In recent years, epoxy flooring has made great progress in China, especially in the production workshop, supermarket, underground garage, exhibition hall, classroom, laboratory and other occasions have been widely used. Epoxy floor has high cleanliness, wear resistance, corrosion resistance, impact resistance, seamless, solid texture, easy maintenance, low maintenance cost and good decorative effect. Of course, to ensure these advantages, it is necessary to control the quality of the whole process, from the quality of the base material, the treatment of the base surface to the painting environment and the painting scheme, combining with the construction process and characteristics of the epoxy floor, to carry out the corresponding quality control. What points should be paid attention to in the construction of epoxy floor?
The base material is the foundation layer of epoxy construction, which is mainly concrete floor. The ground condition has a great influence on the quality of the final epoxy floor project. If the ground condition does not meet the requirements, it is difficult to do well in the epoxy floor project, and in the process of using the epoxy floor, there are often phenomena such as shelling, falling off and foaming. Therefore, good base material condition is the premise to ensure the quality of epoxy flooring project. Some base materials do not meet the requirements of epoxy flooring painting, so this floor decoration method should not be selected. The General requirements of epoxy flooring for concrete substrates are as follows:
1. Concrete should be flat and compact, and its strength should be no less than C20. If the strength is too poor, it will inevitably affect the compressive, impact resistance and durability of the coating.
2. Ground smoothness generally requires a drop of less than 2 m m within the range of 2 m to be smoothed and glowed by a polisher. If the drop is large, the coating on the ground needs to be thickened to reduce the drop.
3. If the ground to be coated is at the bottom and the groundwater level is high, the concrete bottom should be waterproof, so as to avoid the bubbling and shelling caused by the vapor pressure caused by the rise of groundwater.
4. New-built concrete is dried for at least 3 weeks, and its moisture content is not higher than 6%. In the process of curing and drying, local raining and surface water should be avoided. Otherwise, local concrete moisture content will easily exceed the standard.
5. The strength of fine stone concrete leveling layer on floor, reinforced concrete beam and other components should not be lower than C20, and the thickness should not be less than 0 mm.
6. For repairing or leveling damaged concrete surface, fine stone concrete with strength grade not less than C20 should be adopted, leveling thickness should not be less than 30mm; for leveling with cement mortar, a layer of concrete interface treatment agent should be coated first, and then leveling according to the design thickness. Resin mortar or polymer cement mortar can be used to leveling when the above operation is not suitable in the construction process.
7. The details, such as the concrete around the downspout pipe and the threshold, should be level and the edges and corners should be straight.
8. Large area concrete base should cut reasonable expansion joints according to the condition of base material and leave them to be treated when the floor is painted. In order to keep the ground beautiful, the expansion joints should be concealed under the partition as far as possible. If not, the expansion joints should be retained during the construction of epoxy floor and then filled with elastic glue.
Base surface processing
Base surface treatment is not simply "shovel one shovel, sweep one shovel, remove dust", but to remove floating layer and dirt, improve the overall smoothness of the ground, obtain uniform rough surface to facilitate coating adhesion. Scientific floor coating attaches great importance to the treatment of base materials and adopts professional processing machinery to deal with them.
1. Use a grinder for overall grinding, remove surface cement slurry or other adhesives, and grind the surface roughly.
2. Use a vacuum cleaner to clean up.
3. The edge work should focus on manual wool beating.
4. Check the ground. If there is oil stain, clean it with detergent. If there is local damp ground, it needs to be dried.
5. For cracks and pits, resin mortar is used to pre-flatten them; for expansion joints, 0.5 cm * 0.5 cm grooves are cut by cutting machine, and then smoothed with flexible epoxy mortar.
6. For the old lacquer floor, if the old lacquer layer does not adhere well, the whole old lacquer layer should be removed by ground milling machine. The old lacquer layer below 1 mm thickness can be treated by diamond cutter.
The environmental conditions of painting have a great influence on the quality of floor painting project. Only when the construction is carried out in the environment that meets the requirements can the good results be achieved. The requirements of epoxy floor coating for painting environment are generally as follows:
1. The ambient temperature of painting should be above 10 C. Amine curing agents are generally used in floor coating, while the reaction between epoxy group and amine group is very slow below 10 C, and almost no reaction below 5 C.
2. The surface temperature of the base material should be higher than the dew point of the coating environment above 3 C. If this condition is not reached, on the one hand, the surface of the substrate is easy to dew, resulting in poor adhesion of the back coating, on the other hand, after painting, the surface of the paint film is easy to dew before drying (there is a layer of water film), resulting in surface defects. Especially topcoat, in this case, water vapor is easy to react with amine curing agent in the paint, resulting in low gloss, fogging, whitening, sticking, oil point, low hardness and other defects of the film surface, greatly reducing the decorative effect of the surface, causing rework in serious cases.
3. Floor painting requires clean and dustless painting environment, and environmental sealing during maintenance, which also has a great impact on the quality of the project. This includes whether there is dust in the construction site, whether the construction site will be rained and so on.