Bridge expansion joint filling material and method of making same

Abstract

The application relates to the field of building materials, and particularly discloses a bridge expansion joint filling material and a preparation method thereof.A kind of bridge expansion joint filling material, as follows, the weight parts of raw materials: polyurethane resin 10-20 parts, titanium dioxide 1-3 parts, cement 6-8 parts, mineral powder 2-4 parts, magnetic particles 4-8 parts, curing agent 0.1-0.3 parts, dispersing agent 0.5-1 parts, water 5-10 parts; the polyurethane resin is water-based polyurethane; the preparation method is: after ultrasonic treatment of adding magnetic particles and polyurethane into acetone solution, heating to 40-50 DEG C, adding curing agent, titanium dioxide, mineral powder, cement and dispersing agent in sequence and stirring uniformly to obtain a mixture; the mixture is filled into a mold, a uniform magnetic field is applied, and the bridge expansion joint filling material is obtained after waiting for solidification and molding and taking out. The composition can be used for filling of bridge expansion joints, and has the advantages of high tensile strength.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of building materials, more particularly, it relates to a bridge expansion joint filling material and a preparation method thereof. BACKGROUND

[0002] Under the influence of environmental temperature and traffic load and other factors, the bridge will expand and shrink, in order to meet this deformation, it is necessary to set the bridge expansion joint between the two ends of the bridge body or between the end of the bridge body and the abutment, for buffering the expansion and contraction deformation of the bridge caused by temperature change, vehicle load and other factors. The expansion joint material refers to the material filled at the bridge expansion joint, its performance directly affects the safety and service life of the bridge, because the bridge is in the environment, so the expansion joint filling material is required to have high tensile strength, when subjected to external forces such as stretching or compression, it can maintain its shape and structural stability, and has good recovery performance.

[0003] Most of the current technology uses steel fiber reinforced concrete as the expansion joint filling material for expansion joint filling. Among them, the steel fiber reinforced concrete refers to a new type of multiphase composite material formed by mixing randomly distributed short steel fibers in ordinary concrete. However, due to the uneven distribution of steel fibers and the inconsistency with the direction of tensile stress, the tensile strength is improved to a small extent, which cannot well meet the filling requirements of the bridge expansion joint.

[0004] Therefore, it is necessary to prepare a bridge expansion joint filling material with high tensile strength. SUMMARY

[0005] In order to improve the tensile strength of the bridge expansion joint filling material, the present application provides a bridge expansion joint filling material and a preparation method thereof.

[0006] In the first aspect, the present application provides a bridge expansion joint filling material and a preparation method thereof, which adopts the following technical scheme:

[0007] A bridge expansion joint filling material, comprising the following raw materials by weight:

[0008] 10-20 parts of polyurethane resin, 1-3 parts of titanium dioxide, 6-8 parts of cement, 2-4 parts of mineral powder, 4-8 parts of magnetic particles, 0.1-0.3 parts of curing agent, 0.5-1 parts of dispersing agent, and 5-10 parts of water; the polyurethane resin is water-based polyurethane.

[0009] By adopting the technical scheme, the magnetic particles play a role of strengthening and reinforcing in the mixture, the magnetic particles in the material form a chain structure with heads and tails connected in a certain direction, when stretched, the distance between the magnetic particle chains is reduced, the interaction between the particles is enhanced, the combination between the filling materials is more compact, the compact combination can improve the tensile strength of the material, and the interaction between the magnetic particle chains can produce a certain elastic deformation energy during the stretching process, which can effectively absorb and disperse external force, thereby improving the tensile strength of the material.

[0010] Adding titanium dioxide in the polyurethane, the appropriate amount of titanium dioxide can uniformly fill the small pores in the material, form a dense skeleton structure, effectively improve the bonding strength of the interface between the new and old concrete, thereby improving the tensile strength of the filling material. The water-based polyurethane is in liquid state at room temperature, in order to avoid delamination during mixing, a small amount of mineral powder is added as a superfine filler, so that the polyurethane can be uniformly dispersed between the fillers, forming a uniform mixture, increasing the stability of the material, and keeping the filling material in the bridge contraction joint with good strength and stability.

[0011] Optionally, the polyurethane resin is modified and includes the following raw materials by weight: polycaprolactone 10-12 parts, toluene diisocyanate 11-14.4 parts, 1,4-butanediol 0.2-0.4 parts, dimethylol propionic acid 0.3-0.5 parts, and silane coupling agent 2-5 parts.

[0012] Optionally, the preparation of the modified polyurethane includes the following steps:

[0013] The toluene diisocyanate and polycaprolactone are mixed and reacted at 70-80°C under nitrogen protection for 2-3h to obtain a polyurethane prepolymer, 1,4-butanediol and dimethylol propionic acid are continuously added and reacted for 2-3h, then acetone is added to reduce the viscosity, the temperature is reduced to 50-60°C, the silane coupling agent is added dropwise and reacted for 1-2h, the system temperature is reduced to room temperature, and neutralization and emulsification are performed to obtain the modified polyurethane.

[0014] By adopting the technical scheme, the oligomer polyol and diisocyanate are mixed and reacted, 1,4-butanediol and dimethylol propionic acid are used as chain extenders, and the silane coupling agent is used to modify the polyurethane resin. The organic silicon functional group of the silane coupling agent chemically reacts with the molecular chain of the polyurethane to form a chemical bond, which on the one hand enhances the compatibility between the polyurethane and the filler, and on the other hand improves the wettability and adhesion of the polyurethane to the filler, further improves the compatibility of the modified polyurethane with the filler, and improves the dispersibility and stability of the filler in the polyurethane, thereby improving the tensile strength of the filling material.

[0015] Optionally, the magnetic particles are pretreated magnetic particles, and the specific steps are as follows: the magnetic particles are weighed and ball milled, alcohol is used as the ball milling medium, the rotation speed is 300-350 r / min, and the ball milling time is 1-2 h to obtain the pretreated magnetic particles.

[0016] By adopting the above technical scheme, the surface of the pretreated magnetic particles is smoother, the particle aggregation phenomenon is reduced, the surface activity of the pretreated particles is higher, the adhesion of the magnetic particles is enhanced, the magnetic particles can react with the polyurethane matrix to form chemical bonds, and the compatibility of the magnetic particles and the polyurethane is further improved, thereby improving the tensile strength of the filling material.

[0017] Optionally, the particle size of the magnetic particles is 4-8 μm.

[0018] By adopting the above technical scheme, the larger the particle size of the magnetic particles, the higher the magnetic permeability, and the higher the magneto-rheological effect of the filling material. Under the action of the magneto-rheological effect, the magnetic particles can generate a certain magnetic force on the surrounding matrix material, thereby helping to improve the structural strength and rigidity of the matrix material. However, if the particle size is too large, the loss factor will increase, which will reduce the tensile strength of the filling material.

[0019] Optionally, the dispersant is a phosphate ester dispersant.

[0020] By adopting the above technical scheme, the phosphate ester dispersant has good compatibility in the polyurethane, can improve the dispersion effect of the filler in the polyurethane matrix through hydrogen bonding and chemical adsorption, and can be adsorbed on the surface of the solid particles to reduce the interfacial tension between the solid particles and the matrix, so that the surface of the agglomerated solid particles is easy to wet, and the dispersibility of the solid particles in the matrix is improved.

[0021] Optionally, the raw material further comprises 1-3 parts of an epoxy resin.

[0022] By adopting the above technical scheme, the epoxy resin and the polyurethane can perform crosslinking reaction at room temperature to form a crosslinked structure, fully play the advantages of each other, and improve the tensile strength of the polyurethane.

[0023] In a second aspect, the application provides a preparation method of a bridge expansion joint filling material, which adopts the following technical scheme:

[0024] A preparation method of a bridge expansion joint filling material, comprising the following steps:

[0025] (1) After the magnetic particles and the polyurethane are added into an acetone solution and ultrasonically treated, the mixture is heated to 40-50℃, and then a curing agent, titanium dioxide, mineral powder, cement and a dispersant are sequentially added and uniformly stirred to obtain a mixture;

[0026] (2) The mixture is filled into a mold, a uniform magnetic field is applied, and after waiting for solidification and molding, it is taken out to obtain the bridge expansion joint filling material.

[0027] By using the above technical scheme, by ultrasonic treatment of the magnetic particles and polyurethane in the acetone solution, the uniform mixing of the magnetic particles and polyurethane can be promoted, and the stability of the mixture can be improved. After heating to 40-50℃, the curing agent, titanium dioxide, mineral powder, cement, dispersant and water are added and stirred uniformly, which further promotes the uniform mixing of each component and forms a stable mixture. The mixture is filled into a mold, a uniform magnetic field is applied, which can promote the molding and solidification of the filling material and improve the production efficiency. After waiting for solidification and molding, it is taken out to obtain the bridge expansion joint filling material with excellent physical properties and stability.

[0028] In summary, the present application has the following beneficial effects:

[0029] 1. The polyurethane, cement, titanium dioxide and magnetic particles are mixed to obtain a filling material with high strength and toughness, which can withstand large tensile and compressive stress and has good compressive strength.

[0030] 2. The polyurethane modified by silane coupling agent is preferably used in the present application. The polyurethane modified by silane coupling agent improves the wettability and adhesion of the magnetic particles to the polyurethane, improves the adhesion of the magnetic particles to the polyurethane, and the modified polyurethane has good compatibility with other fillers in the raw material, and the fillers have good dispersibility and stability in the polyurethane, ensuring that the filling material has good tensile strength.

[0031] 3. The magnetic particles are pretreated by ball milling to increase the specific surface area of the magnetic particles and improve the activity of the surface, which produces more active sites and can better react with the polyurethane molecular chain and better disperse and adhere to the polyurethane molecular chain, ensuring that the filling material has better tensile properties. DETAILED DESCRIPTION

[0032] The present application is further described below in conjunction with examples.

[0033] Unless otherwise specified, the specific conditions in the examples are carried out according to the conventional conditions or the conditions recommended by the manufacturer. The reagents or instruments used are not specified by the manufacturer, but are conventional products that can be purchased on the market.

[0034] Poly (caprolactone) with a branching degree of 0.7-1.1 was purchased from Shandong Hui'an Chemical Co., Ltd.

[0035] Preparation examples of raw materials and / or intermediates

[0036] Preparation example 1

[0037] A modified polyurethane, the preparation comprising the following steps:

[0038] 10 kg of toluene diisocyanate and 11 kg of polycaprolactone were mixed, heated to 70°C after filling with nitrogen for 2h, to prepare a polyurethane prepolymer, then 0.2 kg of 1,4-butanediol and 0.4 kg of dimethylol propionic acid were added and continued to react for 2h, then an appropriate amount of acetone was added to reduce the viscosity, and the temperature was lowered to 50°C, 5 kg of silane coupling agent was added dropwise and reacted for 1h, the system temperature was lowered to room temperature, and triethylamine was added for neutralization for 5 min, to obtain a modified polyurethane. The silane coupling agent is KH-550.

[0039] Preparation Example 2

[0040] A modified polyurethane, the preparation comprising the following steps:

[0041] 11 kg of toluene diisocyanate and 14.4 kg of polycaprolactone were mixed, heated to 80°C after filling with nitrogen for 3h, to prepare a polyurethane prepolymer, then 0.3 kg of 1,4-butanediol and 0.3 kg of dimethylol propionic acid were added and continued to react for 2h, then an appropriate amount of acetone was added to reduce the viscosity, and the temperature was lowered to 55°C, 3.5 kg of silane coupling agent was added dropwise and reacted for 1.5h, the system temperature was lowered to room temperature, and triethylamine was added for neutralization for 5 min, to obtain a modified polyurethane. The silane coupling agent is KH-550.

[0042] Preparation Example 3

[0043] A modified polyurethane, the preparation comprising the following steps:

[0044] 12 kg of toluene diisocyanate and 13 kg of polycaprolactone were mixed, heated to 75°C after filling with nitrogen for 2.5h, to prepare a polyurethane prepolymer, then 0.4 kg of 1,4-butanediol and 0.5 kg of dimethylol propionic acid were added and continued to react for 3h, then an appropriate amount of acetone was added to reduce the viscosity, and the temperature was lowered to 55°C, 2 kg of silane coupling agent was added dropwise and reacted for 2h, the system temperature was lowered to room temperature, and triethylamine was added for neutralization for 5 min, to obtain a modified polyurethane. The silane coupling agent is KH-550.

[0045] Example

[0046] Example 1

[0047] A bridge expansion joint filling material, the preparation comprising the following steps:

[0048] (1) Take 4 kg of carbonyl iron powder and put it into a ball mill, use zirconium oxide ball milling beads, the ball to material ratio is 3:1, add alcohol, set the rotation speed to 300 r / min, ball mill for 1h, to obtain pretreated magnetic particles;

[0049] (2) The pre-processed carbonyl iron powder and 15 kg of polyurethane prepared in Preparation Example 2 were added to 10 kg of an acetone solution and ultrasonically treated, then heated to 40°C, and 0.3 kg of a curing agent, 2 kg of titanium dioxide, 4 kg of mineral powder, 8 kg of cement, 0.75 kg of a dispersing agent, and 5 kg of water were sequentially added and stirred to obtain a mixture;

[0050] (3) The mixture was filled into a mold, a 1 TB uniform magnetic field was applied, and after waiting for curing and molding, the bridge expansion joint filling material was obtained. The dispersing agent was triethyl phosphate, the curing agent was an HDI trimer curing agent, and the particle size of the carbonyl iron powder was 4 mm.

[0051] Example 2

[0052] A bridge expansion joint filling material was prepared by the following steps:

[0053] (1) 6 kg of carbonyl iron powder was placed in a ball mill, zirconia milling beads were used, the ball-to-material ratio was 3:1, alcohol was added, the rotation speed was set to 350 r / min, and ball milling was performed for 2 h to obtain pre-processed magnetic particles;

[0054] (2) The pre-processed carbonyl iron powder and 20 kg of polyurethane prepared in Preparation Example 2 were added to 10 kg of an acetone solution and ultrasonically treated, then heated to 45°C, and 0.2 kg of a curing agent, 1 kg of titanium dioxide, 2 kg of mineral powder, 6 kg of cement, 0.5 kg of a dispersing agent, and 7.5 kg of water were sequentially added and stirred to obtain a mixture;

[0055] (3) The mixture was filled into a mold, a 1 TB uniform magnetic field was applied, and after waiting for curing and molding, the bridge expansion joint filling material was obtained. The dispersing agent was triethyl phosphate, the curing agent was an HDI trimer curing agent, and the particle size of the carbonyl iron powder was 8 mm.

[0056] Example 3

[0057] A bridge expansion joint filling material was prepared by the following steps:

[0058] (1) 8 kg of carbonyl iron powder was placed in a ball mill, zirconia milling beads were used, the ball-to-material ratio was 3:1, alcohol was added, the rotation speed was set to 350 r / min, and ball milling was performed for 1.5 h to obtain pre-processed magnetic particles;

[0059] (2) The pre-processed magnetic particles and 10 kg of polyurethane prepared in Preparation Example 2 were added to 10 kg of an acetone solution and ultrasonically treated, then heated to 50°C, and 0.1 kg of a curing agent, 3 kg of titanium dioxide, 3 kg of mineral powder, 7 kg of cement, 1 kg of a dispersing agent, and 10 kg of water were sequentially added and stirred to obtain a mixture;

[0060] (3) The mixture is filled into a mold, a 1 TB uniform magnetic field is applied, and after waiting for solidification and molding, it is taken out to obtain the bridge expansion joint filling material. The dispersing agent is triethyl phosphate, the curing agent is an HDI trimer curing agent, and the particle size of the carbonyl iron powder is 6 mm.

[0061] Example 4

[0062] A bridge expansion joint filling material, which differs from Example 1 in that the modified polyurethane used in this example is prepared in Preparation Example 1.

[0063] Example 5

[0064] A bridge expansion joint filling material, which differs from Example 1 in that the modified polyurethane used in this example is prepared in Preparation Example 3.

[0065] Example 6

[0066] A bridge expansion joint filling material, which differs from Example 1 in that a commercially available polyurethane resin is used in this example, and the model number is LB-1532.

[0067] Example 7

[0068] A bridge expansion joint filling material, which differs from Example 1 in that the magnetic particles are not pretreated in this example, and the specific steps are as follows:

[0069] (1) 4 kg of carbonyl iron powder and 15 kg of polyurethane prepared in Preparation Example 2 are added to 10 kg of acetone solution and ultrasonically treated, then heated to 40°C, and 0.3 kg of a curing agent, 2 kg of titanium dioxide, 4 kg of mineral powder, 8 kg of cement, 0.75 kg of a dispersing agent, and 5 kg of water are added in sequence and stirred uniformly to obtain a mixture;

[0070] (2) The mixture is filled into a mold, a 1 TB uniform magnetic field is applied, and after waiting for solidification and molding, it is taken out to obtain the bridge expansion joint filling material. The dispersing agent is triethyl phosphate, the curing agent is an HDI trimer curing agent, and the particle size of the carbonyl iron powder is 4 mm.

[0071] Example 8

[0072] A bridge expansion joint filling material, which differs from Example 1 in that the particle size of the magnetic particles in this example is 10 μm.

[0073] Example 9

[0074] A bridge expansion joint filling material, which differs from Example 1 in that the particle size of the magnetic particles in this example is 3 μm.

[0075] Example 10

[0076] A bridge expansion joint filling material, different from example 1 is that the dispersing agent used in this example is magnesium stearate.

[0077] Example 11

[0078] A bridge expansion joint filling material, different from example 1 is that this example further includes 1 kg of epoxy resin, model EP301.

[0079] Comparative example

[0080] Comparative example 1

[0081] A bridge expansion joint filling material, different from example 1 is that this comparative example does not add titanium dioxide.

[0082] Comparative example 2

[0083] A bridge expansion joint filling material, different from example 1 is that this comparative example does not add carbonyl iron powder.

[0084] Comparative example 3

[0085] A bridge expansion joint filling material, different from example 1 is that this comparative example does not apply a magnetic field to the mold when preparing the filling material.

[0086] Performance detection test

[0087] Detection method / test method

[0088] Split tensile strength detection: 100mm x 100mm x 100mm cubic test pieces are used, the loading rate is 1Mpa / s, the mechanical properties of the composite materials prepared in examples 1-11 and comparative examples 1-3 are tested according to GB / T50081-2002 "Standard for testing methods of mechanical properties of ordinary concrete", and the specific results are shown in Table 1.

[0089] Table 1 test detection results

[0090] Split tensile strength / MPa Example 1 19.9 Example 2 19.4 Example 3 19.6 Example 4 19.5 Example 5 19.7 Example 6 17.6 Example 7 18.4 Example 8 17.2 Example 9 17.0 Example 10 17.5 Example 11 20.7 Comparative Example 1 16.4 Comparative Example 2 15.9 Comparative Example 3 14.8

[0091] It can be seen from examples 1-3 and comparative example 1 and in combination with Table 1 that the test data of examples 1-3 are all better than those of comparative example 1, which shows that the addition of titanium dioxide can uniformly fill the small pores in the filling material, form a dense skeleton structure, improve the strength of the filling material, and prevent deformation and other problems.

[0092] It can be seen from the combination of Examples 1-3 and Comparative Examples 2-3 and Table 1 that the test data of Examples 1-3 are all better than those of Comparative Examples 2-3, indicating that the magnetic particles can form a chain structure with heads and tails connected in a certain direction in the material under the action of a magnetic field, the interaction between the fillers in the filled material is enhanced, the combination between the fillers is more compact, and thus the tensile strength of the material is improved, and the interaction between the magnetic particle chains can produce a certain elastic deformation energy during the stretching process, which can effectively absorb and disperse external force, thereby improving the tensile strength of the material.

[0093] It can be seen from the combination of Examples 1-6 and Table 1 that the test data of Examples 1-5 are all better than those of Example 6, indicating that the modification of the polyurethane further improves the compatibility of the fillers and the polyurethane, the connection is more compact, and thus the tensile strength of the filled material is improved.

[0094] It can be seen from the combination of Example 1 and Example 7 and Table 1 that the test data of Example 1 are all better than those of Example 7, indicating that the pretreatment of the magnetic particles can make the surface of the magnetic particles smoother, reduce the agglomeration phenomenon between the particles, and improve the activity and the adhesion between the polyurethane, thereby improving the tensile strength of the filled material.

[0095] It can be seen from the combination of Examples 1-3 and Examples 8-9 and Table 1 that the test data of Examples 1-3 are all better than those of Examples 8-9, indicating that the particle size of the magnetic particles affects the performance of the finally prepared filled material, and the selection of the magnetic particles with a particle size of 4-8 μm is beneficial to the improvement of the tensile strength of the filled material.

[0096] It can be seen from the combination of Example 1 and Example 10 and Table 1 that the test data of Example 10 are all better than those of Example 1, indicating that the use of the phosphate ester dispersant as a dispersant has better compatibility with the polyurethane than other types of dispersants, helps to improve the dispersibility of the fillers in the polyurethane, and helps to improve the performance of the filled material.

[0097] It can be seen from the combination of Example 1 and Example 11 and Table 1 that the test data of Example 11 are all better than those of Example 1, indicating that the addition of the epoxy resin can further improve the strength of the material, and the good adhesion is also conducive to further improving the bonding performance between the polyurethane and other raw materials.

[0098] The specific embodiments are merely an explanation of the present application, which is not a limitation of the present application, and those skilled in the art can make modifications to the embodiments without creative contribution after reading the present specification, but as long as the modifications are within the scope of the claims of the present application, they are protected by the patent law.

Claims

1. A bridge joint filler material, characterized in that, The raw materials include the following components by weight: polyurethane resin 10-20 parts, titanium dioxide 1-3 parts, cement 6-8 parts, mineral powder 2-4 parts, magnetic particles 4-8 parts, curing agent 0.1-0.3 parts, dispersing agent 0.5-1 parts, and water 5-10 parts; the magnetic particles are oriented and arranged inside the filling material under the action of a magnetic field; the polyurethane resin is a modified polyurethane prepared by the following steps: toluene diisocyanate and polycaprolactone are mixed and reacted at 70-80℃ under nitrogen protection for 2-3h to obtain a polyurethane prepolymer, 1,4-butanediol and dimethylol propionic acid are continuously added and reacted for 2-3h, then acetone is added to reduce the viscosity, the temperature is lowered to 50-60℃, silane coupling agent is added dropwise and reacted for 1-2h, and the system temperature is lowered to room temperature after neutralization to obtain the modified polyurethane.

2. A bridge joint filler material as claimed in claim 1, characterised in that: the modified polyurethane includes the following components by weight: polycaprolactone 10-12 parts, toluene diisocyanate 11-14.4 parts, 1,4-butanediol 0.2-0.4 parts, dimethylol propionic acid 0.3-0.5 parts, and silane coupling agent 2-5 parts.

3. A bridge joint filler material as claimed in claim 1, wherein: the magnetic particles are pretreated magnetic particles, and the specific steps are as follows: the magnetic particles are weighed and ball milled, alcohol is used as the ball milling medium, the rotation speed is 300-350r / min, and the ball milling is performed for 1-2h to obtain the pretreated magnetic particles.

4. The bridge joint filler material of claim 1, wherein: the particle size of the magnetic particles is 4-8μm.

5. A bridge joint filler material as claimed in claim 1, wherein: the dispersing agent is a phosphate dispersing agent.

6. A bridge joint filler material as claimed in claim 1, wherein: 1-3 parts of epoxy resin are further included in the raw materials.

7. A process for the preparation of a bridge joint filler material as claimed in any one of claims 1 to 5, characterised in that, The method includes the following steps: (1) the magnetic particles and the polyurethane are added to an acetone solution and ultrasonically treated, then heated to 40-50℃, and then the curing agent, titanium dioxide, mineral powder, cement, dispersing agent, and water are added in sequence and stirred uniformly to obtain a mixture; (2) the mixture is filled into a mold, a uniform magnetic field is applied, and after waiting for curing and forming, the bridge expansion joint filling material is obtained.