A super thick non-expansive fire retardant coating process

Abstract

The present invention discloses an ultra-thick non-expansion fire retardant coating process, the steps include: S1, dispersedly arranging a plurality of convex column points on the surface to be coated; S2, cleaning the surface to be coated, and spraying the surface to be coated with a non-expansion fire retardant coating; S3, hanging a net, fixing the hanging net with convex column points, spraying the non-expansion fire retardant coating, and making the fire retardant coating completely cover the hanging net; S4, repeating the operation of step S3; S5, plastering the coating surface formed after spraying, thereby completing the coating construction. The present invention evenly arranges convex column points on the surface to be coated in advance, which can play a role of fulcrum and reinforcement, and cooperates with the process of hanging nets layer by layer and spraying layer by layer, which can significantly improve the overall stability and durability of the fire retardant coating, and avoid aging and shedding of the coating and thermal disintegration.

Description

Technical Field

[0001] The invention relates to the technical field of fire retardant coatings, and in particular to an ultra-thick non-expansion fire retardant coating process. Background Art

[0002] Non-expanding steel structure fire retardant coatings are composed of adhesives that are resistant to water, salt spray and weathering, thermal insulation aggregates, reinforcing agents and performance regulators. They can be used for fire protection projects of load-bearing steel structures and open-air buildings, such as supporting steel structures for open-air chemical equipment, steel structure supports for cable trays, and protection projects for outdoor steel structures in petrochemicals, metallurgy and other fields. When the coating encounters fire, the surface is sintered into a high-density oxide glaze layer, which has a thermal insulation function to prevent the spread of flames and can significantly improve the fire resistance limit of the protected steel structure, thereby gaining time for fire extinguishing and saving the steel structure-bearing building.

[0003] Among them, 3h thick fire retardant coating refers to a fire retardant coating with a coating thickness that meets certain standards and a fire resistance limit of 3 hours. At present, the thickness of conventional 3h thick fire retardant coatings on the market is about 26mm. However, in some construction projects under special environments, such as some outdoor corridors, the steel structure fire retardant coating needs to reach a greater thickness, such as 50mm ultra-thick fire retardant coatings. For the coating construction of such ultra-thick fire retardant coatings, the existing construction process cannot meet the durability requirements. Therefore, it is urgent to optimize and improve the coating process of ultra-thick fire retardant coatings to meet the durability requirements. Summary of the invention

[0004] The purpose of the present invention is to provide an ultra-thick non-expansive fire-retardant coating process, which solves the problem that the existing coating process is not suitable for the construction of ultra-thick fire-retardant coatings and cannot meet the durability requirements.

[0005] The present invention achieves the above-mentioned purpose through the following technical solutions:

[0006] An ultra-thick non-expansive fire retardant coating process, comprising the following steps:

[0007] S1. Distribute multiple convex column points on the surface to be coated;

[0008] S2. Clean the surface to be painted and spray the surface with non-expanding fire retardant paint;

[0009] S3, hang the net and fix it by convex column points, then spray the non-expansion fire retardant coating, and make the fire retardant coating completely cover the net;

[0010] S4, repeat the operation of step S3;

[0011] S5, performing a plastering treatment on the coating surface formed after spraying, thereby completing the coating construction;

[0012] The raw materials for preparing the non-expanding fire retardant coating include: desulfurized gypsum, polystyrene, lightweight refractory filler, aluminum silicate fiber, fumed silica, dispersant, slime mold extract and water, and the weight ratio is desulfurized gypsum: polystyrene: lightweight refractory filler: aluminum silicate fiber: fumed silica: dispersant: slime mold extract: water = 1.20-1.33: 0.16-0.30: 0.26-0.30: 0.16-0.20: 0.03-0.08: 0.06-0.08: 0.08-0.16: 1;

[0013] The preparation method of the slime mold extract is as follows: taking a slime mold fruiting body in a mortar, adding a grinding medium and grinding for 2-4 hours, transferring the obtained grinding liquid to a container, adding petroleum ether to the grinding liquid at a ratio of 1 kg grinding liquid: (8-10) L petroleum ether, controlling the temperature to 40-55° C. for ultrasonic extraction, filtering the obtained extract, filtering out the residue and concentrating the filtrate to obtain the slime mold extract.

[0014] A further improvement is that the surface to be painted is a steel structure surface, the boss points are M12X35mm galvanized bolts welded to the surface of the steel structure, and the boss point spacing is 400mm×400mm.

[0015] A further improvement is that the lightweight refractory filler is selected from one or more of silicon micropowder, β-eucryptite, silicon carbide, kaolin, and calcium carbonate, and the dispersant is lignin or polyethylene glycol.

[0016] A further improvement is that the slime mold is mixed with Physarum compressum and Ceratiomyxa fruticulosa in a mass ratio of 1:1-4.

[0017] A further improvement is that the ultrasonic extraction refers to ultrasonic treatment for 20-40 minutes under the conditions of power 150-300W and frequency 20-45kHz.

[0018] A further improvement is that in step S3, the hanging net uses a galvanized steel wire mesh with a diameter of 0.3-0.8 mm, and the mesh size of the hanging net is 25 mm×25 mm.

[0019] A further improvement is that in step S4, before each repetition of step S3, reinforcing wires are uniformly inserted into the surface of the existing coating, with an insertion density of 400-600 wires / m 2 , and expose the reinforcement wire part, and then completely cover the exposed reinforcement wire when repeatedly spraying the non-expanding fire retardant coating;

[0020] The reinforcing wire is made of galvanized steel wire and a carbon fiber bundle spirally wound on the surface of the galvanized steel wire. The diameter of the galvanized steel wire is 2.5-3.0 mm, the diameter of the carbon fiber bundle is 0.8-1.2 mm, and a plurality of spaced nodes are formed on the carbon fiber bundle by knotting.

[0021] A further improvement is that in step S4, the operation of step S3 is repeated once to form two hanging nets, and the specifications of the two hanging nets are the same.

[0022] The beneficial effects of the present invention are:

[0023] (1) The present invention evenly arranges convex column points on the surface to be coated in advance, which can act as a fulcrum and reinforcement. Combined with the layer-by-layer mesh hanging and layer-by-layer spraying process, the overall stability and durability of the fire retardant coating can be significantly improved, and the coating can be prevented from aging and falling off and thermal disintegration;

[0024] (2) The present invention uses a special non-expanding fire-retardant coating, which is added with slime mold extract as an anti-cracking agent. It can show an excellent anti-cracking effect in 50mm ultra-thick coating applications, so that the coating can reduce cracking and failure during the alternating hot and cold environment in daily environments and the severe heating process of sudden fires, and at the same time increase the bonding strength;

[0025] (3) In addition to layer-by-layer meshing, the present invention further uses reinforcing wires to reinforce the coating, and the reinforcing wires are made of galvanized steel wires and carbon fiber bundles spirally wound on the surface of the galvanized steel wires. The galvanized steel wires play a shaping and supporting role and are also convenient for insertion. The spirally wound carbon fiber bundles can utilize their negative thermal expansion characteristics when heated to shrink axially along the winding path, and pull and fix the coating from different directions through their own nodes, so as to reduce the influence of internal stress on the coating during daily heating, increase the bonding strength, and avoid peeling between coating layers. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a construction diagram of the ultra-thick non-expanding fire retardant coating process, in which a is the operation of step S1, b is the operation of steps S2-S4, and c is the operation of step S5. DETAILED DESCRIPTION

[0027] The present application is further described in detail below in conjunction with the accompanying drawings. It is necessary to point out here that the following specific implementation methods are only used to further illustrate the present application and cannot be understood as limiting the scope of protection of the present application. Technical personnel in this field can make some non-essential improvements and adjustments to the present application based on the above application content.

[0028] 1. Main raw materials:

[0029] Desulfurized gypsum: purchased from Jinhai Gypsum Products Factory, Yicheng District, Zaozhuang City;

[0030] Polystyrene: general-purpose GPPS, purchased from Ningbo Yulong Plastic Co., Ltd.;

[0031] Silicon powder, silicon carbide, and calcium carbonate: purchased from Baifeng Mineral Products Processing Plant in Lingshou County;

[0032] Aluminum silicate fiber: purchased from Hebei Siruit Mineral Products Co., Ltd.;

[0033] Fumed silica: purchased from Shandong Kasong New Materials Co., Ltd.

[0034] Physarum compressum: collected from dead branches, fallen leaves, and rotten wood in wild forests. It is generally grayish white, and the diameter of the spores is between 1.1-1.5 mm.

[0035] Ceratiomyxa fruticulosa: collected from dead branches, fallen leaves, and rotten wood in wild forests. Most are white, a few are yellow, and the length is between 4-10mm.

[0036] Lignin: purchased from Shanghai Yunzhe New Material Technology Co., Ltd.;

[0037] Polyethylene glycol: PEG-2000, purchased from Haian Petrochemical Plant, Jiangsu Province;

[0038] Petroleum ether: purchased from Nantong Runfeng Petrochemical Co., Ltd.

[0039] 2. Specific Implementation of Experiments

[0040] Take several pieces of 6mm thick Q235 steel plate substrates, thoroughly remove the surface rust, place them in the same indoor environment (room temperature 23±2℃, humidity 50±5%), and use the following coating processes to construct different steel plate surfaces:

[0041] Example 1

[0042] An ultra-thick non-expansive fire retardant coating process, comprising the following steps:

[0043] S1. Multiple convex points are scattered on the surface of the steel structure to be painted. The convex points are M12X35mm galvanized bolts (nuts facing vertically outward) welded on the surface of the steel structure, and the spacing between the convex points is 400mm×400mm;

[0044] S2, cleaning the surface to be coated (welding slag and surface dirt), and spraying the surface to be coated with a non-expanding fire retardant coating; the raw materials for preparing the non-expanding fire retardant coating include, by weight: 40 parts of desulfurized gypsum, 5 parts of polystyrene, 8 parts of silicon powder, 6 parts of aluminum silicate fiber, 1 part of fumed silica, 2 parts of lignin and 30 parts of water;

[0045] S3, hanging net, the hanging net uses a galvanized steel wire mesh with a diameter of 0.4mm, and the mesh size of the hanging net is 25mm×25mm, and the hanging net is fixed by convex column points, that is, the mesh wire passing through the convex column points is stuck on the convex column points, and the mesh surface is kept as flat as possible. It is better to selectively fix it with silk thread, and then spray non-expansive fire retardant coating, and the fire retardant coating completely covers the hanging net;

[0046] S4, repeating the operation of step S3 once to form two hanging nets, and the specifications of the two hanging nets are the same;

[0047] S5. The coating surface formed after spraying is subjected to a plastering treatment, thereby completing the coating construction.

[0048] Example 2

[0049] An ultra-thick non-expansive fire retardant coating process, comprising the following steps:

[0050] S1. Multiple convex points are scattered on the surface of the steel structure to be painted. The convex points are M12X35mm galvanized bolts (nuts facing vertically outward) welded on the surface of the steel structure, and the spacing between the convex points is 400mm×400mm;

[0051] S2, cleaning the surface to be coated (welding slag and surface dirt), and spraying the surface to be coated with a non-expanding fire retardant coating; the raw materials for preparing the non-expanding fire retardant coating include, by weight: 50 parts of desulfurized gypsum, 10 parts of polystyrene, 12 parts of silicon carbide, 7 parts of aluminum silicate fiber, 2 parts of fumed silica, 3 parts of polyethylene glycol and 40 parts of water;

[0052] S3, hanging net, the hanging net uses a galvanized steel wire mesh with a diameter of 0.5mm, and the mesh size of the hanging net is 25mm×25mm, and the hanging net is fixed by convex column points, that is, the mesh wire passing through the convex column points is stuck on the convex column points, and the mesh surface is kept as flat as possible. It is better to selectively fix it with silk thread, and then spray non-expansive fire retardant coating, and the fire retardant coating completely covers the hanging net;

[0053] S4, repeating the operation of step S3 once to form two hanging nets, and the specifications of the two hanging nets are the same;

[0054] S5. The coating surface formed after spraying is subjected to a plastering treatment, thereby completing the coating construction.

[0055] Example 3

[0056] An ultra-thick non-expansive fire retardant coating process, comprising the following steps:

[0057] S1. Multiple convex points are scattered on the surface of the steel structure to be painted. The convex points are M12X35mm galvanized bolts (nuts facing vertically outward) welded on the surface of the steel structure, and the spacing between the convex points is 400mm×400mm;

[0058] S2, clean the surface to be coated (welding slag and surface dirt), and spray the surface to be coated with a non-expanding fire retardant coating; the raw materials for preparing the non-expanding fire retardant coating include, by weight: 60 parts of desulfurized gypsum, 15 parts of polystyrene, 15 parts of calcium carbonate, 8 parts of aluminum silicate fiber, 4 parts of fumed silica, 4 parts of polyethylene glycol and 50 parts of water;

[0059] S3, hanging net, the hanging net uses a galvanized steel wire mesh with a diameter of 0.8mm, and the mesh size of the hanging net is 25mm×25mm, and the hanging net is fixed by convex column points, that is, the mesh wire passing through the convex column points is stuck on the convex column points, and the mesh surface is kept as flat as possible. It is better to selectively fix it with silk thread, and then spray non-expansive fire retardant coating, and the fire retardant coating completely covers the hanging net;

[0060] S4, repeating the operation of step S3 once to form two hanging nets, and the specifications of the two hanging nets are the same;

[0061] S5. The coating surface formed after spraying is subjected to a plastering treatment, thereby completing the coating construction.

[0062] Example 4

[0063] An ultra-thick non-expansive fire retardant coating process, comprising the following steps:

[0064] S1. Multiple convex points are scattered on the surface of the steel structure to be painted. The convex points are M12X35mm galvanized bolts (nuts facing vertically outward) welded on the surface of the steel structure, and the spacing between the convex points is 400mm×400mm;

[0065] S2. Clean the surface to be coated (welding slag and surface dirt), and spray the surface to be coated with a non-expanding fire retardant coating; the raw materials for preparing the non-expanding fire retardant coating include, by weight: 60 parts of desulfurized gypsum, 15 parts of polystyrene, 15 parts of calcium carbonate, 8 parts of aluminum silicate fiber, 4 parts of fumed silica, 4 parts of anti-cracking agent, 4 parts of polyethylene glycol and 50 parts of water; wherein the anti-cracking agent is a slime mold extract, and the preparation method thereof is as follows: take slime mold (composed of Physarum compressum and Ceratiomyxa fruticulosa in a mass ratio of 1:1) in a mortar, add grinding media and grind for 2 hours, transfer the obtained grinding liquid to a container, add petroleum ether to the grinding liquid at a ratio of 1kg grinding liquid: 8L petroleum ether, control the temperature to 40°C for ultrasonic extraction, perform ultrasonic treatment for 40 minutes under the conditions of power 150W and frequency 20kHz, filter the obtained extract, filter out the residue and concentrate the filtrate to obtain the slime mold extract;

[0066] S3, hanging net, the hanging net uses a galvanized steel wire mesh with a diameter of 0.8mm, and the mesh size of the hanging net is 25mm×25mm, and the hanging net is fixed by convex column points, that is, the mesh wire passing through the convex column points is stuck on the convex column points, and the mesh surface is kept as flat as possible. It is better to selectively fix it with silk thread, and then spray non-expansive fire retardant coating, and the fire retardant coating completely covers the hanging net;

[0067] S4, repeating the operation of step S3 once to form two hanging nets, and the specifications of the two hanging nets are the same;

[0068] S5. The coating surface formed after spraying is subjected to a plastering treatment, thereby completing the coating construction.

[0069] Example 5

[0070] An ultra-thick non-expansive fire retardant coating process, comprising the following steps:

[0071] S1. Multiple convex points are scattered on the surface of the steel structure to be painted. The convex points are M12X35mm galvanized bolts (nuts facing vertically outward) welded on the surface of the steel structure, and the spacing between the convex points is 400mm×400mm;

[0072] S2. Clean the surface to be coated (welding slag and surface dirt), and spray the surface to be coated with a non-expanding fire retardant coating; the raw materials for preparing the non-expanding fire retardant coating include, by weight: 60 parts of desulfurized gypsum, 15 parts of polystyrene, 15 parts of calcium carbonate, 8 parts of aluminum silicate fiber, 4 parts of fumed silica, 6 parts of anti-cracking agent, 4 parts of polyethylene glycol and 50 parts of water; wherein the anti-cracking agent is a slime mold extract, and the preparation method thereof is as follows: take slime mold (composed of Physarum compressum and Ceratiomyxa fruticulosa in a mass ratio of 1:2) in a mortar, add a grinding medium and grind for 3 hours, transfer the obtained grinding liquid to a container, add petroleum ether to the grinding liquid at a ratio of 1kg grinding liquid: 9L petroleum ether, control the temperature to 45°C for ultrasonic extraction, and perform ultrasonic treatment for 30 minutes at a power of 250W and a frequency of 30kHz, then filter the obtained extract, filter out the residue, and concentrate the filtrate to obtain the slime mold extract;

[0073] S3, hanging net, the hanging net uses a galvanized steel wire mesh with a diameter of 0.8mm, and the mesh size of the hanging net is 25mm×25mm, and the hanging net is fixed by convex column points, that is, the mesh wire passing through the convex column points is stuck on the convex column points, and the mesh surface is kept as flat as possible. It is better to selectively fix it with silk thread, and then spray non-expansive fire retardant coating, and the fire retardant coating completely covers the hanging net;

[0074] S4, repeating the operation of step S3 once to form two hanging nets, and the specifications of the two hanging nets are the same;

[0075] S5. The coating surface formed after spraying is subjected to a plastering treatment, thereby completing the coating construction.

[0076] Example 6

[0077] An ultra-thick non-expansive fire retardant coating process, comprising the following steps:

[0078] S1. Multiple convex points are scattered on the surface of the steel structure to be painted. The convex points are M12X35mm galvanized bolts (nuts facing vertically outward) welded on the surface of the steel structure, and the spacing between the convex points is 400mm×400mm;

[0079] S2. Clean the surface to be coated (welding slag and surface dirt), and spray the surface to be coated with a non-expanding fire retardant coating; the raw materials for preparing the non-expanding fire retardant coating include, by weight: 60 parts of desulfurized gypsum, 15 parts of polystyrene, 15 parts of calcium carbonate, 8 parts of aluminum silicate fiber, 4 parts of fumed silica, 8 parts of anti-cracking agent, 4 parts of polyethylene glycol and 50 parts of water; wherein the anti-cracking agent is a slime mold extract, and the preparation method thereof is as follows: take slime mold (composed of Physarum compressum and Ceratiomyxa fruticulosa in a mass ratio of 1:4) in a mortar, add a grinding medium and grind for 4 hours, transfer the obtained grinding liquid to a container, add petroleum ether to the grinding liquid in a ratio of 1kg grinding liquid: 10L petroleum ether, control the temperature to 55°C for ultrasonic extraction, perform ultrasonic treatment for 20 minutes at a power of 300W and a frequency of 45kHz, filter the obtained extract, filter out the residue, and concentrate the filtrate to obtain a slime mold extract;

[0080] S3, hanging net, the hanging net uses a galvanized steel wire mesh with a diameter of 0.8mm, and the mesh size of the hanging net is 25mm×25mm, and the hanging net is fixed by convex column points, that is, the mesh wire passing through the convex column points is stuck on the convex column points, and the mesh surface is kept as flat as possible. It is better to selectively fix it with silk thread, and then spray non-expansive fire retardant coating, and the fire retardant coating completely covers the hanging net;

[0081] S4, repeating the operation of step S3 once to form two hanging nets, and the specifications of the two hanging nets are the same;

[0082] S5. The coating surface formed after spraying is subjected to a plastering treatment, thereby completing the coating construction.

[0083] Comparative Example 1

[0084] An ultra-thick non-expansive fire retardant coating process, comprising the following steps:

[0085] S1. Multiple convex points are scattered on the surface of the steel structure to be painted. The convex points are M12X35mm galvanized bolts (nuts facing vertically outward) welded on the surface of the steel structure, and the spacing between the convex points is 400mm×400mm;

[0086] S2. Clean the surface to be coated (welding slag and surface dirt), and spray the surface to be coated with a non-expanding fire retardant coating; the raw materials for preparing the non-expanding fire retardant coating include, by weight: 60 parts of desulfurized gypsum, 15 parts of polystyrene, 15 parts of calcium carbonate, 8 parts of aluminum silicate fiber, 4 parts of fumed silica, 10 parts of an anti-cracking agent, 4 parts of polyethylene glycol and 50 parts of water; wherein the anti-cracking agent is a slime mold extract, and the preparation method thereof is as follows: take a slime mold (composed of Physarum compressum and Ceratiomyxa fruticulosa in a mass ratio of 1:4) in a mortar, add a grinding medium and grind for 4 hours, transfer the obtained grinding liquid to a container, add petroleum ether to the grinding liquid in a ratio of 1kg grinding liquid: 10L petroleum ether, control the temperature to 55°C for ultrasonic extraction, perform ultrasonic treatment for 20 minutes at a power of 300W and a frequency of 45kHz, filter the obtained extract, filter out the residue, and concentrate the filtrate to obtain a slime mold extract;

[0087] S3, hanging net, the hanging net uses a galvanized steel wire mesh with a diameter of 0.8mm, and the mesh size of the hanging net is 25mm×25mm, and the hanging net is fixed by convex column points, that is, the mesh wire passing through the convex column points is stuck on the convex column points, and the mesh surface is kept as flat as possible. It is better to selectively fix it with silk thread, and then spray non-expansive fire retardant coating, and the fire retardant coating completely covers the hanging net;

[0088] S4, repeating the operation of step S3 once to form two hanging nets, and the specifications of the two hanging nets are the same;

[0089] S5. The coating surface formed after spraying is subjected to a plastering treatment, thereby completing the coating construction.

[0090] Comparative Example 2

[0091] An ultra-thick non-expansive fire retardant coating process, comprising the following steps:

[0092] S1. Multiple convex points are scattered on the surface of the steel structure to be painted. The convex points are M12X35mm galvanized bolts (nuts facing vertically outward) welded on the surface of the steel structure, and the spacing between the convex points is 400mm×400mm;

[0093] S2. Clean the surface to be coated (welding slag and surface dirt), and spray the surface to be coated with a non-expanding fire retardant coating; the raw materials for preparing the non-expanding fire retardant coating include, by weight: 60 parts of desulfurized gypsum, 15 parts of polystyrene, 15 parts of calcium carbonate, 8 parts of aluminum silicate fiber, 4 parts of fumed silica, 12 parts of an anti-cracking agent, 4 parts of polyethylene glycol and 50 parts of water; wherein the anti-cracking agent is a slime mold extract, and the preparation method thereof is as follows: take a slime mold (composed of Physarum compressum and Ceratiomyxa fruticulosa in a mass ratio of 1:4) in a mortar, add a grinding medium and grind for 4 hours, transfer the obtained grinding liquid to a container, add petroleum ether to the grinding liquid in a ratio of 1kg grinding liquid: 10L petroleum ether, control the temperature to 55°C for ultrasonic extraction, perform ultrasonic treatment for 20 minutes at a power of 300W and a frequency of 45kHz, filter the obtained extract, filter out the residue, and concentrate the filtrate to obtain a slime mold extract;

[0094] S3, hanging net, the hanging net uses a galvanized steel wire mesh with a diameter of 0.8mm, and the mesh size of the hanging net is 25mm×25mm, and the hanging net is fixed by convex column points, that is, the mesh wire passing through the convex column points is stuck on the convex column points, and the mesh surface is kept as flat as possible. It is better to selectively fix it with silk thread, and then spray non-expansive fire retardant coating, and the fire retardant coating completely covers the hanging net;

[0095] S4, repeating the operation of step S3 once to form two hanging nets, and the specifications of the two hanging nets are the same;

[0096] S5. The coating surface formed after spraying is subjected to a plastering treatment, thereby completing the coating construction.

[0097] Example 7

[0098] An ultra-thick non-expansive fire retardant coating process, comprising the following steps:

[0099] S1. Multiple convex points are scattered on the surface of the steel structure to be painted. The convex points are M12X35mm galvanized bolts (nuts facing vertically outward) welded on the surface of the steel structure, and the spacing between the convex points is 400mm×400mm;

[0100] S2. Clean the surface to be coated (welding slag and surface dirt), and spray the surface to be coated with a non-expanding fire retardant coating; the raw materials for preparing the non-expanding fire retardant coating include, by weight: 60 parts of desulfurized gypsum, 15 parts of polystyrene, 15 parts of calcium carbonate, 8 parts of aluminum silicate fiber, 4 parts of fumed silica, 8 parts of anti-cracking agent, 4 parts of polyethylene glycol and 50 parts of water; wherein the anti-cracking agent is a slime mold extract, and the preparation method thereof is as follows: take slime mold (composed of Physarum compressum and Ceratiomyxa fruticulosa in a mass ratio of 1:4) in a mortar, add a grinding medium and grind for 4 hours, transfer the obtained grinding liquid to a container, add petroleum ether to the grinding liquid in a ratio of 1kg grinding liquid: 10L petroleum ether, control the temperature to 55°C for ultrasonic extraction, perform ultrasonic treatment for 20 minutes at a power of 300W and a frequency of 45kHz, filter the obtained extract, filter out the residue, and concentrate the filtrate to obtain a slime mold extract;

[0101] S3, hanging net, the hanging net uses a galvanized steel wire mesh with a diameter of 0.8mm, and the mesh size of the hanging net is 25mm×25mm, and the hanging net is fixed by convex column points, that is, the mesh wire passing through the convex column points is stuck on the convex column points, and the mesh surface is kept as flat as possible. It is better to selectively fix it with silk thread, and then spray non-expansive fire retardant coating, and the fire retardant coating completely covers the hanging net;

[0102] S4. Insert reinforcement wires evenly on the existing coating surface with a density of 500 wires / m 2 , and the reinforcement wire is partially exposed (the reinforcement wires are inserted at an approximate vertical angle, and the inserted part and the exposed part are both about 2 cm long); the reinforcement wire is made of galvanized steel wire and a carbon fiber tow spirally wound on the surface of the galvanized steel wire, the diameter of the galvanized steel wire is 2.8 mm, the diameter of the carbon fiber tow is 0.8 mm, and a plurality of spaced nodes are formed on the carbon fiber tow by knotting, and each reinforcement wire has more than 6 nodes;

[0103] Then, the operation of step S3 is repeated once to form two hanging nets, and the specifications of the two hanging nets are the same, and the exposed reinforcement wires are completely covered when the non-expanding fire retardant coating is repeatedly sprayed;

[0104] S5. The coating surface formed after spraying is subjected to a plastering treatment, thereby completing the coating construction.

[0105] Comparative Example 3

[0106] An ultra-thick non-expansive fire retardant coating process, comprising the following steps:

[0107] S1. Multiple convex points are scattered on the surface of the steel structure to be painted. The convex points are M12X35mm galvanized bolts (nuts facing vertically outward) welded on the surface of the steel structure, and the spacing between the convex points is 400mm×400mm;

[0108] S2. Clean the surface to be coated (welding slag and surface dirt), and spray the surface to be coated with a non-expanding fire retardant coating; the raw materials for preparing the non-expanding fire retardant coating include, by weight: 60 parts of desulfurized gypsum, 15 parts of polystyrene, 15 parts of calcium carbonate, 8 parts of aluminum silicate fiber, 4 parts of fumed silica, 8 parts of anti-cracking agent, 4 parts of polyethylene glycol and 50 parts of water; wherein the anti-cracking agent is a slime mold extract, and the preparation method thereof is as follows: take slime mold (composed of Physarum compressum and Ceratiomyxa fruticulosa in a mass ratio of 1:4) in a mortar, add a grinding medium and grind for 4 hours, transfer the obtained grinding liquid to a container, add petroleum ether to the grinding liquid in a ratio of 1kg grinding liquid: 10L petroleum ether, control the temperature to 55°C for ultrasonic extraction, perform ultrasonic treatment for 20 minutes at a power of 300W and a frequency of 45kHz, filter the obtained extract, filter out the residue, and concentrate the filtrate to obtain a slime mold extract;

[0109] S3, hanging net, the hanging net uses a galvanized steel wire mesh with a diameter of 0.8mm, and the mesh size of the hanging net is 25mm×25mm, and the hanging net is fixed by convex column points, that is, the mesh wire passing through the convex column points is stuck on the convex column points, and the mesh surface is kept as flat as possible. It is better to selectively fix it with silk thread, and then spray non-expansive fire retardant coating, and the fire retardant coating completely covers the hanging net;

[0110] S4. Insert reinforcement wires evenly on the existing coating surface with a density of 500 wires / m 2 , and the reinforcement wire is partially exposed (the reinforcement wires are inserted at an approximate vertical angle, and the inserted part and the exposed part are both about 2 cm long); the reinforcement wire is made of galvanized steel wire and carbon fiber tow bonded side by side (acrylic pressure-sensitive adhesive with low viscosity can be used for bonding, the purpose is to facilitate the insertion and spraying of carbon fiber without deformation, and the carbon fiber can expand and shrink freely in the later stage), the diameter of the galvanized steel wire is 2.8mm, the diameter of the carbon fiber tow is 0.8mm, and a plurality of spaced nodes are formed on the carbon fiber tow by knotting, and there are more than 6 nodes on each reinforcement wire;

[0111] Then, the operation of step S3 is repeated once to form two hanging nets, and the specifications of the two hanging nets are the same, and the exposed reinforcement wires are completely covered when the non-expanding fire retardant coating is repeatedly sprayed;

[0112] S5. The coating surface formed after spraying is subjected to a plastering treatment, thereby completing the coating construction.

[0113] Comparative Example 4

[0114] An ultra-thick non-expansive fire retardant coating process, comprising the following steps:

[0115] S1. Multiple convex points are scattered on the surface of the steel structure to be painted. The convex points are M12X35mm galvanized bolts (nuts facing vertically outward) welded on the surface of the steel structure, and the spacing between the convex points is 400mm×400mm;

[0116] S2. Clean the surface to be coated (welding slag and surface dirt), and spray the surface to be coated with a non-expanding fire retardant coating; the raw materials for preparing the non-expanding fire retardant coating include, by weight: 60 parts of desulfurized gypsum, 15 parts of polystyrene, 15 parts of calcium carbonate, 8 parts of aluminum silicate fiber, 4 parts of fumed silica, 8 parts of anti-cracking agent, 4 parts of polyethylene glycol and 50 parts of water; wherein the anti-cracking agent is a slime mold extract, and the preparation method thereof is as follows: take slime mold (composed of Physarum compressum and Ceratiomyxa fruticulosa in a mass ratio of 1:4) in a mortar, add a grinding medium and grind for 4 hours, transfer the obtained grinding liquid to a container, add petroleum ether to the grinding liquid in a ratio of 1kg grinding liquid: 10L petroleum ether, control the temperature to 55°C for ultrasonic extraction, perform ultrasonic treatment for 20 minutes at a power of 300W and a frequency of 45kHz, filter the obtained extract, filter out the residue, and concentrate the filtrate to obtain a slime mold extract;

[0117] S3, hanging net, the hanging net uses a galvanized steel wire mesh with a diameter of 0.8mm, and the mesh size of the hanging net is 25mm×25mm, and the hanging net is fixed by convex column points, that is, the mesh wire passing through the convex column points is stuck on the convex column points, and the mesh surface is kept as flat as possible. It is better to selectively fix it with silk thread, and then spray non-expansive fire retardant coating, and the fire retardant coating completely covers the hanging net;

[0118] S4. Insert reinforcement wires evenly on the existing coating surface with a density of 500 wires / m 2 , and the reinforcement wire is partially exposed (the reinforcement wires are inserted at an approximately vertical angle, and the inserted part and the exposed part are both about 2 cm long); the reinforcement wire is made of galvanized steel wire and a carbon fiber tow spirally wound on the surface of the galvanized steel wire, the diameter of the galvanized steel wire is 2.8 mm, the diameter of the carbon fiber tow is 0.8 mm, and there are no nodes;

[0119] Then, the operation of step S3 is repeated once to form two hanging nets, and the specifications of the two hanging nets are the same, and the exposed reinforcement wires are completely covered when the non-expanding fire retardant coating is repeatedly sprayed;

[0120] S5. The coating surface formed after spraying is subjected to a plastering treatment, thereby completing the coating construction.

[0121] 3. Performance Test

[0122] (I) For the samples (steel plates and their fire retardant coatings) obtained by the coating process construction of the above-mentioned Examples 1-7 and Comparative Examples 1-4, conventional maintenance was carried out, and the following physical and chemical performance tests were carried out on each sample with reference to the detection method of GB14907-2018 "Steel Structure Fire Retardant Coatings". The specific test items mainly include:

[0123] ① Initial drying crack resistance:

[0124] Sample size and quantity: two pieces of 300mm×150mm×6mm; minimum qualification standard: 1-3 cracks are allowed, and their width should be ≤0.5mm.

[0125] ② Bond strength:

[0126] Sample size and quantity: five pieces of 70mm×70mm×6mm; minimum qualification standard: ≥0.04MPa.

[0127] ③ Explosion resistance:

[0128] Sample size and quantity: one piece of 150mm×70mm×6mm, one piece of 500mm×500mm×6mm; Minimum qualification standard: After 720h test, the coating should not have delamination, shedding, hollowing, or cracking, and the thermal insulation efficiency attenuation should be ≤35%.

[0129] ④Moisture and heat resistance:

[0130] Sample size and quantity: one piece of 150mm×70mm×6mm, one piece of 500mm×500mm×6mm; minimum qualification standard: after 504h test, the coating should not have delamination or falling off, and the thermal insulation efficiency attenuation should be ≤35%.

[0131] ⑤Freeze-thaw cycle resistance:

[0132] Sample size and quantity: one piece of 150mm×70mm×6mm, one piece of 500mm×500mm×6mm; minimum qualification standard: after 15 tests, the coating should not have cracking, peeling, or blistering, and the thermal insulation efficiency attenuation should be ≤35%.

[0133] ⑥ Resistance to ultraviolet radiation:

[0134] Sample size and quantity: one piece is 150mm×70mm×6mm, and one piece is 500mm×500mm×6mm; minimum qualification standard: after 60 tests, the coating should not have delamination, cracking, or powdering, and the thermal insulation efficiency attenuation should be ≤35%.

[0135] (II) Based on the above (I), the test method of GB14907-2018 "Fire Retardant Coatings for Steel Structures" is still used, but the test intensity is increased to varying degrees, and the durability of each sample is strengthened. The specific test items include:

[0136] ① Strengthened test of explosion resistance: After 1440h test, observe whether the coating has delamination, shedding, hollowing and cracking, and calculate the attenuation of thermal insulation efficiency.

[0137] ② Strengthened test of moisture and heat resistance: After 1008h test, observe whether the coating has delamination, shedding, hollowing and cracking, and calculate the attenuation of thermal insulation efficiency.

[0138] ③ Enhanced test of freeze-thaw cycle resistance: After 30 tests, observe whether the coating has delamination, shedding, hollowing, or cracking, and calculate the attenuation of thermal insulation efficiency.

[0139] ④ Strengthened testing of resistance to ultraviolet radiation: After 120 tests, observe whether the coating has delamination, shedding, hollowing, or cracking, and calculate the attenuation of thermal insulation efficiency.

[0140] Note: The measurement and calculation methods of the above indicators refer to the GB14907-2018 "Steel Structure Fire Retardant Coating" testing standard.

[0141] 4. Test results and analysis

[0142] The test results of the samples of Examples 1-7 and Comparative Examples 1-4 are summarized to obtain the following Tables 1 and 2:

[0143] Table 1: Performance test results of test (I)

[0144]

[0145] Table 2: Performance test results of test (II)

[0146]

[0147] Referring to Table 1 and Table 2 above, it can be seen that:

[0148] In the coating process of Examples 1-3 of the present invention, by pre-arranging convex column points evenly on the surface to be coated, and coordinating the mesh hanging and spraying processes layer by layer, the coating can meet the national qualified standards in various indicators in conventional tests and meet the requirements of thick fire retardant coatings. However, at the same time, in more stringent enhanced testing, some indicators did not meet the qualified standards, especially the freeze-thaw cycle resistance and explosion heat resistance.

[0149] The coating process of Examples 4-6 of the present invention is based on Example 3, and a slime mold extract is further added as an anti-cracking agent, and the amount added gradually increases. It can be seen that as the amount of slime mold extract added gradually increases, various indicators are improved to varying degrees, especially the bonding strength and freeze-thaw cycle resistance are significantly improved. At the same time, in the enhanced detection, Examples 4-6 are significantly improved in the phenomena of delamination, hollowing, falling off, and cracking, and the thermal insulation efficiency attenuation is also significantly reduced. In addition, Comparative Examples 1-2 continue to increase the amount of slime mold extract added on the basis of Example 6. It can be seen that whether it is a conventional test or an enhanced test, the amount of slime mold extract added is not the more the better, and the improvement of performance by too much slime mold extract becomes unobvious, and even the phenomenon of performance degradation occurs.

[0150] The coating process of Example 7 of the present invention is based on Example 6, and further uses a reinforcing wire to strengthen the coating. It can be seen that this measure enables the coating to basically meet the qualified standards even in the reinforcement test, especially in terms of delamination, hollowing, and shedding, which are further significantly improved. In addition, compared with Example 7, Comparative Example 3 replaces the spiral winding method with a side-by-side bonding method for carbon fibers, and Comparative Example 4 cancels the nodes on the carbon fibers compared with Example 7, which makes the various effects significantly worse, and even comparable to Example 6 without using a reinforcing wire, which shows that the measures of spiral winding and knotting of carbon fibers are very important, otherwise they cannot play their due characteristics in fire retardant coatings.

[0151] 5. Outdoor on-site construction

[0152] like Figure 1 As shown, it is a protective construction site of an outdoor corridor steel structure of a project in Guangzhou. The project is carried out with reference to the specific steps of the above-mentioned Example 7. The overall thickness standard of the coating is 50 mm. After conventional maintenance, there are no cracks in the initial drying, and the stability and durability of the coating can meet the requirements.

[0153] The above-mentioned embodiments only express several implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the present invention. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention.

Claims

1. An ultra-thick non-expansive fire-retardant coating process, characterized in that the steps include: S1. Distribute multiple convex column points on the surface to be coated; S2. Clean the surface to be painted and spray the surface with non-expanding fire retardant paint; S3, hang the net and fix it by convex column points, then spray the non-expansion fire retardant coating, and make the fire retardant coating completely cover the net; S4, repeat the operation of step S3; S5, performing a plastering treatment on the coating surface formed after spraying, thereby completing the coating construction; The raw materials for preparing the non-expanding fire retardant coating include: desulfurized gypsum, polystyrene, lightweight refractory filler, aluminum silicate fiber, fumed silica, dispersant, slime mold extract and water, and the weight ratio is desulfurized gypsum: polystyrene: lightweight refractory filler: aluminum silicate fiber: fumed silica: dispersant: slime mold extract: water = 1.20-1.33: 0.16-0.30: 0.26-0.30: 0.16-0.20: 0.03-0.08: 0.06-0.08: 0.08-0.16: 1; The preparation method of the slime mold extract is as follows: taking a slime mold fruiting body in a mortar, adding a grinding medium and grinding for 2-4 hours, transferring the obtained grinding liquid to a container, adding petroleum ether to the grinding liquid at a ratio of 1 kg grinding liquid: 8-10 L petroleum ether, controlling the temperature to 40-55° C. for ultrasonic extraction, filtering the obtained extract, filtering out the residue and concentrating the filtrate to obtain the slime mold extract.

2. The ultra-thick non-expansive fire retardant coating process according to claim 1, characterized in that: The surface to be painted is a steel structure surface, and the boss points are M12X35mm galvanized bolts welded to the surface of the steel structure, and the boss point spacing is 400mm×400mm.

3. The ultra-thick non-expansive fire-retardant coating process according to claim 1, characterized in that: The lightweight refractory filler is selected from one or more of silicon micropowder, β-eucryptite, silicon carbide, kaolin, and calcium carbonate, and the dispersant is lignin or polyethylene glycol.

4. The ultra-thick non-expansive fire retardant coating process according to claim 1, characterized in that: The slime mold is prepared by mixing Physarum compressum and Ceratiomyxa fruticulosa in a mass ratio of 1:1-4.

5. The ultra-thick non-expansive fire retardant coating process according to claim 1, characterized in that: The ultrasonic extraction refers to ultrasonic treatment for 20-40 minutes under the conditions of power 150-300W and frequency 20-45kHz.

6. The ultra-thick non-expansive fire retardant coating process according to claim 1, characterized in that: In step S3, the hanging net is a galvanized steel wire mesh with a diameter of 0.3-0.8 mm, and the mesh size of the hanging net is 25 mm×25 mm.

7. The ultra-thick non-expansive fire retardant coating process according to claim 1, characterized in that: In step S4, before each repetition of step S3, reinforcing wires are uniformly inserted into the surface of the existing coating, with an insertion density of 400-600 wires / m 2 , and expose the reinforcement wire part, and then completely cover the exposed reinforcement wire when repeatedly spraying the non-expanding fire retardant coating; The reinforcing wire is made of galvanized steel wire and a carbon fiber bundle spirally wound on the surface of the galvanized steel wire. The diameter of the galvanized steel wire is 2.5-3.0 mm, the diameter of the carbon fiber bundle is 0.8-1.2 mm, and a plurality of spaced nodes are formed on the carbon fiber bundle by knotting.

8. The ultra-thick non-expansive fire retardant coating process according to claim 1, characterized in that: In step S4, the operation of step S3 is repeated once to form two hanging nets, and the specifications of the two hanging nets are the same.

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