I. Introduction

With the application and development of curtain wall technology, various advanced curtain wall design concepts and curtain wall structures have been widely used in various projects. The application of aluminum plate decorative lines on the facade of the curtain wall is a kind of new technology. This process is different from the traditional method of façade division. The parametric design concept of the façade is used to generate a very rhythmic skin, which is modern and fashionable.

The curtain wall has a good visual effect, first-class overall performance and no noise. It is an ideal structural system. It has great advantages in safety, durability, and replaceability. It not only achieves the effect of external shading, but also To meet the needs of ventilation and lighting. This application is suitable for large-scale high-end office buildings, shopping malls, complexes, etc. with a simple and generous curtain wall.

2. Project Overview

The first phase of Nantong Central Innovation District Science and Technology Innovation Center (Nantong Institute for Advanced Study)/A-2 project is located in the planned Central Innovation District of Chongchuan District, Nantong City. It is adjacent to Jumei Road in the south, Xingfu Road in the east, Jujia Road in the north, and Shengli Road in the west. The project is a project for commercial use, which integrates business hotels, administrative offices, business offices, headquarters offices, R&D institutes, commercial and catering services, underground parking and public facilities.

The total construction area of ​​the project is 173,200 square meters, and the curtain wall area is 95,000 square meters. Frame structure, 1 floor underground, 1--14 floors above ground. The elevation of the building is 34.60m. The fire resistance level is one, the fire resistance limit of the floor fire layer is 2 hours, and the seismic fortification is 7 degrees. The construction cost of the curtain wall of this project is 1,000,000,000,000,000,000 yuan (60,064,900 yuan), and the owner is Nantong Central Innovation Zone Construction Investment Co., Ltd., and Nantong Bluestar Decoration Engineering Co., Ltd. is responsible for the curtain wall construction. The construction buildings include W1#, W2#, W3#, W4#, W5#, W6#. The construction scope mainly includes glass curtain wall (vertical and horizontal hidden), aluminum plate curtain wall, aluminum alloy grille, lighting ceiling, glass canopy, Glass floor pop-up doors, aluminum alloy shutters, fire partitions between floors, etc. The curtain wall construction started on March 10, 2019, and the curtain wall was completed on June 30, 2019.

3. Engineering Features

The aluminum plate decorative lines are selected outside the project, which has good waterproof and moisture-proof effect and good durability. At the same time, the precision of factory production is greatly improved, which greatly reduces the phenomenon of missing edges and corners on the surface, and significantly improves the appearance quality of the product. All panels are processed and manufactured in the factory to facilitate the control of the processing quality and precision of the panels. The most complex processing and assembly work of this system is carried out in the processing plant, and the overall lifting and installation are adopted on site, which effectively ensures the quality of plate processing and assembly, as well as the on-site construction period. While the construction process perfectly displays the architectural effect, it effectively guarantees the quality of processing and assembly of the curtain wall, shortens the processing and installation time, guarantees the construction period and saves labor costs.

4. Construction preparation

1. Technical disclosure of design drawings and joint review of drawings

After receiving the construction drawings, the relevant professionals of the project will be organized to read and familiarize themselves with the drawings, understand the design intent, master the form and characteristics of the engineering building and structure, master the curtain wall structure, node requirements, design grid characteristics, and be familiar with the new technologies used in design. , new method, at the same time, check the accuracy of the design bill of material and processing order, and organize the problems found in the reading drawings to form a drawing self-examination record and submit it to the design institute and the deepening designer. Arrange and form the design disclosure record, and the construction basis will be formed after all parties countersign.

2. Preparation of technical data

First, prepare the construction drawings: our company starts the detailed design of the construction drawings of the project on the day of winning the bid, and provides one set of construction drawings for the detailed design of the curtain wall for the owner, the general contractor, the supervisor, the project department, and the construction team. At the same time, organize the management personnel of the project department and the technical management personnel of the construction team to study the drawings.

The management personnel of the project department and the technical management personnel of the construction team should be fully familiar with the drawings and design, and they should ask and understand the unclear and difficult places. Formulate the specifications, standards and catalogues of the project, and ensure their validity, supplement the purchase of relevant books according to the proposed catalogues, and establish a management system.

Compile various project construction plans, and prepare quarterly and monthly construction progress plans. Prepare construction safety technical quality disclosure card. Sign the safety, fire protection, quality, progress, civilized construction guarantee agreement with the construction team, and draw the layout plan of temporary construction and temporary power facilities on site. Collect relevant information such as relevant plans, qualifications, material inspection reports, product quality assurance certificates, and product qualification certificates.

3. Preparation for construction survey

The actual size of the original structure is measured on site to provide data for the design, contact the general contractor for process handover, and ask the general contractor for technical documents on the measurement elevation and axis reference point of the civil structure. With the progress of the civil structure, make preparations for the positioning, measurement and lay-out of the embedded parts in advance.

4. Preparation of embedded parts

Contact the general contractor to prepare for the setting of the embedded parts in advance. The general contractor needs to cooperate, provide the general contractor with the positioning drawings of the embedded parts, and set the embedded parts with the progress of the civil structure.

5. Construction technology

(1) Glass installation

(1) Measure and pay off

a. According to the large scale drawing of the curtain wall and the elevation points, the entry and exit lines and the position of the axis, use tools such as heavy hammers, steel wires, measuring instruments and spirit levels on the main body to determine the curtain wall plane, column division and corners. Weiyi adjusted and retested.

b. The horizontal elevation should be drawn up from the ground layer by layer to avoid accumulation of errors.

(2) Installation of embedded parts

a. Position the embedded parts according to the drawings while measuring and laying out the lines.

b. Check whether the position of the embedded parts is accurate. The upper and lower deviation should not be greater than 10mm or so and the deviation should not be greater than 20mm. If the deviation is too large, install the post-embedded parts.

(3) Installation of the skeleton

The column is connected to the connector first, and then the connector is spot welded on the embedded steel plate, and then the position is adjusted. The verticality of the column can be controlled by the hanging hammer. After the position is adjusted accurately, the iron code can be formally welded to the embedded iron piece.

a. Columns are generally vertical components, which are one of the keys to the installation and construction of curtain walls. Its accuracy and quality will affect the installation quality of the entire curtain wall. The allowable deviation of the distance between the plane axis of the curtain wall through the connector and the outer plane axis of the building should be controlled within 2mm, especially for the curtain wall whose building plane is arc-shaped, circular and closed around, the distance between the inner and outer axis will affect the circumference of the curtain increase. long and should be taken seriously.

b. The beam is generally a horizontal member, which is embedded and connected in sections in the column, and the connectors at both ends of the beam are installed at the predetermined position of the column. The beam is sleeved on the connector, do not fix it, and intentionally shorten the blanking length slightly during production, so that there is a certain gap at the joint. Since the columns are connected by sleeves, there is a gap at the joint, and there is also a gap between the beam and the column, so that the column and the beam can form a frame skeleton with a certain deformation ability after installation, so as to adapt to and eliminate building deflection deformation and temperature deformation. impact and increase its carrying capacity. However, if the beam has an arc, broken line or corner, in order to prevent the beam from falling off, the beam and the connector should be fixed.

c. Installation sequence

The installation of beams on the same floor should be carried out from bottom to top. When the height of the first floor is installed, it should be checked, adjusted, corrected and fixed to meet the quality requirements.

d. After the anti-rust and anti-corrosion treatment of the skeleton is in place, install the aluminum profile cover. At the same time, the treatment of avoidance and the installation of thermal insulation and fireproof materials have passed the concealed acceptance and entered the construction of the next process.

(4) Skeleton production

a. Determine the position of the outrigger frame of the overhanging aluminum plate by measuring the line.

b. The outrigger frame is made of 50*50*3 stainless steel tube as the supporting frame, and the stainless steel tube is processed. One end of the stainless steel square tube is welded with an 8mm thick stainless steel connecting plate and sealed, and the other end is welded with an aluminum alloy pressure plate. This material needs to be processed. , for customized materials, completed by the processing plant, not welding connection on site.

c. One end of the stainless steel welded aluminum alloy pressure plate is connected to the aluminum alloy column through stainless steel bolts and protrudes from the glass glue seam. Therefore, when installing the skeleton, find the position of the connecting piece by measuring the wire. Before installing the glass panel, place the outer The outrigger is fixed on the aluminum alloy column together with the pressure plate. After the glass panel is installed, adjust the outrigger. After adjusting the level according to the stainless steel tube, tighten the stainless steel bolt to fix the position. The fixation should be safe and reliable. The outrigger is vertical and horizontal. Lines are required to adjust the position.

d. After the installation of the outrigger frame is completed, the vertical decorative strip starts to be installed. The vertical decorative strip and the glass need to be glued to prevent water leakage.

(5) Glue injection and cleaning

a. Stuffing the pad: Select the suitable size and quality to fill the pad into the glue injection seam, keep the pad and the side of the plate with enough friction, and the protruding surface of the pad is about 4mm away from the glass surface after filling.

b. Clean the glue injection seam: Use a clean and non-hairing cleaning cloth and xylene, and use the "two-piece rag method" to clean the glue injection seam within half an hour before the glue injection.

c. Paste textured paper.

d. Glue injection: The glue joint should be injected with glue as soon as possible within half an hour after cleaning, and it should be cleaned again after the time is exceeded.

f. Squeegee: The squeegee should smooth the glue seam (or concave surface) along the same side, and pay attention to the curing time of the sealant.

(2) Installation of aluminum decorative lines

(1) Measure and pay off

a. Offset the axis of the main body outwards according to the design, so as to determine the positioning line and dividing line of the curtain wall. Use theodolite or laser vertical instrument to lead the axis, outside and inside corners of the curtain wall to a high place according to the requirements of the large sample drawing, and use the steel wire fixed on the steel bracket as the marking control line.

b. Use a spirit level and a standard steel tape measure to draw out an elevation line of ±0.00, and pop up an elevation line on the wall to review the accuracy of the aluminum panel keel.

c. Draw detailed drawings of plate arrangement. Due to the many changes in the external dimensions of this project and the required specifications of the plates, in order to facilitate processing and construction needs, detailed processing drawings should be prepared for all aluminum plates to ensure the accuracy of the stone materials.

d. The distribution measurement error should be controlled during measurement, and the error should not be accumulated.

e. The measurement and release should be carried out under the condition that the wind force is not greater than level 4, and measures to avoid the wind should be taken.

f. After the positioning of the line, the control line should be checked regularly to ensure the correctness of the verticality of the curtain wall and the position of the metal beam.

(2) Installation of outrigger skeleton

a. Process flow

Construction preparation→transport aluminum plate→initial installation→adjustment→fixation→acceptance

b. Construction preparation

Make adequate preparations before construction. The preparation work includes personnel preparation, material preparation, and construction site preparation. When arranging the plan, firstly arrange the personnel according to the actual situation and the requirements of the project progress plan. Generally, there are 3 people in each group. The construction site preparation should leave enough working surface in the construction section to meet the installation needs, and at the same time, the frame plate should be cleaned. And adjust the shelf plate to meet the installation requirements.

c. After the keel is installed and passed the inspection and acceptance by the supervisor, the aluminum veneer can be installed. Before installation, first familiarize yourself with the aluminum veneer installation numbering diagram and confirm the installation position of each aluminum plate.

(3) Installation of aluminum decorative lines

a. Transportation of aluminum decorative lines

After confirming that the aluminum plate has no quality problems, use the hanging basket to transport the processed aluminum plate to the designated position. When transporting, pay attention to protect the paint film of the aluminum plate from damage. The dust and dirt should be wiped clean of the aluminum plate installation. The protective film outside the board is strictly prohibited to be removed at this time to protect the aluminum plate mask from damage. Before delivery, pay attention to the placement method to prevent the aluminum plate from being deformed.

b. Initial installation

The installation of aluminum panels is from top to bottom, and the principle of each layer is from left to right. Avoid direct contact between aluminum plate and components.

c. Adjustment and fixation

Through the hanging wire, ensure the levelness and verticality of the aluminum plate installation. , to ensure that the aluminum plate is flush with the fixed profile. After the adjustment, fix the aluminum plate on the profile and fix it with stainless steel machine screws. There are no less than 3 screws on each side of each aluminum plate.

d. Clean up

The aluminum plate installation can be partitioned and installed in different parts. After each piece is installed, the overall secondary adjustment of the plate should be carried out to ensure that the flatness and gaps are horizontal and vertical, and the gaps are uniform. The gap between the upper and lower aluminum plates is 2mm, and the gap is not glued. Before removing the hanging basket, remove the protective film on the aluminum plate, and it is strictly forbidden to remove the protective film below 2.0 meters above the ground to prevent damage to the finished product during the construction process. Then apply for inspection in parts and batches.

(3) caulking, capping and edge sealing of weather-resistant glue

After the aluminum plate is installed, it should be sealed and the wall, top, bottom, etc. should be trimmed. Special attention should be paid when applying sealing and weathering adhesive:

1. Fully clean the gap between the plates, there should be no water, oil stains, dust and other sundries, and the adhesion surface should be fully cleaned and dried. Xylene or methyl diethyl ketone can be used as cleaning agent;

2. In order to adjust the depth of the seam and avoid glue on three sides, the seam should be filled with polyvinyl chloride foam material (small round rod);

3. The thickness of the glue should be between 3.5mm and 4.5mm, and it should not be too thin or too thick. And the surface of the colloid should be flat and smooth, and the glass should be clean and free of dirt. The top, edge, and back cover should be firm and beautiful, without water seepage, and the water on the top should be drained inward.

(4) Protection of finished products

After the aluminum plate is installed, it is necessary to arrange full-time personnel to protect the product. The measures are as follows:

1. Do not tear the protective tape of the aluminum plate for the time being, and do not tear it until it is to be accepted;

2. Use plywood or other materials to block the places that are easy to collide with to prevent mechanical impact and corrosion of chemicals, cement mortar and corrosive gases, such as strong acid, strong alkali and asphalt burning gases, etc.;

(5) Delivery and acceptance

When all the decoration works are completed, it is necessary to clean up and sanitize comprehensively from top to bottom, and return the firm and beautiful products to Party A. At the time of delivery, the hardware is beautiful (product) and the software is complete (data).

The most important thing in the whole construction is to improve the machining accuracy of the components and strengthen the control of quality and safety, so as to achieve the expected results.

6. Quality assurance measures

1. The variety, quality, color, pattern and line of the aluminum plate should meet the design requirements, and there should be a product qualification certificate.

2. The skeleton of the curtain wall is made of profiled steel keel, whose specifications and shapes should meet the design requirements, and should be treated with rust removal and anti-rust treatment.

3. For aluminum plate installation, when the design has no requirements, core-pulling aluminum rivets should be used, and a rubber ring must be placed in the middle. Blind rivet spacing should be controlled within 100-150mm.

4. Ensure that the connectors are firmly fixed, and the wires are positioned during installation.

5. Strengthen the inspection and acceptance of materials at the site, and try to use materials from one unit.

6. Strengthen protection measures after the metal sheet enters the site, increase inspection efforts during the process, and improve the protection awareness of finished products.

7. Only machine screws can be used to fix the aluminum plate, and the use of rivets is strictly prohibited, and the inspection efforts shall be increased during the construction process.

8. Acceptance shall be carried out in strict accordance with the relevant quality requirements, and the parts that do not meet the requirements shall be rectified. After the rectification is passed, the construction of the next process can be entered.

7. Engineering Evaluation

The project successfully passed the completion acceptance in June 2019, and there was no quality problem in the construction process and acceptance process, indicating that the construction method is feasible. In this project, by setting the outer side of the hollow glass curtain wall with an aluminum plate, the solar radiation is effectively shielded, and part of the solar radiation heat is prevented from entering the room from the glass window, which saves the energy consumption of building operation, achieves the purpose of energy saving and emission reduction.