Talking about the quality and safety of building curtain wall doors and windows

Column:Industry News Time:2016-11-04
As we all know, building curtain walls, doors and windows are the outer protective structure of the building. The building curtain wall is suspended on the main body and has relative displacement ability.

As we all know, building curtain walls, doors and windows are the outer protective structure of the building. The building curtain wall is suspended on the main body and has relative displacement ability. It adopts light-weight and high-strength surface with decorative effects, safe and reliable heat preservation, fire protection and energy saving materials, which must be in accordance with relevant standards. Design and construction in accordance with the requirements of the specification can ensure its quality and safety, otherwise it will cause safety hazards and accidents. "The quality of a century-old plan" is by no means empty talk. According to relevant statistics, the average annual total area of construction projects in my country in the past 20 years is about 2 billion square meters, of which the cumulative total of designed and applied building curtain walls has accounted for more than 80% of the world's total. The consumption is about 10 billion square meters. Many of these projects meet the requirements of relevant standards and codes and meet the requirements of building energy efficiency and green building standards. At present, many projects (including building curtain walls, doors and windows) generally adopt bidding methods in the construction market, and the construction party proposes the bidding documents. The content requirements in the bidding documents are also based on the characteristics of the project and the specific project content and the design specifications and standards followed. And quality, quotation, etc. The content of the bids of the bidders should also meet the content requirements of the bidding documents before they can be shortlisted and await review. The construction party shall select several experts for review according to the specific content of the project. Expert review is also based on the content requirements of the bidding documents to review the tender technical data provided (including construction organization, design plan drawings or construction drawings, quotations, etc.).

Building curtain walls, doors and windows are special technologies, which are reviewed by experts who have been engaged in building curtain walls, doors and windows for many years and have rich practical experience with senior titles. From market research, it is found that the bidding units for a curtain wall, door and window project are as few as a few, as many as a dozen or more, and the registered units are all curtain wall, door and window construction enterprises with first-class qualifications and first-class design qualifications. , And including units that may have multiple branches or affiliates, there are not many real main construction or design units. At present, there are more than 400 first-level qualified enterprises in the construction and design of curtain walls, doors and windows in the country, and there are about a thousand branches and affiliates. There are not many units with strong design and construction capabilities. It is inevitable that there will be fierce market competition due to a large number of people. The bidding price may become the main factor of victory or defeat. In this regard, sufficient attention must be paid to the quality, safety and hidden dangers of construction curtain walls, doors and windows bidding and construction.

We have discovered price-related issues from some reviewed architectural curtain walls, door and window design schemes or construction drawings, mainly in the following two aspects:

1. There are many hidden dangers in the structural design of building curtain walls or doors and windows

⒈The design and construction of the curtain wall should meet the JGJ102, JGJ133 glass curtain wall engineering technical specifications and the metal plate and stone curtain wall technical specifications, and the design service life of the curtain wall structure system should meet the requirements of no less than 25 years. From the materials reviewed, it is found that many curtain wall structural system designs lack specific and complete architectural curtain wall structural systems and structural designs that have relative displacement capabilities with the main body, and a simple embedded part and angle steel are used to fix the columns. This is a structural design that does not meet the requirements of the specification.

2. The semi-concealed or non-concealed curtain wall glass in the component glass curtain wall is mostly fixed by pressing plates, and the columns and beams use the broken bridge aluminum material of the heat insulation strip to solve the problem of heat insulation and energy saving. The end connection is wrong, because when the curtain wall glass is under negative wind pressure, the bonding force between the heat insulation strip and the end of the heat insulation aluminum material cannot satisfy the negative wind pressure, and it is very likely to blow the glass plate off and cause serious Accidents, especially the use of low-quality and low-cost domestic insulation strips (about 1 yuan) are more dangerous.

3. In the design of the stone curtain wall structure, the stone pendant adopts pin type, T type, dish type, oblique insertion type, glue connection type, etc. for structural force connection, especially when used on the structure with complex concave and convex facade. Due to the influence of insufficient supporting force, the stone is not firmly connected and falls off, causing hidden dangers.

4. Various types and uses of glue, rubber strips, rubber pads and hardware accessories are used on building curtain walls, doors and windows. The quality and performance of these accessories have clear standard requirements. The bidders also use their types and uses when bidding. It’s all clear, but the quality of the actual purchase and application is very different from the performance quality of standard products. The specification requires that the use should be no less than 25 years, but in fact, it takes less than a few years to appear tape, rubber pad, etc. Aging hardening loses elasticity, cracks, etc. In the process of use, the doors and windows are often not closed tightly, leaking, ventilating, improper connection, window sash deformation or falling off, etc., all of which have a negative impact on the quality of the project.

5. The height of the side ribs in the design and processing of the curtain wall aluminum plate is lower than the standard requirements and is not connected with the reinforcement ribs, which makes the reinforcement ribs not bear the load.

6. The self-detonation phenomenon and the harm caused by the quality of the curtain wall tempered glass have attracted wide attention in the society, so there are clear technical requirements for the selection and treatment of glass in the bidding documents.

Second, the low price of building curtain wall doors and windows is very harmful

According to the survey, the material cost for a component curtain wall project will account for about 65% of the project cost, and the construction cost will account for about 20%; other expenses such as processing and design, on-site management personnel, etc. are also quite a lot. Therefore, we will do a good job in bidding for curtain wall, doors and windows in the future. It is very important to deal with the systematic supervision and inspection of the whole process of its work. Supervisors represent the construction party. They have great supervision power and influence. If they can find and point out some existing problems in time during construction. If the use of counterfeit and shoddy products or non-compliance with specifications and standards in installation and construction are prevented and their supervision power is fully exerted, the quality of curtain walls or doors and windows will not have many current problems. At present, there is a large discrepancy between the bid prices and the general construction parties are willing to accept companies with low prices. Even if the bidding unit is strong, the quality of the design drawings and the technical level are very good, and the construction team with good materials and high standards is due to the high price. And being eliminated, this phenomenon runs counter to fairness and justice. In order to avoid the occurrence of similar things, we should start from the source, strictly implement the bidding law and expert review system, and enrich and strengthen the power of the supervision and inspection system. The personnel involved in the review, supervision, supervision, and inspection of this industry should carefully study and master the relevant standards and norms to ensure fair and impartial bidding and the quality and safety of construction.