1. Visual inspection. Conduct a preliminary inspection of the quality of fire-resistant coating with the naked eye. The main inspection items include whether the appearance and color of the coating are uniform, whether there are any missed areas, obvious cracks, and protrusions. Touch the coating with your hand to observe whether there is any obvious powder detachment. Lightly tap the coating with a 0.5-1kg hammer to observe whether it is firmly bonded, and whether there is any hollow sound or block-like detachment

2. Measurement with a thickness gauge. When using a thickness gauge, spot checks are mainly conducted to inspect its uniformity. The method of selecting points varies for different structures. For the fireproof coating on floor slabs and firewall surfaces, an area intersected by two adjacent longitudinal and transverse axes can be selected as a unit, and one point is selected every meter along its diagonal for testing. For beams and columns in a fully framed structure, as well as the top and bottom chords of a truss structure, a cross-section is taken every 3 meters within the length of the component. For floor slabs and walls, at least 5 points are measured in the selected area; for components such as beams and columns, 6 or 8 points are measured respectively. The average values are calculated separately, accurate to 0.5mm.

The quality standard for thick fire-resistant coatings is as follows: the average thickness of the coating should be equal to or greater than the thickness specified in the fire protection design. If there are individual areas where the thickness is below the original standard, it must still be greater than 85% of the standard, and the continuous length of the insufficiently thickened area should not exceed 1m, with no similar issues occurring within a 5m radius. The coating should be completely sealed, with no exposed areas or holidays. The quality standard for thin fire-resistant coatings is as follows: the thickness of the coating should be equal to or greater than the thickness specified in the fire protection design. There should be no holidays, powder detachment, or visible cracks.

  Fireproof putty has a very wide range of applications in our architectural life. It can be said to bring great convenience to our lives and housing, as it has excellent fireproof performance and can meet high safety standards. Now, let's introduce what factors a high-quality fireproof putty should possess.

Firstly, the performance indicator of fireproof mud is that it does not have any odor, which means it will not have any adverse effects on the environment and our health. Secondly, the surface density of fireproof mud should be low, because the lower the density, the better the fireproof effect, which can better provide us with safety guarantees. Additionally, we must ensure that the water resistance of fireproof mud is very good. In rainy or humid weather, good water resistance is necessary to improve its use effect. Its oil resistance should also be guaranteed to ensure long-term use of the product, which, of course, can also bring more convenience to customers.

We must ensure the corrosion resistance of fire-resistant mud, so that when it encounters some acidic or alkaline environments or is accidentally contaminated with some acidic or alkaline substances, there is no need to worry excessively about the impact on the product's performance. Fire-resistant mud manufacturers remind you that as a fire-resistant material, the fire resistance of fire-resistant mud is very important.

The bonding strength is most significantly influenced by high-alumina cement, followed by the fire-resistant filler. Using redispersible emulsion powder and high-alumina cement as a combined binder can enhance the bonding strength of the coating. This is because the redispersible emulsion powder penetrates into the pores and capillaries of the substrate along with the liquid phase of the high-alumina cement suspension. The polymer forms a film within the pores and capillaries and adheres firmly to the surface of the substrate, thereby ensuring good bonding strength between the adhesive material and the substrate.

The influence of main components on the fire resistance and bonding strength of tunnel fireproof coatings

 1. The influence of high-alumina cement on the fire resistance and bonding strength of tunnel fireproof coatings 

As the addition of high-alumina cement increases, the bonding strength of the fire-resistant coating increases, while the fire resistance limit decreases. This is because increasing the amount of high-alumina cement increases the content of binder per unit area of the coating, and the content of fire-resistant fillers and flame retardants decreases relatively. On the one hand, this makes the bonding between the substrate and the coating, as well as between the coatings, more tight, thereby enhancing the bonding strength. On the other hand, the relative decrease in flame retardants and fire-resistant fillers reduces the fire resistance of the coating.

2. The influence of fireproof filler on the fire resistance and bonding strength of tunnel fireproof coating 

With the increase of fire-resistant fillers, the fire resistance limit of the coating increases, while the bonding strength decreases. The content of fire-resistant fillers should be appropriate. If the content is too high, the amount of binder per unit area is relatively small, resulting in a decrease in the bonding strength of the coating. Jiangxi Youlinsheng Fire-Resistant Coating