3.9.1. Introduction to technology.
Autoclaved lightweight aerated concrete slab is a porous concrete slab (referred to as ALC board) made of cement, silica sand and other main raw materials, reinforced by anti-rust treated steel bars, and cured by high temperature and high pressure steam. ALC slabs are fast to construct and easy to install, and are suitable for use as partition panels, exterior wall panels, roof panels and small-span floor slabs in multi-storey and high-rise buildings. ALC boards are widely used in Europe and Japan. At present, it has also been developed to a certain extent in China, and has successively introduced advanced equipment and patented technology from Sweden and Japan in Beijing, Shanghai, Nanjing and other places, and has established a large-scale production enterprise of ALC products. ALC products have been recognized by the Ministry of Construction as "National Recommended Products for Residential Construction".
3.9.2 technical points.
The exterior wall panels are mainly fixed on the structure through U-shaped cards, pipe clamps, right-angle steel parts and bolts, etc., to achieve the flatness and stability of the plates. During the construction of exterior wall panels, every step is very important, from elastic line to installation, and it is necessary to grasp the key points of construction. Due to the similarity between the steel structure and the steel-concrete structure in construction, the following is described as a whole and will not be described one by one.
1) If the U-shaped card method is adopted, the U-shaped card is installed according to the elastic wall position line, and each plate is welded with a U-shaped card and the steel beam, or connected with concrete with two nails. The middle position of the U-shaped card should be as close to the seam between the board and the board as possible (except for the first one), and the height of the stuck plate should be 20mm. If the U-shaped clamp is fixed by nails, it shall not be less than 2;If it is spot welding, there shall be no less than four fixed points, the welding wave should be uniform, there shall be no cracks, unmelted, slag inclusions, welding nodules, undercuts, burn-through and needle-like porosity and other defects, and there shall be no residue at the welding place and anti-rust treatment. If the right-angle steel method is used, after the plate is cushioned, it is fixed with nails or welding. If the hook bolt method is used, the angle steel is fixed by nailing or welding, and then the hook bolt is fixed. If the pipe clamp is used, the pipe clamp should be fixed on the end face of the plate first, and after the plate is cushioned, it is fixed on the structural beam by nailing or welding. In order to.
The above four methods can be used at the same time.
2) install the plate in turn, the gap between the top of the plate and the concrete or the steel beam is filled with polyurethane material or other flexible materials, the bottom of the plate and the concrete or the steel beam are fixed with a wooden wedge, and the gap between the bottom of the plate and the concrete, the steel beam or the floor slab are filled with expansion mortar. Generally, after 3 to 5 days, the wooden wedge can be pulled out, and the wooden wedge hole and bolt installation notch can be filled with polymer mortar.
3) Regardless of flat mouth or notch, it is necessary to bond a mesh cloth with a width of 100 200mm at the joint of the plate and press into the polymer cement mortar, with a total thickness of about 5 10mm and a width of about 100 200mm.
The installation and connection structure of the fixing method involved in ALC installation can be constructed with reference to the atlas "Autoclaved Aerated Concrete Block and Plate Structure" (13J104), "Autoclaved Aerated Concrete Slab" (GB17562-2008), and "Autoclaved Aerated Concrete Slab (NALC) Structure Details" (03SG715-1).