With the elimination of solid clay bricks, various new wall materials come out, such as aerated concrete bricks, fly ash bricks, shale bricks, aerated concrete blocks, lightweight GKC partition boards, and other new wall materials. Due to the advantages of lightweight, high strength, no environmental damage, and land resource protection, it is increasingly popular among customers. But also, some technical problems could be solved by using a new-type wall material. Although the physical properties of the surface of these new materials are very different from those of traditional clay bricks, mainly because of large surface voids, high water absorption, lightweight and porous, and low bond strength, ordinary mortar is not suitable for the above-mentioned new bricks at all. Moreover, the masonry and plastering of materials often cause a series of quality problems, such as cracking, hollowing, shedding, and leakage of the bonding layer. These problems can be effectively solved by using a multi-purpose interface agent.
(1) Product characteristics
1) High bonding strength, no cracking, great plasticity.
2) Applicable to the plastering of various substrates, greatly improving the bonding force.
3) Good water retention and high early strength.
4) Quick construction can reduce labor intensity and cost.
(2)Technical Description
For smooth concrete walls, dry walls, and columns after demolding, there is no need to chisel and scrape directly to increase surface adhesion and strength.
Surface treatment for various porous and high water absorption lightweight bricks to improve bond strength and impermeability. Thin layer construction, no cracking, no hollowing, no falling off.
During the construction of external thermal insulation, the interface treatment of the base surface can significantly improve the adhesion and sag resistance with polystyrene board and XPS board.
Scrape the surface of the old tiles directly to renovate. The multi-purpose interface agent has high bonding strength, which can significantly reduce construction costs and speed up construction progress.
The multi-purpose interface agent is packaged in 20kg powder bags, added about 25% water, and mixed well before construction.
Use temperature is advisable with 5～40 degrees Celsius, and thickness is less than 1mm.
Bonding gypsum
With the development of construction technology, construction adhesives are having an essential impact on construction industrialization, especially in terms of facilitating construction, saving labor, reducing costs, and reducing the self-weight of buildings. They have shown a considerable role and have become necessary supporting materials in contemporary construction.
Bonding gypsum is based on building gypsum, adding the appropriate amount of additives such as retarder, water retaining agent, thickener, and adhesive to mix uniformly. It is non-toxic, tasteless, safe, and easy to use and operate (add a certain amount of water and stir evenly to reach the consistency for construction), has instant solid adhesion, thick layer adhesion, no shrinkage, and no condensation, as well as fast speed and labor-saving. It is suitable for the bonding of various gypsum products (such as gypsum boards, gypsum blocks, gypsum strips, gypsum insulation boards, and decorative gypsum boards), moldings, and other cosmetic art products; it is also suitable for aerated concrete products and can be used for bonding between other inorganic building wall materials (such as bricks and cement concrete blocks).
The raw material quality and performance of bonding gypsum are the keys to ensuring product quality; the main requirements are as follows.
1) Building gypsum
Building gypsum is the primary raw material for bonding gypsum to ensure bonding strength, and it should meet the requirements of the national standard (GB 9776-8).
2) Retarder
The setting time of building gypsum requires an initial set of more than 6 minutes and a final set of fewer than 30 minutes in the product standard. In actual construction, the time of setting needed is more complicated. That’s why the setting time required by the product standard is not qualified for construction operations. The bonded gypsum is divided into the fast-setting type and slow-setting type according to the different materials and parts to be bonded, so it is necessary to add an appropriate retarder when preparing. Unlike plaster and gypsum putty, bonding gypsum requires a long setting time. Generally, fast-setting products require an initial setting time of at least 8 minutes and a final setting time of 30 minutes; ordinary products require an initial setting time of not less than 30 minutes. The last setting time is at most 120 minutes, so there are many kinds of retarders to choose from. Currently, citric acid and sodium citrate are the most used in the market, especially sodium citrate. Due to the small amount required, it has little effect on the strength of gypsum.
3) Water retention agent, thickener
Like other gypsum building materials, the water retention of bonding gypsum is poor, so the water in the slurry is quickly absorbed by the base material, which not only increases the difficulty of construction operations but also reduces the adhesive property due to the loss of water required. Furthermore, it will lose all the bonding strength in severe cases, so the water-retaining agent, like methylcellulose with high viscosity, is an essential admixture for preparing bonding gypsum. It can improve the water retention of the bonding gypsum and significantly thicken it, thus increasing its adhesion and facilitating the bonding operation.
4) Adhesive
The adhesive is used as a raw material to enhance the adhesive property of bonding gypsum and is generally added to bonding gypsum with special requirements (such as bonding polystyrene insulation boards on brick walls or concrete walls, etc.). Commonly used are polyvinyl alcohol and ethylene-vinyl acetate binary copolymerization, vinyl chloride-ethylene-vinyl laurate polymerization, and other re-dispersible polymer powders.
