Low-temperature underwater epoxy repair mortar and method of making same

Abstract

The application discloses a low-temperature underwater epoxy repair mortar and a preparation method thereof, and relates to the technical field of building materials. The low-temperature underwater epoxy repair mortar comprises the following components: 60-80 parts of low-viscosity epoxy resin, 20-40 parts of multi-epoxy functional group resin, 35-40 parts of active diluent, 57-67 parts of curing agent and 518.4-572.4 parts of filler. The Dinger-Funk optimization filler grading is adopted to improve the fluidity of the mortar. The high-content active diluent is adopted to greatly reduce the resin viscosity and improve the fluidity of the mortar. Meanwhile, the multi-functional group epoxy resin is compounded to improve the activity of the resin base liquid, solve the problem of the reduction of the underwater compressive strength and the bonding strength caused by too much diluent, make the underwater repair construction convenient, improve the underwater repair quality, and ensure the safe operation of the hydraulic discharge building.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of building materials, in particular to a low-temperature underwater epoxy repair mortar and a preparation method thereof. BACKGROUND

[0002] In the last century, a large number of hydropower stations were built in China. After decades of operation, the discharge structures of these hydropower stations have defects caused by water flow erosion. To prevent further expansion of the defects and ensure the safe operation of the power station, direct underwater construction is more advantageous for projects with difficult drainage and tight construction schedules. Underwater construction mainly relies on divers, but divers have difficulty moving underwater and are unable to perform operations such as inserting and troweling. Therefore, the repair material needs to have good flowability to facilitate construction.

[0003] Epoxy mortar is a commonly used repair material that can be cured underwater. Many units have researched underwater epoxy mortar technology. For example, CN106242372A discloses an underwater epoxy repair mortar that improves underwater bonding strength by optimizing the components of the epoxy resin and curing agent. CN103979883A discloses an underwater epoxy mortar that has excellent compression resistance, impact resistance, permeability resistance, and seawater corrosion resistance in special underwater environments. CN104650790B discloses an epoxy grouting material for reinforcing and strengthening concrete underwater, which has a 7-day compressive strength of up to 45.6 MPa and a wet bonding strength between the epoxy mortar and the concrete of up to 4.08 MPa. The epoxy mortars prepared by the above research and patents have good strength, but they do not consider the adverse effects of the underwater repair environment on the material properties.

[0004] To improve the flowability of epoxy mortar, diluents and other methods are usually used for viscosity reduction modification. Generally, epoxy resin diluents with a viscosity of less than 10 cps are added as viscosity-reducing components to epoxy resin, which can effectively reduce the viscosity of the resin and improve the flowability of the mortar. However, the addition of diluents reduces the crosslinking density of the epoxy resin, thus generally reducing the strength of the cured resin body. KONG Ling-hui et al. found that although the addition of 20% benzyl glycidyl ether diluent can reduce the viscosity of the epoxy resin by 71%, it reduces the compressive strength of the epoxy mortar by 9%.

[0005] Commercially available underwater epoxy repair mortar is prepared and tested at room temperature around 20℃. The mortar has good flowability at room temperature, which can meet the construction needs. However, the water temperature during underwater repair construction of hydropower stations is generally 5-10℃. When the temperature decreases by 15℃, the viscosity of the epoxy resin increases by nearly 10 times. Therefore, the commercially available underwater epoxy repair mortar cannot flow in the underwater low-temperature environment, and the construction quality cannot be guaranteed under the condition that the diver cannot move and the operation cannot be supervised. Moreover, the construction time is significantly prolonged, and the labor cost is also increased.

[0006] On the other hand, in the low-temperature environment under water, the resin cross-linking reaction activity of the commercially available epoxy resin mortar is reduced, resulting in the decrease of the compressive strength of the cured product and the bonding strength with the repaired concrete base. At the same time, the viscosity of the resin in the commercially available epoxy resin mortar under low temperature is increased, resulting in the decrease of the wettability of the repaired concrete base, thereby resulting in the underwater bonding strength of the repair mortar with the concrete base being less than 1.0 MPa. SUMMARY

[0007] The present application aims to overcome the deficiencies of the prior art and provide a low-temperature underwater epoxy repair mortar and a preparation method thereof. A high amount of active diluent is used to greatly reduce the viscosity of the resin and improve the flowability of the mortar. At the same time, a multi-functional epoxy resin is compounded to improve the activity of the resin base liquid, thereby solving the problems of the decrease of the underwater compressive strength and the bonding strength caused by the excessive diluent and low temperature.

[0008] The purpose of the present application is achieved by the following technical solutions:

[0009] The low-temperature underwater epoxy repair mortar comprises the following components in mass parts: 60-80 parts of low-viscosity epoxy resin, 20-40 parts of multi-epoxy functional resin, 35-40 parts of active diluent, 57-67 parts of curing agent, and 518.4-572.4 parts of filler.

[0010] The low-viscosity epoxy resin is bisphenol F epoxy resin 170.

[0011] The curing agent is hydrophobic CX-28 phenolic amine curing agent.

[0012] The filler is stone powder and quartz sand, which is obtained by using the Dinger-Funk equation for optimization. The Dinger-Funk equation is used to optimize the particle size distribution of the fine powder and quartz sand, thereby reducing the void ratio of the filler and maximizing the promotion of the flow of different coarse and fine fillers, thereby improving the flowability of the underwater epoxy resin mortar. The Dinger-Funk equation is used for the first time in the filler grading design of the underwater epoxy resin mortar to improve the flowability of the mortar.

[0013] The multi-epoxy functional resin is any one of glycerol triglycidyl ether, pentaerythritol tetraglycidyl ether, or trisglycidyl m-aminophenol, preferably pentaerythritol tetraglycidyl ether XY-671 or trisglycidyl m-aminophenol TT-300. The addition of the multi-epoxy functional resin can improve the activity of the resin and solve the problem of the decrease of the underwater bonding strength caused by the excessive diluent.

[0014] The diluent is any one of ortho-methyl phenyl glycidyl ether, carbon dodecyl glycidyl ether, octyl glycidyl ether, benzyl glycidyl ether or phenyl glycidyl ether, preferably ortho-methyl phenyl glycidyl ether 691, benzyl glycidyl ether 692, high content active diluent is used to greatly reduce the viscosity of the resin, and the flowability of the low-temperature underwater epoxy resin mortar is improved.

[0015] The organic modified fine powder is further included in an amount of 20-25 parts by mass.

[0016] The organic modified fine powder is a surface-porous and hydrophobic organic modified alumina powder, and the organic modified alumina powder is prepared by an oxalic acid gel method.

[0017] Further, the application also provides a preparation method of the low-temperature underwater epoxy repair mortar, including the following steps:

[0018] S1, the low-viscosity epoxy resin, the multifunctional epoxy resin, the active diluent and the curing agent are weighed, and the resin base liquid component is obtained by stirring with a stirrer;

[0019] S2, the filler is added into the stirrer, and the low-temperature underwater epoxy repair mortar is obtained by continuing to stir.

[0020] The application has the following beneficial effects:

[0021] The low-temperature underwater epoxy repair mortar provided by the application improves the flowability and underwater bonding strength of the low-temperature underwater epoxy resin mortar, facilitates underwater repair construction, improves underwater repair quality, and ensures the safe operation of hydraulic discharge structures. DETAILED DESCRIPTION

[0022] The technical solutions of the application will be described below in conjunction with the embodiments, and obviously, the described embodiments are only part of the embodiments of the application, rather than all the embodiments. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative labor are within the protection scope of the application.

[0023] The first technical solution provided by the application is:

[0024] The Dinger-Funk equation is used to optimize the particle size distribution of the filler

[0025]

[0026] In the formula, U(Dp) is the cumulative percentage of the particle size Dp, %; Dp is the particle size of the particle; Dmax is the particle size of the largest particle in the system; Dmin is the particle size of the smallest particle in the system; n is the distribution index, by which the proportion of fine particles in the system can be adjusted to a certain extent, and when n is larger (n = 0.4-0.7), the mixed system is coarse matching, and when n is smaller, the content of fine particles in the mixture is higher, and the particle size of the filler in the epoxy resin mortar is smaller, and in the present embodiment, n ≤ 0.7.

[0027] The fillers used are stone powder (fine powder, particle size 0-0.11 mm) and quartz sand (particle size 0.11 mm-1.65 mm), and by theoretical calculation, the volume ratio of each particle size filler is as shown in Table 1, the void ratio of each filler is as shown in Table 2, and the particle size distribution index n is from 0.1 to 0.7, and the filler numbers are TL-1-TL-7.

[0028] Table 1 Filler ratio based on Dinger-Funk equation

[0029]

[0030]

[0031] Table 2 Filler void ratio based on Dinger-Funk equation

[0032] No. TL-1 TL-2 TL-3 TL-4 TL-5 TL-6 TL-7 Tight packing porosity / % 1.0 1.0 1.0 1.0 1.0 1.0 1.0 0.0 0.0 0.0 0.0 0.0 0.323 0.298 0.274 0.251 0.281 0.310 0.346

[0033] The preferred filler is TL-4. The comparative filler is TL-0, wherein 0-0.11 mm: 0.11 mm-0.21 mm: 0.21 mm-0.35 mm: 0.35 mm-0.83 mm: 0.83 mm-1.65 mm = 1:1:1:1:1.

[0034] Example 1:

[0035] Prepare a low-temperature underwater epoxy repair mortar, in mass parts:

[0036] S1, weigh 80 parts of bisphenol F epoxy resin 170, 20 parts of triglycidyl m-aminophenol TT-300, 35 parts of benzyl glycidyl ether 692, and 57 parts of CX-28 phenolic amine curing agent, and stir for 60 s by a mortar mixer to obtain a resin base liquid component;

[0037] S2, add 518.4 parts of filler TL-4 to the mortar mixer, and continue to stir for 60 s to obtain a low-temperature underwater epoxy repair mortar.

[0038] Example 2:

[0039] Prepare a low-temperature underwater epoxy repair mortar, in mass parts:

[0040] S1, take 70 parts of bisphenol F epoxy resin 170, 30 parts of tri glycidyl m-aminophenol TT-300, 40 parts of benzyl glycidyl ether 692, 62 parts of CX-28 phenolic amine curing agent, stirring by mortar mixer for 60s, to get resin base liquid component;

[0041] S2, add 545.4 parts of filler TL-4 into mortar mixer, continue to stir for 60s, to get low temperature underwater epoxy repair mortar.

[0042] Example 3:

[0043] Prepare low temperature underwater epoxy repair mortar, in mass parts:

[0044] S1, take 60 parts of bisphenol F epoxy resin 170, 40 parts of tri glycidyl m-aminophenol TT-300, 45 parts of benzyl glycidyl ether 692, 67 parts of CX-28 phenolic amine curing agent, stirring by mortar mixer for 60s, to get resin base liquid component;

[0045] S2, add 572.4 parts of filler TL-4 into mortar mixer, continue to stir for 60s, to get low temperature underwater epoxy repair mortar.

[0046] Example 4:

[0047] Prepare low temperature underwater epoxy repair mortar, in mass parts:

[0048] S1, take 70 parts of bisphenol F epoxy resin 170, 30 parts of tri glycidyl m-aminophenol TT-300, 40 parts of benzyl glycidyl ether 692, 62 parts of CX-28 phenolic amine curing agent, stirring by mortar mixer for 60s, to get resin base liquid component;

[0049] S2, add 545.4 parts of filler TL-4 into mortar mixer, continue to stir for 60s, to get low temperature underwater epoxy repair mortar.

[0050] Example 5:

[0051] Prepare low temperature underwater epoxy repair mortar, in mass parts:

[0052] S1, take 70 parts of bisphenol F epoxy resin 170, 30 parts of tri glycidyl m-aminophenol TT-300, 40 parts of benzyl glycidyl ether 692, 62 parts of CX-28 phenolic amine curing agent, stirring by mortar mixer for 60s, to get resin base liquid component;

[0053] S2, add 545.4 parts of filler TL-4 into mortar mixer, continue to stir for 60s, to get low temperature underwater epoxy repair mortar.

[0054] Example 6:

[0055] Prepare the low-temperature underwater epoxy repair mortar, in mass parts:

[0056] S1, take 60 parts of bisphenol F epoxy resin 170, 40 parts of pentaerythritol tetraglycidyl ether XY-671, 40 parts of o-tolyl glycidyl ether 691, 67 parts of CX-28 phenolic amine curing agent, stir for 60s by mortar mixer, get resin base liquid component;

[0057] S2, add 558.9 parts of filler TL-4 into the mortar mixer, continue to stir for 60s, get low-temperature underwater epoxy repair mortar.

[0058] Example 7:

[0059] Prepare the low-temperature underwater epoxy repair mortar, in mass parts:

[0060] S1, take 70 parts of bisphenol F epoxy resin 170, 30 parts of pentaerythritol tetraglycidyl ether XY-671, 40 parts of benzyl glycidyl ether 692, 62 parts of CX-28 phenolic amine curing agent, stir for 60s by mortar mixer, get resin base liquid component;

[0061] S2, add 545.4 parts of filler TL-4 into the mortar mixer, continue to stir for 60s, get low-temperature underwater epoxy repair mortar.

[0062] Example 8:

[0063] Prepare the low-temperature underwater epoxy repair mortar, in mass parts:

[0064] S1, take 60 parts of bisphenol F epoxy resin 170, 40 parts of pentaerythritol tetraglycidyl ether XY-671, 40 parts of o-tolyl glycidyl ether 691, 67 parts of CX-28 phenolic amine curing agent, stir for 60s by mortar mixer, get resin base liquid component;

[0065] S2, add 572.4 parts of filler TL-4 and 20 parts of modified powder into the mortar mixer, continue to stir for 60s, get low-temperature underwater epoxy repair mortar.

[0066] Example 9:

[0067] Prepare the low-temperature underwater epoxy repair mortar, in mass parts:

[0068] S1, take 60 parts of bisphenol F epoxy resin 170, 40 parts of pentaerythritol tetraglycidyl ether XY-671, 40 parts of o-tolyl glycidyl ether 691, 67 parts of CX-28 phenolic amine curing agent, stir for 60s by mortar mixer, get resin base liquid component;

[0069] S2, 572.4 parts of filler TL-4 and 25 parts of modified powder were added into the mortar mixer, and continued to stir for 60 s, to obtain the low-temperature underwater epoxy repair mortar.

[0070] Example 10:

[0071] The low-temperature underwater epoxy repair mortar was prepared, and the mass parts were as follows:

[0072] S1, 60 parts of bisphenol F epoxy resin 170, 40 parts of triepoxy glycidyl m-aminophenol TT-300, 45 parts of benzyl glycidyl ether 692, and 67 parts of CX-28 phenolic amine curing agent were weighed, and stirred for 60 s by a mortar mixer to obtain a resin base liquid component;

[0073] S2, 572.4 parts of filler TL-4 and 25 parts of modified powder were added into the mortar mixer, and continued to stir for 60 s, to obtain the low-temperature underwater epoxy repair mortar.

[0074] Example 11:

[0075] The low-temperature underwater epoxy repair mortar was prepared, and the mass parts were as follows:

[0076] S1, 60 parts of bisphenol F epoxy resin 170, 40 parts of triepoxy glycidyl m-aminophenol TT-300, 45 parts of benzyl glycidyl ether 692, and 67 parts of CX-28 phenolic amine curing agent were weighed, and stirred for 60 s by a mortar mixer to obtain a resin base liquid component;

[0077] S2, 572.4 parts of filler TL-4 and 25 parts of modified powder were added into the mortar mixer, and continued to stir for 60 s, to obtain the low-temperature underwater epoxy repair mortar.

[0078] Comparative Example 1:

[0079] The low-temperature underwater epoxy repair mortar was prepared, and the mass parts were as follows:

[0080] S1, 60 parts of bisphenol F epoxy resin 170, 40 parts of triepoxy glycidyl m-aminophenol TT-300, 45 parts of benzyl glycidyl ether 692, and 67 parts of CX-28 phenolic amine curing agent were weighed, and stirred for 60 s by a mortar mixer to obtain a resin base liquid component;

[0081] S2, 572.4 parts of filler TL-4 and 25 parts of modified powder were added into the mortar mixer, and continued to stir for 60 s, to obtain the low-temperature underwater epoxy repair mortar.

[0082] Comparative Example 2:

[0083] The low-temperature underwater epoxy repair mortar was prepared, and the mass parts were as follows:

[0084] S1, take 70 parts of bisphenol F epoxy resin 170, 30 parts of tri glycidyl m-aminophenol TT-300, 40 parts of benzyl glycidyl ether 692, 62 parts of CX-28 phenolic amine curing agent, stirring by mortar mixer for 60s, to obtain resin base liquid component;

[0085] S2, add 545.4 parts of filler TL-3 into the mortar mixer, continue to stir for 60s, to obtain low-temperature underwater epoxy repair mortar.

[0086] Comparative example 3:

[0087] Prepare low-temperature underwater epoxy repair mortar, in mass parts:

[0088] S1, take 70 parts of bisphenol F epoxy resin 170, 30 parts of tri glycidyl m-aminophenol TT-300, 40 parts of benzyl glycidyl ether 692, 62 parts of CX-28 phenolic amine curing agent, stirring by mortar mixer for 60s, to obtain resin base liquid component;

[0089] S2, add 545.4 parts of filler TL-5 into the mortar mixer, continue to stir for 60s, to obtain low-temperature underwater epoxy repair mortar.

[0090] Comparative example 4:

[0091] Prepare low-temperature underwater epoxy repair mortar, in mass parts:

[0092] S1, take 70 parts of bisphenol F epoxy resin 170, 30 parts of tri glycidyl m-aminophenol TT-300, 40 parts of benzyl glycidyl ether 692, 62 parts of CX-28 phenolic amine curing agent, stirring by mortar mixer for 60s, to obtain resin base liquid component;

[0093] S2, add 545.4 parts of filler TL-0 into the mortar mixer, continue to stir for 60s, to obtain low-temperature underwater epoxy repair mortar.

[0094] The second technical scheme provided by the application comprises:

[0095] Preparation of organic modified fine powder:

[0096] An ethanol solution of Al(NO3)9H2O was prepared at room temperature with a metal cation concentration of 1 mol / L, and heated to 50°C to fully dissolve the aluminum nitrate in ethanol, and cooled to room temperature. Under vigorous stirring (600 r / min), an ethanol solution of 20% oxalic acid was quickly poured into the nitrate solution, and stirring was continued for 10 min, and the suspension was aged at 23°C for 6 h. The suspension was separated by solid-liquid using a high-speed centrifuge at 1000 r / min and washed 3 times with ethanol, and the obtained solid mixture was dried at 110°C for 12 h. The powder-like alumina precursor powder was obtained by grinding and crushing using a agate mortar, and the obtained powder-like alumina precursor powder was calcined at 500°C to prepare the organically modified alumina powder.

[0097] Test:

[0098] (1) Preparation of underwater compressive strength test piece

[0099] Referring to the standard DL / T 5193-2021 Appendix E "Compressive Strength Test Method", the test mold was placed in water, the water surface was higher than the upper surface of the test mold by 5 cm, the mortar was poured into the mold at a height of 3 cm above the water surface, and the pouring was stopped when the mortar was 1 cm higher than the mold, and the surface was collected with a spatula, the test piece was cured for 24 h, and then placed in water for further curing for 28 days after demolding.

[0100] (2) Preparation of underwater bonding strength test piece

[0101] A smooth iron sheet was inserted into the "8" shaped test mold to form a half "8" shaped test block. The bonding surface of 22.2 mm*22.5 mm was polished by an angle grinder to remove the surface cement paste. According to the method in DL / T 5150-2017 7.8, a half "8" shaped base block was first installed in the test mold, then the test mold was placed underwater, and after 48 h, the prepared epoxy resin mortar was poured into the test mold and leveled with a spatula. After 48 h, the mold was removed, and then placed in water for further curing for 28 days after demolding.

[0102] (3) Performance test

[0103] The packing density and void ratio of the filler were tested according to the "Packing Density and Void Ratio Test Method" in GB / T 14685-2011; the flowability of the epoxy resin mortar was tested according to the "Cement Paste Flowability Test Method" in GB / T 8077-2012; the viscosity of the underwater epoxy resin base fluid was tested according to GB / T 22314-2008; the compressive strength was tested according to DL / T 5193-2021; and the underwater bonding strength was tested according to DL / T 5150-2017.

[0104] Table 3 Low-temperature underwater epoxy repair mortar flowability and mechanical properties

[0105]

[0106] Conclusion:

[0107] From the test results, it can be seen that the low-temperature underwater epoxy repair mortar prepared by the application has high strength, fluidity, bonding strength and compressive strength, and can solve the problems of poor flow and low underwater bonding strength of low-temperature underwater mortar.

[0108] The above description is only preferred embodiments of the present application, and it should be understood that the present application is not limited to the forms disclosed herein, and should not be considered as excluding other embodiments, but can be used in various other combinations, modifications and environments, and can be modified within the scope of the concepts described herein by the above-mentioned teaching or related art or knowledge. Any modification and change made by those skilled in the art without departing from the spirit and scope of the present application shall be within the protection scope of the claims of the present application.

Claims

1. A low temperature underwater epoxy repair mortar, characterized in that: The components include the following: 60-80 parts of low viscosity epoxy resin, 20-40 parts of multi-epoxy functional resin, 35-40 parts of active diluent, 57-67 parts of curing agent and 518.4-572.4 parts of fillers, which are stone powder and quartz sand, and are obtained by using Dinger-Funk equation optimization; the low viscosity epoxy resin is bisphenol F epoxy resin 170.

2. The cryogenic underwater epoxy repair mortar according to claim 1, characterized in that: The curing agent is hydrophobic CX-28 phenolic amine curing agent.

3. The cryogenic underwater epoxy repair mortar according to claim 1, characterized in that: The multi-epoxy functional resin is any one of glycerol triglycidyl ether, pentaerythritol tetraglycidyl ether or trisglycidyl m-aminophenol.

4. The cryogenic underwater epoxy repair mortar of claim 1, wherein: The diluent is any one of o-tolyl glycidyl ether, dodecyl glycidyl ether, octyl glycidyl ether, benzyl glycidyl ether or phenyl glycidyl ether.

5. The cryogenic underwater epoxy repair mortar of claim 1, wherein: 20-25 parts of organic modified fine powder are further included.

6. The cryogenic underwater epoxy repair mortar according to claim 5, characterized in that: The organic modified fine powder is organic modified alumina powder, which is prepared by oxalic acid gel method.

7. The method of claim 1-6, wherein the low temperature underwater epoxy repair mortar is prepared by the following steps: The steps include the following: S1, weigh low viscosity epoxy resin, multi-functional epoxy resin, active diluent and curing agent, and obtain resin base liquid component by stirring machine; S2, add fillers into the stirring machine, and continue to stir to obtain low temperature underwater epoxy repair mortar.

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