In our highway tunnels, it is necessary to apply fire-resistant coating to reduce the occurrence of fires and ensure the safety of traffic participants' lives and property to the greatest extent possible. However, whether the expected effect can be achieved ultimately depends on the quality of the tunnel fireproof coating. How can this quality be tested? Today, let's follow Dingxin Architecture to learn more. First, let's take a look at the appearance of the tunnel fireproof coating. What should be the appearance? The coating should be completely closed, without any exposed or missed areas, and there should be no nipple appearance; Visual inspection is sufficient. The second is to look at the color: the color of the arch should be uniform and consistent with the planned color; Visual inspection method.

The third is to test the bonding strength: the bonding strength is sampled every 500t; According to Article 6.14.2.2 of JC/T24-2000 Specification for Synthetic Resin lotion Sand Wall Construction Coatings requested in Fire Retardant Coatings for Concrete Structures.

Fourth hollowing and delamination: no appearance of hollowing, delamination, or looseness is allowed; Use a 0.75-1kg hammer to lightly tap and check.

Fifth, check the flatness: flat, uniform, round and smooth, with no significant height difference; Visual inspection method.

Sixth, look for cracks: the coating should not show cracks after timely cutting; Visual inspection method.

Most consumers feel that pigments are just a visual representation, and they don't know what impact pigments have on the fire resistance of tunnel specific fireproof coatings. Pigments are an important factor in fireproof coatings, as they can not only give the coating color and enhance its decorative properties, but also improve the performance of the coating to a certain extent. It has two major performance impacts on tunnel fireproof coatings. Below we will explain to you:

Influence 1: The impact of organic pigments on the fire resistance performance of tunnel fireproof coatings

Commonly used organic pigments include phthalocyanine blue and alcohol soluble sun resistant red pigments, and the addition of different pigments affects the fire resistance of fireproof coatings. When the dosage of phthalocyanine pigment is 1.7%, the foaming ratio of the corresponding coating can reach 16.34 times. However, the coating is difficult to level, and after burning, the edges curl up, making it easy to peel off. When the addition amount of phthalocyanine blue pigment is 2.3% and 2.8%, the foaming ratio of the corresponding coating is slightly smaller, but the surface performance of the coating is much better than when the addition amount of phthalocyanine blue pigment is 1.7%. Therefore, the appropriate amount of phthalocyanine blue pigment added is 2.3% to 2.8%. When the addition amount of alcohol soluble sun resistant red pigment reaches 2.3%, the foaming ratio of the coating reaches the maximum value of 11.35 times, and the surface physical properties of the coating film are the best.

Influence 2: The impact of inorganic pigments on the fire resistance performance of fireproof coatings

The inorganic pigments used are all nanoscale transparent iron oxide pigments (iron brown, iron red, and iron black) and chromium oxide green pigments. For coatings with iron red pigment added, the maximum amount is reached at 2.3%, and then decreases with the increase of pigment addition. When the amount of iron brown pigment added was 2.3%, the foaming ratio of the corresponding coating also reached its maximum value, and it did not decrease much afterwards.

Chromium green pigment is an exception, as the foaming ratio of the coating increases with the amount of chromium green pigment added. When the amount of chromium green pigment added is 2.8%, the foaming ratio of the coating reaches 1-4 times or more. But at this time, the foam layer is uneven and the strength is not high. However, when the amount of chromium green pigment added is 2.3%, the apparent morphology and foam ratio of the corresponding coating are good. After adding iron black pigment, the overall foaming performance of the coating is not high, and the highest foaming ratio of the coating is only about 8 times, which is worse than the other three pigments. It can be seen that iron black pigment has a significant impact on the fire resistance of the coating. Guangdong Tunnel Fireproof Coating