Bridge expansion joint transition zone concrete composite
By designing concrete composite materials for the transition zone of bridge expansion joints, and utilizing interpenetrating mesh structures and anchoring effects, the problems of easy debonding, cracking, and breakage of concrete in the transition zone of bridge expansion joints are solved, thereby improving impact resistance and service life.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- CHONGQING JIAOTONG UNIV
- Filing Date
- 2024-03-14
- Publication Date
- 2026-05-15
AI Technical Summary
The concrete in the transition zone of bridge expansion joints is prone to debonding, cracking, and breakage during use, resulting in the inability to effectively transfer loads and poor impact resistance, failing to meet design and actual service life requirements.
A concrete composite material for the transition zone of bridge expansion joints is adopted, comprising ordinary silicate cement, acrylic modified emulsified asphalt, hydroxyl styrene-butadiene latex, polymer emulsion, loofah fiber and other components. By forming an interpenetrating network structure and anchoring effect, the bonding strength and toughness are improved, and the impact resistance is enhanced.
It achieves high strength and high toughness, excellent crack resistance and impact resistance, good compatibility between new and old materials, avoids cracking and damage again in a short period of time, and extends service life.
Smart Images
Figure BDA0004741714740000101 
Figure BDA0004741714740000111
Abstract
Description
Technical Field
[0001] This invention relates to the field of road materials, and more specifically to a concrete composite material for the transition zone of bridge expansion joints. Background Technology
[0002] To ensure that bridge structures can deform freely under temperature changes and loads, and to avoid stress caused by obstructed deformation leading to bridge structural damage, bridge expansion joints are widely used in various bridge structures, becoming one of the important components of bridge structures. They are generally installed between adjacent spans of a bridge and between the beam ends and the abutment back walls, serving as an important auxiliary structure to ensure free deformation of the bridge deck, reinforce both ends, and fill gaps. Currently, the main types of bridge expansion joints used domestically and internationally are: comb-plate type, modular type, rubber plate type, embedded type, and seamless type. Except for seamless expansion joints, which directly bond the expansion joint to the pavement layer to achieve seamless bridge structure, other types of expansion joints require a transition layer of concrete between the expansion joint and the pavement layer to achieve integration between the expansion joint and the main beam structure. Investigations have found that the most significant damage to bridge expansion joints is debonding, cracking, and breakage of the concrete in the transition zone. When the concrete breaks, the edge beams bear the majority of the vehicle load, causing the load to be unable to be effectively transferred to the underlying concrete, causing the steel beams to quickly reach their fatigue life. Another reason for the damage to the transition zone concrete is that rainwater seeps into the internal cracks of the concrete. Under the combined effect of vehicle loads and rainwater, the concrete is far from reaching its service life. Because the transition zone concrete is poured later, its modulus and shrinkage differ significantly from the matrix concrete. Furthermore, the bond strength between the new and old concrete is inherently low. Under repeated vehicle loads and temperature changes, inconsistent deformation between the concrete can lead to "debonding" at the expansion joint interface. The early shrinkage of freshly poured concrete is rapid, and the transition zone concrete components, constrained by the bridge deck and reinforcement, are prone to shrinkage cracks. Since expansion joints are a final stage of bridge construction, inadequate concrete curing and premature opening to traffic can also lead to early cracking. Under the repeated impact of vehicle loads, the early damage to the transition zone concrete further develops, and fragmentation begins. After rainwater penetration, the internal anchoring reinforcement corrodes, reducing its bond performance with the concrete. Concrete debris is ejected by vehicle wheels, causing the transition zone concrete to become void and lose its load-bearing capacity. Because the concrete in the transition zone breaks down and becomes void, it loses its ability to share the load with the steel beam. This can cause the steel beam to detach or become void under repeated vehicle traffic. In severe cases, the entire central beam can break, causing the expansion joint to completely lose its load-bearing function. Vehicles traveling at high speeds will experience severe bouncing when passing over the fracture zone of the central beam, threatening driving safety.The current concrete used in the transition zone of bridge expansion joints mainly consists of steel fiber reinforced concrete, ordinary concrete (such as C50 concrete), and rapid-setting concrete. However, judging from their use and maintenance in past projects, they have all failed to meet the design and actual service life requirements. Some even require reconstruction every 1-2 years. The main reasons for their substandard quality are threefold: 1) Steel fiber reinforced concrete, ordinary concrete, and rapid-setting concrete are all brittle materials with poor flexural and impact resistance, and cannot well adapt to the working environment of frequent impacts on bridge expansion joints; 2) They have low cohesive strength and interfacial bond strength, resulting in poor adhesion between them and concrete beams, slabs, embedded bars, and steel sections. Under stress, the bond interface is prone to cracking. Once cracked, the function is basically lost, ultimately leading to the destruction of the entire anchorage system; 3) Due to the low interfacial bond strength, in order to achieve the corresponding mechanical anchorage effect, extremely high requirements are placed on the surface flatness of beams, slabs, abutment back walls, the embedding effect of embedded bars, and the connection arrangement of embedded bars and steel sections. This places higher demands on construction quality control and makes it difficult to guarantee construction quality. In addition, regarding the time required for opening to traffic, steel fiber reinforced concrete and ordinary concrete have a longer curing time, usually requiring 28 days; although rapid concrete has higher early strength than steel fiber reinforced concrete and ordinary concrete, it is more brittle, has poor impact resistance, and a particularly short service life.
[0003] Therefore, it is necessary to solve the aforementioned technical problems with the concrete in the transition zone of bridge expansion joints. Summary of the Invention
[0004] In view of this, the purpose of this invention is to provide a concrete composite material for the transition zone of bridge expansion joints, which has high strength and high toughness, good crack resistance and impact resistance, and high bonding strength with road materials and expansion joint steel. While meeting the requirements of excellent early strength and early hardening performance, it can also meet many performance requirements such as later strength, elastic toughness, impact resistance, and elastic modulus. At the same time, the new and old materials have good compatibility, avoiding secondary damage such as cracking and breakage in a short period of time. This concrete can be used for the installation and construction of bridge expansion joints, as well as for the rapid repair of concrete in the transition zone of bridge expansion joints.
[0005] The bridge expansion joint transition zone concrete composite material of the present invention comprises the following components by weight:
[0006] 60-80 parts of ordinary silicate cement, 20-30 parts of acrylic-modified emulsified asphalt, 20-30 parts of hydroxyl styrene-butadiene latex, 5-10 parts of polymer emulsion A, 2-6 parts of methyl methacrylate, 2-6 parts of dimethyl 4,4'-biphenyl dicarboxylate, 5-10 parts of loofah fiber, 10-20 parts of redispersible latex powder, 1-3 parts of coupling agent, 1-3 parts of chain extender, and 1-3 parts of adhesion promoter;
[0007] Furthermore, the composite material raw material comprises the following components by weight:
[0008] 70 parts of ordinary silicate cement, 25 parts of acrylic modified emulsified bitumen, 25 parts of hydroxyl styrene-butadiene latex, 7 parts of polymer emulsion A, 4 parts of methyl methacrylate, 4 parts of dimethyl 4,4'-biphenyl dicarboxylate, 7 parts of loofah fiber, 15 parts of redispersible latex powder, 2 parts of coupling agent, 2 parts of chain extender, and 2 parts of adhesion promoter.
[0009] Furthermore, the polymer emulsion A is prepared in the following manner:
[0010] S1, benzylphenol polyoxyethylene ether, tris-(hydroxymethyl)aminomethane, and porphyrin molecules are mixed and then added to deionized water and stirred thoroughly to dissolve. The mixture is heated to 80-100℃, then styrene is added and stirred to emulsify. Finally, potassium persulfate dissolved in water is added and reacted thoroughly to obtain a seed emulsion.
[0011] S2, after mixing the seed emulsion and tris-(hydroxymethyl)aminomethane, heat to 70-90℃ and keep constant, then add potassium persulfate dissolved in water, and then add butyl acrylate dropwise. After the dropwise addition is completed, continue the reaction for 1 hour.
[0012] Furthermore, the coupling agent is a mixture of 3-aminopropyltriethoxysilane and monoalkoxytitanate, wherein the mass ratio of 3-aminopropyltriethoxysilane to monoalkoxytitanate is 5:2;
[0013] Furthermore, the chain extender is prepared by the following method: (1) maleimide-based phenol and furfuryl alcohol are added to a reaction vessel containing dioxane at a molar ratio of 1:1 to obtain a homogeneous mixed solution;
[0014] (4) After adding the magnetic particle, nitrogen gas is introduced to purge the air and the reaction vessel is sealed. The sealed reaction vessel is placed in a constant temperature water bath at 70-90℃ and heated to carry out the DA cycloaddition reaction.
[0015] (5) The product after the reaction is completed is concentrated by rotary evaporation under reduced pressure and the solvent is recovered; then it is dissolved in acetone, concentrated to obtain the product, then precipitated with ice-cold ether, repeatedly dissolved and concentrated, and then dried in a vacuum oven.
[0016] Furthermore, the adhesion promoter is one or more of γ-(2,3-epoxypropoxy)propyltrimethoxysilane, N-(β-aminoethyl)-γ-aminopropylmethyldimethoxysilane, N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane, propyltriethoxysilane, and tetraethyl orthosilicate.
[0017] The beneficial effects of this invention are as follows: The concrete composite material for the transition zone of bridge expansion joints of this invention has high strength and high toughness, good crack resistance and impact resistance, and high bonding strength with road materials and expansion joint steel. While meeting the requirements of excellent early strength and early hardening performance, it can also meet many performance requirements such as later strength, elastic toughness, impact resistance, and elastic modulus. At the same time, the new and old materials have good compatibility, avoiding secondary damage such as cracking and breakage in a short period of time. This concrete can be used for the installation and construction of bridge expansion joints, as well as for the rapid repair of concrete in the transition zone of bridge expansion joints.
[0018] The expansion joint composite material of this invention uses ordinary silicate cement and acrylic-modified emulsified asphalt as composite cementitious materials, resulting in higher bonding performance. Hydroxystyrene-butadiene latex can modify the dry crack resistance of concrete while improving the bonding performance of the composite material, ensuring its later impact resistance. Simultaneously, the acrylic-modified emulsified asphalt, coupling agent, and redispersible latex powder work together to ensure the early strength, later strength, and impact resistance of the composite material. The chain extender increases the elongation of the material, achieving high resistance to displacement deformation. The interpenetrating network structure formed between polymer A and cement hydration products, combined with the synergistic effect of loofah fibers, results in higher mechanical strength and toughness. Furthermore, it exhibits greater tensile and shear resistance under vibration, shock, and other impact loads, and can self-repair damage caused by similar structural defects, thereby increasing its lifespan and reliability. This is because loofah fibers and polymer A help to form higher shear strength and toughness within the concrete and can create an anchoring effect similar to a dense needle, making the concrete less prone to breakage and separation, while also improving the interfacial bond strength between new and old concrete. The use of dimethyl 4,4'-biphenyl dicarboxylate further enhances the toughness and tensile strength of the composite material. Detailed Implementation
[0019] To better understand the present invention, the following embodiments are further illustrations of the present invention, but the content of the present invention is not limited to the following embodiments.
[0020] Unless otherwise specified, the experimental methods used in the embodiments are conventional methods, and the materials and reagents used are commercially available unless otherwise specified.
[0021] Example 1
[0022] The concrete composite material for the bridge expansion joint transition zone in this embodiment comprises the following components by weight:
[0023] 60 parts of ordinary silicate cement, 20 parts of acrylic modified emulsified bitumen, 20 parts of hydroxyl styrene-butadiene latex, 5 parts of polymer emulsion A, 2 parts of methyl methacrylate, 2 parts of dimethyl 4,4'-biphenyl dicarboxylate, 5 parts of loofah fiber, 10 parts of redispersible latex powder, 1 part of coupling agent, 1 part of chain extender, and 1 part of adhesion promoter.
[0024] The polymer emulsion A is prepared in the following manner:
[0025] S1, benzylphenol polyoxyethylene ether (emulsifier), tris-(hydroxymethyl)aminomethane (buffer), and porphyrin molecules are mixed and then added to deionized water and stirred thoroughly to dissolve. The mixture is heated to 80°C, then styrene is added and stirred to emulsify. Finally, potassium persulfate dissolved in water is added and reacted thoroughly to obtain a seed emulsion.
[0026] S2, after mixing the seed emulsion and tris-(hydroxymethyl)aminomethane, heat to 70°C and keep constant, then add potassium persulfate dissolved in water, and then add butyl acrylate dropwise. After the addition is complete, continue the reaction for 1 hour.
[0027] The coupling agent is a mixture of 3-aminopropyltriethoxysilane and monoalkoxytitanate, wherein the mass ratio of 3-aminopropyltriethoxysilane to monoalkoxytitanate is 5:2.
[0028] The chain extender is prepared by the following method: (1) Maleimide-based phenol and furfuryl alcohol are added to a reaction vessel containing dioxane at a molar ratio of 1:1 to obtain a homogeneous mixed solution;
[0029] (2) After adding the magnetic particle, nitrogen gas is introduced to purge the air and the reaction vessel is sealed. The sealed reaction vessel is placed in a constant temperature water bath at 70°C and heated to carry out the DA cycloaddition reaction.
[0030] (3) The product after the reaction is completed is concentrated by rotary evaporation under reduced pressure and the solvent is recovered; then it is dissolved in acetone, concentrated to obtain the product, then precipitated with ice-cold ether, repeatedly dissolved and concentrated, and then dried in a vacuum oven;
[0031] The adhesion promoter is γ-(2,3-epoxypropoxy)propyltrimethoxysilane.
[0032] Example 2
[0033] The concrete composite material for the bridge expansion joint transition zone in this embodiment comprises the following components by weight:
[0034] 80 parts of ordinary silicate cement, 30 parts of acrylic modified emulsified asphalt, 30 parts of hydroxyl styrene-butadiene latex, 10 parts of polymer emulsion A, 6 parts of methyl methacrylate, 6 parts of dimethyl 4,4'-biphenyl dicarboxylate, 10 parts of loofah fiber, 20 parts of redispersible latex powder, 3 parts of coupling agent, 3 parts of chain extender, and 3 parts of adhesion promoter.
[0035] The polymer emulsion A is prepared in the following manner:
[0036] S1, benzylphenol polyoxyethylene ether, tris-(hydroxymethyl)aminomethane, and porphyrin molecules are mixed and then added to deionized water and stirred thoroughly to dissolve. The mixture is heated to 100°C, then styrene is added and stirred to emulsify. Finally, potassium persulfate dissolved in water is added and reacted thoroughly to obtain a seed emulsion.
[0037] S2, after mixing the seed emulsion and tris-(hydroxymethyl)aminomethane, heat to 90°C and keep constant, then add potassium persulfate dissolved in water, and then add butyl acrylate dropwise. After the addition is complete, continue the reaction for 1 hour.
[0038] The coupling agent is a mixture of 3-aminopropyltriethoxysilane and monoalkoxytitanate, wherein the mass ratio of 3-aminopropyltriethoxysilane to monoalkoxytitanate is 5:2.
[0039] The chain extender is prepared by the following method: (1) Maleimide-based phenol and furfuryl alcohol are added to a reaction vessel containing dioxane at a molar ratio of 1:1 to obtain a homogeneous mixed solution;
[0040] (2) After adding the magnetic particle, nitrogen gas is introduced to purge the air and the reaction vessel is sealed. The sealed reaction vessel is placed in a constant temperature water bath at 90°C and heated to carry out the DA cycloaddition reaction.
[0041] (3) The product after the reaction is completed is concentrated by rotary evaporation under reduced pressure and the solvent is recovered; then it is dissolved in acetone, concentrated to obtain the product, then precipitated with ice-cold ether, repeatedly dissolved and concentrated, and then dried in a vacuum oven;
[0042] The adhesion promoter is one or more of γ-(2,3-epoxypropoxy)propyltrimethoxysilane, N-(β-aminoethyl)-γ-aminopropylmethyldimethoxysilane, N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane, propyltriethoxysilane, and tetraethyl orthosilicate.
[0043] Example 3
[0044] The concrete composite material for the bridge expansion joint transition zone in this embodiment comprises the following components by weight:
[0045] 60 parts of ordinary silicate cement, 20 parts of acrylic modified emulsified asphalt-based styrene-butadiene latex, 10 parts of polymer emulsion A, 2 parts of methyl methacrylate, 6 parts of dimethyl 4,4'-biphenyl dicarboxylate, 5 parts of loofah fiber, 20 parts of redispersible latex powder, 1 part of coupling agent, 3 parts of chain extender, and 1 part of adhesion promoter.
[0046] The polymer emulsion A is prepared in the following manner:
[0047] S1, benzylphenol polyoxyethylene ether, tris-(hydroxymethyl)aminomethane, and porphyrin molecules are mixed and then added to deionized water and stirred thoroughly to dissolve. The mixture is heated to 85°C, then styrene is added and stirred to emulsify. Finally, potassium persulfate dissolved in water is added and reacted thoroughly to obtain a seed emulsion.
[0048] S2, after mixing the seed emulsion and tris-(hydroxymethyl)aminomethane, heat to 75°C and keep constant, then add potassium persulfate dissolved in water, and then add butyl acrylate dropwise. After the dropwise addition is completed, continue the reaction for 1 hour.
[0049] The coupling agent is a mixture of 3-aminopropyltriethoxysilane and monoalkoxytitanate, wherein the mass ratio of 3-aminopropyltriethoxysilane to monoalkoxytitanate is 5:2.
[0050] The chain extender is prepared by the following method: (1) Maleimide-based phenol and furfuryl alcohol are added to a reaction vessel containing dioxane at a molar ratio of 1:1 to obtain a homogeneous mixed solution;
[0051] (2) After adding the magnetic particle, nitrogen gas is introduced to purge the air and the reaction vessel is sealed. The sealed reaction vessel is placed in a constant temperature water bath at 75°C and heated to carry out the DA cycloaddition reaction.
[0052] (3) The product after the reaction is completed is concentrated by rotary evaporation under reduced pressure and the solvent is recovered; then it is dissolved in acetone, concentrated to obtain the product, then precipitated with ice-cold ether, repeatedly dissolved and concentrated, and then dried in a vacuum oven;
[0053] The adhesion promoter is N-(β-aminoethyl)-γ-aminopropylmethyldimethoxysilane.
[0054] Example 4
[0055] The concrete composite material for the bridge expansion joint transition zone in this embodiment comprises the following components by weight:
[0056] 80 parts of ordinary silicate cement, 30 parts of acrylic modified emulsified asphalt, 30 parts of hydroxyl styrene-butadiene latex, 5 parts of polymer emulsion A, 4 parts of methyl methacrylate, 3 parts of dimethyl 4,4'-biphenyl dicarboxylate, 9 parts of loofah fiber, 15 parts of redispersible latex powder, 1 part of coupling agent, 3 parts of chain extender, and 2 parts of adhesion promoter.
[0057] The polymer emulsion A is prepared in the following manner:
[0058] S1, benzylphenol polyoxyethylene ether, tris-(hydroxymethyl)aminomethane, and porphyrin molecules are mixed and then added to deionized water and stirred thoroughly to dissolve. The mixture is heated to 90°C, then styrene is added and stirred to emulsify. Finally, potassium persulfate dissolved in water is added and reacted thoroughly to obtain a seed emulsion.
[0059] S2, after mixing the seed emulsion and tris-(hydroxymethyl)aminomethane, heat to 80°C and keep constant, then add potassium persulfate dissolved in water, and then add butyl acrylate dropwise. After the addition is complete, continue the reaction for 1 hour.
[0060] The coupling agent is a mixture of 3-aminopropyltriethoxysilane and monoalkoxytitanate, wherein the mass ratio of 3-aminopropyltriethoxysilane to monoalkoxytitanate is 5:2.
[0061] The chain extender is prepared by the following method: (1) Maleimide-based phenol and furfuryl alcohol are added to a reaction vessel containing dioxane at a molar ratio of 1:1 to obtain a homogeneous mixed solution;
[0062] (2) After adding the magnetic particle, nitrogen gas is introduced to purge the air and the reaction vessel is sealed. The sealed reaction vessel is placed in a constant temperature water bath at 85°C and heated to carry out the DA cycloaddition reaction.
[0063] (3) The product after the reaction is completed is concentrated by rotary evaporation under reduced pressure and the solvent is recovered; then it is dissolved in acetone, concentrated to obtain the product, then precipitated with ice-cold ether, repeatedly dissolved and concentrated, and then dried in a vacuum oven;
[0064] The adhesion promoter is N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane.
[0065] Example 5
[0066] The concrete composite material for the bridge expansion joint transition zone in this embodiment comprises the following components by weight:
[0067] 78 parts of ordinary silicate cement, 25 parts of acrylic modified emulsified asphalt, 28 parts of hydroxyl styrene-butadiene latex, 7 parts of polymer emulsion A, 3 parts of methyl methacrylate, 5 parts of dimethyl 4,4'-biphenyl dicarboxylate, 7 parts of loofah fiber, 17 parts of redispersible latex powder, 1 part of coupling agent, 3 parts of chain extender, and 1.5 parts of adhesion promoter.
[0068] The polymer emulsion A is prepared in the following manner:
[0069] S1, benzylphenol polyoxyethylene ether, tris-(hydroxymethyl)aminomethane, and porphyrin molecules are mixed and then added to deionized water and stirred thoroughly to dissolve. The mixture is heated to 95°C, then styrene is added and stirred to emulsify. Finally, potassium persulfate dissolved in water is added and reacted thoroughly to obtain a seed emulsion.
[0070] S2, after mixing the seed emulsion and tris-(hydroxymethyl)aminomethane, heat to 88°C and keep constant, then add potassium persulfate dissolved in water, and then add butyl acrylate dropwise. After the dropwise addition is completed, continue the reaction for 1 hour.
[0071] The coupling agent is a mixture of 3-aminopropyltriethoxysilane and monoalkoxytitanate, wherein the mass ratio of 3-aminopropyltriethoxysilane to monoalkoxytitanate is 5:2.
[0072] The chain extender is prepared by the following method: (1) Maleimide-based phenol and furfuryl alcohol are added to a reaction vessel containing dioxane at a molar ratio of 1:1 to obtain a homogeneous mixed solution;
[0073] (2) After adding the magnetic particle, nitrogen gas is introduced to purge the air and the reaction vessel is sealed. The sealed reaction vessel is placed in a constant temperature water bath at 70-90℃ and heated to carry out the DA cycloaddition reaction.
[0074] (3) The product after the reaction is completed is concentrated by rotary evaporation under reduced pressure and the solvent is recovered; then it is dissolved in acetone, concentrated to obtain the product, then precipitated with ice-cold ether, repeatedly dissolved and concentrated, and then dried in a vacuum oven;
[0075] The adhesion promoter is propyltriethoxysilane 3-isocyanate.
[0076] Example 6
[0077] The concrete composite material for the bridge expansion joint transition zone in this embodiment comprises the following components by weight:
[0078] 70 parts of ordinary silicate cement, 25 parts of acrylic modified emulsified bitumen, 25 parts of hydroxyl styrene-butadiene latex, 7 parts of polymer emulsion A, 4 parts of methyl methacrylate, 4 parts of dimethyl 4,4'-biphenyl dicarboxylate, 7 parts of loofah fiber, 15 parts of redispersible latex powder, 2 parts of coupling agent, 2 parts of chain extender, and 2 parts of adhesion promoter.
[0079] The polymer emulsion A is prepared in the following manner:
[0080] S1, benzylphenol polyoxyethylene ether, tris-(hydroxymethyl)aminomethane, and porphyrin molecules are mixed and then added to deionized water and stirred thoroughly to dissolve. The mixture is heated to 90°C, then styrene is added and stirred to emulsify. Finally, potassium persulfate dissolved in water is added and reacted thoroughly to obtain a seed emulsion.
[0081] S2, after mixing the seed emulsion and tris-(hydroxymethyl)aminomethane, heat to 80°C and keep constant, then add potassium persulfate dissolved in water, and then add butyl acrylate dropwise. After the addition is complete, continue the reaction for 1 hour.
[0082] The coupling agent is a mixture of 3-aminopropyltriethoxysilane and monoalkoxytitanate, wherein the mass ratio of 3-aminopropyltriethoxysilane to monoalkoxytitanate is 5:2.
[0083] The chain extender is prepared by the following method: (1) Maleimide-based phenol and furfuryl alcohol are added to a reaction vessel containing dioxane at a molar ratio of 1:1 to obtain a homogeneous mixed solution;
[0084] (2) After adding the magnetic particle, nitrogen gas is introduced to purge the air and the reaction vessel is sealed. The sealed reaction vessel is placed in a constant temperature water bath at 80°C and heated to carry out the DA cycloaddition reaction.
[0085] (3) The product after the reaction is completed is concentrated by rotary evaporation under reduced pressure and the solvent is recovered; then it is dissolved in acetone, concentrated to obtain the product, then precipitated with ice-cold ether, repeatedly dissolved and concentrated, and then dried in a vacuum oven;
[0086] The adhesion promoter is tetraethyl orthosilicate.
[0087] The preparation method of the bridge expansion joint transition zone concrete composite material in the above embodiment includes: mixing ordinary silicate cement with water, then adding acrylic modified emulsified asphalt and polymer emulsion and continuing to stir, and finally adding methyl methacrylate, dimethyl 4,4'-biphenyl dicarboxylate, chain extender, adhesion promoter, loofah fiber, redispersible latex powder and coupling agent in sequence and stirring.
[0088] 1. Strength Test and Result Analysis
[0089] According to the provisions of GB / T 17671—2021 "Test for Strength of Cement Mortar", flexural and compressive strength specimens were prepared, demolded after standard curing for 2 hours, and the 2-hour strength was tested. The test results are as follows:
[0090]
[0091] 2. Impact resistance test and result analysis
[0092] According to GB / T 21120—2018 "Synthetic Fibers for Cement Concrete and Mortar", specimens with a diameter of (152±1) mm and a thickness of (63.5±1.0) mm were molded, cured to the specified age, and subjected to impact tests. The test results are shown in the table.
[0093] 28-day impact test results
[0094] Sample Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Number of impacts / times >190 >190 >190 >190 >190 >190
[0095] >
[0096] 3. Abrasion Test and Result Analysis The abrasion test was conducted according to JTG E30—2017 "Test Procedures for Cement and Cement Concrete in Highway Engineering". Abrasion specimens were prepared, cured for 28 days, and their abrasion amount was measured. The test results are shown in the table below:
[0097] 28-day wear test results
[0098] Sample Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 <![CDATA[Wear amount / (kg·m -2 )]]> 2.61 2.35 2.51 2.38 2.43 2.46
[0099] 4. Elastic Modulus Test and Result Analysis The elastic modulus test was conducted according to GB / T 50081—2019 "Test Methods for Physical and Mechanical Properties of Concrete". Prismatic specimens with dimensions of 150mm×150mm×300mm were prepared, and the 28-day elastic modulus was measured. The test results are shown in the table below:
[0100] Sample Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Elastic modulus / GPa 16.7 15.8 15.4 15.1 16.2 15.3
[0101] 5. Results of tensile bond strength test:
[0102]
[0103] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.
Claims
1. A concrete composite material for the transition zone of bridge expansion joints, characterized in that: The composite material raw material comprises the following components by weight: The composition comprises: 60-80 parts ordinary silicate cement, 20-30 parts acrylic-modified emulsified asphalt, 20-30 parts hydroxyl-butyl styrene latex, 5-10 parts polymer emulsion A, 2-6 parts methyl methacrylate, 2-6 parts dimethyl 4,4'-biphenyl dicarboxylate, 5-10 parts loofah fiber, 10-20 parts redispersible latex powder, 1-3 parts coupling agent, 1-3 parts chain extender, and 1-3 parts adhesion promoter; wherein polymer emulsion A is prepared by the following method: S1, benzylphenol polyoxyethylene ether, tris-(hydroxymethyl)aminomethane, and porphyrin molecules are mixed and then added to deionized water and stirred thoroughly to dissolve. The mixture is heated to 80-100℃, then styrene is added and stirred to emulsify. Finally, potassium persulfate dissolved in water is added and reacted thoroughly to obtain a seed emulsion. S2, after mixing the seed emulsion and tris-(hydroxymethyl)aminomethane, heat to 70-90℃ and keep constant, then add potassium persulfate dissolved in water, and then add butyl acrylate dropwise. After the addition is complete, continue the reaction for 1 hour.
2. The concrete composite material for the transition zone of bridge expansion joints according to claim 1, characterized in that: The composite material raw material comprises the following components by weight: 70 parts of ordinary silicate cement, 25 parts of acrylic-modified emulsified bitumen, 25 parts of hydroxyl styrene-butadiene latex, 7 parts of polymer emulsion A, 4 parts of methyl methacrylate, 4 parts of dimethyl 4,4'-biphenyl dicarboxylate, 7 parts of loofah fiber, 15 parts of redispersible latex powder, 2 parts of coupling agent, 2 parts of chain extender, and 2 parts of adhesion promoter.
3. The concrete composite material for the transition zone of bridge expansion joints according to claim 1, characterized in that: The coupling agent is a mixture of 3-aminopropyltriethoxysilane and monoalkoxytitanate, wherein the mass ratio of 3-aminopropyltriethoxysilane to monoalkoxytitanate is 5:
2.
4. The concrete composite material for the transition zone of bridge expansion joints according to claim 1, characterized in that: The chain extender is prepared by the following method: (1) Maleimide-based phenol and furfuryl alcohol are added to a reaction vessel containing dioxane at a molar ratio of 1:1 to obtain a homogeneous mixed solution; (2) After adding the magnetic particle, nitrogen gas is introduced to purge the air and the reaction vessel is sealed. The sealed reaction vessel is placed in a constant temperature water bath at 70-90℃ and heated to carry out the DA cycloaddition reaction. (3) The product after the reaction is completed is concentrated by rotary evaporation under reduced pressure and the solvent is recovered; then it is dissolved in acetone, concentrated to obtain the product, then precipitated with ice-cold ether, repeatedly dissolved and concentrated, and then dried in a vacuum oven.
5. The concrete composite material for the transition zone of bridge expansion joints according to claim 1, characterized in that: The adhesion promoter is one or more of γ-(2,3-epoxypropoxy)propyltrimethoxysilane, N-(β-aminoethyl)-γ-aminopropylmethyldimethoxysilane, N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane, propyltriethoxysilane, and tetraethyl orthosilicate.