Glass fiber reinforced plastic lining reinforced concrete pipe interface reinforcing agent as well as preparation method and application thereof

Abstract

The invention relates to a glass fiber reinforced plastic lining reinforced concrete pipe interface reinforcing agent and a preparation method and application thereof. The interface reinforcing agent comprises a component A and a component B, the component A comprises epoxy resin and filler; the component B comprises a first curing agent, a second curing agent and a filler; the gelation time of the first curing agent is 10 to 30 minutes, and the gelation time of the second curing agent is 120 to 180 minutes; the mass ratio of the first curing agent to the second curing agent is 1: 3-3: 2. The glass fiber reinforced plastic lining reinforced concrete pipe interface reinforcing agent has excellent comprehensive properties such as adhesive property, mechanical property and processability, and the gelation time is 40-90 minutes; the compressive strength can reach 60 MPa or above, the tensile strength can reach 15 MPa or above, the bonding strength can reach 2.0 MPa, and the performance far exceeds the corresponding standard.

Description

Technical Field

[0001] The invention belongs to the technical field of cement concrete, and specifically relates to an interface enhancer for a glass fiber reinforced plastic lined reinforced concrete pipe, and a preparation method and application thereof. Background Art

[0002] FRP lined reinforced concrete pipe is a composite concrete pipe, which combines the corrosion resistance of FRP and the low cost and good durability of concrete. It is widely used in drainage projects with high corrosion requirements. At present, domestic FRP lined reinforced concrete pipes are prepared according to the design requirements of T / CCPA19-2020 "FRP lined reinforced concrete composite pipe". Since FRP is an unsaturated resin material, it has almost no adhesion with concrete. In order to improve the integrity of FRP lined reinforced concrete pipe, a steel wire mesh with angles is embedded in the FRP pipe, so that the steel wire angles are inserted into the concrete to strengthen the interface adhesion. The standard requires that the interface adhesion between FRP pipes and concrete pipes shall not be less than 0.7MPa. However, in production, affected by various factors such as the quality of the steel mesh, design size, concrete mix ratio and production management, the interface adhesion between FRP pipes and reinforced concrete pipes is poor, and the interface adhesion often fails to meet the standard requirements. In addition, the process of pre-embedding angle steel wire mesh in the production of FRP pipes is complicated and costly, which is not conducive to the large-scale promotion and application of FRP lined reinforced concrete pipes.

[0003] Patent CN 204328238U discloses a FRP concrete composite pipe, in which the interface adhesive applied to the outer wall of the FRP inner liner pipe is a modified epoxy resin, but the bonding strength of the resin is not high enough. Ordinary interface adhesives or structural adhesives are usually difficult to use for bonding FRP inner liner reinforced concrete pipes, and the FRP inner liner pipe and the concrete pipe are easy to fall off.

[0004] FRP lined reinforced concrete pipes have excellent performance in treating sewage discharge and have broad market prospects. However, the composite process of FRP lined pipes and concrete pipes is complicated and the effect is poor. FRP pipes are prone to fall off after long-term use. Therefore, it is very important to solve the problem of FRP lined pipes and concrete pipes having excellent overall properties such as bonding properties, mechanical properties, and processability. Summary of the invention

[0005] In view of the deficiencies in the prior art, one of the purposes of the present invention is to provide an improved FRP-lined reinforced concrete pipe interface enhancer having excellent comprehensive properties such as bonding properties, mechanical properties and processability.

[0006] In order to achieve the above object, the technical solution adopted by the present invention is:

[0007] An interface enhancer for a glass fiber reinforced plastic lined reinforced concrete pipe, the interface enhancer comprising component A and component B; the component A comprises epoxy resin and filler; the component B comprises a first curing agent, a second curing agent and filler; the gel time of the first curing agent is 10-30 minutes, and the gel time of the second curing agent is 120-180 minutes; the mass ratio of the first curing agent to the second curing agent is 1:3 to 3:2.

[0008] In the present invention, the gel time is measured according to GB / T7123.1-2015 "Determination of operable time of multi-component adhesives", and the test temperature is about 23°C. Throughout the present invention, unless otherwise specified, the test temperature of the gel time is about 23°C.

[0009] In the prior art, ordinary interface adhesives or structural adhesives are usually difficult to be used for bonding of FRP lined reinforced concrete pipes, and FRP lined pipes and concrete pipes are easy to fall off. Although the prior art discloses modified epoxy resin as an interface adhesive applied to the outer wall of FRP lined pipes, it does not involve its bonding strength, and its bonding strength is not enough, which still causes the FRP lined pipes and concrete pipes to fall off easily, and cannot meet the requirements of mechanical properties. The inventors of the present application have found through a large number of experimental studies that by using a two-component modified epoxy resin as an interface enhancer for FRP lined reinforced concrete pipes, and using two curing agents with different gel times in the curing agent component for compounding, and controlling the mass ratio of the two, the final interface enhancer can be achieved to have a suitable gel time, excellent processing performance, and significantly improved mechanical properties and bonding properties. In both component A and component B of the two components, fillers are contained, and both are paste-like. Compared with one component in a liquid state and the other component in a solid state, the two-component composition of the present invention is more conducive to the uniform mixing of the two components during construction, and further improves the processability.

[0010] In some specific embodiments, the gel time of the first curing agent is 15-25 min, and the gel time of the second curing agent is 140-160 min.

[0011] In some specific embodiments, the first curing agent is a phenolic amine curing agent; the second curing agent is selected from a combination of one or more of aliphatic amine curing agents, alicyclic amine curing agents, and aromatic amine curing agents.

[0012] Preferably, the first curing agent is T31 phenolic amine curing agent (with a gel time of 20 minutes), and the second curing agent is DE423 aromatic amine curing agent (4,4'-diaminodiphenyl sulfone) (with a gel time of 150 minutes).

[0013] In some specific embodiments, the filler in component A and the filler in component B both include aggregates and powders.

[0014] Preferably, the aggregate is selected from a combination of one or more of quartz sand, river sand, and machine-made sand; and the powder is a combination of one or more of calcite powder, talcum powder, and calcium carbonate.

[0015] Preferably, the particle size of the aggregate is 0.1-1 mm; the particle size of the powder is 10-30 μm.

[0016] In some specific embodiments, the component A further comprises a diluent, a toughening agent and a thixotropic agent.

[0017] In some specific embodiments, the component B further includes a coupling agent and a thixotropic agent.

[0018] In some specific embodiments, the component A includes, by weight, 45 to 65 parts of epoxy resin, 5 to 25 parts of diluent, 5 to 15 parts of toughening agent, 5 to 15 parts of aggregate, 25 to 45 parts of powder and 2.0 to 6.0 parts of thixotropic agent.

[0019] In some specific embodiments, the component B includes, by weight, 5 to 20 parts of a first curing agent, 5 to 20 parts of a second curing agent, 8 to 18 parts of powder, 1 to 10 parts of aggregate, 1 to 5 parts of a coupling agent, and 1.0 to 3.5 parts of a thixotropic agent.

[0020] In some specific embodiments, the component A includes, by weight, 50 to 60 parts of epoxy resin, 10 to 20 parts of diluent, 5 to 10 parts of toughening agent, 5 to 15 parts of aggregate, 30 to 40 parts of powder and 3.0 to 5.0 parts of thixotropic agent.

[0021] In some specific embodiments, the component B includes, by mass, 7 to 15 parts of a first curing agent, 10 to 18 parts of a second curing agent, 10 to 15 parts of powder, 1 to 10 parts of aggregate, 1 to 5 parts of a coupling agent and 1.5 to 3.0 parts of a thixotropic agent.

[0022] In some specific embodiments, the epoxy resin is 128 epoxy resin.

[0023] In some specific embodiments, the diluent is a reactive diluent with an epoxy value of 0.6 to 0.8; preferably, it is a 622 reactive diluent with an epoxy value of 0.78.

[0024] In some specific embodiments, the toughening agent is a reactive epoxy toughening agent, which contains multiple active end groups in the molecular chain and can participate in the curing reaction of the epoxy resin to form a stable cross-linked network structure.

[0025] In some specific embodiments, the toughening agent is selected from CYH-277 and A40 toughening agent.

[0026] In some specific embodiments, the thixotropic agent is selected from a combination of one or more of hydrated silica, organic bentonite, and kaolin.

[0027] In some specific embodiments, the coupling agent is a silane coupling agent.

[0028] Preferably, the coupling agent is selected from one or a combination of γ-aminopropyltriethoxysilane (KH550), γ-glycidyloxypropyltrimethoxysilane (KH560), and γ-methacryloxypropyltrimethoxysilane (KH570).

[0029] In some specific embodiments, the mass ratio of component A to component B is 2.5-3.0:1.

[0030] In some specific embodiments, the gel time of the interface enhancer is 40-90min; the compressive strength is 60-75MPa, the tensile strength is 15-20MPa, and the bonding strength is 2.0-3.0MPa. The interface enhancer of the present invention has excellent processing performance, mechanical properties and bonding strength. In the construction process of FRP lined reinforced concrete pipes, after casting the interface enhancer, it is necessary to put in steel bars, and this step takes a certain amount of time. Therefore, the interface enhancer cannot gel too quickly and requires a suitable open time for the steel bars to be put in. If the gel time is too short, the steel bars cannot be put in, and the construction is inconvenient. If the gel time is too long, the construction efficiency is significantly reduced. The gel time of the present invention can not only ensure the construction efficiency, but also ensure that the steel bars are effectively put in, thereby ensuring the quality of the FRP lined reinforced concrete pipe.

[0031] The present invention also provides a method for preparing the interface enhancer of the aforementioned FRP-lined reinforced concrete pipe, the preparation method comprising the steps of mixing the raw materials of component A to obtain component A; and mixing the raw materials of component B to obtain component B.

[0032] The present invention also provides the use of the above-mentioned interface reinforcing agent of the glass fiber reinforced plastic lined reinforced concrete pipe in bonding the glass fiber reinforced plastic lined pipe and the reinforced concrete pipe.

[0033] Due to the application of the above technical solution, the present invention has the following advantages compared with the prior art:

[0034] The present invention adopts a two-component modified epoxy resin as an interface enhancer for a glass fiber reinforced plastic lined reinforced concrete pipe, and simultaneously adopts two curing agents with different gel times in a curing agent component for compounding, and controls the mass ratio of the two, so that the final interface enhancer can have a suitable gel time, excellent processing performance, and significantly improved mechanical properties and bonding properties.

[0035] The present invention can significantly improve the interface bonding force between the FRP pipe and the reinforced concrete pipe, ensure the integrity of the FRP lined reinforced concrete pipe, thereby reducing the risk of bonding failure of the pipe and extending the safe service life of the pipe.

[0036] The gel time of the interface enhancer of the present invention is 40-90 minutes; the 7d compressive strength can reach more than 60MPa, the 7d tensile strength can reach more than 15MPa, and the 7d bonding strength can reach 2.0MPa, and the performance far exceeds the corresponding standard (bonding strength greater than 0.7MPa).

[0037] The present invention can eliminate the production process of pre-embedded steel wire mesh in glass fiber reinforced plastic pipes, simplify the entire process flow, save labor, reduce production costs, and has good market promotion prospects. DETAILED DESCRIPTION

[0038] The technical solution of the present invention is described in detail below in conjunction with specific embodiments so that those skilled in the art can better understand and implement the technical solution of the present invention, but the present invention is not limited to the scope of the examples.

[0039] Some of the raw materials used in the following examples and comparative examples come from the following sources:

[0040] The epoxy resin is 128 from Baling Petrochemical;

[0041] The toughening agent is CYH-277;

[0042] The aggregate is quartz sand with a particle size of 0.3 mm;

[0043] The powder is calcium carbonate powder with a particle size of 23 μm;

[0044] The diluent is active diluent 622;

[0045] The thixotropic agent is hydrated silicon dioxide;

[0046] The coupling agent is KH560;

[0047] The first curing agent is T31 or LT-734A;

[0048] The second curing agent is DE423 or 590.

[0049] Example 1

[0050] This embodiment provides an interface enhancer for a glass fiber reinforced plastic lined reinforced concrete pipe, the raw material formula (weight parts) is shown in Table 1, and the preparation method is as follows:

[0051] (1) Weigh all the raw materials of Component A according to the ratio, add epoxy resin, diluent and toughening agent in sequence and stir slowly for 1 min, then add aggregate, powder and thixotropic agent and stir slowly for 5 min until all components are uniform, thus obtaining Component A.

[0052] (2) Weigh all the raw materials of Component B according to the ratio, add the first curing agent, the second curing agent and the coupling agent in turn, stir slowly for 1 min, then add the aggregate, powder and thixotropic agent and stir for 3 min until all the components are uniform, thereby obtaining Component B.

[0053] (3) Component A and component B were mixed in a mass ratio of 3:1 and stirred for 120 seconds until they were uniform, thereby obtaining an interface enhancer.

[0054] Example 2-3

[0055] This embodiment provides an interface enhancer for a glass fiber reinforced plastic lined reinforced concrete pipe, which is basically the same as that of Embodiment 1, except that the raw material formula is different, see Table 1 for details.

[0056] Comparative Example 1

[0057] This comparative example provides an interface enhancer, which is basically the same as Example 1, except that the raw material formula is different, see Table 1 for details. Specifically, the second curing agent is replaced by LT-734A (purchased from a certain company, whose product manual records that it is a low-temperature, fast-drying, high-toughness special amine epoxy curing agent, and records that its gel time at 25°C is 12 minutes), that is, two curing agents with short gel time are used.

[0058] Comparative Example 2

[0059] This comparative example provides an interface enhancer, which is basically the same as Example 1, except that the raw material formula is different, see Table 1 for details. Specifically, the first curing agent is replaced by T31 with 590 (whose gel time is 240 min), that is, two curing agents with long gel time are used.

[0060] Comparative Example 3

[0061] This comparative example provides an interface enhancer, which is basically the same as Example 1, except that the raw material formula is different, see Table 1 for details.

[0062] Comparative Example 4

[0063] This comparative example provides an interface enhancer, which is basically the same as Example 1, except that the raw material formula is different, see Table 1 for details.

[0064] Table 1 Raw material formula of each embodiment and comparative example (by weight)

[0065]

[0066]

[0067] Performance Testing

[0068] For the interface enhancers prepared in the above embodiments and comparative examples, the gel time is in accordance with GB / T7123.1-2015 "Determination of operable time of multi-component adhesives"; the compressive strength, tensile strength and bonding strength are tested in accordance with GB 50728-2011 standard, and the results are shown in Table 2.

[0069] Table 2 Performance test results

[0070]

[0071] As can be seen from Table 2, the spraying state of the interface enhancer of the present invention is good, and the gel time, compressive strength, tensile strength and bonding strength all meet the requirements of the glass fiber reinforced plastic lined reinforced concrete pipe, especially the gel time is 40-90min, the 7d compressive strength can reach 60MPa, and the 7d bonding strength can reach more than 2MPa, which is much greater than the standard requirement of 0.7MPa. However, if two curing agents with long gel time or two curing agents with short gel time are compounded, or the mass ratio range of the two curing agents is changed, the gel time (manifestation of processability), mechanical properties and bonding properties of the obtained interface enhancer cannot be excellent at the same time.

[0072] The above embodiments are only for illustrating the technical concept and features of the present invention, and their purpose is to enable people familiar with the technology to understand the content of the present invention and implement it accordingly, and they cannot be used to limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit of the present invention should be included in the protection scope of the present invention.

[0073] The endpoints and any values ​​of the ranges disclosed in this article are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this article.

Claims

1. An interface enhancer for a glass fiber reinforced plastic lined reinforced concrete pipe, characterized in that: The interface enhancer includes component A and component B; the component A includes epoxy resin and filler; the component B includes a first curing agent, a second curing agent and a filler; the gel time of the first curing agent is 10-30 minutes, and the gel time of the second curing agent is 120-180 minutes; the mass ratio of the first curing agent to the second curing agent is 1:3 to 3:

2.

2. The interface enhancer for the FRP lined reinforced concrete pipe according to claim 1, characterized in that: The gel time of the first curing agent is 15-25 minutes, and the gel time of the second curing agent is 140-160 minutes.

3. The interface enhancer for the FRP lined reinforced concrete pipe according to claim 1, characterized in that: The first curing agent is a phenolic amine curing agent; the second curing agent is selected from a combination of one or more of aliphatic amine curing agents, alicyclic amine curing agents, and aromatic amine curing agents; preferably, the first curing agent is T31 phenolic amine curing agent, and the second curing agent is DE423 aromatic amine curing agent.

4. The interface enhancer for the FRP lined reinforced concrete pipe according to claim 1, characterized in that: The filler in component A and the filler in component B both include aggregate and powder; preferably, the aggregate is selected from a combination of one or more of quartz sand, river sand, and machine-made sand; the powder is a combination of one or more of calcite powder, talcum powder, and calcium carbonate; and / or the particle size of the aggregate is 0.1-1mm; the particle size of the powder is 10-30μm.

5. The interface enhancer for the FRP lined reinforced concrete pipe according to claim 1, characterized in that: The component A further comprises a diluent, a toughening agent and a thixotropic agent; and / or the component B further comprises a coupling agent and a thixotropic agent.

6. The interface enhancer for the FRP lined reinforced concrete pipe according to claim 5, characterized in that: Calculated by mass, the component A includes 45 to 65 parts of epoxy resin, 5 to 25 parts of diluent, 5 to 15 parts of toughening agent, 5 to 15 parts of aggregate, 25 to 45 parts of powder and 2.0 to 6.0 parts of thixotropic agent; and / or, calculated by mass, the component B includes 5 to 20 parts of first curing agent, 5 to 20 parts of second curing agent, 8 to 18 parts of powder, 1 to 10 parts of aggregate, 1 to 5 parts of coupling agent and 1.0 to 3.5 parts of thixotropic agent.

7. The interface enhancer for the FRP lined reinforced concrete pipe according to claim 5, characterized in that: Measured in parts by mass, the component A comprises 50 to 60 parts of epoxy resin, 10 to 20 parts of diluent, 5 to 10 parts of toughening agent, 5 to 15 parts of aggregate, 30 to 40 parts of powder and 3.0 to 5.0 parts of thixotropic agent; and / or, measured in parts by mass, the component B comprises 7 to 15 parts of first curing agent, 10 to 18 parts of second curing agent, 10 to 15 parts of powder, 1 to 10 parts of aggregate, 1 to 5 parts of coupling agent and 1.5 to 3.0 parts of thixotropic agent.

8. The interface enhancer for the FRP lined reinforced concrete pipe according to claim 5, characterized in that: The epoxy resin is 128 epoxy resin; and / or the diluent is an active diluent, and the epoxy value is 0.6-0.8; and / or the toughening agent is selected from CYH-277, A40 toughening agent; and / or the thixotropic agent is selected from a combination of one or more of hydrated silica, organic bentonite, and kaolin; and / or the coupling agent is a silane coupling agent.

9. The interface enhancer for the FRP lined reinforced concrete pipe according to claim 1, characterized in that: The mass ratio of component A to component B is 2.5-3.0:

1.

10. The interface enhancer for the FRP lined reinforced concrete pipe according to claim 1, characterized in that: The gel time of the interface enhancer is 40-90 minutes; the compressive strength is 60-75 MPa, the tensile strength is 15-20 MPa, and the bonding strength is 2.0-3.0 MPa.

11. A method for preparing the interface enhancer of the glass fiber reinforced plastic lined reinforced concrete pipe according to any one of claims 1 to 10, characterized in that: The preparation method comprises the steps of mixing the raw materials of the component A to obtain the component A; and mixing the raw materials of the component B to obtain the component B.

12. Use of the interface enhancer for FRP lined reinforced concrete pipes according to any one of claims 1 to 10 in bonding FRP lined pipes and reinforced concrete pipes.

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