Selection and construction of stone curtain wall materials
[Students' questions] Selection and construction of stone curtain wall materials?
[Answer] In recent years, with the development of social economy and the improvement of the city's appearance, in the exterior decoration of buildings, the stone curtain wall has been favored by the majority of owners and architects, and has occupied a considerable proportion in the existing buildings. Moreover, the application of stone curtain wall is getting higher and higher, and the volume is getting larger and larger; the variety of stone used is more and more, from the original single granite to the marble, limestone, sandstone and other varieties; the shape is more and more complicated, The installation and construction process requirements are becoming more and more strict, and the requirements for safety are getting higher and higher. However, the domestic stone curtain wall material market is chaotic, the production unit lacks technical specifications, and the construction personnel's technical quality is low, which brings great safety hazards to the project. For various reasons, the selection of stone boards, dry hanging glues, dry hanging parts and the preparation and installation of pre- (post) embedded parts are the most easily overlooked, and a brief analysis of how the four materials should be selected.
Stone board
As the stone curtain wall of the outer protective structure, it does not bear the load of the main structure, but it is on the outer surface of the building. In addition to its own weight, it also bears the influence of wind load and seismic action and temperature change. Therefore, stone is required. Must be safe and reliable. The performance and quality requirements for stone include: compressive strength, flexural strength, flexural strength, hardness, wear resistance, frost resistance, fire resistance, and processability.
The stone used in the stone curtain wall is naturally formed. The natural stone is mined from the mountain. Its important performance depends on the mineral composition and structure. However, the above-mentioned series of properties tested and tested have different samples, which are not as good as industrial products. The difference is small. Due to the different materials, the measured performance will not be exactly the same.
Based on the above situation, when the architect determines the stone type, the use of the stone board must be cautious, and we must do the following work:
1. Do a basic material test: its compressive strength, flexural strength, flexural strength, hardness, wear resistance, frost resistance, fire resistance, and processability must meet specifications and design requirements, and be used for curtain walls. For slate, each batch should be tested for flexural strength. For areas where negative temperatures may occur, freeze-thaw tests are also required. Only when the performance indicators meet the design and specification requirements.
2. Control the processing precision of the stone to avoid secondary cutting at the construction site. Affected by the installation process, the commonly used stone dry hanging process now needs to be perforated or slotted in the stone plate section. Therefore, the thickness of the stone is limited by the installation process, and a structural thickness must be ensured, so when the stone board process is accepted. Pay special attention to the thickness of the sheet, the allowable deviation is +2 mm, no negative difference is allowed, and inspection is performed block by block.
3, in the mining, transportation, cutting and installation process to avoid damage, stone has become a plate once the collision, the damage caused, especially the internal injury is difficult to check out, but it will develop over time, serious will Breaking, which poses a safety hazard. In the processing, transportation and installation of stone, it should be strictly controlled.
4, do a good job of the stone surface protection, to ensure the dryness of the stone inside, to ensure that the natural properties of the stone.
5, the area of ​​a single stone should not be too large, "metal and stone curtain wall engineering technical specifications" provisions can not exceed 1.5 square meters.
6. Stacking of stone: 1 Stacked in the specified site according to the specifications of the plate; 2 It is strictly forbidden to mix with corrosive materials. Eliminate contact with acid and alkali substances; 3 mark the order of product processing sequence, pay attention to no collision, pollution, etc. Use a long permeable material to raise the height of the bottom of the plate by 100 mm and ensure it is stable.
Stone dry glue
The load on the stone curtain wall panel is transmitted to the pendant through the glue between the stone and the pendant, and then transferred to the support structure by the pendant. Therefore, the dry glue of the stone curtain wall must be structural adhesive, and the dry hanging glue must be good with the stone. The adhesion is also good to the pendant (the material of the pendant can be stainless steel or aluminum alloy), and the adhesive layer itself has suitable strength, good toughness and elasticity. This point is stipulated in the "Technical Specifications for Metal and Stone Curtain Wall Engineering" (JGJ133-2001): the joint between the slate and the stainless steel pendant should be bonded with epoxy resin-type stone. The State Economic and Trade Commission issued the "Epoxy Adhesive for Dry-hanging Stone Curtain Wall" (JC887-2001) in December 2001. It was implemented on June 1, 2002. According to the characteristics of the stone curtain wall, six mandatory indicators were also stipulated. It has been more than 5 years, but in some projects, structural adhesives have not been used, and epoxy resin-type stone structural adhesives have not been used. At present, it is still commonly used in strong rubber. Strong rubber is a glue for bonding stone and stone. It is unscientific to use it for the bonding of stone and metal. Its toughness, elasticity and bond strength are weaker than Stone dry glue is many times, and it is easy to penetrate and corrode stone when metal is rusted. Although some are also used for publicity and advertising of stone curtain walls, in fact these glues can not be used for stone curtain wall. On the basis of the implementation of "Technical Specifications for Metal and Stone Curtain Wall Engineering" (JGJ133-2001), the selection of the right stone curtain wall dry hanging glue is the current priority for ensuring the safety of stone curtain wall!
On the basis of the correct selection of dry glue for stone, the compatibility and adhesion test of dry-hanging glue is also required. It can be used in the project after passing the test. How to use dry hanging glue reasonably during the construction process is also very important. Please pay attention to the following points:
1. The modulation and smearing of the stone opening and hanging glue, and the fixing of the dry hanging parts should be carried out directly in the processing workshop; the stone grooving must be machined, and the grooving process control and processing inspection should be strengthened to avoid damage to the stone.
2, the adhesive surface should be dry and not wet (humidity is not higher than 15%), dust-free, clean, rough, no oil stains.
3. The physical and mechanical properties of dry-hanging glue are directly related to the thickness of the rubber (generally 1 mm to 2 mm). The processing of dry hanging parts and dry hanging grooves should be strict, ensuring the processing size and precision, and the cooperation of dry hanging parts and dry hanging grooves. Be strict and ensure the thickness and depth of the dry hanging glue.
4. Since the strength of the dry glue of the stone is related to the curing time and the curing temperature, it is necessary to ensure sufficient curing and curing time, and it is impossible to move and load the load at the initial stage of curing.
Naips LED Emergency Ceiling Light-A power failure light with a modern design that provides high quality lighting with an adjustable cct color switch attached to each fixture. Every round light fixture is pre-installed with the built-in lithium ion emergency batterry pack, damp location rated for reliability, ETL listed for your safety, is 85-265V AC input, has a brushed chrome finish, and backed by a 5 YEAR WARRANTY.
Led Emergency Ceiling Light,Emergency Led Ceiling Light,Emergency Light For Ceiling,Emergency Light Ceiling Type
Foshan Nai An Lighting Electric Co.,ltd , https://www.naipslighting.com