CN107987302B - Surface-reinforced resin matrix composite stiffener and preparation method thereof - Google Patents

Abstract

The invention discloses a surface-enhanced resin matrix composite reinforcing rib and a preparation method thereof, and belongs to the field of composite building reinforcement. The surface-enhanced resin-based composite material reinforcing rib comprises an internal reinforced fiber resin-based composite material, an outer winding layer and an outermost reinforcing particle, wherein the reinforced fiber is formed for the first time through a pultrusion process after being impregnated into a resin matrix, then the outer layer of the pultruded composite material is wound for the second time to impregnate the resin matrix, and finally the surface reinforcing particle is covered in a semi-cured state for re-curing forming. The invention not only has the advantages of the existing composite material reinforcing ribs, but also has the outstanding characteristics of stronger binding force with the base material, better reinforcing effect and the like.

Description

Surface-reinforced resin matrix composite stiffener and preparation method thereof

Technical field

The invention relates to the field of composite material building reinforcement, in particular to a surface-reinforced resin-based composite material reinforcement and a preparation method thereof.

Background technique

Steel bars have been used as reinforcing bars in the construction field for many years. They have the advantages of easy availability of raw materials and low prices. However, the strength of steel bars is limited, they are easy to corrode in humid environments, they are heavy, and they are inconvenient to transport. Therefore, in recent years, composite materials have been reinforced. Jin came into being. Compared with traditional steel bars, composite reinforced bars have many advantages such as high strength, corrosion resistance, and light weight, and have been widely used.

Today's composite reinforcements are made of reinforcing fibers and a resin matrix through a pultrusion winding process, with a smooth surface. This kind of composite reinforcing bar achieves a fast connection with basic materials, such as concrete, through the thread structure on the surface. However, the surface of this composite reinforcing bar is smooth, the bonding force with concrete is weak, and the reinforcing effect is limited.

Contents of the invention

The invention provides a surface-reinforced resin-based composite reinforcing rib and a preparation method thereof. It not only has the advantages of existing composite reinforcing ribs, but also has outstanding features such as stronger binding force with basic materials and better reinforcing effect.

In order to solve the above technical problems, the present invention provides the following technical solutions:

On the one hand, the present invention provides a surface-reinforced resin-based composite stiffener, which includes an inner reinforced fiber resin-based composite material, an outer winding layer, and an outermost layer of reinforced particles. The reinforced fibers are impregnated with a resin matrix. The first molding is carried out through the pultrusion process, and then the second layer of impregnated resin matrix is wrapped around the outer layer of the pultruded composite material. Finally, the surface reinforcement particles are covered in a semi-cured state and solidified again.

Further, the fiber is one or more of carbon fiber, glass fiber, basalt fiber, aramid fiber, polyethylene fiber, and silicon carbide fiber.

Further, the resin matrix includes a thermosetting resin system and/or a thermoplastic resin system, wherein:

The thermosetting resin system is one or more of an epoxy resin system, a phenolic resin system, and a vinyl resin system;

The thermoplastic resin system is one or more of polypropylene, nylon, thermoplastic polyester resin, polyphenylene sulfide resin, and polyether ether ketone resin.

Further, the reinforcing particles include one or more of sand, silica, glass beads, barium sulfate, and kaolin.

On the other hand, the present invention also provides a method for preparing the above-mentioned surface-reinforced resin matrix composite reinforcement, including:

Step 1: The internal reinforcing fibers are arranged on the creel, and then the resin matrix is impregnated through the dipping tank, and pre-cured through the pre-curing box;

Step 2: The winding fiber impregnated with the resin matrix by the glue adding device is wound on the internal composite material driven by the winding unit;

Step 3: Enter the reinforced particle tank, coat the outermost layer with reinforced particles, and then enter the curing box together for solidification and molding.

Further, in step 1, the pre-curing degree is 60% or less.

Further, if the resin matrix in step 1 is in a solid state, the dipping tank is a closed heated and pressurized glue injection tank. If the resin matrix in step 1 is a thermosetting resin system, , then the pre-curing box needs to be heated.

Further, in the step 2, after winding, it enters the heat treatment box for heat treatment.

Further, in step 3, the specific way to coat the outermost layer with reinforcing particles is to enter the semi-cured composite material into a tank filled with reinforcing particles, and a vibration device is provided at the bottom of the tank filled with reinforcing particles so that the reinforcing particles Apply evenly to the outer layer of the composite material.

The invention has the following beneficial effects:

According to the present invention, surface-reinforced resin-based composite reinforcing bars and their preparation method are used. The surface-reinforced composite reinforcing bars are reinforced with surface particles, which greatly increases the friction force and can be more closely combined with concrete. The composite reinforcing bars prepared by the present invention have reinforcing particles on the surface and have good compatibility with basic materials, especially the most commonly used concrete, and the surface roughness is greatly enhanced. When used as reinforcing bars, the interface with the basic material The binding force will also be greatly improved. Therefore, the composite reinforcing rib of the present invention has the advantages of the existing composite reinforcing ribs, and also has outstanding features such as stronger binding force with the basic material and better reinforcing effect.

Description of drawings

Figure 1 is a schematic structural diagram of the surface-reinforced resin matrix composite stiffener of the present invention;

Figure 2 is a schematic diagram of the preparation method of the surface-reinforced resin-based composite stiffener of the present invention.

Detailed ways

In order to make the technical problems, technical solutions and advantages to be solved by the present invention clearer, a detailed description will be given below with reference to the accompanying drawings and specific embodiments.

On the one hand, the present invention provides a surface-reinforced resin-based composite material reinforcement, as shown in Figures 1 and 2, including an internal reinforced fiber resin-based composite material 1, an outer winding layer 2 and an outermost layer of reinforcement. Particle 3: The reinforcing fibers are impregnated with a resin matrix and then molded for the first time through a pultrusion process. Then, the outer layer of the pultruded composite material is wrapped with a second layer of impregnated resin matrix, and finally the surface reinforcement particles are covered in a semi-cured state. Solidify again.

The surface-reinforced resin-based composite reinforcing ribs of the present invention are reinforced with surface particles, which greatly increases the friction and can be more closely combined with concrete. The composite reinforcing bars prepared by the present invention have reinforcing particles on the surface and have good compatibility with basic materials, especially the most commonly used concrete, and the surface roughness is greatly enhanced. When used as reinforcing bars, the interface with the basic material The binding force will also be greatly improved. Therefore, the composite reinforcing rib of the present invention has the advantages of the existing composite reinforcing ribs, and also has outstanding features such as stronger binding force with the basic material and better reinforcing effect.

In the present invention, reinforcing fiber and resin matrix are formed for the first time through pultrusion and winding processes, covering the surface reinforcement particles in a semi-cured state, and then undergo secondary solidification molding. First, the arranged reinforced fibers are preheated and preformed through the curing mold of the pultrusion production line. The fiber-reinforced composite material coming out of the curing mold mouth is not completely cured, but a semi-cured composite material with a curing degree of less than 60%; then The impregnated reinforcing fibers are wound around the semi-cured composite material mandrel. The reinforcing fibers and resin matrix used in the winding step can be the same as those in the pultrusion step, or they can be different; the composite material after pultrusion and winding is traction Continue to move forward under the traction of the machine. At this time, heat treatment can be carried out. The advantage of heat treatment is that it can initially solidify the reinforced fibers wrapped around the outer layer and have a certain strength. If the fibers wrapped around the outer layer fibers are tight, under the tension, It can maintain its shape under action, and it does not need to be heated. The composite material after pultrusion and winding passes through a reinforced particle tank, which is filled with reinforced particles. The bottom of the reinforced particle tank is equipped with a vibration device, so that the surface of the composite material can be evenly coated with reinforced particles. The composite material through the reinforced particle tank is stained with reinforced particles on the outer layer, and then enters the curing box together for solidification and molding.

Preferably, the fiber can be one or more of organic fibers or/and inorganic fibers such as carbon fiber, glass fiber, basalt fiber, aramid fiber, polyethylene fiber, silicon carbide fiber, etc., which can include but is not limited to the above fibers. .

Further, the resin matrix may include thermosetting resin systems such as epoxy resin system, phenolic resin system, and vinyl resin system, or/and thermoplastic resin systems such as polypropylene, nylon, thermoplastic polyester resin, polyphenylene sulfide resin, and polyether ether ketone resin. One or more of the resin systems may include but are not limited to the above resins.

As an improvement of the present invention, the reinforcing particles may include one or more of sand, silica, glass beads, barium sulfate, kaolin and other granular objects, and may include but are not limited to the above reinforcing particles.

On the other hand, the present invention also provides a method for preparing the above-mentioned surface-reinforced resin matrix composite reinforcement, including:

Step 1: The internal reinforcing fibers 10 are arranged on the creel 1, and then the resin matrix is impregnated through the dipping tank 2, and pre-cured through the pre-curing box 3;

Step 2: The winding fiber 11 impregnated with the resin matrix by the glue adding device 9 is wound on the internal composite material driven by the winding unit 4;

Step 3: Enter the reinforced particle tank 6, coat the outermost layer with reinforced particles 12, and then enter the curing box 8 together for solidification and molding.

In the preparation method of the surface-reinforced resin-based composite reinforcing bar of the present invention, the surface-reinforced composite reinforcing bar is reinforced with surface particles, which greatly increases the friction force and can be more closely combined with concrete. The composite reinforcing bars prepared by the present invention have reinforcing particles on the surface and have good compatibility with basic materials, especially the most commonly used concrete, and the surface roughness is greatly enhanced. When used as reinforcing bars, the interface with the basic material The binding force will also be greatly improved. Therefore, the composite reinforcing rib of the present invention has the advantages of the existing composite reinforcing ribs, and also has outstanding features such as stronger binding force with the basic material and better reinforcing effect.

Further, in step 1, the pre-curing degree is 60% or less.

In the present invention, if the resin matrix in step 1 is in a solid state, the dipping tank 2 is a closed heated and pressurized glue injection tank. If the resin matrix in step 1 is a thermosetting resin system, it is necessary to The pre-curing box 3 is heated.

Preferably, in step 2, after winding, it can enter the heat treatment box 5 for heat treatment.

As an improvement of the present invention, in step 3, the specific way to coat the outermost layer with reinforced particles is to enter the semi-cured composite material into a tank filled with reinforced particles. The bottom of the tank filled with reinforced particles is preferably provided with a vibration device 7 , so that the reinforced particles are evenly attached to the outer layer of the composite material.

The features and details of the present invention will be further described below with reference to specific examples, but the listed processes and data do not mean to limit the scope of the present invention.

Embodiment 1

The preparation of a thermosetting resin matrix composite reinforcement consisting of an inner layer of carbon fiber, an outer layer of glass fiber, and an outermost layer of sand is taken as an example.

50 bundles of 12K carbon fibers are arranged on the creel 1, and then impregnated with the epoxy-anhydride resin system through the dipping tank 2, and pre-cured through the pre-curing box 3. The diameter of the curing box is 6.5mm, the length is 90cm, and every 30cm A heating section, the heating temperatures are 60°C, 80°C, and 100°C respectively. When the composite material comes out of the curing box 3, the curing degree reaches 55%, and then is impregnated with 3 bundles of 12K phenolic resin matrix resin by the glue adding device 9 The glass fiber is wound on the internal composite material driven by the winding unit 4, and then enters the heat treatment box 5. The heat treatment oven is 90cm long and the heating temperature is 100°C. Then it enters the reinforced particle tank 6 and is stained with reinforced particles on the outermost layer. The sand 12, under the action of the vibration device 7, the reinforced granular sand 6 is evenly attached to the outer layer of the composite material, and finally enters the curing box 8 for solidification and molding. The curing temperature is 150°C, and the fiber advancement speed is 600mm/min.

Embodiment 2

Take the preparation of a thermoplastic resin-based composite reinforcement consisting of an inner layer of aramid fiber, an outer layer of basalt fiber, and an outermost layer of kaolin as an example.

The internal reinforcing fibers 49 bundles of 6K aramid fibers are arranged on the creel 1, and then impregnated with the nylon resin system through the dipping tank 2. Since nylon is in a solid state, the dipping tank in Example 2 is heated and pressurized in a closed manner. Glue injection type dipping tank, temperature 230℃, 5MPa. Pre-curing is carried out through the pre-curing box 3. The curing box has a diameter of 3mm and a length of 90cm. There is a heating section every 30cm. The thermoplastic composite material needs to be cooled and formed. At this time, the pre-curing box 3 does not need to be heated. The composite material comes out of the curing box 3. When the crystallinity reaches 55%, the winding fiber 3 bundles of 6K basalt fiber impregnated with nylon resin powder resin are then impregnated by the gluing device 9. They are wound on the internal composite material driven by the winding unit 4, and then enter the heat treatment box 5 for heat treatment. The oven is 90cm long and has a heating temperature of 150°C, so that the thermoplastic composite material has a certain strength but the surface is in a viscous state. Then it enters the reinforced particle tank 6, and the outermost layer is stained with reinforced particle sand 12. Under the action of the vibration device 7 , the reinforced granular sand 6 is evenly adhered to the outer layer of the composite material, and finally enters the curing box 8 for solidification and molding. At this time, the curing box is not heated, and the fiber advancement speed is 700mm/min.

In the present invention, the conditions of the preparation method are different, and the performance of the obtained surface-reinforced resin-based composite material stiffeners will be different. In order to better prove that the surface-reinforced resin-based composite material stiffeners prepared by the present invention have large friction, With stronger bonding force with basic materials and better performance enhancement, the following comparison examples are constructed:

Comparative example 1:

A surface-reinforced resin-based composite reinforcing bar that no longer covers the surface with reinforcing particles, but is fastened to basic materials such as concrete through a threaded structure on the surface. The remaining conditions are the same as in Example 1. Preparation and use methods It is also the same as Example 1.

The bonding strength performance between the surface-reinforced resin-based composite reinforcement ribs prepared in the above Example 1 and Comparative Example 1 and the base material was tested, that is, the force used when the reinforcement rib is pulled out from the base material. The test results are shown in Table 1 .

Table 1

Test items Example 1 Comparative example 1 Pulling out forces from base material 80kN 50kN

As can be seen from Table 1, compared with Comparative Example 1, the surface-reinforced resin-based composite reinforcement ribs of the present invention have stronger binding force with the base material and better reinforcement effect.

The above is the preferred embodiment of the present invention. It should be pointed out that for those of ordinary skill in the art, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications can also be made. should be regarded as the protection scope of the present invention.

Claims (7)

1. A method for preparing surface-reinforced resin-based composite reinforcement ribs, characterized in that the surface-reinforced resin-based composite reinforcement ribs include an internal reinforcing fiber resin-based composite material, an outer winding layer, and an outermost layer of reinforcement. Particles, the reinforcing fibers are first formed through a pultrusion process after being impregnated with a resin matrix, and then wrapped around the outer layer of the pultruded composite material with a second layer of impregnated resin matrix, and finally covered with surface-reinforced particles in a semi-cured state, Carry out solidification and molding again; specific steps include: Step 1: Arrange the internal reinforcing fibers on the creel, then impregnate the resin matrix through the dipping tank, and pre-cure through the pre-curing box; Step 2: The winding fiber impregnated with the resin matrix by the glue adding device is wound on the internal composite material driven by the winding unit; Step 3: Enter the reinforced particle tank, coat the outermost layer with reinforced particles, and then enter the curing box together for solidification and molding; In the step 3, the specific way to coat the outermost layer with reinforced particles is that the semi-cured composite material enters a tank filled with reinforced particles, and a vibration device is provided at the bottom of the tank filled with reinforced particles so that the reinforced particles can be evenly coated. on the outer layer of composite material. 2. The preparation method of surface-reinforced resin-based composite reinforcement ribs according to claim 1, characterized in that the surface-reinforced particles are covered in a semi-cured state, and the specific method for re-solidifying the composite material is to enter the semi-cured composite material into the device. There is a trough with reinforced particles. The bottom of the trough containing reinforced particles is equipped with a vibration device to make the reinforced particles evenly adhere to the outer layer of the composite material; The reinforcing particles include one or more of sand, silica, glass beads, barium sulfate, and kaolin. 3. The preparation method of surface-reinforced resin-based composite material reinforcement according to claim 2, characterized in that the fiber is carbon fiber, glass fiber, basalt fiber, aramid fiber, polyethylene fiber, silicon carbide fiber. of one or more. 4. The preparation method of surface-reinforced resin-based composite stiffeners according to claim 3, wherein the resin matrix includes a thermosetting resin system and/or a thermoplastic resin system, wherein: The thermosetting resin system is one or more of an epoxy resin system, a phenolic resin system, and a vinyl resin system; The thermoplastic resin system is one or more of polypropylene, nylon, thermoplastic polyester resin, polyphenylene sulfide resin, and polyether ether ketone resin. 5. The method for preparing surface-reinforced resin matrix composite stiffeners according to claim 1, wherein in step 1, the pre-curing degree is 60% or less. 6. The preparation method of surface-reinforced resin-based composite stiffeners according to claim 4, if the resin matrix in step 1 is in a solid state, the dipping tank adopts a closed heating and pressurized injection tank. In the glue-type dipping tank, if the resin matrix in step 1 is a thermosetting resin system, the pre-curing box needs to be heated. 7. The method for preparing surface-reinforced resin-based composite stiffeners according to claim 1, in step 2, after winding, the reinforcing bars are placed in a heat treatment box for heat treatment.