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CN-121990802-A - High-strength and toughness cement-based repair material based on bionic adhesion and self-repair functions and preparation method thereof

CN121990802ACN 121990802 ACN121990802 ACN 121990802ACN-121990802-A

Abstract

The invention belongs to the technical field of building materials, and discloses a high-strength and toughness cement-based repair material based on bionic adhesion and self-repair functions and a preparation method thereof, wherein the repair material comprises, by mass, 400-500 parts of ordinary Portland cement, 250-300 parts of high belite sulphoaluminate cement, 100-150 parts of mineral powder, 20-50 parts of silica fume, 10-30 parts of redispersible latex powder, 5-20 parts of fumed silica, 800-1000 parts of machine-made sand, 0.05-0.5 part of polydopamine modified graphene oxide, 1-5 parts of an epoxy curing agent, 2-5 parts of a water reducing agent, 2.5-3 parts of a defoaming agent, 0.4-0.5 part of a retarder and 250-300 parts of water, wherein the epoxy curing agent is wrapped in a resin microcapsule. The invention can improve the interfacial bonding strength and toughness of the cement-based repair material and enable the repair material to have damage self-recovery capability.

Inventors

  • SHI CHEN
  • GUO KEYU
  • LI XIAOJUAN
  • HE TINGSHU
  • LIU XIGUANG

Assignees

  • 西安建筑科技大学

Dates

Publication Date
20260508
Application Date
20260127

Claims (10)

  1. 1. The high-strength and toughness cement-based repair material based on bionic adhesion and self-repair functions is characterized by comprising the following raw materials in parts by weight: 400-500 parts of ordinary silicate cement, 250-300 parts of high belite sulphoaluminate cement, 100-150 parts of mineral powder, 20-50 parts of silica fume, 10-30 parts of redispersible emulsion powder, 5-20 parts of gas phase nano silicon dioxide, 800-1000 parts of machine-made sand, 0.05-0.5 part of polydopamine modified graphene oxide, 1-5 parts of epoxy curing agent, 2-5 parts of water reducer, 2.5-3 parts of defoamer, 0.4-0.5 part of retarder and 250-300 parts of water; Wherein, the epoxy curing agent is wrapped in the resin microcapsule.
  2. 2. The high-strength and toughness cement-based repair material based on bionic adhesion and self-repairing function according to claim 1, wherein microcapsule wall material of the resin microcapsule adopts urea resin, melamine resin or polyurethane.
  3. 3. The high-strength and toughness cement-based repair material based on bionic adhesion and self-repairing function according to claim 1 or 2, wherein the process of encapsulating the epoxy curing agent in the resin microcapsule comprises the following steps: mixing an epoxy resin curing agent and an isocyanate monomer to form an oil phase, wherein the mass ratio of the epoxy resin curing agent to the isocyanate monomer is 5:1; Adding the oil phase into an aqueous phase, and shearing and emulsifying for 10-30 minutes at a rotating speed of 1000-3000 rpm to form an oil-in-water emulsion, wherein the mass volume ratio of the oil phase to the aqueous phase is 24 (195-205); Dripping diamine compound aqueous solution into the oil-in-water emulsion, stirring at 40-60 ℃ and rotating speed of 340-360rpm for 2-6 hours, filtering, washing and drying after the reaction is finished, grinding into powder, and obtaining the epoxy curing agent wrapped by the resin microcapsule, so as to wrap the epoxy curing agent in the resin microcapsule, wherein the molar ratio of diamine compound to isocyanate monomer is (0.9-1.1): 1, and the diamine compound in the diamine compound aqueous solution accounts for 3-8% of the water mass.
  4. 4. The high-strength and toughness cement-based repair material based on bionic adhesion and self-repairing functions according to claim 3, wherein the epoxy resin curing agent adopts isophorone diamine or hexamethylene diamine; The emulsifier adopts polyvinyl alcohol and/or sodium dodecyl sulfate; the diamine compound adopts ethylenediamine or hexamethylenediamine; And (3) washing and drying the filtered solid product by adopting deionized water for 2-4 times, then vacuum drying at 40-60 ℃ for 12-24 hours, removing water, and grinding into powder to obtain the epoxy curing agent wrapped by the resin microcapsule.
  5. 5. The high-strength and toughness cement-based repair material based on bionic adhesion and self-repairing function according to claim 3, wherein the average particle size of the epoxy curing agent encapsulated by the resin microcapsules is 10-100 microns.
  6. 6. The high-strength and toughness cement-based repair material based on bionic adhesion and self-repairing functions according to claim 1, wherein the preparation method of the polydopamine modified graphene oxide comprises the following steps: dispersing graphene oxide in a buffer solution with the pH value of 8.0-9.0 to form uniform graphene oxide dispersion liquid; Adding dopamine hydrochloride into the graphene oxide dispersion liquid, stirring and reacting for 12-48 hours at 20-30 ℃, then carrying out solid-liquid separation, washing and drying the separated solid product to obtain the polydopamine modified graphene oxide, wherein the mass ratio of dopamine to graphene oxide is (0.5-2): 1, and the stirring speed in the stirring and reacting is 390-410rpm.
  7. 7. The high-strength and toughness cement-based repair material based on bionic adhesion and self-repairing functions according to claim 6, wherein the buffer solution is a tris (hydroxymethyl) aminomethane hydrochloride buffer solution, and each gram of graphene oxide is correspondingly dispersed in the tris (hydroxymethyl) aminomethane hydrochloride buffer solution of 495-505 mL; And (3) adding graphene oxide into a tris hydrochloride buffer solution, and then treating the graphene oxide in an ice-water bath under the ultrasonic condition of 300-500W for 30-60 minutes to form a uniform graphene oxide dispersion liquid.
  8. 8. The high-strength and toughness cement-based repair material based on bionic adhesion and self-repairing function according to claim 6, wherein the solid product is obtained by washing and drying the separated solid product, alternately washing the solid product with deionized water and ethanol for 2-4 times, drying at-45 ℃ to-55 ℃ for 24-48 hours, and grinding into powder.
  9. 9. The high-strength and toughness cement-based repair material based on bionic adhesion and self-repair functions according to claim 1, wherein the water reducer is a polycarboxylic acid high-efficiency water reducer, the defoamer is an organosilicon defoamer, the retarder is sodium gluconate, the ordinary Portland cement is P.O42.5 ordinary Portland cement, and the mineral powder is S95-grade mineral powder.
  10. 10. The method for preparing the high-strength and toughness cement-based repair material based on bionic adhesion and self-repairing functions as claimed in any one of claims 1 to 9, which is characterized by comprising the following steps: Mixing ordinary Portland cement, high belite sulphoaluminate cement, mineral powder, silica fume, gas phase nano silicon dioxide, redispersible emulsion powder and machine-made sand by a dry method to obtain uniform premix, wherein the rotating speed during mixing is 15-30 r/min, and the mixing time is 10-20 min; Adding polydopamine modified graphene oxide into the premix, and continuously mixing for 5-10 minutes to obtain a first mixture; Under the stirring condition of 100-300 rpm, adding an epoxy curing agent wrapped by a resin microcapsule into the first mixture, mixing for 3-8 minutes, and discharging after mixing to obtain repair material dry powder; And mixing the repairing material dry powder with water, a water reducing agent, a defoaming agent and a retarder to obtain the high-strength and toughness cement-based repairing material based on bionic adhesion and self-repairing functions.

Description

High-strength and toughness cement-based repair material based on bionic adhesion and self-repair functions and preparation method thereof Technical Field The invention belongs to the technical field of building materials, and particularly relates to a high-strength and toughness cement-based repair material based on bionic adhesion and self-repair functions and a preparation method thereof. Background Cement concrete is the most widely used material in modern engineering construction, however, existing structures commonly have damages such as cracking, peeling and the like under the action of environment and load. Repair, but not demolish, rebuild the damaged structure, it is resources are saved, guarantee the safety's key, has also hasten the huge repair material market demand. At present, inorganic repairing materials based on cement are commonly adopted in repairing engineering. The material has the inherent defects of high brittleness and insufficient toughness, and the key is that the interface bonding between new and old materials is weak, and the material is often the most failure link in a repairing system. The prior art mainly improves part of performances by adding polymers and the like, but still fails to fundamentally solve the core technical bottlenecks of weak interfacial chemical bonding force and lack of microcrack autonomous repair capability. Therefore, the novel high-performance repair material which can actively strengthen interface bonding, improve body toughness and has the damage self-repairing capability is developed, and has great significance for improving the reliability and durability of repair engineering. Disclosure of Invention In order to solve the problems in the prior art, the invention aims to provide the high-strength and high-toughness cement-based repair material based on bionic adhesion and self-repair functions and the preparation method thereof. The aim of the invention can be achieved by the following technical scheme: the high-strength and toughness cement-based repair material based on bionic adhesion and self-repair functions comprises the following raw materials in parts by mass: 400-500 parts of ordinary silicate cement, 250-300 parts of high belite sulphoaluminate cement, 100-150 parts of mineral powder, 20-50 parts of silica fume, 10-30 parts of redispersible emulsion powder, 5-20 parts of gas phase nano silicon dioxide, 800-1000 parts of machine-made sand, 0.05-0.5 part of polydopamine modified graphene oxide, 1-5 parts of epoxy curing agent, 2-5 parts of water reducer, 2.5-3 parts of defoamer, 0.4-0.5 part of retarder and 250-300 parts of water; Wherein, the epoxy curing agent is wrapped in the resin microcapsule. Preferably, the microcapsule wall material of the resin microcapsule is urea resin, melamine resin or polyurethane. Preferably, the process of encapsulating the epoxy hardener in the resin microcapsule comprises: mixing an epoxy resin curing agent and an isocyanate monomer to form an oil phase, wherein the mass ratio of the epoxy resin curing agent to the isocyanate monomer is 5:1; Adding the oil phase into an aqueous phase, and shearing and emulsifying for 10-30 minutes at a rotating speed of 1000-3000 rpm to form an oil-in-water emulsion, wherein the mass volume ratio of the oil phase to the aqueous phase is 24 (195-205); Dripping diamine compound aqueous solution into the oil-in-water emulsion, stirring and reacting for 2-6 hours at 40-60 ℃ and the rotating speed of 340-360rpm, filtering, washing and drying after the reaction is finished, grinding into powder to obtain powdery epoxy curing agent wrapped by resin microcapsules, and wrapping the epoxy curing agent in the resin microcapsules, wherein the molar ratio of diamine compound to isocyanate monomer is (0.9-1.1): 1, and the diamine compound in the diamine compound aqueous solution accounts for 3-8% of the water mass. Preferably, the epoxy resin curing agent adopts isophorone diamine or hexamethylenediamine, and the isocyanate monomer adopts toluene diisocyanate or hexamethylene diisocyanate; The emulsifier adopts polyvinyl alcohol and/or sodium dodecyl sulfate; the diamine compound adopts ethylenediamine or hexamethylenediamine; And (3) washing and drying the filtered solid product by adopting deionized water for 2-4 times, then vacuum drying at 40-60 ℃ for 12-24 hours, removing water, and grinding into powder to obtain the powdered epoxy curing agent wrapped by the resin microcapsule. Preferably, the average particle size of the epoxy hardener encapsulated by the resin microcapsules is 10-100 microns. Preferably, the preparation method of the polydopamine modified graphene oxide comprises the following steps: dispersing graphene oxide in a buffer solution with the pH value of 8.0-9.0 to form uniform graphene oxide dispersion liquid; Adding dopamine hydrochloride into the graphene oxide dispersion liquid, stirring and reacting for 12-48 hours at 20-30 ℃, then carrying out solid-liquid sep