ALC board installation process
Structural base cleaning, leveling → measuring and laying out → welding angle steel → plate selection and transportation → plate installation and connection → inspection and correction → anti-rust treatment → repair and caulking → acceptance.
2.1 Structural base cleaning and leveling
Clean up the structural top beam and bottom structural concrete slag and debris, and carry out the base surface leveling treatment.
2.2 Lay the installation wire
According to the construction drawings, at the structural installation wall panel position, the wall panel installation position line pops up, and the installation position of the wall panel is indicated according to the layout (selection board) design. During installation, use a ruler to adjust the verticality of the wall, and coincide the lower edge of the wall panel with the installation position line of the wall panel to ensure that the verticality and flatness of the wall panel installation meet the requirements of the specification.
2.3 Welding angle steel
First, M12@600mm expansion anchor bolts are used to fix the 100×100×6mm connecting steel plate at the installation edge of the wall panel to connect with the concrete of the main structure. Then, according to the layout and positioning diagram of the wall panel and the line position of the wall panel, weld the angle steel with a length of 63×63×6mm on the connecting steel plate.
2.4 Option board transportation
Strictly select the corresponding plate according to the layout drawing, and punch holes in the middle of the upper and lower ends of the plate before installation, so that the hook bolt can pass through and be welded to the angle steel.
2.5 Plate installation and connection
The outer wall panel is placed on the wall structure, and is welded on the 63×63×6mm angle steel through the plate with quasi-12 hook head bolts (one end is covered with a circular gasket with a diameter of 50mm). Before installing the inner wall panel, nail the tube clip into the wall panel, and use 2*M8 anchor bolts to fix it after it is in place.
2.6 Check calibration
For each board installed, use a hanging wire and a 2m ruler to check the verticality and flatness. If there is a deviation, use a special crowbar to adjust to meet the requirements before welding.
2.7 Anti-rust treatment
All welding parts and angle steel shall be painted with gray anti-rust paint after slag removal.
2.8 Repair caulking
After the wall panel is installed, use special repair powder to repair the missing edges and corners. Alkali-resistant mesh cloth and anti-cracking mortar are used to fill the gaps between the wall panel and the structure and the gap between the wall panels.
3 Common quality problems prevention measures
The common quality problems of ALC wallboard are mainly cracks. Cracks usually occur in the following areas:
3.1 Cracks appear at the splicing between the wallboard and the wallboard, often on one side but sometimes even on both sides;
3.2 Cracks appear at the joints between the wall panel and the ground and at the junction with the ceiling;
3.3 Cracks appear between wall panels and concrete columns or between shear walls.
4 Precautions
4.1 Improve the production process
The production methods of autoclaved lightweight aerated concrete panels mainly include flat formwork and vertical formwork. Taking the vertical mold as an example, its production requires large slump and water-cement ratio, too much moisture, and a large number of pores will be generated when the cementitious material solidifies. The mixing ratio of various materials should be strictly controlled. A reasonable ratio can not only increase its strength, but also greatly reduce shrinkage. In order to ensure safety and reliability, before selecting wallboard materials, you should go deep into the production enterprises to conduct on-site inspections to understand their production technology, production scale, product quality and production capacity, so as to ensure that the wallboard materials used meet the national standards. item standard.
4.2 Choose the right seam material
The joint material should not only have high strength, but also have good deformation ability, and the joint material has an important influence on whether cracks appear. When installing wall panels, use special functional mortar instead of ordinary cement mortar as the caulking mortar for installation. Special functional mortar has better workability, adhesion, durability, frost resistance, water resistance, etc.
4.3 Proper control of the installation unit
For the construction and installation of a long wall, the long wall is divided into several installation units, and the installation is carried out at a certain distance to reduce the shrinkage stress of the wall and prevent cracking.
4.4 Pretreatment of crack-prone parts
ALC wall panels are easily cracked at the contact parts with the frame, the grooved parts of the line pipes, and the joints. Wedges should be removed after the mortar has hardened and filled with homogeneous mortar. The gap at the upper end of the board and the connection between the board and the column wall are filled with PU foaming agent and foam rod, and the surface is filled with alkali-resistant mesh cloth and special functional mortar; the joints of the board are filled with alkali-resistant mesh cloth and special functional mortar.
