife at the end of the gel sample, and pinch the cut by hand The head is torn backwards at an angle of >90 degrees, only allowed to tear along the colloid. If the colloid is peeled off from the substrate, the peeling test fails.

  3.6.8 The quality of components requires that the structural glue fills the cavity, the bonding is firm, the glue seam is smooth, there is no glue stains outside the glue seam, the warpage of the aluminum frame after the glue seam is cured is not more than 1mm.

  3.7 Installation of structural glass assembly components

  3.7.1 Positioning scribe line: Determine the horizontal and vertical position of the glass plate on the vertical surface, and draw a line on the main frame.

  3.7.2 Adjustment: After the glass plate is temporarily fixed, adjust the plate to adjust the standard horizontal, vertical and flat.

  3.7.3 Fixation: Fix the glass plate on the main frame with a pressing block. The distance between pressing blocks is not more than 300mm. Pay attention to drilling holes when pressing the block. The bolts use M5×20 stainless steel mechanical bolts. The pressing block must be pressed tightly.

  3.8 Weatherproof silicone sealant caulking

  3.8.1 Fully clean the gaps between the plates, there should be no water, oil stains, paint, rust, cement mortar, dust, etc. Fully clean the adhesive surface and dry it.

  3.8.2 is to adjust the depth of the seam to avoid three-sided glue, and fill the seam with foam plastic rods.

  3.8.3 Stick protective tape on both sides of the seam to protect the glass from contamination.

  3.8.4 Smooth the surface of the glue seam after the glue injection, and remove the excess glue.

  3.8.5 After the injection of glue, tear off the protective paper and wipe the glass with solvent if necessary.

  3.8.6 The glue is not contaminated with dust and scratches before it is completely hardened.

  3.9 Protection and cleaning

  4. Quality control

  4.1 Quality standards

  Refer to "Glass Curtain Wall Engineering Technical Specifications" (JGJ102-96) and "Glass Curtain Wall Engineering Quality Inspection Standards" (JGJ/T139-20016).

  4.2 Key points of quality management

  Material control: Various materials used in the curtain wall must meet the design and specification requirements. Before purchasing materials, it is necessary to understand what quality requirements the specifications have for the material. Various components must have reliable protection measures during transportation.

   Column pay-off: Column pay-off is a relatively tedious process in curtain wall construction. Whether the column pay-off is accurate will affect the entire construction process. Surveyors must proofread repeatedly during their work to ensure the accuracy of pay-off.

   Qualified welders must be used in the construction of the connection point between the column and the main structure. Welding, rust prevention, and installation accuracy must be qualified. During the component installation process, technicians should work hard to ensure that the installation accuracy and reliability of various components meet the requirements. The corners, upper and lower edges of the curtain wall, and settlement joints must be handled beautifully, and fire protection, waterproofing, and lightning protection must meet the requirements.

  5. Safety measures

  5.1 The construction equipment used to install the curtain wall must be strictly inspected before use. The insulation voltage test shall be carried out before the hand-held power tools are used; the hand-held glass suction cup and the glass suction cup installation machine shall be tested for adsorption weight and adsorption duration.

  5.2 The construction personnel shall be equipped with necessary labor protection articles to prevent the personnel and objects from falling.

  5.3 To prevent the poisoning of the sealing material in the use of the engineering solvent, and the solvent should be kept well to prevent fire.

  5.4 When welding on site, a fire connection should be added below the weldment.

  5.5 Set up a full-time security officer to carry out supervision and patrol inspection.

  6. Economic indicators

  6.1 Aluminum profile

  The amount of aluminum is generally 8~10 kg per square meter. Mainly depends on the elevation separation and main rod section.

  6.2 Glass

  There are many types of glass, such as tempered glass, coated glass, insulating glass, wire glass, laminated glass, etc. The factors that affect the unit price of glass include varieties and specifications.

  6.3 Sealant

  The structural adhesive is generally 1.5~2.0 sticks per square meter (300ml each), and the weather resistant glue is generally around 1 stick per square meter (300ml each). Mainly depends on the cross-sectional size of the rubber strip and the vertical separation.