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CN-117985972-B - High-toughness waterproof self-repairing concrete and preparation method and application thereof

CN117985972BCN 117985972 BCN117985972 BCN 117985972BCN-117985972-B

Abstract

The invention discloses a preparation and construction process of high-toughness waterproof self-repairing concrete for a sealing layer, the high-toughness waterproof self-repairing concrete comprises fly ash, fine sand, an expanding agent, a repairing agent, heavy calcium powder, fibers, cellulose ether, dispersible latex powder, a water reducing agent, a water repellent agent, water and optional cement. The invention also provides a construction process for applying the high-toughness waterproof self-repairing concrete to the high-speed railway ballastless track sealing layer. The invention has the advantages of simple and easily obtained raw materials, high toughness, high crack resistance, ultra-water resistance, self-repairing and the like of the concrete, can be constructed in a pumping mode, and is convenient to construct.

Inventors

  • SUN HONGBIN
  • PENG XUETAO
  • ZHENG YONG
  • ZHAO GUANG
  • Fang Xuannian
  • JIANG JINFENG
  • ZHANG YANRONG
  • GAO LIANG
  • ZHANG HAITAO
  • ZHA BENYI
  • WANG BAOKAI
  • ZHANG XUESONG
  • WANG XIAOYU

Assignees

  • 山东铁路投资控股集团有限公司
  • 北京交通大学
  • 中铁四局集团有限公司
  • 中铁大桥局集团第二工程有限公司
  • 中铁十局集团有限公司青岛分公司

Dates

Publication Date
20260512
Application Date
20240104

Claims (12)

  1. 1. The high-toughness waterproof self-repairing concrete for the high-speed railway sealing layer is characterized by comprising, by weight, 250-350 parts of fly ash, 500-600 parts of fine sand, 30-40 parts of an expanding agent, 50-100 parts of a repairing agent, 200-300 parts of heavy calcium powder, 10-20 parts of fiber, 0.1-0.2 part of cellulose ether, 10-20 parts of dispersible emulsion powder, 10-20 parts of a water reducer, 10-20 parts of a hydrophobing agent, 200-300 parts of water and 500-600 parts of cement; The expanding agent is one or more selected from calcium oxide expanding agent, magnesium oxide expanding agent or calcium sulfoaluminate expanding agent; The fibers are selected from polyvinyl alcohol fibers; The hydrophobizing agent is selected from organosilicon emulsion hydrophobizing agents; the repairing agent is selected from cement particle microcapsules.
  2. 2. The concrete according to claim 1, wherein the concrete comprises, by weight, 280-330 parts of fly ash, 530-580 parts of fine sand, 33-38 parts of an expanding agent, 65-90 parts of a repairing agent, 230-280 parts of heavy calcium powder, 13-18 parts of fiber, 0.13-0.18 part of cellulose ether, 13-18 parts of dispersible latex powder, 13-18 parts of a water reducer, 13-18 parts of a hydrophobizing agent, 230-280 parts of water and 530-580 parts of cement.
  3. 3. The concrete according to claim 1, wherein the concrete comprises, by weight, 290-310 parts of fly ash, 540-560 parts of fine sand, 34-36 parts of an expanding agent, 70-80 parts of a repairing agent, 240-260 parts of heavy calcium powder, 14-16 parts of fibers, 0.14-0.16 part of cellulose ether, 14-16 parts of dispersible latex powder, 14-16 parts of a water reducing agent, 14-16 parts of a hydrophobizing agent, 240-260 parts of water and 540-560 parts of cement.
  4. 4. A concrete according to any one of claims 1 to 3, wherein the fly ash is selected from the group consisting of class F fly ash, and/or The fine sand is selected from natural fine sand, and/or The heavy calcium powder is selected from calcium carbonate powder, and/or The fibers have a length of 5-20mm, a diameter of 30-45 μm, and/or The cellulose ether is selected from one or more of hydroxypropyl methylcellulose, methyl cellulose ether and hydroxyethyl cellulose ether, and/or The water reducer is selected from one or more of naphthalene water reducer or polycarboxylate water reducer, and/or The cement is selected from one or more of ordinary silicate cement, early strength silicate cement or sulphoaluminate cement.
  5. 5. The concrete according to claim 4, wherein the fine sand has a fineness modulus of 1.6 to 2.2 and a mud content of 3 wt.% or less, and/or The particle size of the heavy calcium powder is less than 0.045mm, the content of calcium carbonate is more than or equal to 98%, and/or The polycarboxylate water reducer is a polyether polycarboxylate water reducer.
  6. 6. The method for preparing concrete according to any one of claims 1 to 5, comprising mixing fly ash, fine sand, an expanding agent, a repairing agent, heavy calcium powder, fibers, cellulose ether, dispersible latex powder, a water reducing agent, a water repellent, water and cement.
  7. 7. A method of constructing a high speed railway closure comprising casting the concrete of any one of claims 1 to 5 to the high speed railway closure.
  8. 8. The construction method according to claim 7, wherein the concrete is poured into the area to be poured of the high-speed railway ballastless track sealing layer.
  9. 9. The method of construction according to claim 7 or 8, further comprising curing the poured concrete.
  10. 10. The construction method according to claim 9, wherein the curing is performed within 12 hours of completing the pouring.
  11. 11. The method of claim 9, wherein the maintenance time is 28 days.
  12. 12. Use of the concrete of any one of claims 1 to 5 or the concrete obtained by the preparation method of claim 6 or the construction method of any one of claims 7 to 11 in a high-speed railway closure.

Description

High-toughness waterproof self-repairing concrete and preparation method and application thereof Technical Field The invention relates to the field of waterproof sealing layers of ballastless tracks of high-speed railways, in particular to a preparation and construction process of high-toughness waterproof self-repairing concrete for a sealing layer. Background The high-speed railway of China is developed rapidly, the ballastless track line roadbed sealing layer can effectively prevent rainwater from invading, and the strength and stability of the roadbed bed and the smoothness and durability of the track structure are guaranteed. The concrete is used as a main sealing layer material, the brittleness and the drying shrinkage of the traditional concrete enable the traditional concrete to easily generate cracks during service, an expansion joint is arranged at intervals of 4m-6m in engineering to reduce the occurrence of cracking failure diseases of a waterproof sealing layer caused by the shrinkage of the concrete, but when the temperature in summer is higher, the sealing material is partially melted and then extruded out of the expansion joint, or cracking phenomena can occur when asphalt caulking materials are used in winter, the sealing material fails, the sealing waterproof function of the sealing material is lost, water enters into the surface layer of a foundation bed, a dynamic water pressure is formed under the repeated action of dynamic load of a high-speed train, and the ballastless track bed or the surface layer of the foundation bed is caused to be turned into slurry. And the traditional sealing layer is arranged between the road shoulder and the line of the road bed surface layer, and the joint between the traditional sealing layer and the base plate is also a weak area. In order to reduce the problem of waterproof failure of the sealing layer caused by expansion joints and seams, patent CN 215518173U proposes a full-section sealing layer structure, namely, a sealing layer structure is paved on the full section of the surface layer of the roadbed, so that the problems of a base plate, a vertical surface seam of a structure and the like are avoided, and fiber concrete doped with super-hydrophobic agent is adopted as a rigid waterproof layer. However, the cracking phenomenon still occurs in the service process of the fiber concrete, the skylight of the high-speed railway has short time, the disease repair time is short, the passive repair difficulty is high, and the active self-repair material can save maintenance cost and repair internal cracks and microcracks. Therefore, the development of the concrete for the sealing layer has the advantages of high toughness, crack resistance, water resistance and self-repairing performance, simple operation, convenient construction and low cost. Disclosure of Invention The invention aims to provide high-toughness high-crack-resistance ultra-waterproof self-repairing concrete, a preparation method thereof and a construction process applied to a high-speed railway ballastless track sealing layer. In order to achieve the above purpose, the invention adopts the following technical scheme: in a first aspect, the present invention provides a high toughness waterproof self-repairing concrete comprising fly ash, fine sand, an expanding agent, a repairing agent, heavy calcium powder, fibers, cellulose ether, dispersible latex powder, a water reducing agent, a water repellent, water and optionally cement. In the concrete, the repairing agent is a repairing capsule, the repairing agent in a capsule form is doped, after the concrete is cracked, the capsule wall of the repairing capsule is cracked, and core materials such as microorganisms or cement are exposed at the crack to form inorganic salt or generate hydration products to fill the crack, so that the effect of repairing the crack is achieved. In the concrete, the fly ash is doped to play a filling effect, a grading effect and a later pozzolan effect in the cement stone, so that the method is beneficial to refining the pore structure of the later cement stone, improving the microstructure and improving the mechanical strength and durability. According to the concrete disclosed by the invention, the expansion agent is doped, so that the shrinkage of the concrete can be reduced, the generation of cracks is reduced, the expansion agent reacts with water to generate crystals such as ettringite, calcium hydroxide and the like, the pores can be filled, the early strength is improved, the shrinkage of the concrete caused by temperature, humidity change and the like in the early stage is compensated, the early cracking of the concrete is restrained, and the repair agent is promoted to repair the cracks better. The heavy calcium powder is added into the concrete, so that the toughness and strength of the concrete can be improved, and the production cost is reduced. According to the concrete disclosed by the invention, the wa