A water-resistant anti-cracking gypsum building block and preparation method thereof

Abstract

The invention discloses a water-resistant anti-cracking gypsum building block, which is composed of the following raw materials in parts by weight: 600-750 parts of building gypsum, 150-200 parts of ash, 50-100 parts of rubber particles, 20-40 parts of quicklime, 10-20 parts of basalt fiber, 5-10 parts of water repellent, 1-3 parts of water reducer, 0.5-2 parts of defoamer, 50-100 parts of water-based polyurethane and 500-650 parts of water. The gypsum building block uses building gypsum as a main material, and improves the strength and water resistance of gypsum by adding ash, quicklime, water repellent and the like; fills capillary pores with hydrates formed between the raw materials and wraps with water-based polyurethane, thereby avoiding the problems of yellowing and whitening caused by impurity migration and affecting the appearance; and prevents the gypsum from brittle fracture and cracking when a large deformation occurs due to the synergistic effect of rubber particles, basalt fiber and water-based polyurethane. The invention also discloses a preparation method of the water-resistant anti-cracking gypsum building block.

Description

Technical Field

[0001] The invention relates to a gypsum building block, in particular to a water-resistant and crack-resistant gypsum building block and a preparation method thereof. Background Art

[0002] Ordinary gypsum blocks are made of building gypsum, additives and appropriate amount of water. They absorb moisture quickly when exposed to water, with a water absorption rate of up to 40%. The strength performance decreases sharply after water absorption. Moisture-proof gypsum blocks produced by surface coating or internal addition of water repellent can reduce the short-term water absorption rate of the product and increase the 24h softening coefficient to 0.6, but the product performance is still poor after long-term immersion in water. In the use of projects, local water leakage often occurs, soaking or scouring the wall for a long time, causing problems such as water absorption and powdering on the wall surface, which affects subsequent construction.

[0003] In addition, after ordinary gypsum blocks are built into partition walls, due to their brittle texture, deformation of beams and columns may cause vertical cracks or step cracks in the wall.

[0004] In addition, since the soluble impurities such as potassium, sodium, chlorine and fluorine in the industrial by-product gypsum raw materials used in the production of building gypsum often exceed the standard, the soluble impurities migrate to the surface of the gypsum blocks during the drying process or after they are used in buildings, causing yellowing or whitening of the walls, or even falling off of the surface decorative layer, resulting in rework and repair costs. Summary of the invention

[0005] In view of this, one of the objects of the present invention is to provide a water-resistant and crack-resistant gypsum block to solve the technical problems that ordinary gypsum blocks have poor long-term water immersion performance, resulting in low strength performance, deformation brittle cracking and impurity migration affecting the appearance. The second object of the present invention is to provide a method for preparing a water-resistant and crack-resistant gypsum block.

[0006] One of the purposes of the present invention is achieved through the following technical solutions:

[0007] A water-resistant and crack-resistant gypsum building block, composed of the following raw materials in parts by weight:

[0008] 600-750 parts of building gypsum, 150-200 parts of ash, 50-100 parts of rubber particles, 20-40 parts of quicklime, 10-20 parts of basalt fiber, 5-10 parts of water repellent, 1-3 parts of water reducing agent, 0.5-2 parts of defoaming agent, 50-100 parts of water-based polyurethane, and 500-650 parts of water.

[0009] Furthermore, 700 parts of building gypsum, 180 parts of ash, 75 parts of rubber particles, 30 parts of quicklime, 15 parts of fiber, 8 parts of water repellent, 2 parts of water reducing agent, 1 part of defoaming agent, 80 parts of water-based polyurethane, and 550 parts of water.

[0010] Furthermore, the ash is obtained by drying the ash from a power plant at 100° C. and grinding it to 300 meshes.

[0011] Furthermore, the basalt fiber has a length of 6-12 mm and a diameter of 15-20 um.

[0012] Furthermore, the rubber particles have a particle size of 20-60 meshes.

[0013] Furthermore, the water repellent is emulsified silicone oil.

[0014] Furthermore, the building gypsum is obtained by calcining phosphogypsum or desulfurized gypsum, and has a grade of 3.0 or above.

[0015] The second object of the present invention is achieved through the following technical solutions:

[0016] A method for preparing a water-resistant anti-cracking gypsum building block comprises the following steps:

[0017] (1) Material preparation: 600-750 parts of building gypsum, 150-200 parts of ash, 50-100 parts of rubber particles, 20-40 parts of quicklime, 10-20 parts of basalt fiber, 5-10 parts of water repellent, 1-3 parts of water reducing agent, 0.5-2 parts of defoaming agent, 50-100 parts of water-based polyurethane, and 500-650 parts of water;

[0018] (2) mixing and stirring building gypsum, ash, rubber particles, quicklime and basalt fiber to form a mixed powder at a stirring speed of 300 r / min for 3 min;

[0019] (3) Mixing the water repellent, water reducing agent, defoaming agent, waterborne polyurethane and water to form a uniform solution at a stirring speed of 1000 r / min for 2 min;

[0020] (4) Mixing the mixed powder and solution to obtain a uniform slurry at a stirring speed of 1000 r / min for 20 s;

[0021] (5) Pour the slurry into the mold, vibrate and compact it, scrape the surface of the slurry after initial setting, demould after final setting, then autoclave and cure at 100°C and 0.5MPa for 6h, and then dry at 50°C to obtain water-resistant and crack-resistant gypsum blocks.

[0022] Furthermore, the mixing and stirring equipment in step (2) is a mixer; the mixing and stirring equipment in step (3) is a stirrer; the autoclave curing equipment in step (5) is an autoclave, and the drying equipment is an oven.

[0023] The water-resistant anti-cracking gypsum building block of the present invention has the following beneficial effects:

[0024] (1) Water-resistant hydration products such as hydrated calcium silicate are formed by adding ash, activating quicklime and autoclaving. The water-resistant hydration products fill the pores and improve the density. Water repellent and water reducing agent are added to reduce the water absorption of gypsum. Water-based polyurethane is added to form a wrapping effect inside the gypsum to reduce the dissolution of gypsum. The above effects are combined to improve the water resistance of gypsum blocks and enhance the strength performance of gypsum blocks.

[0025] (2) By adding rubber particles and water-based polyurethane, flexible particles and flexible membrane structures are introduced into the gypsum, thereby reducing deformation stress; adding basalt fibers improves the brittleness of the gypsum through the friction and mechanical bite force between the gypsum and the fiber surface; through the above synergistic effect, the gypsum blocks will not produce brittle fracture when undergoing large deformation.

[0026] (3) Through the hydration reaction of ash and quicklime, soluble impurities such as potassium, sodium, chlorine, and fluorine in the gypsum pore solution are embedded in the hydration products; at the same time, the hydration products fill the capillaries, blocking the migration of soluble impurities; the film-forming and wrapping effect of water-based polyurethane further hinders the migration of soluble impurities; the above effects jointly solve the problem of yellowing and whitening of products caused by soluble impurities in gypsum blocks.

[0027] The method for preparing the water-resistant anti-cracking gypsum building block of the present invention has a simple process flow and is easy to implement.

[0028] Other advantages, objectives and features of the present invention will be set forth in part in the following description and, in part, will be apparent to those skilled in the art based on an examination of the following or may be taught from the practice of the present invention. DETAILED DESCRIPTION

[0029] The preferred embodiments of the present invention will be described in detail below. It should be understood that the preferred embodiments are only for illustrating the present invention, rather than for limiting the protection scope of the present invention.

[0030] The present invention provides 4 embodiments and 3 comparative examples, and the 4 embodiments and 3 comparative examples are composed of the following raw materials in parts by weight:

[0031] raw material Example 1 Example 2 Example 3 Example 4 Comparative Example 1 Comparative Example 2 Comparative Example 3 Building plaster 700 600 750 680 1000 1000 800 Ash 180 200 150 150 150 Rubber Granules 75 80 50 100 quicklime 30 40 20 30 30 Basalt fiber 15 20 10 20 Water repellent 8 10 7 5 7 5 Water reducing agent 2 3 1.5 1 1 Defoaming agent 1 2 1 0.5 0.5 Waterborne polyurethane 80 70 50 100 water 550 500 600 650 800 700 650

[0032] Comparative Example 1 is a common gypsum block, Comparative Example 2 is an internally mixed moisture-proof gypsum block, and Comparative Example 3 is a gypsum block in which the rubber particles, basalt fibers, and waterborne polyurethane components are removed from Example 4 and the amount of building gypsum is increased accordingly.

[0033] In the table:

[0034] The ash is made from power plant ash that is dried at 100°C and ground to 300 mesh.

[0035] The length of basalt fiber is 6-12mm and the diameter is 15-20um.

[0036] The rubber particle size is 20-60 mesh.

[0037] The water repellent is emulsified silicone oil.

[0038] Building gypsum is made by calcining phosphogypsum or desulfurized gypsum, with a grade of 3.0 and above.

[0039] The four embodiments and three comparative examples prepared gypsum blocks by the following methods:

[0040] (1) Prepare materials according to the above table;

[0041] (2) putting building gypsum, ash, rubber particles, quicklime and basalt fiber into a mixer and mixing them at a speed of 300 r / min for 3 min to prepare a mixed powder;

[0042] (3) putting a water repellent, a water reducing agent, a defoaming agent, a waterborne polyurethane and water into a mixer and mixing them at a speed of 1000 r / min for 2 min to prepare a uniform solution;

[0043] (4) Then pour the mixed powder into the solution and mix at a speed of 1000 r / min for 20 seconds to obtain a uniform slurry;

[0044] (5) Pour the slurry into the mold, vibrate and compact it, scrape the surface of the slurry after initial setting, demould after final setting, and then autoclave and cure it in a steam curing kettle at 100°C and 0.5MPa for 6 hours, then put it in an oven and dry it at 50 degrees to obtain gypsum blocks with a length, height and thickness of 600 mm, 250 mm and 200 mm respectively.

[0045] The obtained gypsum blocks were subjected to performance tests, and the test contents and methods were as follows:

[0046] The compressive strength is tested according to GB / T 17669.3-1999; the breaking load, 24h softening coefficient and 4d softening coefficient are tested according to JC / T698-2010; the breaking deflection is the deflection of the midpoint of the span at the moment of breaking of the specimen during the breaking load test. This index can reflect the ease of damage of the block after deformation by external force. The larger the breaking deflection, the smaller the possibility of cracking after deformation; yellowing and whitening are visually observed before testing after the specimen is dried, and are divided into none, slight and severe according to the degree of yellowing or whitening.

[0047] The above test results are listed in the following table:

[0048] project Compressive strength / MPa Breaking load / N Fracture deflection / mm 24h softening coefficient 4d softening coefficient Yellow vomiting White Example 1 13.2 13296 6.134 0.94 0.90 none none Example 2 14.8 15721 7.021 0.97 0.94 none none Example 3 11.5 11243 5.428 0.88 0.85 none none Example 4 10.4 9857 7.514 0.85 0.80 none none Comparative Example 1 3.0 3255 2.135 0.45 0.31 serious serious Comparative Example 2 5.7 6859 2.874 0.64 0.42 slight slight Comparative Example 3 11.1 12146 3.015 0.72 0.67 none slight

[0049] According to the test results in the above table:

[0050] (1) It can be seen from Examples 1-4 and Comparative Examples 1-3 that the 24h and 4d softening coefficients of the gypsum blocks of the present invention exceed 0.85 and 0.8, respectively, showing water-resistant properties, which are far superior to 0.31-0.64 of ordinary gypsum blocks and internally added moisture-proof gypsum blocks.

[0051] (2) It can be seen from Examples 1-4 and Comparative Example 3 that the synergistic effect of rubber particles, basalt fibers, and waterborne polyurethane increases the fracture deflection of gypsum by 80-130%, and the ability to resist deformation and cracking is greatly improved.

[0052] (3) It can be seen from Examples 1-4 and Comparative Examples 1-2 that ash, quicklime, water repellent, water reducing agent, and aqueous polyurethane have a significant effect on embedding and sealing soluble impurities, thus solving the problem of yellowing and whitening of the product.

[0053] The gypsum building block of the invention has water resistance to meet the use in various working conditions, avoids brittle cracking, and solves the quality problem caused by impurity migration.

[0054] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the purpose and scope of the technical solution, which should be included in the scope of the claims of the present invention.

Claims

1. A water-resistant and crack-resistant gypsum block, characterized in that: It is composed of the following raw materials in parts by weight: 600-750 parts of building gypsum, 150-200 parts of ash, 50-100 parts of rubber particles, 20-40 parts of quicklime, 10-20 parts of basalt fiber, 5-10 parts of water repellent, 1-3 parts of water reducing agent, 0.5-2 parts of defoaming agent, 50-100 parts of waterborne polyurethane, and 500-650 parts of water; the particle size of the rubber particles is 20-60 meshes.

2. A water-resistant anti-cracking gypsum block according to claim 1, characterized in that: 700 parts of building gypsum, 180 parts of ash, 75 parts of rubber particles, 30 parts of quicklime, 15 parts of basalt fiber, 8 parts of water repellent, 2 parts of water reducing agent, 1 part of defoaming agent, 80 parts of water-based polyurethane, and 550 parts of water.

3. The water-resistant anti-cracking gypsum block according to claim 1, characterized in that: The ash is obtained by drying the ash from a power plant at 100° C. and grinding it to 300 meshes.

4. The water-resistant anti-cracking gypsum block according to claim 1, characterized in that: The basalt fiber has a length of 6-12 mm and a diameter of 15-20 μm.

5. The water-resistant anti-cracking gypsum block according to claim 1, characterized in that: The water repellent is emulsified silicone oil.

6. A water-resistant, crack-resistant gypsum building block according to any one of claims 1 to 5, characterized in that: The building gypsum is prepared by calcining phosphogypsum or desulfurized gypsum.

7. A method for preparing a water-resistant, crack-resistant gypsum building block according to any one of claims 1 to 6, characterized in that: The steps include: (1) Material preparation: building gypsum, ash, rubber particles, quicklime, basalt fiber, water repellent, water reducing agent, defoaming agent, water-based polyurethane, water; (2) Mix and stir building gypsum, ash, rubber particles, quicklime and basalt fiber to form a mixed powder at a stirring speed of 300 r / min for 3 min; (3) Mix the water repellent, water reducing agent, defoaming agent, waterborne polyurethane and water to form a uniform solution at a stirring speed of 1000 r / min for 2 min; (4) Mix the mixed powder and solution to obtain a uniform slurry at a stirring speed of 1000 r / min for 20 s; (5) Pour the slurry into the mold, vibrate and compact it, scrape the surface of the slurry after initial setting, demould after final setting, then autoclave and cure at 100°C and 0.5MPa for 6h, and then dry at 50°C to obtain water-resistant and crack-resistant gypsum blocks.

8. The method for preparing a water-resistant anti-cracking gypsum building block according to claim 7, characterized in that: The mixing and stirring equipment in step (2) is a mixer; the mixing and stirring equipment in step (3) is a stirrer; the autoclave curing equipment in step (5) is an autoclave, and the drying equipment is an oven.