Air-supported structure description
Air-supported structure description
An air-supported structure refers to pre-fabricated structures made of PVC coated fabrics and using excess pressure inside the structure to ensure stability and resist external loads (snow, wind, etc.). They can be used in all climatic conditions from -30 ° C to + 50 ° C and are installed mainly on a strip-type concrete foundation. They have high performance indicators (light weight, ease of installation and operation, good thermal insulation, autonomy, price, etc.).
Air-supported structure is a single or multi-layer shell (usually two layers). The outer shell is UV protected. The inner shell is suspended from the outer shell on spars and provides thermal insulation for the structure. On the inner shell, there are fixing points for fixtures and wiring, as well as valves for the discharge line.
The air-supported structure shell can consist of several mounting parts weighing 1.5 ... 1.8 tons each. The parts are connected to each other using assembly seams compressed by aluminum plates 6x40x195 mm. Two M8 bolts are pressed into the upper plate, bolt holes are made in the lower one. The assembly seam is sealed with silicone sealant and closed with a 250 mm wide protective tape, which is fixed with 6 mm fire carabiners to the attachment points on the awning.
The shell is attached to the foundation using a foundation edge and a steel equal-flange angle (50x5, 63x6, 80x6) 1 m long, which is fixed with anchors with a step of 500 mm. An apron is located along the perimeter of the air-supported structure, covering the place of attachment to the foundation.
The air-supported structure can be installed on the ground using screw piles and a tensioning system of pipes located along the perimeter of the structure inside the shell pocket. Such air-supported structures are equipped with an additional internal apron to seal the structure.
Air-supported structures are constantly pumped and must have an emergency power or air supply system. The working overpressure inside the air-supported structure is 150 ... 400 Pa.
For the manufacture of the shell, a PVC coated fabric is used. The outer shell fabric has an extra layer of PVDF or acryl to protect the fabric from UV radiation and premature deterioration. A characteristic parameter of PVC fabric is its density (g / m2) and physical parameters of strength along the warp and weft (along and across the roll). For structures up to 25 m wide, fabric with a density of 650 ... 680 g / m2 is used, over 25 m - 900 g / m2 and more. The type of fabric used also depends on the blowing radius of the casing and operating conditions and must be chosen by the designer. Fabric parts are connected to each other by welding or glue. Welding is carried out with a wedge / air or HFC (high frequency currents). The main type of seam НХ40 is 40 mm wide.
Air-supported structure is installed on any level area, free of sharp objects. Anchoring to the base can be carried out using screw piles or foundations. The foundation can be formed using reinforced concrete slabs with a thickness of at least 150 mm or a solid ring foundation with reinforcement is poured.
Air-supported structure can be equipped with entrance groups of various types: metal doors on a frame with a quick-release mechanism, swing gates, overhead sectional gates, roller shutters, cargo lock with gates, revolving lock (revolving lock). The metal frame of the opening is installed on the site independently and has an individual fastening. The metal frame is connected to the VOS shell by means of an expansion joint, which prevents the shell from breaking when the structure is lowered to the ground. The compensator is attached to the metal frame with 4x25 mm pressure plates. The shell at the location of the entrance groups is equipped with cable reinforcement around the opening, and the ends of the cables are attached to the base through lanyards.
Any structures located in the air-supported structure should have smooth bending lines so that when the shell is lowered it does not damage it.
The structure can partially or completely rely on other buildings, walls or adjoin them.
Air-supported structure can be equipped with additional equipment: heating, air conditioning, autonomous power supply, etc.
The lighting equipment includes fixing points for fixtures (metal frame with a fixing plate) and, by agreement, fixtures with 400 W metal halide lamps and a luminous flux of 35,000 lumens. With an illumination of 300..350 lux at 50 ... 60 sq. M, one lamp is needed. LED lamp is 2 ... 4 times more expensive.
Heating / ventilation / cooling equipment is located outside the air-supported structure and is connected to it by air ducts-tubes. The length of the tube should be 200 ... 300 mm longer than the distance between the air-supported structure shell and the injection equipment to compensate for vibrations in strong winds. Heating equipment can be of any type. The air recirculation opening is covered with a grid and PVC fabric.
To determine the approximate power of the equipment, you can apply the formula: Q = Δt * S * 3.5 (W); where Δt, (° С) is the temperature difference between the street and the room, S, (sq. m) is the surface area of the structure.
When equipped with a mobile generator set, the structure can be operated autonomously without being connected to the mains.
An image can be applied to the surface of the shell using full-color printing or removable banners can be attached.