Preparation method of fiber shrinkage-compensating concrete

Abstract

The invention relates to the technical field of concrete preparation methods, and discloses a fiber shrinkage-compensating concrete preparation method which comprises the following preparation steps: 1) pouring aggregate into a stirring barrel, and adding a fiber material in the stirring process to form a primary mixture; 2) adding cement, fly ash, an expanding agent and the primary mixture into the stirring barrel, and mixing to form a secondary mixture; (3) adding a water reducing agent, a water body and the secondary mixed material into the stirring barrel, mixing to form fiber-compensating shrinkage concrete, and spraying the water body into the concrete in multiple directions in the stirring and mixing process; through a step-by-step stirring mode, the fibers are uniformly distributed in the concrete, the fiber agglomeration phenomenon is avoided, and meanwhile, through a stirring mode that water is sprayed into the fiber compensation shrinkage concrete in multiple directions, the mixing uniformity of the concrete is optimized, the binding force of the fibers and the concrete is enhanced, and the stress is effectively dispersed; the anti-cracking performance of the concrete is obviously improved.

Description

Technical Field

[0001] This invention patent relates to the technical field of concrete preparation methods, specifically, to a preparation method of fiber compensated shrinkage concrete. Background Art

[0002] Traditional concrete crack resistance measures mainly focus on aspects such as material selection, mix ratio optimization, and construction process control. For example, by reducing the water-binder ratio and adding mineral admixtures to improve the compactness and durability of concrete, thereby reducing the generation of cracks.

[0003] In recent years, with the development of concrete technology, by adding steel fibers, polymer fibers, etc. to concrete, the toughness and crack resistance of concrete can be effectively improved.

[0004] In the prior art, although the crack resistance performance of fiber compensated shrinkage concrete has been improved, the uniformity of fiber distribution and the dosage control of the expansion agent are still technical bottlenecks. Because fibers are prone to agglomeration, resulting in uneven mixing and affecting the overall performance of concrete. It is difficult to precisely control the addition timing and mixing uniformity of the expansion agent, resulting in uneven internal stress distribution of concrete.

[0005] In addition, in the prior art, the concrete mixing process, material ratio, as well as the control of temperature and humidity, fail to meet the requirements for improving the crack resistance performance of concrete. Summary of the Invention

[0006] The purpose of this invention is to provide a preparation method of fiber compensated shrinkage concrete, aiming to solve the problem of poor crack resistance performance of concrete in the prior art.

[0007] This invention is realized as follows. The preparation method of fiber compensated shrinkage concrete includes the following preparation steps:

[0008] 1), Pour the aggregate into the mixing drum and stir and mix. During the process of stirring the aggregate, add the fiber material into the mixing drum, and the fiber material and the aggregate are stirred and mixed to form a primary mixture.

[0009] 2), Add cement, fly ash, and expansion agent into the mixing drum. The cement, fly ash, expansion agent, and the primary mixture are stirred and mixed to form a secondary mixture.

[0010] 3), Add water reducing agent and water into the mixing drum. The water reducing agent, water, and the secondary mixture are stirred and mixed to form fiber compensated shrinkage concrete; during the stirring and mixing process of the fiber compensated shrinkage concrete, water is sprayed into the interior of the fiber compensated shrinkage concrete in multiple directions.

[0011] Further, in the preparation step 1), the aggregate includes crushed stone material and sand material. After the crushed stone material and the sand material are premixed, they are added to the mixing drum.

[0012] Further, in the preparation step 1), the aggregate is sequentially washed, screened, and dried, and then added to the mixing drum.

[0013] Further, in the preparation step 1), the fiber material is polypropylene mesh fiber.

[0014] Further, in the preparation step 2), during the stirring and mixing of the primary mixture, cement, fly ash, and an expansive agent are sequentially added to the mixing drum.

[0015] Further, in the preparation step 2), the expansive agent is a powder material, and the expansive agent contains calcium sulfoaluminate and calcium oxide.

[0016] Further, in the preparation step 3), the water reducing agent is a polycarboxylate retarder water reducing agent.

[0017] Further, in the preparation step 3), the water reducing agent is a liquid material, and the solid content in the water reducing agent is between 13% and 16%.

[0018] Further, the interior of the mixing drum has a mixing chamber. A stirring shaft arranged longitudinally is provided in the mixing chamber. A plurality of stirring blades extend outward from the outer periphery of the stirring shaft. The plurality of stirring blades are arranged at intervals along the circumferential direction of the stirring shaft and are arranged in a staggered manner along the axial direction of the stirring shaft. The inner ends of the stirring blades are butted against the stirring shaft, and the outer ends of the stirring blades extend outward in a multi-segment curved manner away from the stirring shaft.

[0019] A water spray pipe is wound around the outer periphery of the stirring blade. The water spray pipe is arranged in a multi-segment spiral manner along the circumferential direction of the stirring blade and is attached to the outer surface of the stirring blade. A plurality of water spray nozzles are provided on the water spray pipe. The plurality of water spray nozzles are arranged at intervals along the axial direction of the water spray pipe. An internal water pipe is provided inside the stirring shaft. The internal water pipe is communicated with a water pump and is communicated with the plurality of water spray pipes.

[0020] The bottom of the mixing drum is connected to a rotating table arranged to rotate. The mixing drum is eccentrically connected to the rotating table and is rotationally connected to the rotating table. The rotation direction of the rotating table is different from the rotation direction of the stirring shaft. When the rotating table rotates, it drives the mixing drum to rotate eccentrically, and the mixing drum rotates synchronously relative to the rotating table.

[0021] When the stirring shaft rotates, the rotating table rotates synchronously; in the preparation step 3), when the stirring shaft rotates and drives a plurality of stirring blades to stir the fiber compensated shrinkage concrete, the water pump injects high-pressure water into a plurality of water spray pipes through an internal water pipe, and the high-pressure water sprays water bodies in multiple directions inside the fiber compensated shrinkage concrete through a plurality of water spray ports.

[0022] Further, the inner side of the mixing drum has an inner side wall facing the mixing cavity, and a plurality of annular tracks are convexly arranged on the inner side wall. The plurality of annular tracks are arranged at intervals along the height direction of the mixing cavity, and the annular tracks are arranged in a circumferential direction around the mixing cavity;

[0023] A rotating block is connected to the annular track. Scraping wall pieces extend from the top and bottom of the rotating block respectively. Elastic scraping wall sides are provided on the scraping wall pieces, and the scraping wall sides are abutted against the inner side wall; during the synchronous rotation of the mixing drum with the rotating table, the rotating block moves along the annular track, and the scraping wall sides elastically scrape the inner side wall.

[0024] Compared with the prior art, the fiber compensated shrinkage concrete preparation method provided by the present invention, through a step-by-step stirring method, first mixes the fiber material with the aggregate to form a preliminary mixture, and then sequentially adds cement, fly ash, expansion agent, water reducing agent and water body, so that the fibers are evenly distributed in the concrete, avoiding the phenomenon of fiber agglomeration, thereby improving the overall performance of the concrete;

[0025] At the same time, the stirring method of spraying water bodies into the fiber compensated shrinkage concrete in multiple directions optimizes the mixing uniformity of the concrete, enhances the bonding force between the fibers and the concrete, effectively disperses the stress, and significantly improves the crack resistance of the concrete;

[0026] In addition, the addition of the expansion agent can generate pre-compressive stress during the hardening process of the concrete, thereby offsetting the internal tensile stress, compensating for the shrinkage deformation of the concrete, and at the same time playing a role in filling pores and improving the compactness of the concrete, thereby further enhancing the crack resistance of the concrete. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 is a schematic flow chart of the fiber compensated shrinkage concrete preparation method provided by the present invention;

[0028] Figure 2 is a schematic structural diagram of the stirring shaft provided by the present invention;

[0029] Figure 3 is a schematic structural diagram of the mixing cavity and the annular track provided by the present invention;

[0030] Figure 4 is a schematic structural diagram of the annular track provided by the present invention;

[0031] In the figure: stirring shaft 100, stirring blade 101, water spraying pipe 102, internal water pipe 103, stirring cylinder 104, annular track 200, rotating block 201, wall scraping blade 202, stirring chamber 203, rotating table 204, linkage block 205, inner side wall 206. Detailed implementation manners

[0032] In order to make the objectives, technical solutions and advantages of the present invention clearer and more understandable, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0033] The implementation of the present invention will be described in detail below with reference to specific embodiments.

[0034] In the accompanying drawings of this embodiment, the same or similar reference numerals correspond to the same or similar components; in the description of the present invention, it should be understood that if there are terms such as "upper", "lower", "left", "right", etc. indicating the orientation or positional relationship, they are based on the orientation or positional relationship shown in the accompanying drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, the terms describing the positional relationship in the accompanying drawings are only for illustrative purposes and cannot be understood as a limitation of this patent. For those of ordinary skill in the art, the specific meanings of the above terms can be understood according to specific circumstances.

[0035] Refer to Figures 1-4 As shown, it is a preferred embodiment provided by the present invention.

[0036] The preparation method of fiber compensated shrinkage concrete includes the following preparation steps:

[0037] 1), Pour the aggregate into the stirring cylinder 104 for stirring and mixing. During the stirring of the aggregate, add the fiber material into the stirring cylinder 104, and the fiber material and the aggregate are stirred and mixed to form a primary mixture.

[0038] 2), Add cement, fly ash and expansion agent into the stirring cylinder 104, and the cement, fly ash, expansion agent and the primary mixture are stirred and mixed to form a secondary mixture.

[0039] 3), Add water reducing agent and water body into the stirring cylinder 104, and the water reducing agent, water body and the secondary mixture are stirred and mixed to form fiber compensated shrinkage concrete; during the stirring and mixing process of the fiber compensated shrinkage concrete, spray the water body in multiple directions inside the fiber compensated shrinkage concrete.

[0040] The fiber compensated shrinkage concrete preparation method provided above, the fiber compensated shrinkage concrete preparation method, through the way of step-by-step mixing, first mixes the fiber material with the aggregate to form a preliminary mixture, and then successively adds cement, fly ash, expansion agent, water reducing agent and water body, so that the fibers are evenly distributed in the concrete, avoiding the phenomenon of fiber agglomeration, thereby improving the overall performance of the concrete;

[0041] At the same time, the mixing method of spraying water body into the fiber compensated shrinkage concrete in multiple directions optimizes the mixing uniformity of the concrete, enhances the bonding force between the fibers and the concrete, effectively disperses the stress, and significantly improves the crack resistance of the concrete;

[0042] In addition, the addition of the expansion agent can generate pre-compressive stress during the hardening process of the concrete, thereby offsetting the internal tensile stress, compensating for the shrinkage deformation of the concrete, and at the same time playing the role of filling pores and improving the compactness of the concrete, thereby further enhancing the crack resistance of the concrete.

[0043] In this embodiment, in preparation step 1), the aggregate includes crushed stone material and sand material. After the crushed stone material and the sand material are pre-mixed, they are added to the mixing drum 104.

[0044] In this way, the crushed stone material and the sand material are more evenly distributed during the mixing process, thereby improving the overall uniformity and compactness of the concrete, and providing a good foundation for the subsequent mixing of fibers and aggregates.

[0045] In this embodiment, in preparation step 1), the aggregate is successively washed, screened and dried, and then added to the mixing drum 104.

[0046] The aggregate that has been washed and screened can remove impurities and fine particles, reduce the weak points inside the concrete, and improve the strength and durability of the concrete. The dried aggregate can ensure that the water-cement ratio of the concrete is more accurate, avoiding the performance fluctuation of the concrete caused by inconsistent water content of the aggregate, thereby effectively improving the crack resistance of the concrete.

[0047] In this embodiment, in preparation step 1), the fiber material is polypropylene mesh fiber.

[0048] The polypropylene mesh fiber has the characteristics of high strength, high elastic modulus and good hydrophilicity, etc., and can effectively prevent the generation of shrinkage cracks in the concrete, improve the mechanical properties and durability of the concrete;

[0049] Coupled with its good dispersibility and toughness, it can form a three-dimensional network structure inside the concrete, effectively disperse the stress, and prevent the expansion of cracks, thereby realizing a significant improvement in the crack resistance of the concrete.

[0050] In this embodiment, in preparation step 2), during the stirring and mixing of the preliminary mixture, cement, fly ash, and expansive agent are sequentially added into the mixing drum 104.

[0051] By adding in steps, it can ensure that each component is fully mixed during stirring, avoiding uneven stirring caused by adding all at once; the synergistic effect of cement and fly ash can improve the compactness of concrete, while the expansive agent can generate pre-compressive stress during the hardening process of concrete to compensate for the shrinkage of concrete, thereby further enhancing the crack resistance of concrete.

[0052] In this embodiment, in preparation step 2), the expansive agent is a powder material, and the expansive agent contains calcium sulfoaluminate and calcium oxide.

[0053] The combined action of calcium sulfoaluminate and calcium oxide causes the concrete to expand moderately during the hardening process, forming pre-compressive stress, effectively compensating for the shrinkage of concrete, and reducing the generation of cracks.

[0054] In this embodiment, in preparation step 3), the water reducing agent is a polycarboxylate retarder water reducing agent.

[0055] Using the polycarboxylate retarder water reducing agent can reduce the water consumption during the concrete mixing process, while delaying the hydration reaction rate of cement, improving the workability and fluidity of concrete, and helping to reduce the autogenous shrinkage of concrete.

[0056] In this embodiment, in preparation step 3), the water reducing agent is a liquid material, and the solid content in the water reducing agent is between 13% and 16%.

[0057] This water reducing agent with such a solid content can ensure the water reducing effect while avoiding the problems of concrete segregation and bleeding caused by too high a concentration of the water reducing agent, further optimizing the uniformity and crack resistance of concrete.

[0058] In this embodiment, the inside of the mixing drum 104 has a mixing chamber 203. A stirring shaft 100 arranged longitudinally is provided in the mixing chamber 203. A plurality of stirring blades 101 extend outward from the outer periphery of the stirring shaft 100. The plurality of stirring blades 101 are arranged at intervals along the circumferential direction of the stirring shaft 100 and are arranged in a staggered manner along the axial direction of the stirring shaft 100; the inner ends of the stirring blades 101 are butted against the stirring shaft 100, and the outer ends of the stirring blades 101 extend outward in multiple sections with a bend away from the stirring shaft 100;

[0059] A water spraying pipe 102 is wound around the outer periphery of the stirring blade 101. The water spraying pipe 102 is arranged in multiple sections in a spiral manner along the circumferential direction of the stirring blade 101 and is attached to the outer surface of the stirring blade 101; a plurality of water spraying nozzles are provided on the water spraying pipe 102, and the plurality of water spraying nozzles are arranged at intervals along the axial direction of the water spraying pipe 102; an internal water pipe 103 is provided inside the stirring shaft 100. The internal water pipe 103 is communicated with a water pump and is communicated with the plurality of water spraying pipes 102;

[0060] The bottom of the mixing drum 104 is connected to the rotatable turntable 204. The mixing drum 104 is eccentrically connected to the turntable 204 and is rotatably connected to the turntable 204. The rotation direction of the turntable 204 is different from the rotation direction of the mixing shaft 100. When the turntable 204 rotates, it drives the mixing drum 104 to rotate eccentrically, and the mixing drum 104 rotates synchronously relative to the turntable 204.

[0061] When the mixing shaft 100 rotates, the turntable 204 rotates synchronously. In the preparation step 3), when the mixing shaft 100 rotates and drives the plurality of mixing blades 101 to stir the fiber compensated shrinkage concrete, the water pump injects high-pressure water into the plurality of spray pipes 102 through the internal water pipe 103, and the high-pressure water jets the water body in multiple directions inside the fiber compensated shrinkage concrete through the plurality of spray nozzles.

[0062] Through the multi-segment bending design and staggered arrangement of the mixing blades 101, the concrete is subjected to shear forces in multiple directions during the mixing process, optimizing the mixing effect of fibers with components such as aggregates and cement.

[0063] By jetting high-pressure water in multiple directions inside the concrete through the plurality of spray nozzles, it can effectively prevent fiber agglomeration, promote the uniform progress of cement hydration reaction at the same time, reduce the porosity and defects inside the concrete, not only improve the compactness of the concrete, but also enhance the bonding force between the fibers and the concrete, thereby effectively dispersing stress and enhancing the crack resistance of the concrete.

[0064] In this embodiment, a linkage block 205 is eccentrically connected between the mixing drum 104 and the turntable. The linkage block 205 is arranged deviating from the central position between the mixing drum 104 and the turntable. Or, in other embodiments, other eccentric connection methods can be set to eccentrically connect the mixing drum 104 and the turntable.

[0065] Driving the mixing drum 104 to rotate eccentrically through the eccentric connection enables a larger rotation range of the mixing drum 104, which helps the concrete to be stirred and mixed more evenly during the process of stirring the fiber compensated shrinkage concrete, and enhances the bonding force between the fibers and the concrete.

[0066] In this embodiment, the inner side of the mixing drum 104 has an inner side wall facing the mixing chamber 203. A plurality of annular tracks 200 are convexly provided on the inner side wall. The plurality of annular tracks 200 are arranged at intervals along the height direction of the mixing chamber 203, and the annular tracks 200 are arranged in a circumferential direction around the mixing chamber 203.

[0067] A rotating block 201 is connected to the annular track 200. Scraping wall pieces 202 extend from the top and bottom of the rotating block 201 respectively. Elastic scraping wall sides are provided on the scraping wall pieces 202, and the scraping wall sides are abutted against the inner side wall. During the synchronous rotation of the mixing drum 104 with the rotating table 204, the rotating block 201 moves along the annular track 200, and the scraping wall sides elastically scrape the inner side wall.

[0068] Through the scraping wall device inside the mixing drum 104, the residual concrete adhering to the inner wall of the mixing drum 104 during the mixing process can be effectively removed. The cooperation of the annular track 200 and the rotating block 201 enables the scraping wall piece 202 to move along the track as the mixing drum 104 rotates. The elastic setting of the scraping wall sides ensures the softness and high efficiency of the scraping wall process.

[0069] In this way, not only the agglomeration of concrete during the mixing process is prevented, but also the mixing dead corners are reduced. By continuously removing the residues on the inner wall, the mixing process becomes smoother, the mixing quality of the concrete is improved, thereby indirectly improving the crack resistance of the concrete and ensuring that the concrete always maintains good workability during the mixing process.

[0070] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A preparation method of fiber compensated shrinkage concrete, characterized in that It includes the following preparation steps: 1), Pour the aggregate into the mixing drum and mix. During the mixing of the aggregate, add fiber material into the mixing drum. The fiber material and the aggregate are mixed to form a primary mixture. 2), Add cement, fly ash and expansion agent into the mixing drum. The cement, fly ash, expansion agent and the primary mixture are mixed to form a secondary mixture. 3), Add water reducing agent and water into the mixing drum. The water reducing agent, water and the secondary mixture are mixed to form fiber compensated shrinkage concrete. During the mixing process of the fiber compensated shrinkage concrete, water is sprayed into the interior of the fiber compensated shrinkage concrete in multiple directions.

2. The preparation method of fiber compensated shrinkage concrete according to claim 1, characterized in that, In the preparation step 1), the aggregate includes crushed stone and sand. After the crushed stone and sand are pre-mixed, they are added into the mixing drum.

3. The preparation method of fiber compensated shrinkage concrete according to claim 1, characterized in that, In the preparation step 1), the aggregate is sequentially washed, screened and dried, and then added into the mixing drum.

4. The preparation method of fiber compensated shrinkage concrete according to any one of claims 1-3, characterized in that, In the preparation step 1), the fiber material is polypropylene mesh fiber.

5. The preparation method of fiber compensated shrinkage concrete according to any one of claims 1-3, characterized in that, In the preparation step 2), during the mixing process of the primary mixture, cement, fly ash and expansion agent are sequentially added into the mixing drum.

6. The preparation method of fiber compensated shrinkage concrete according to claim 5, characterized in that, In the preparation step 2), the expansion agent is a powder material, and the expansion agent contains calcium sulfoaluminate and calcium oxide.

7. The preparation method of fiber compensated shrinkage concrete according to any one of claims 1-3, characterized in that, In the preparation step 3), the water reducing agent is polycarboxylate retarder water reducing agent.

8. The preparation method of fiber compensated shrinkage concrete according to claim 7, characterized in that, In the preparation step 3), the water reducing agent is a liquid material, and the solid content in the water reducing agent is between 13% and 16%.

9. The preparation method of fiber compensated shrinkage concrete according to any one of claims 1-3, characterized in that, The interior of the mixing drum has a mixing chamber. A mixing shaft arranged longitudinally is provided in the mixing chamber. A plurality of mixing blades extend outward from the outer periphery of the mixing shaft. The plurality of mixing blades are arranged at intervals along the circumferential direction of the mixing shaft and are arranged in a staggered manner along the axial direction of the mixing shaft. The inner end of the mixing blade is butted against the mixing shaft, and the outer end of the mixing blade extends outward in multiple sections and bends away from the mixing shaft. A water spraying pipe is wound around the outer periphery of the mixing blade. The water spraying pipe is arranged in multiple sections and spirally along the circumferential direction of the mixing blade and is attached to the outer surface of the mixing blade. A plurality of water spraying nozzles are provided on the water spraying pipe. The plurality of water spraying nozzles are arranged at intervals along the axial direction of the water spraying pipe. An internal water pipe is provided inside the mixing shaft. The internal water pipe is communicated with a water pump and is communicated with a plurality of water spraying pipes. The bottom of the mixing drum is connected to a rotating table arranged in a rotating manner. The mixing drum is eccentrically connected to the rotating table and is rotationally connected to the rotating table. The rotating direction of the rotating table is different from the rotating direction of the mixing shaft. When the rotating table rotates, it drives the mixing drum to rotate eccentrically, and the mixing drum rotates synchronously relative to the rotating table. When the mixing shaft rotates, the rotating table rotates synchronously. In the preparation step 3), when the mixing shaft rotates and drives a plurality of mixing blades to mix the fiber compensated shrinkage concrete, the water pump injects high-pressure water into a plurality of water spraying pipes through the internal water pipe, and the high-pressure water sprays water into the interior of the fiber compensated shrinkage concrete in multiple directions through a plurality of water spraying nozzles.

10. The preparation method of fiber compensated shrinkage concrete according to any one of claims 1 to 3, characterized in that, The inner side of the mixing drum has an inner-facing wall arranged towards the mixing chamber. A plurality of annular tracks are convexly provided on the inner-facing wall. The plurality of annular tracks are arranged at intervals along the height direction of the mixing chamber, and the annular tracks are arranged in a circumferential direction around the mixing chamber; A rotating block is connected to the annular track. Scraping blades extend respectively from the top and bottom of the rotating block. Elastic scraping blade sides are provided on the scraping blades, and the scraping blade sides are abutted against the inner-facing wall; during the synchronous rotation of the mixing drum with the rotating table, the rotating block moves along the annular track, and the scraping blade sides elastically scrape the inner-facing wall.

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