Anti-cracking construction method for internal and external corners of steel structure

Abstract

The invention provides an anti-cracking construction method for internal and external corners of a steel structure, and relates to the technical field of construction.The anti-cracking construction method comprises the following steps that pozzolanic composite cement, quartz sand, redispersible latex powder, cellulose ether and a defoaming agent are evenly mixed, water is added, stirring is conducted, and a steel structure interface agent is obtained; impurities on the surface of the steel structure are cleaned, and abrasive paper or a steel brush is used for polishing the surface of the steel structure when necessary; constructing a first layer: brushing a newly mixed steel structure interface agent on the internal and external corners of the steel structure, so that the interface agent forms a coating similar to a net structure on the surfaces of the internal and external corners of the steel structure; and second-layer construction: after the first-layer coating is finally set, coating treatment is carried out on the whole surface of the steel structure including internal and external corner parts by adopting a steel structure interface agent, and the second layer and the first layer are compounded to form a final steel structure interface coating. The method can effectively solve the problem that internal and external corners crack in the using process of the steel structure interface agent, the steel structure is prevented from being eroded by other materials, and the service life of the steel structure is prolonged.

Description

Technical Field

[0001] The invention relates to the technical field of construction, and in particular to an anti-cracking construction method for positive and negative corners of a steel structure. Background Art

[0002] With the continuous application of steel structures, steel structure interface agents are gradually being promoted and applied. The current steel structure interface agents often use a higher dosage of polymers. This enhances the bonding performance between the interface agent and the steel structure, but also brings some problems. Interface agents with high polymer dosages often crack in the plastic stage due to the film-forming effect of the polymer and the rapid loss of water. As a result, fine cracks are easily formed during the use of the steel structure interface agent, especially at the corners. This may cause the steel structure to be eroded by other materials, bringing hidden dangers to the application and promotion of the interface agent. Summary of the invention

[0003] The technical problem to be solved by the present invention is: in view of the shortcomings of the existing technology, a method for anti-cracking construction of the inner and outer corners of steel structures is provided, which can effectively solve the problem of cracking of the inner and outer corners during the use of steel structure interface agents, avoid erosion of the steel structure by other materials, and extend the service life of the steel structure.

[0004] In order to solve the above technical problems, the technical solution of the present invention is:

[0005] A method for anti-cracking construction of steel structure internal and external corners comprises the following steps:

[0006] S1: Preparation of steel structure interface agent:

[0007] The volcanic ash composite cement, quartz sand, redispersible latex powder, cellulose ether and defoamer are uniformly mixed, and water is added and stirred to prepare the steel structure interface agent;

[0008] S2: Surface preparation:

[0009] Clean the impurities on the surface of the steel structure and polish the surface of the steel structure with sandpaper or steel brush if necessary;

[0010] S3: Construction:

[0011] First layer construction: brush the newly mixed steel structure interface agent on the steel structure's internal and external corners, so that the interface agent forms a coating similar to a mesh structure on the surface of the steel structure's internal and external corners;

[0012] Construction of the second layer: After the first layer of coating has finally set, a steel structure interface agent is used to coat the entire surface of the steel structure, including the corners. The second layer is combined with the first layer to form the final steel structure interface coating with a total coating thickness of 1-3mm.

[0013] Preferably, in step S1, the amounts of the components in the steel structure interface agent are as follows in parts by weight: 200-600 parts of pozzolanic composite cement, 300-800 parts of quartz sand, 50-150 parts of redispersible latex powder, 1-3 parts of cellulose ether, 0.5-2 parts of defoaming agent, and 20-25 parts of water.

[0014] Preferably, in step S1, the pozzolanic composite cement is a mixture of ordinary Portland cement, sulphoaluminate cement and calcined attapulgite, and the mass ratio of the ordinary Portland cement, sulphoaluminate cement and calcined attapulgite is 1:(0.1-0.2):(0.05-0.15).

[0015] Preferably, in step S1, the calcination temperature during the preparation of attapulgite is 300-450°C, the heating time is 15-23min, the heat preservation time is 97-225min, and the calcination is completed and the attapulgite is cooled to room temperature in the furnace.

[0016] Preferably, in step S1, the quartz sand is a mixture of 40-80 mesh quartz sand and 80-120 mesh quartz sand, and the mass ratio of 40-80 mesh quartz sand to 80-120 mesh quartz sand is 1:(1.2-1.5).

[0017] Preferably, in step S1, the redispersible latex powder is ethylene-vinyl acetate copolymer, the cellulose ether is hydroxypropyl methyl cellulose ether having a viscosity of 30000 mPa·s, and the defoaming agent is a silicone defoaming agent.

[0018] Preferably, in step S1, the stirring speed when adding water and stirring is 200-400 r / min, and the time is 5 min.

[0019] Preferably, the specific operations of the first layer construction are:

[0020] (1) Use a brush to evenly apply a layer of freshly mixed steel structure interface agent along the direction of the steel structure's internal and external corners, so that the coating is evenly spread on the surface of the steel structure's internal and external corners;

[0021] (2) Continue to use the brush to apply along a fixed direction at the corners for multiple times, leaving fine brush marks on the steel structure interface agent that expose the steel structure. During the process, the overall thickness of the coating should be kept uniform, so that the steel structure interface agent presents a mesh-like coating at the corners of the steel structure, with a coating thickness of 0.5-1.2mm.

[0022] Preferably, in step S2, when cleaning the surface of the steel structure, oil stains, rust and dust on the surface of the steel structure are removed.

[0023] Preferably, in step S3, when the second layer is applied, the coating method adopted is any one of rolling, brushing or scraping.

[0024] Due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0025] The invention discloses an anti-cracking construction method for the inner and outer corners of a steel structure. First, a steel structure interface agent with good performance is prepared. Secondly, the surface of the steel structure is cleaned to improve the adhesion of the interface agent. Then, the newly mixed steel structure interface agent is brushed on the inner and outer corners of the steel structure to form a coating with a mesh structure on the surface of the inner and outer corners of the steel structure. After the coating is finally set, any one of rolling, brushing or scraping is used to treat the entire surface of the steel structure to form a final steel structure interface coating. The method can effectively solve the problem of cracking of the inner and outer corners during the use of the steel structure interface agent, prevent the steel structure from being eroded by other materials, and extend the service life of the steel structure.

[0026] The steel structure interface agent of the present invention comprises volcanic ash composite cement, quartz sand, redispersible latex powder, cellulose ether, defoamer and water; the volcanic ash composite cement is a mixture of ordinary Portland cement, sulphoaluminate cement and calcined attapulgite, ordinary Portland cement provides basic strength, and the rapid hardening and micro-expansion characteristics of sulphoaluminate cement can compensate for shrinkage; the calcined attapulgite has both volcanic ash activity and micro-aggregate filling after activation, which can react with cement hydration products to generate CSH gel, and can also refine the pore structure and reduce shrinkage stress. The present invention uses quartz sand of different particle sizes to form a tightly packed structure, reduce the internal porosity of the interface agent, and can also improve the shear resistance of the coating, which is particularly suitable for the alternating stress environment of the yin and yang corners.

[0027] During construction, the present invention firstly forms a base layer with a directional fibrous texture by applying paint multiple times with a brush. The structure disperses stress through the "microgrid" inside the interface agent, and the micro-protrusion structure produced by the directional brush marks can play a role similar to a "shear key", thereby increasing the contact area and mechanical locking force between the first layer and the second layer. The present invention also uses a second layer formed by rolling, brushing or scraping to form a "rigid-flexible composite" system with the first layer, thereby improving the anti-cracking performance of the coating. DETAILED DESCRIPTION

[0028] In order to more clearly understand the above-mentioned objectives, features and advantages of the present invention, the scheme of the present invention will be further described below. It should be noted that the embodiments of the present invention and the features in the embodiments can be combined with each other without conflict.

[0029] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein; it is obvious that the embodiments in the specification are only part of the embodiments of the present invention, rather than all of the embodiments.

[0030] In order to further understand the present invention, preferred embodiments of the present invention are described below in conjunction with examples. However, it should be understood that these descriptions are only for further illustrating the features and advantages of the present invention, rather than limiting the claims of the present invention.

[0031] Unless otherwise specified, the raw materials in the following examples and comparative examples are all commercially available, and the conditions are all conventional conditions well known to those skilled in the art unless otherwise specified.

[0032] Example 1

[0033] A method for anti-cracking construction of steel structure internal and external corners comprises the following steps:

[0034] S1: Preparation of steel structure interface agent:

[0035] In parts by weight, 400 parts of pozzolanic composite cement (ordinary Portland cement, sulphoaluminate cement and calcined attapulgite are mixed in a mass ratio of 1:0.1:0.05; the calcination temperature of the calcined attapulgite is 350°C, the heating time is 18 minutes, and the insulation time is 162 minutes), 500 parts of quartz sand (40-80 mesh quartz sand and 80-120 mesh quartz sand are mixed in a mass ratio of 1:1.25), 80 parts of ethylene-vinyl acetate copolymer, 1.5 parts of hydroxypropyl methylcellulose ether (viscosity is 30000mPa·s), and 0.5 parts of silicone defoamer are mixed evenly, 20 parts of water are added, and the mixture is stirred at a speed of 250r / min for 5 minutes to prepare a steel structure interface agent;

[0036] S2: Surface preparation:

[0037] Clean the steel structure, remove the oil, rust and dust on the surface of the steel structure, and polish the surface of the steel structure with sandpaper or steel brush when necessary;

[0038] S3: Construction:

[0039] First layer construction:

[0040] Use a brush to evenly apply a layer of freshly mixed steel structure interface agent on the corners of the steel structure along the direction of the corners, so that the coating is evenly spread on the surface of the corners of the steel structure; continue to use the brush to brush along a fixed direction of the corners for many times, so that the brush leaves fine brush marks on the steel structure interface agent to expose the steel structure. During the process, the overall thickness of the coating should be kept uniform, so that the steel structure interface agent presents a mesh-like coating at the corners of the steel structure, and the coating thickness is 0.8mm;

[0041] Second layer construction:

[0042] After the first layer of coating has finally set, the entire surface of the steel structure, including the corners, is coated by roller coating. The second layer is combined with the first layer to form the final steel structure interface coating with a total coating thickness of 2.0 mm.

[0043] Example 2

[0044] A method for anti-cracking construction of steel structure internal and external corners comprises the following steps:

[0045] S1: Preparation of steel structure interface agent:

[0046] In parts by weight, 450 parts of pozzolanic composite cement (ordinary Portland cement, sulphoaluminate cement and calcined attapulgite are mixed in a mass ratio of 1:0.15:0.07; the calcination temperature during the preparation of the calcined attapulgite is 350°C, the heating time is 18 minutes, and the insulation time is 192 minutes), 550 parts of quartz sand (40-80 mesh quartz sand and 80-120 mesh quartz sand are mixed in a mass ratio of 1:1.25), 100 parts of ethylene-vinyl acetate copolymer, 2.0 parts of hydroxypropyl methylcellulose ether (viscosity is 30000 mPa·s), and 1 part of silicone defoamer are mixed evenly, 22 parts of water are added, and the mixture is stirred at a speed of 250 r / min for 5 minutes to obtain a steel structure interface agent;

[0047] S2: Surface preparation:

[0048] Clean the steel structure, remove the oil, rust and dust on the surface of the steel structure, and polish the surface of the steel structure with sandpaper or steel brush when necessary;

[0049] S3: Construction:

[0050] First layer construction:

[0051] Use a brush to evenly apply a layer of freshly mixed steel structure interface agent on the corners of the steel structure along the direction of the corners, so that the coating is evenly spread on the surface of the corners of the steel structure; continue to use the brush to brush along a fixed direction of the corners for many times, so that the brush leaves fine brush marks on the steel structure interface agent to expose the steel structure. During the process, the uniformity of the overall thickness of the coating should be maintained, so that the steel structure interface agent presents a mesh-like coating at the corners of the steel structure, and the coating thickness is 0.7mm;

[0052] Second layer construction:

[0053] After the first layer of coating has finally set, the entire surface of the steel structure, including the corners, is coated by roller coating. The second layer is combined with the first layer to form the final steel structure interface coating with a total coating thickness of 2.5 mm.

[0054] Example 3

[0055] A method for anti-cracking construction of steel structure internal and external corners comprises the following steps:

[0056] S1: Preparation of steel structure interface agent:

[0057] In parts by weight, 600 parts of pozzolanic composite cement (ordinary Portland cement, sulphoaluminate cement and calcined attapulgite are mixed in a mass ratio of 1:0.2:0.11; the calcination temperature during the preparation of the calcined attapulgite is 400°C, the heating time is 20 minutes, and the insulation time is 190 minutes), 700 parts of quartz sand (40-80 mesh quartz sand and 80-120 mesh quartz sand are mixed in a mass ratio of 1:1.25), 120 parts of ethylene-vinyl acetate copolymer, 2.5 parts of hydroxypropyl methylcellulose ether (viscosity is 30000 mPa·s), and 1.5 parts of silicone defoamer are mixed evenly, 25 parts of water are added, and the mixture is stirred at a speed of 250 r / min for 5 minutes to obtain a steel structure interface agent;

[0058] S2: Surface preparation:

[0059] Clean the steel structure, remove the oil, rust and dust on the surface of the steel structure, and polish the surface of the steel structure with sandpaper or steel brush when necessary;

[0060] S3: Construction:

[0061] First layer construction:

[0062] Use a brush to evenly apply a layer of freshly mixed steel structure interface agent on the corners of the steel structure along the direction of the corners, so that the coating is evenly spread on the surface of the corners of the steel structure; continue to use the brush to brush along a fixed direction of the corners for many times, so that the brush leaves fine brush marks on the steel structure interface agent to expose the steel structure. During the process, the uniformity of the overall thickness of the coating should be maintained, so that the steel structure interface agent presents a mesh-like coating at the corners of the steel structure, and the coating thickness is 1.0mm;

[0063] Second layer construction:

[0064] After the first layer of coating has finally set, the entire surface of the steel structure, including the corners, is coated by scraping. The second layer is combined with the first layer to form the final steel structure interface coating with a total coating thickness of 2.8 mm.

[0065] Example 4

[0066] A method for anti-cracking construction of steel structure internal and external corners comprises the following steps:

[0067] S1: Preparation of steel structure interface agent:

[0068] In parts by weight, 600 parts of pozzolanic composite cement (ordinary Portland cement, sulphoaluminate cement and calcined attapulgite are mixed in a mass ratio of 1:0.2:0.15; the calcination temperature during the preparation of the calcined attapulgite is 450°C, the heating time is 23 minutes, and the insulation time is 217 minutes), 800 parts of quartz sand (40-80 mesh quartz sand and 80-120 mesh quartz sand are mixed in a mass ratio of 1:1.25), 150 parts of ethylene-vinyl acetate copolymer, 3 parts of hydroxypropyl methylcellulose ether (viscosity of 30000 mPa·s), and 2 parts of silicone defoaming agent are mixed evenly, 25 parts of water are added, and the mixture is stirred at a speed of 250 r / min for 5 minutes to obtain a steel structure interface agent;

[0069] S2: Surface preparation:

[0070] Clean the steel structure, remove the oil, rust and dust on the surface of the steel structure, and polish the surface of the steel structure with sandpaper or steel brush when necessary;

[0071] S3: Construction:

[0072] First layer construction:

[0073] Use a brush to evenly apply a layer of freshly mixed steel structure interface agent on the corners of the steel structure along the direction of the corners, so that the coating is evenly spread on the surface of the corners of the steel structure; continue to use the brush to brush along a fixed direction of the corners for many times, so that the brush leaves fine brush marks on the steel structure interface agent to expose the steel structure. During the process, the uniformity of the overall thickness of the coating should be maintained, so that the steel structure interface agent presents a mesh-like coating at the corners of the steel structure, and the coating thickness is 1.1mm;

[0074] Second layer construction:

[0075] After the first layer of coating has finally set, it is coated on the entire surface of the steel structure including the corners by brushing. The second layer is combined with the first layer to form the final steel structure interface coating with a total coating thickness of 3.0 mm.

[0076] The coatings prepared in the above embodiment were cured at room temperature for 7 days, and then divided into groups and subjected to the following treatments:

[0077] (1) Untreated: The coating is not treated and is cured at room temperature for 7 days;

[0078] (2) Thermal aging: Place in a 70°C aging box for 7 days;

[0079] (3) Resistance to saturated Ca(OH) 2 Solution: Place in saturated Ca(OH) 2 In the solution, the curing time is 7 days;

[0080] (4) Freeze-thaw cycle: Freeze-thaw cycles were performed between a (-15±3)℃ freezer and (20±3)℃ water, with each freeze and thaw cycle lasting 2 h, and the number of cycles was 25.

[0081] The coating was then tested and the test results are shown in Table 1.

[0082] Table 1

[0083]

[0084] It can be seen from the above test results that the interface agent provided by the present invention has good bonding performance with the surface of the steel structure, can effectively improve the durability of the surface of the steel structure, and has good flexibility and crack resistance.

[0085] During construction, the first layer of the present invention adopts a "net structure" construction method to form a mechanical bite interface, and then the second layer is formed by rolling, brushing or scraping to form a "rigid-flexible composite" system with the first layer to improve the comprehensive performance of the coating.

[0086] Specific examples are used herein to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core ideas, including the best mode, and also enable any technician in the field to practice the present invention, including making and using any device or system, and implementing any combined method. It should be pointed out that for ordinary technicians in this technical field, without departing from the principle of the present invention, the present invention can also be improved and modified, and these improvements and modifications also fall within the scope of protection of the claims of the present invention. The scope of patent protection of the present invention is defined by the claims and may include other embodiments that can be thought of by those skilled in the art. If these other embodiments have structural elements similar to the literal expression of the claims, or if they include equivalent structural elements that are not substantially different from the literal expression of the claims, then these other embodiments should also be included in the scope of the claims.

Claims

1. A method for anti-cracking construction of steel structure corners, characterized in that: The following steps are involved: S1: Preparation of steel structure interface agent: The volcanic ash composite cement, quartz sand, redispersible latex powder, cellulose ether and defoamer are uniformly mixed, and water is added and stirred to prepare the steel structure interface agent; S2: Surface preparation: Clean the impurities on the surface of the steel structure and polish the surface of the steel structure with sandpaper or steel brush if necessary; S3: Construction: First layer construction: brush the newly mixed steel structure interface agent on the steel structure's internal and external corners, so that the interface agent forms a coating similar to a mesh structure on the surface of the steel structure's internal and external corners; Construction of the second layer: After the first layer of coating has finally set, a steel structure interface agent is used to coat the entire surface of the steel structure, including the corners. The second layer is combined with the first layer to form the final steel structure interface coating with a total coating thickness of 1-3mm.

2. The anti-cracking construction method for the internal and external corners of a steel structure according to claim 1, characterized in that: In step S1, the amounts of the components in the steel structure interface agent are specifically as follows in parts by weight: 200-600 parts of volcanic ash composite cement, 300-800 parts of quartz sand, 50-150 parts of redispersible latex powder, 1-3 parts of cellulose ether, 0.5-2 parts of defoaming agent, and 20-25 parts of water.

3. The anti-cracking construction method for the internal and external corners of a steel structure according to claim 2, characterized in that: In step S1, the pozzolanic composite cement is a mixture of ordinary Portland cement, sulphoaluminate cement and calcined attapulgite, and the mass ratio of the ordinary Portland cement, sulphoaluminate cement and calcined attapulgite is 1:(0.1-0.2):(0.05-0.15).

4. The anti-cracking construction method for the internal and external corners of a steel structure according to claim 3 is characterized by: In step S1, the calcination temperature during the preparation of attapulgite is 300-450°C, the heating time is 15-23min, the heat preservation time is 97-225min, and the calcination is completed and the furnace is cooled to room temperature.

5. The anti-cracking construction method for the internal and external corners of a steel structure according to claim 1, characterized in that: In step S1, the quartz sand is a mixture of 40-80 mesh quartz sand and 80-120 mesh quartz sand, and the mass ratio of 40-80 mesh quartz sand to 80-120 mesh quartz sand is 1:(1.2-1.5).

6. The anti-cracking construction method for the internal and external corners of a steel structure according to claim 1, characterized in that: In step S1, the redispersible latex powder is ethylene-vinyl acetate copolymer, the cellulose ether is hydroxypropyl methyl cellulose ether with a viscosity of 30000 mPa·s, and the defoaming agent is an organosilicon defoaming agent.

7. The anti-cracking construction method for the internal and external corners of a steel structure according to claim 1, characterized in that: In step S1, the stirring speed when adding water and stirring is 200-400 r / min, and the time is 5 min.

8. The anti-cracking construction method for the internal and external corners of a steel structure according to claim 1, characterized in that: The specific operations of the first layer construction are: (1) Use a brush to evenly apply a layer of freshly mixed steel structure interface agent along the direction of the steel structure's internal and external corners, so that the coating is evenly spread on the surface of the steel structure's internal and external corners; (2) Continue to use the brush to apply along a fixed direction at the corners for multiple times, leaving fine brush marks on the steel structure interface agent that expose the steel structure. During the process, the overall thickness of the coating should be kept uniform, so that the steel structure interface agent presents a mesh-like coating at the corners of the steel structure, with a coating thickness of 0.5-1.2mm.

9. The anti-cracking construction method for the internal and external corners of a steel structure according to claim 1, characterized in that: In step S2, when cleaning the surface of the steel structure, oil stains, rust and dust on the surface of the steel structure are removed.

10. The anti-cracking construction method for the internal and external corners of a steel structure according to claim 1, characterized in that: In step S3, when the second layer is applied, the coating method used is any one of rolling, brushing or scraping.

Images