CN205476579U - Improve device of FRP reinforced structure ductility and FRP utilization ratio - Google Patents

Abstract

The utility model discloses a device for improving the ductility of an FRP reinforced structure and the utilization rate of FRP. The FRP reinforced structure includes an end anchoring device, an FRP sheet, expansion bolts and a binder. The end anchoring device and the The FRP sheets are all fixed in the reinforcement area of the concrete to be reinforced by the adhesive, the material of the end anchorage device is low carbon steel, the end anchorage device includes an anchorage section, a deformation section and a connecting section, and the anchorage section The section is provided with two circular holes, the deformation section connects the anchor section and the connection section, the width of the deformation section is variable, the connection section is provided with a rectangular slot, and the concrete to be reinforced is provided with There are two pre-drilled holes corresponding to the circular holes, and the expansion bolts pass through the circular holes and are pressed into the pre-drilled holes to fix the FRP reinforcement structure on the concrete to be reinforced. Due to the end anchoring device in the utility model, the ductility of the FRP structure and the utilization rate of the FRP are improved, and the existing problem of brittle failure is solved.

Description

Device for Improving Ductility of FRP Strengthened Structures and FRP Utilization

technical field

The utility model relates to the field of FRP reinforcement, in particular to a device for improving the ductility of FRP reinforcement structures and the utilization rate of FRP.

Background technique

Fiber Reinforced Polymer/Plastic (FRP) is widely used in structural reinforcement due to its outstanding advantages such as light weight, high strength, corrosion resistance, and convenient processing. At present, the most widely used and most in-depth research in the world is the external FRP reinforcement technology, also known as EB-FRP reinforcement technology. The method of EB-FRP reinforcement technology is to directly paste the FRP sheet to the structure to be reinforced with epoxy resin, so that the load on the structure will be transferred to the FRP material through the epoxy resin adhesive, so that the FRP Share the unbearable load for the original structure, and achieve the effect of reinforcement through this method. It is not difficult to see that the bond strength between FRP and concrete will play a decisive role in the strengthening effect of FRP reinforced concrete structures. However, a large number of experimental studies have shown that the FRP-concrete bond interface is relatively fragile, and the typical failure form is the peeling failure of FRP peeling from the concrete. There are significant disadvantages in this destruction: (1) FRP utilization rate is low, and FRP will be peeled off from the concrete interface when only reaching about 30% utilization rate, which is a huge problem for FRP materials with very high strength. waste, but also increases the economic cost; (2) the ductility is poor, and the failure mode is brittle failure. Brittle failure is a kind of sudden failure. The time from the failure to the collapse of the building is extremely short, which is prohibited in engineering, because when the reinforced structure is affected by external effects, such as changes in the use of houses, earthquakes, etc., once the structure occurs If the house is brittle, it will collapse suddenly, and people will have no time to escape, which will pose a great threat to people's life safety. Therefore, it is imperative to find a way to improve the ductility of FRP-strengthened structures and improve the utilization of FRP to solve the bottleneck that limits the development and application of externally attached FRP reinforcement technology.

At present, scholars around the world have proposed some overcoming methods to control FRP peeling: FRPU hoop anchoring method, FRP mechanical anchoring method, FRP embedded anchoring method, etc. These methods have a significant inhibitory effect on FRP peeling, but unfortunately they cannot guarantee the ductility of FRP-concrete-reinforced structures. This also means that the essence of brittle failure of EB-FRP reinforcement technology has not changed, which means that the most fatal weakness of EB-FRP reinforcement technology—the problem of brittle failure has not been fundamentally solved, which is very regrettable. In view of this, this patent will propose a device to improve the ductility of FRP structures and the utilization of FRP to solve the existing brittle failure problems.

Utility model content

The purpose of the utility model is to provide a device with high ductility and high utilization rate to improve the ductility of FRP reinforced structures and the utilization rate of FRP.

In order to achieve the above object, the utility model provides the following scheme: the utility model provides a device for improving the ductility of the FRP reinforced structure and the utilization rate of the FRP, and the FRP reinforced structure includes an end anchoring device, an FRP sheet, an expansion bolt and Adhesive, the end anchoring device is two, and the two end anchoring devices are fixedly connected through a described FRP sheet, and the end anchoring device and the FRP sheet are both bonded The agent is fixed in the reinforcement area of the concrete to be reinforced. The material of the end anchoring device is low carbon steel. The end anchoring device includes an anchoring section, a deformation section and a connecting section. shaped hole, the deformed section connects the anchoring section and the connecting section, the width of the deformed section is variable, and the ultimate strength of the deformed section is less than the ultimate strength of the FRP sheet, and the connecting section is provided with There is a rectangular channel, the FRP sheet is fixedly connected with the rectangular channel, two pre-drilled holes corresponding to the circular holes are arranged on the concrete to be reinforced, and the expansion bolts pass through the Circular holes are pressed into the pre-drilled holes to fix the FRP reinforced structure on the concrete to be reinforced.

Optionally, the wider the width of the deformation section, the greater the ultimate strength of the deformation section.

Optionally, the diameter of the circular hole is the same as that of the pre-drilled hole, and the diameter of the pre-drilled hole is larger than that of the expansion bolt.

Optionally, the binder is epoxy resin.

Optionally, the connection between the deformation section and the anchor section and the connection between the deformation section and the connection section are both provided with rounded corner structures.

According to the specific embodiment provided by the utility model, the utility model discloses the following technical effects:

In the device for improving the ductility of FRP reinforced structures and the utilization rate of FRP provided by the utility model, firstly, the reinforcement mechanism is composed of two end anchorage devices connected together by an FRP sheet, and the reinforcement mechanism is connected with the reinforcement area of the concrete to be reinforced. The FRP reinforced structure with the FRP sheet is anchored in the reinforcement area of the concrete to be reinforced through the expansion bolt, and the expansion bolt is used to fix it, avoiding the direct paste of the FRP sheet to the reinforcement area. On the reinforced structure, the FRP peeling phenomenon occurs, which improves the utilization rate of FRP.

Furthermore, because the end anchorage device in the FRP reinforced structure includes anchorage section, deformation section, and connection section, the end anchorage device is made of low-carbon steel plate, and low-carbon steel has very good ductility. When FRP strengthens the structure When under load, as the load increases, the deformation section of the end anchorage device deforms, which increases the ductility of the reinforced structure. The ductility of the reinforced structure can be controlled by changing the length of the deformed section, so that the damage of the structure becomes A relatively slow ductile failure process;

In addition, the utilization rate of FRP can be controlled by changing the width of the deformed section. As the width of the deformed section changes, the cross-section of the deformed section also changes. When the cross-section of the deformed section increases, the capacity of the deformed section The ultimate tensile force bears is correspondingly increased (to ensure that the ultimate tensile force of the deformed section is less than the breaking tensile force of the FRP sheet), the increase of the ultimate tensile force of the deformed section enables the FRP reinforced structure to withstand greater loads, and at the same time increases the FRP sheet The utilization rate of the material realizes the controllability of the utilization rate of the FRP sheet.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the accompanying drawings required in the embodiments will be briefly introduced below. Obviously, the accompanying drawings in the following description are only the present invention. For some embodiments of the invention, those skilled in the art can also obtain other drawings according to these drawings without paying creative efforts.

Fig. 1 is the local structure schematic diagram of FRP reinforced structure in the utility model embodiment;

Fig. 2 is the top view of the partial structure of the FRP reinforcement structure in the utility model embodiment;

Fig. 3 is the comparison diagram of the load-slip curve adopting the utility model device;

Fig. 4 is a schematic diagram of the overall structure of the FRP reinforcement structure in the embodiment of the utility model.

Among them: 1-expansion bolt, 2-end anchoring device, 3-FRP sheet, 4-adhesive, 5-concrete to be reinforced, 6-anchor section, 7-deformation section, 8-connection section, 9-circle shaped hole, 10-rounded structure, 11-rectangular slot.

detailed description

The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. example. Based on the embodiments of the present utility model, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the scope of protection of the present utility model.

The purpose of the utility model is to provide a device with high ductility and high utilization rate to improve the ductility of FRP reinforced structures and the utilization rate of FRP.

In order to make the above purpose, features and advantages of the utility model more obvious and understandable, the utility model will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

As shown in Figure 4, the schematic diagram of the overall structure of the FRP reinforced structure, the end anchoring devices on the FRP reinforced structure are bonded to the stressed surface of the concrete to be reinforced through an adhesive, and one end of the two end anchoring devices is punched The expansion bolts are reliably connected to the concrete to be reinforced, and the other ends of the two end anchorage devices are connected to the FRP sheet to control the peeling stress and deformation capacity of the FRP sheet from the surface of the concrete to be reinforced.

As shown in Figures 1, 2, and 4, the utility model provides a method for improving the ductility of FRP reinforced structures and the utilization rate of FRP. The FRP reinforced structure includes end anchorage devices 2, FRP sheets 3, and expansion bolts 1 and adhesive 4, the end anchoring device 2 and the FRP sheet 3 are connected together, the end anchoring device 2 is processed by low carbon steel plate, the end anchoring device 2 An anchoring section 6, a deforming section 7 and a connecting section 8 are arranged on the anchoring section 6, two circular holes 9 are arranged on the anchoring section 6, and an expansion bolt 1 is installed on each of the circular holes 9, and the anchoring The section 6 and the connecting section 8 are connected through the deformed section 7, the width of the deformed section 7 is variable, and the ultimate strength of the deformed section 7 is less than the yield strength of the FRP sheet 3, and the deformed section 7 is connected Section 8 is provided with a rectangular through-slot 11, said FRP reinforcement structure has said end anchorage devices 2 arranged in pairs, and the rectangular through-slot 11 in each pair of end anchorage devices 2 arranged in pairs is connected with a set of The FRP sheet 3 is connected; the method includes:

Arrange two pre-punched holes (not shown in the figure) in the reinforcement area of concrete 5 to be reinforced, wherein, the distance between the two pre-punched holes is the same as the distance between the circular holes 9;

The adhesive 4 is applied in the reinforcement area of the concrete 5 to be reinforced;

Bonding the end anchoring device 2 and the FRP sheet 3 on the adhesive 4;

Press the expansion bolt 1 through the circular hole 9 on the anchoring device 2 into the pre-drilled hole.

As an optional implementation manner, the wider the deformation section 7 is, the greater the ultimate strength of the deformation section 7 is.

As an optional embodiment, the diameter of the circular hole 9 is the same as the diameter of the pre-drilled hole (not shown in the figure), and the diameter of the pre-drilled hole is larger than the diameter of the expansion bolt 1 .

As an optional implementation, the adhesive 4 is epoxy resin.

As an optional implementation manner, the connection between the deformation section 7 and the anchor section 6 and the connection section between the deformation section 7 and the connection section 8 are both treated with a smooth cross-section transition.

The utility model provides a method for FRP reinforced structure ductility and FRP utilization rate. The FRP reinforced structure is fixed on the concrete to be reinforced through expansion bolts. Friction force produces self-locking effect to achieve the fixing effect; in the end anchorage device, the connection between the deformation section and the anchor section and the connection between the deformation section and the connection section are all arranged with a rounded structure, so that the deformation section and the anchor section and the deformation section There is a smooth transition between the connecting section and the connecting section, thereby avoiding the stress concentration problem at the connecting place.

In the method of FRP reinforced structure ductility and FRP utilization provided by the utility model, the end anchoring device made of low-carbon steel with good ductility is used. Low-carbon steel has the advantages of low strength and soft hardness, and has very good ductility , which improves the ductility of the entire FRP reinforced structure. When the reinforced structure is overloaded, it can avoid brittle failure of the structure, so that the failure of the structure is a relatively slow ductile failure process, and the FRP sheet is expensive. Common FRP reinforcement technology , will cause damage to the FRP sheet, resulting in an increase in cost, but no damage to the FRP sheet will occur in the utility model, and even if the rated load of the reinforced structure is exceeded, only the end anchoring device will be damaged by the utility model deformation segment.

The utility model also provides a device for improving the ductility of FRP reinforced structures and the utilization rate of FRP. The FRP reinforced structure includes end anchoring devices 2, FRP sheets 3, expansion bolts 1 and adhesives 4. The end There are two anchoring devices 2, and the two end anchoring devices 2 are fixedly connected by an FRP sheet 3, and both the end anchoring devices 2 and the FRP sheet 3 are fixed by the adhesive 4 In the reinforcement area of the concrete 5 to be reinforced, the material of the end anchoring device 2 is low carbon steel, and the end anchoring device 2 includes an anchoring section 6, a deformation section 7 and a connecting section 8, on the anchoring section 6 There are two circular holes 9, the deformed section 7 connects the anchoring section 6 and the connecting section 8, the width of the deformed section 7 is variable, and the ultimate strength of the deformed section 7 is smaller than that of the FRP sheet The ultimate strength of the material 3, the connecting section 8 is provided with a rectangular through groove 11, the FRP sheet 3 is fixedly connected with the rectangular through groove 11, and the concrete to be reinforced is provided with two circular The pre-drilled holes corresponding to the circular holes 9, the expansion bolts 1 are pressed into the pre-drilled holes through the circular holes 9, and the FRP reinforcement structure is fixed on the concrete to be reinforced.

As an optional implementation manner, the wider the deformation section 7 is, the greater the ultimate strength of the deformation section 7 is.

As an optional embodiment, the diameter of the circular hole 9 is the same as that of the pre-drilled hole, and the diameter of the pre-drilled hole is larger than that of the expansion bolt 1 .

As an optional implementation, the adhesive 4 is epoxy resin.

As an optional embodiment, rounded corner structures 10 are provided at the connection between the deformation section 7 and the anchoring section 6 and the connection between the deformation section 7 and the connection section 8 .

The load-slip curve comparison chart after adopting the device of the present invention is shown in the solid line in Figure 3, and the curve without the device of the present invention is shown in the dotted line in Figure 3. By reasonably setting the width of the deformation section 7, that is, the cross-sectional area of the deformation section, the steel in the deformation section 7 can enter the yield stage when the FRP reaches its peeling load Pd. Due to the end anchorage device, with the increase of load, the deformation section of the end anchorage device gradually enters the strengthening stage, and the load increases until it reaches the ultimate strength Pu. After the strength of the deformation section is fully exerted, it begins to enter the necking stage, and finally broken. In this process, the ultimate load of the reinforced structure is determined by the end anchorage device, which is Pu, and the load is increased by P compared to that without the end anchorage device. Due to the greater ductility of steel, the ductility of the strengthened structure is also significantly improved. Compared with the unused S, the failure of the structure is a relatively slow ductile failure process. Therefore, the utility model changes the brittle failure mode of the FRP reinforced concrete structure, and also improves the utilization rate of the FRP.

In this paper, specific examples have been used to illustrate the principle and implementation of the present utility model, and the description of the above embodiments is only used to help understand the method of the present utility model and its core idea; meanwhile, for those of ordinary skill in the art, according to Thoughts of the present utility model all have changes in specific implementation and scope of application. To sum up, the contents of this specification should not be understood as limiting the utility model.

Claims (5)

1. one kind is improved FRP ruggedized construction ductility and the device of FRP utilization rate, it is characterised in that described FRP ruggedized construction includes end anchorage device, FRP sheet material, expansion bolt and binding agent, described end anchor Being fixedly mounted with and be set to two, two described end anchorage devices connect by FRP sheet material described in is fixing, described End anchorage device and described FRP sheet material are all fixed on the reinforcing treating reinforced concrete by described binding agent In region, the material of described end anchorage device is mild steel, described end anchorage device include anchoring section, Deformation section and linkage section, described anchoring section is provided with two circular ports, and described deformation section connects described anchoring Section and described linkage section, the variable-width of described deformation section, the ultimate strength of described deformation section is less than described The ultimate strength of FRP sheet material, described linkage section is provided with rectangular through slot, and described FRP sheet material is with described Rectangular through slot is fixing to be connected, described in treat to be provided with on reinforced concrete two corresponding with described circular port pre- Punching, described expansion bolt is pressed in described pre-punching through described circular port, described FRP is added consolidation Structure is fixed on to be treated on reinforced concrete.

The most according to claim 1 a kind of improve FRP ruggedized construction ductility and the dress of FRP utilization rate Putting, it is characterised in that the width of described deformation section is the widest, the ultimate strength of described deformation section is the biggest.

The most according to claim 1 a kind of improve FRP ruggedized construction ductility and the dress of FRP utilization rate Put, it is characterised in that the diameter of described circular port is identical with the diameter of described pre-punching, described pre-punching Diameter is bigger than the diameter of described expansion bolt.

The most according to claim 1 a kind of improve FRP ruggedized construction ductility and the dress of FRP utilization rate Put, it is characterised in that described binding agent is epoxy resin.

The most according to claim 1 a kind of improve FRP ruggedized construction ductility and the dress of FRP utilization rate Put, it is characterised in that described deformation section is connected with described with the junction of described anchoring section and described deformation section The junction of section is provided with fillet structure.