CN-121974639-A - Composite material for minimally invasive active repair of concrete cracks, preparation method and repair method

CN121974639ACN 121974639 ACN121974639 ACN 121974639ACN-121974639-A

Abstract

The invention provides a composite material for minimally invasive active repair of concrete cracks, a preparation method and a repair method, and relates to the technical field of concrete repair, wherein the composite material comprises, by mass, 100 parts of cement-based cementing materials, 20-40 parts of functional aggregates, 40-100 parts of fine aggregates, 0-2.5 parts of fibers, 20-30 parts of polymer latex, 0.5-0.8 part of water-retaining agents, 0.2-1.2 parts of water reducers and 18-25 parts of water; the functional aggregate is porous ceramsite or expanded perlite fine powder with lithium silicate and pH response releasing agent loaded in the internal pores. The invention has the beneficial effects of systematically solving the core defects of weak repairing interface, uncontinuous performance, invalidity to anhydrous cracks and lack of active intervention capability in the prior art.

Inventors

REN ZUNCHAO
LIN FENG
CHENG FEI
XU ZHENHAI
LI SHUJUN
CUI LEI
Jiao Maopeng
ZHANG AIJUN
ZHANG GUOHUI

Assignees

中建八局第一建设有限公司

Dates

Publication Date: 20260505
Application Date: 20260121

Claims (10)

1. The composite material for minimally invasive active repair of the concrete cracks is characterized by comprising the following components in parts by weight: 100 parts of cement-based cementing material, 20-40 parts of functional aggregate, 40-100 parts of fine aggregate, 0-2.5 parts of fiber, 20-30 parts of polymer latex, 0.5-0.8 part of water-retaining agent, 0.2-1.2 parts of water reducer and 18-25 parts of water; The functional aggregate is porous ceramsite or expanded perlite fine powder loaded with lithium silicate and pH response releasing agent in the internal pores.
2. The composite material for minimally invasive active repair of concrete cracks according to claim 1, wherein the cement-based cementitious material is rapid hardening sulfoaluminate cement; the fine aggregate is one or more of quartz sand, superfine quartz powder and silica fume; The water-retaining agent is hydroxypropyl methyl cellulose ether; the water reducer is a polycarboxylic acid water reducer.
3. The composite material for minimally invasive active repair of concrete cracks according to claim 1, wherein the fibers are polypropylene fibers or polyvinyl alcohol fibers.
4. The composite material for minimally invasive active repair of concrete cracks according to claim 1, wherein the polymer latex is silicone-acrylic emulsion and/or redispersible latex powder.
5. The composite material for minimally invasive active repair of concrete cracks according to claim 1, wherein the porous ceramsite has a porosity of 40-60% and a particle size of 100-120 mesh; the pH response releasing agent is sodium citrate or potassium tartrate.
6. The composite material for minimally invasive active repair of concrete cracks according to claim 1, wherein the loading of lithium silicate in the functional aggregate is 10-18% of the mass of the porous ceramic particles, and the loading of the pH responsive release agent is 5-8% of the mass of the porous ceramic particles.
7. A method for preparing the composite material for minimally invasive active repair of concrete cracks according to claim 1, comprising the following steps: Step A, preparing functional aggregate, namely placing porous ceramic powder into a vacuum container, and adsorbing mixed active substances containing lithium silicate and a pH response releasing agent into ceramic pores in a vacuum state to obtain the functional aggregate with the preloaded active substances; step B, dry mixing, namely adding the cement-based cementing material, the functional aggregate prepared in the step A, the fine aggregate, the water-retaining agent and the fiber into a mixer, and carrying out dry mixing for 2-5 minutes until the materials are uniformly mixed; And C, wet mixing, namely sequentially adding polymer latex, a water reducing agent and water into the dry mixture prepared in the step B, and mechanically stirring for 3-8 minutes to obtain the composite material.
8. A repair method based on the composite material for minimally invasive active repair of concrete cracks according to claim 1, characterized by comprising the following steps: step one, minimally invasive slotting, namely cutting an inverted trapezoid slot along the center of a crack by using a diamond saw blade; Step two, preparing interface slurry; step three, interface treatment, namely uniformly brushing the prepared interface catalytic slurry on concrete basal planes in the groove and on two sides; filling and reinforcing, namely filling the composite material into the groove; and fifthly, expanding covering and curing, namely immediately carrying out cross brushing on two sides of the notch by using the same composite material, and covering a water-retaining curing film after finishing the cross brushing, so as to keep moist.
9. The repair method of the composite material for minimally invasive active repair of concrete cracks according to claim 8, wherein the preparation method of the interfacial catalysis slurry is as follows: step a, dissolving calcium nitrate in deionized water, and stirring until the calcium nitrate is completely dissolved; step b, slowly adding the solution prepared in the step a into the nano silicon dioxide sol under the stirring state; and c, adding an organosilicon penetrant into the product prepared in the step b, and continuously stirring to obtain uniform and transparent interfacial catalysis slurry.
10. The method for repairing composite material for minimally invasive active repair of concrete cracks according to claim 8, wherein in the fourth step, the composite material is filled into the groove, and the method is divided into two layers: Filling the first layer to a depth of about 8mm, and lightly vibrating with a vibrating rod; and filling the second layer to be level with the notch, paving an electrode plate on the surface of the repair area, switching on a pulse power supply, and applying a direct current pulse electric field for 2-5 minutes.

Description

Composite material for minimally invasive active repair of concrete cracks, preparation method and repair method Technical Field The invention relates to the technical field of concrete repair, in particular to a composite material for minimally invasive active repair of concrete cracks, a preparation method and a repair method. Background At present, concrete crack treatment mainly depends on passive technologies such as chemical grouting, surface plugging and the like, and has three major industry pain points, namely that a repairing body is only physically bonded with a concrete matrix, the interface is weak and easy to peel, the repairing behavior is not sustainable and cannot cope with later microcrack expansion, and an effective prevention means is lacking for potential cracks which are not penetrated. The closest prior art such as crystalline waterproof material (CN 202111375061.2) can generate crystals blocking pores, but is only suitable for structural surface operation and is ineffective for drying tiny microcracks, while the expanded waterproof polyurethane material (CN 201510167073.4) only optimizes physical properties and lacks a long-acting self-repairing mechanism. How to solve the technical problems is the subject of the present invention. Disclosure of Invention In order to solve the defects of the prior art, the invention provides a composite material for minimally invasive active repair of concrete cracks, a preparation method and a repair method, which systematically solve the core defects of weak repair interface, uncontinuous performance, invalidity to anhydrous cracks and lack of active intervention capability in the prior art. The invention provides a composite material for minimally invasive active repair of concrete cracks, which is characterized by comprising the following components in parts by mass: 100 parts of cement-based cementing material, 20-40 parts of functional aggregate, 40-100 parts of fine aggregate, 0-2.5 parts of fiber, 20-30 parts of polymer latex, 0.5-0.8 part of water-retaining agent, 0.2-1.2 parts of water reducer and 18-25 parts of water; The functional aggregate is porous ceramsite or expanded perlite fine powder loaded with lithium silicate and pH response releasing agent in the internal pores. The cement-based cementing material is quick hardening sulphoaluminate cement; the fine aggregate is one or more of quartz sand, superfine quartz powder and silica fume; The water-retaining agent is hydroxypropyl methyl cellulose ether; the water reducer is a polycarboxylic acid water reducer. The fibers are polypropylene fibers or polyvinyl alcohol fibers. The polymer emulsion is silicone-acrylic emulsion and/or redispersible emulsion powder. The porosity of the porous ceramsite is 40-60%, and the particle size is 100-120 meshes; the pH response releasing agent is sodium citrate or potassium tartrate. The loading amount of lithium silicate in the functional aggregate is 10-18% of the mass of the porous ceramic particles, and the loading amount of the pH response releasing agent is 5-8% of the mass of the porous ceramic particles. A preparation method of a composite material for minimally invasive active repair of concrete cracks comprises the following steps: Step A, preparing functional aggregate, namely placing porous ceramic powder into a vacuum container, and adsorbing mixed active substances containing lithium silicate and a pH response releasing agent into ceramic pores in a vacuum state to obtain the functional aggregate with the preloaded active substances; step B, dry mixing, namely adding the cement-based cementing material, the functional aggregate prepared in the step A, the fine aggregate, the water-retaining agent and the fiber into a mixer, and carrying out dry mixing for 2-5 minutes until the materials are uniformly mixed; And C, wet mixing, namely sequentially adding polymer latex, a water reducing agent and water into the dry mixture prepared in the step B, and mechanically stirring for 3-8 minutes to obtain the composite material. A composite-based repair method comprising the steps of: step one, minimally invasive slotting, namely cutting an inverted trapezoid slot along the center of a crack by using a diamond saw blade; Step two, preparing interface slurry, namely dissolving calcium nitrate in deionized water, stirring until the calcium nitrate is completely dissolved, slowly adding the solution prepared in the step a into nano silicon dioxide sol in a stirring state, adding an organosilicon penetrating agent into the product prepared in the step b, and continuously stirring to obtain uniform and transparent interface catalytic slurry; step three, interface treatment, namely uniformly brushing the prepared interface catalytic slurry on concrete basal planes in the groove and on two sides; filling and reinforcing, namely filling the composite material into a groove, and performing two-layer operation, namely filling the first layer to the depth o