Elastic polyurea mortar and preparation method thereof

Abstract

The invention belongs to the technical field of concrete crack repairing materials, and particularly relates to elastic polyurea mortar and a preparation method thereof. The elastic polyurea mortar is prepared from the following components in parts by weight: 20 to 25 parts of polyurea, 60 to 85 parts of inorganic filler, 0.5 to 1.5 parts of coupling agent, 0.5 to 1.5 parts of defoaming agent, 3 to 6 parts of diluent and 0.3 to 1.2 parts of anti-aging agent. The elastic polyurea mortar disclosed by the invention has the characteristic that existing mortar can be poured, has relatively high strength after being cured, and also has extensibility and flexibility, the elastic polyurea mortar is deformed under the action of external force, the elastic polyurea mortar recovers an original structure under the action of elasticity after the external force disappears, and the elastic polyurea mortar has the performance advantages of high toughness, high strength and low elastic modulus.

Description

Technical Field

[0001] The invention belongs to the technical field of concrete crack repair materials, and in particular relates to an elastic polyurea mortar and a preparation method thereof. Background Art

[0002] Concrete is a non-homogeneous brittle material made of aggregate, cementitious materials, water and other added materials. The non-homogeneity means that gaps will inevitably appear between the components of concrete, which is easily eroded and damaged. Specifically, it can be attributed to cracks caused by deformation and cracks caused by external loads. Cracks caused by deformation are also called non-structural cracks. For example, deformation caused by temperature changes, concrete shrinkage, uneven foundation settlement and other factors. When this deformation is constrained, self-stress will be generated inside the structural member. When this self-stress exceeds the tensile strength of concrete, it will cause cracks in the concrete. This type of crack accounts for about 80% of the total structural cracks. Cracks caused by external loads are also called structural cracks, load cracks, and stress cracks. This type of crack accounts for about 20% of the total structural cracks.

[0003] Commonly used repair materials for concrete cracks include three categories: inorganic materials, polymer materials, and composite modified materials. Inorganic repair materials are mainly various hydraulic cementitious materials, which are rigid materials and suitable for reinforcement. Organic repair materials are a type of organic materials processed by organic synthesis or polymerization reaction. They are characterized by having certain plasticity, elasticity and mechanical strength at room temperature, but can undergo changes such as decomposition, cross-linking and aging under other external factors such as environmental conditions. Organic-inorganic composite materials are made by mixing organic materials and inorganic materials in a certain ratio, which combines the rigidity of inorganic materials and the flexibility of organic materials. Different types of repair materials are selected under different working conditions. When repairing cracks in the deformation period or other special-shaped buffer structure joints, it is not appropriate to use inorganic rigid repair materials or single organic repair materials. Summary of the invention

[0004] In view of the above problems, the purpose of the present invention is to provide an elastic polyurea mortar and a preparation method thereof. The elastic polyurea mortar of the present invention has the castable property of the existing mortar, has a high strength after curing, and also has ductility and flexibility. When used in concrete joints, under certain displacement and deformation conditions, it has the ability to follow the changes of the joints, can adapt to certain joint displacement and deformation, and has the ability to resist cracks in the base concrete. When the concrete is subjected to excessive external force to produce cracks, the elastic mortar is deformed by extrusion and stretching. After the external force disappears, the crack structure and strength of the damaged concrete are gradually restored under the elastic recovery action of the elastic mortar, thereby ensuring the safety and durability of the concrete structural components.

[0005] The technical solution of the present invention is: an elastic polyurea mortar, which comprises, by weight, 20-25 parts of polyurea, 60-85 parts of inorganic filler, 0.5-1.5 parts of coupling agent, 0.5-1.5 parts of defoamer, 3-6 parts of diluent and 0.3-1.2 parts of antioxidant.

[0006] The polyurea is a two-component polyurea or a single-component polyurea, wherein the two-component polyurea comprises a component A and a component B, wherein the component A is a diphenylmethane diisocyanate isocyanate semi-prepolymer, and the component B is made of a combination of a highly active polyether, a liquid amine chain extender, an active plasticizer, a functional filler and a color paste, wherein the highly active polyether comprises one or more of polyether polyol CHE-328N and polyether polyol CHE-828, wherein the liquid amine chain extender comprises one or more of dichloro-diaminodiphenylmethane, diethylenetriamine and dihydroxyaniline, wherein the active plasticizer comprises one or more of propylene carbonate, methyl methacrylate and linseed oil, wherein the functional filler comprises one or more of talc powder, mica powder, carbon black and glass microbeads, and the single-component polyurea is a polyurethane-urea prepolymer.

[0007] The mass ratio of component A to component B in the two-component polyurea is 3:1, 2:1 or 1:1, and the mass ratio of high-activity polyether: liquid amine chain extender: active plasticizer: functional filler: color paste in component B is 62-75:2-5:16-23:3-8:1-3.

[0008] The inorganic filler is one or more of natural sand, artificial sand, silica fume powder, fly ash and nano silicon dioxide.

[0009] The coupling agent is one or more of KH550 aminopropyl triethoxy silane coupling agent, KH560 glycidyloxypropyl trimethoxy silane coupling agent and KH570 methacryloxypropyl trimethoxy silane coupling agent.

[0010] The defoamer is one or more of BYK-028 polysiloxane defoamer, BYK-054 polymer non-silicone defoamer, BYK141 silicone defoamer and BYK066N silicone defoamer.

[0011] The diluent is an inactive diluent, which is one or more of acetone, butanone and chloroform.

[0012] The antioxidant is one or both of the ultraviolet absorber 9735A and the hindered amine light stabilizer UV-970.

[0013] The elastic polyurea mortar has a starting curing time of ≥30 minutes and a complete curing time of ≤48 hours.

[0014] A method for preparing an elastic polyurea mortar, comprising the following steps: S1: According to the raw material ratio of elastic polyurea mortar, weigh polyurea, coupling agent, defoamer, diluent and antioxidant respectively and mix them; S2: After mixing, stir slowly for 5 to 10 minutes; S3: Add inorganic filler and stir for 3 to 6 minutes to obtain elastic polyurea mortar.

[0015] The technical effects of the present invention are as follows: 1. The present invention is used to repair concrete. When the concrete is subjected to excessive external force and cracks are generated, the elastic polyurea mortar is deformed by compression and stretching. After the external force disappears, the damaged concrete is gradually restored to its crack structure and strength under the elastic recovery effect of the elastic polyurea mortar, thereby ensuring the safety and durability of concrete structural components; 2. When the elastic polyurea mortar of the present invention is used in concrete joints, under certain displacement and deformation conditions, it has the ability to follow the changes in the joints, can adapt to certain joint displacement and deformation, and has the ability to resist cracks in the base concrete. DETAILED DESCRIPTION Example 1

[0016] An elastic polyurea mortar comprises, by weight, 20-25 parts of polyurea, 60-85 parts of inorganic filler, 0.5-1.5 parts of coupling agent, 0.5-1.5 parts of defoamer, 3-6 parts of diluent and 0.3-1.2 parts of antioxidant.

[0017] The polyurea is a two-component polyurea or a single-component polyurea, wherein the two-component polyurea comprises a component A and a component B, wherein the component A is a diphenylmethane diisocyanate isocyanate semi-prepolymer, and the component B is made of a combination of a highly active polyether, a liquid amine chain extender, an active plasticizer, a functional filler and a color paste, wherein the highly active polyether comprises one or more of polyether polyol CHE-328N and polyether polyol CHE-828, wherein the liquid amine chain extender comprises one or more of dichloro-diaminodiphenylmethane, diethylenetriamine and dihydroxyaniline, wherein the active plasticizer comprises one or more of propylene carbonate, methyl methacrylate and linseed oil, wherein the functional filler comprises one or more of talc powder, mica powder, carbon black and glass microbeads, and the single-component polyurea is a polyurethane-urea prepolymer.

[0018] The mass ratio of component A to component B in the two-component polyurea is 3:1, 2:1 or 1:1, and the mass ratio of high-activity polyether: liquid amine chain extender: active plasticizer: functional filler: color paste in component B is 62-75:2-5:16-23:3-8:1-3.

[0019] The inorganic filler is one or more of natural sand, artificial sand, silica fume powder, fly ash and nano silicon dioxide.

[0020] The coupling agent is one or more of KH550 aminopropyl triethoxy silane coupling agent, KH560 glycidyloxypropyl trimethoxy silane coupling agent and KH570 methacryloxypropyl trimethoxy silane coupling agent.

[0021] The defoamer is one or more of BYK-028 polysiloxane defoamer, BYK-054 polymer non-silicone defoamer, BYK141 silicone defoamer and BYK066N silicone defoamer.

[0022] The diluent is an inactive diluent, which is one or more of acetone, butanone and chloroform.

[0023] The antioxidant is one or both of the ultraviolet absorber 9735A and the hindered amine light stabilizer UV-970.

[0024] The elastic polyurea mortar has a starting curing time of ≥30 minutes and a complete curing time of ≤48 hours. Example 2

[0025] A method for preparing an elastic polyurea mortar, comprising the following steps: S1: According to the raw material ratio of elastic polyurea mortar, weigh polyurea, coupling agent, defoamer, diluent and antioxidant respectively and mix them; S2: After mixing, stir slowly for 5 to 10 minutes; S3: Add inorganic filler and stir for 3 to 6 minutes to obtain elastic polyurea mortar.

[0026] The elastic polyurea mortar according to Example 2 is prepared by the method for preparing an elastic polyurea mortar, as described in Example 1, specifically as in Example 3 to Example 6, and compared with Comparative Example 1 and Comparative Example 2. Example 3

[0027] The elastic polyurea mortar material formula and preparation method of this embodiment include the following raw materials in parts by weight, as shown in Table 1: Table 1 Ratio of raw materials in Example 3 Raw material ingredients Number of copies Two-component polyurea (A:B=1:1) 20 Inorganic filler (natural sand: fly ash: nano-silicon dioxide = 90:3:7) 60 Coupling agent (KH550) 0.5 Defoamer (BYK-054 polymer-based non-silicone defoamer) 0.5 Thinner (methyl ethyl ketone) 3 Anti-aging agent (UV absorber 9735A) 0.3 The two-component polyurea, coupling agent, defoamer, diluent and antioxidant were weighed using an electronic analytical balance, stirred slowly for 5 minutes, and an inorganic filler was added and stirred for 3 minutes to obtain an elastic polyurea mortar material, which was completely cured after 48 hours and achieved optimal performance. Example 4

[0028] The elastic polyurea mortar material formula and preparation method of this embodiment include the following raw materials in parts by weight, as shown in Table 2: Table 2 Ratio of raw materials in Example 4 Raw material ingredients Number of copies Two-component polyurea (A:B=2:1) 22 Inorganic filler (artificial sand: silica fume powder: fly ash: nano silicon dioxide = 84:2:4:10) 66 Coupling agent (KH560) 1 Defoaming agent (BYK-028 polysiloxane) 1 Thinner (acetone) 5 Anti-aging agent (UV absorber 9735A) 0.8 The two-component polyurea, coupling agent, defoamer, diluent and antioxidant were weighed using an electronic analytical balance, stirred slowly for 6 minutes, and an inorganic filler was added and stirred for 3.5 minutes to obtain an elastic polyurea mortar material, which was completely cured after 48 hours and achieved optimal performance. Example 5

[0029] The elastic polyurea mortar material formula and preparation method of this embodiment include the following raw materials in parts by weight, as shown in Table 3: Table 3 Ratio of raw materials in Example 5 Raw material ingredients Number of copies Two-component polyurea (A:B=3:1) 22 Inorganic filler (artificial sand: silica fume powder: fly ash = 92:3:5) 66 Coupling agent (KH570) 1 Defoamer (BYK066N silicone defoamer) 1 Diluent (chloroform) 5 Antiaging agent (hindered amine light stabilizer UV-970) 0.8 The two-component polyurea, coupling agent, defoamer, diluent and antioxidant were weighed using an electronic analytical balance, stirred slowly for 10 minutes, and an inorganic filler was added and stirred for 6 minutes to obtain an elastic polyurea mortar material, which was completely cured after 48 hours and achieved optimal performance. Example 6

[0030] The elastic polyurea mortar material formula and preparation method of this embodiment include the following raw materials in parts by weight, as shown in Table 4: Table 4 Ratio of raw materials in Example 6 Raw material ingredients Number of copies One-component polyurea 22 Inorganic filler (artificial sand: silica fume powder: fly ash: nano silicon dioxide = 84:2:4:10) 66 Coupling agent (KH560) 1 Defoaming agent (BYK-028 polysiloxane) 1 Thinner (acetone) 5 Anti-aging agent (UV absorber 9735A) 0.8 The single-component polyurea, coupling agent, defoamer, diluent and antioxidant were weighed using an electronic analytical balance, stirred slowly for 6 minutes, and an inorganic filler was added and stirred for 4.5 minutes to obtain an elastic polyurea mortar material, which was completely cured after 48 hours and achieved optimal performance.

[0031] Comparative Example 1 A high elastic repair mortar material formula of this comparative example includes the following raw materials in parts by weight, as shown in Table 5: Table 5 Ratio of raw materials in comparative example 1 Raw material ingredients Number of copies SK flexible anti-seepage coating 10 Inorganic filler (coarse sand: fine sand = 2:1) 30 The raw materials were weighed using an electronic analytical balance and stirred for 4.5 minutes to obtain a high-elastic repair mortar, which was completely cured after 48 hours.

[0032] Comparative Example 2 A polyurethane elastic mortar (Masteremaco T2900) in this comparative example includes the following raw materials in parts by weight, as shown in Table 6: Table 6 Ratio of raw materials in comparative example 2 Raw material ingredients Number of copies Component A 2.1 Component B 4.3 Component C 32.6 The raw materials were weighed using an electronic analytical balance and stirred for 4.5 minutes to obtain a polyurethane elastic mortar, which was completely cured after 48 hours.

[0033] Table 7 shows the basic performance indicators of the elastic mortars in the above embodiments and comparative examples. It can be seen from the test results that compared with the comparative example, the early compressive strength, tensile strength and elongation at break of Examples 3 to 6 are greatly improved, and the tensile modulus of the embodiments is lower than that of the comparative example, indicating that compared with the existing elastic mortar, the elastic polyurea mortar of the present invention has the advantages of high strength, high toughness and low elastic modulus.

[0034] Table 7 Comparison of basic properties of elastic mortar in examples and comparative examples The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by any technician familiar with the technical field within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention.

Claims

1. An elastic polyurea mortar, characterized in that: Calculated by weight, it includes 20-25 parts of polyurea, 60-85 parts of inorganic filler, 0.5-1.5 parts of coupling agent, 0.5-1.5 parts of defoaming agent, 3-6 parts of diluent and 0.3-1.2 parts of antioxidant.

2. The elastic polyurea mortar according to claim 1, characterized in that: The polyurea is a two-component polyurea or a single-component polyurea, wherein the two-component polyurea comprises a component A and a component B, wherein the component A is a diphenylmethane diisocyanate isocyanate semi-prepolymer, and the component B is made of a combination of a highly active polyether, a liquid amine chain extender, an active plasticizer, a functional filler and a color paste, wherein the highly active polyether comprises one or more of polyether polyol CHE-328N and polyether polyol CHE-828, wherein the liquid amine chain extender comprises one or more of dichloro-diaminodiphenylmethane, diethylenetriamine and dihydroxyaniline, wherein the active plasticizer comprises one or more of propylene carbonate, methyl methacrylate and linseed oil, wherein the functional filler comprises one or more of talc powder, mica powder, carbon black and glass microbeads, and the single-component polyurea is a polyurethane-urea prepolymer.

3. The elastic polyurea mortar according to claim 2, characterized in that: The mass ratio of component A to component B in the two-component polyurea is 3:1, 2:1 or 1:1, and the mass ratio of high-activity polyether: liquid amine chain extender: active plasticizer: functional filler: color paste in component B is 62-75:2-5:16-23:3-8:1-3.

4. The elastic polyurea mortar according to claim 1, characterized in that: The inorganic filler is one or more of natural sand, artificial sand, silica fume powder, fly ash and nano silicon dioxide.

5. The elastic polyurea mortar according to claim 1, characterized in that: The coupling agent is one or more of KH550 aminopropyl triethoxy silane coupling agent, KH560 glycidyloxypropyl trimethoxy silane coupling agent and KH570 methacryloxypropyl trimethoxy silane coupling agent.

6. The elastic polyurea mortar according to claim 1, characterized in that: The defoamer is one or more of BYK-028 polysiloxane defoamer, BYK-054 polymer non-silicone defoamer, BYK141 silicone defoamer and BYK066N silicone defoamer.

7. The elastic polyurea mortar according to claim 1, characterized in that: The diluent is an inactive diluent, which is one or more of acetone, butanone and chloroform.

8. The elastic polyurea mortar according to claim 1, characterized in that: The antioxidant is one or both of the ultraviolet absorber 9735A and the hindered amine light stabilizer UV-970.

9. The elastic polyurea mortar according to claim 1, characterized in that: The elastic polyurea mortar has a starting curing time of ≥30 minutes and a complete curing time of ≤48 hours.

10. A method for preparing an elastic polyurea mortar, comprising preparing the elastic polyurea mortar as claimed in claim 1, characterized in that: The following steps are involved: S1: According to the raw material ratio of elastic polyurea mortar, weigh polyurea, coupling agent, defoamer, diluent and antioxidant respectively and mix them; S2: After mixing, stir slowly for 5 to 10 minutes; S3: Add inorganic filler and stir for 3 to 6 minutes to obtain elastic polyurea mortar.