CFRP-SMA intelligent reinforced concrete structure integrating cathodic protection, force sensing and bearing capacity self-adjustment

Abstract

The present invention belongs to the technical field of concrete, and specifically relates to a CFRP-SMA smart reinforced concrete structure that integrates cathodic protection, stress perception, and self-regulation of bearing capacity. In the CFRP-SMA smart reinforced concrete structure provided by the present invention, the SMA embedded optical fiber and the CFRP composite reinforcement wrapped with the external CFRP are concrete reinforcement bars, and are also auxiliary anodes of ICCP to prevent steel bar corrosion; at the same time, the SMA has the ability to adjust stress after excitation, and the embedded optical fiber can sense the stress state of the composite reinforcement. This structural system greatly improves the durability of concrete structures in coastal environments, solves the problem of real-time intelligent perception and bearing capacity regulation of structural service, and provides a new solution to the performance degradation problem caused by the deterioration of CFRP anodes during the use of traditional ICCP.

Description

Technical Field

[0001] The present invention belongs to the technical field of concrete, and specifically relates to a CFRP-SMA intelligent reinforced concrete structure integrating cathodic protection, force sensing and bearing capacity self-regulation. Background Art

[0002] Impressed current cathodic protection (ICCP) technology is considered to be an effective control method to prevent steel corrosion. Impressed current cathodic protection technology is one of the methods used to prevent metals (such as pipes, steel bars, etc.) in coastal infrastructure from being damaged by corrosion. It is based on controlling the current applied to the metal surface, making the metal surface a cathode, thereby reducing or preventing the corrosion process. Commonly used auxiliary anodes are aluminum, magnesium, and zinc. They are easy to install, have good electrochemical activity, and can provide effective cathodic protection effects. However, these auxiliary anodes have a fast corrosion rate and are consumables that need to be replaced frequently. Summary of the invention

[0003] In view of this, the purpose of the present invention is to provide a CFRP-SMA smart reinforced concrete structure integrating cathodic protection, force perception and self-regulation of bearing capacity. The SMA embedded optical fiber and outwrapped CFRP composite reinforcement in the CFRP-SMA smart reinforced concrete structure integrating cathodic protection, force perception, stress regulation and structural reinforcement is a multifunctional smart reinforcement material. It is a concrete reinforcement bar itself and an auxiliary anode of ICCP to prevent steel corrosion. At the same time, SMA has the ability to adjust stress after excitation, and the embedded optical fiber can self-sense the stress state of the reinforcement. This structural system effectively solves the durability of concrete structures in coastal environments and the problems of real-time intelligent perception and bearing capacity regulation in service, and at the same time solves the performance degradation problem caused by CFRP deterioration during the use of traditional ICCP.

[0004] In order to achieve the above object, the present invention provides the following technical solutions:

[0005] The present invention provides a CFRP-SMA intelligent reinforced concrete structure integrating cathodic protection, force sensing and bearing capacity self-adjustment, including: an ICCP system and an ICCP system degradation enhancement system;

[0006] The ICCP system includes a steel cage, concrete, SMA embedded optical fiber wrapped CFRP composite reinforcement, steel bars and a first external power source; the steel cage is placed in the concrete; the SMA embedded optical fiber wrapped CFRP composite reinforcement and the steel bars are dispersed in the concrete; the CFRP winding layer of the SMA embedded optical fiber wrapped CFRP composite reinforcement is connected to the positive electrode of the first external power source through a wire; the steel bar is connected to the negative electrode of the first external power source through a wire;

[0007] The ICCP system degradation enhancement system includes a second external power supply;

[0008] The positive electrode and the negative electrode of the second external power supply are respectively connected to the two ends of the SMA embedded optical fiber and the CFRP composite rib through wires;

[0009] The first external power supply is used to provide a DC power supply for the ICCP system;

[0010] The second external power source is an excitation device for the smooth round Fe-SMA tendons.

[0011] Preferably, the voltage of the first external power supply is 5-20V.

[0012] Preferably, the current of the first external power supply is 200mA-3A.

[0013] Preferably, the steel cage is made of ribbed bars.

[0014] The present invention also provides a method for preparing the CFRP-SMA smart reinforced concrete structure according to the above technical solution, comprising the following steps:

[0015] Place the steel cage with built-in SMA embedded optical fiber and external CFRP composite bars and steel bars in the mold, pour concrete, and then perform maintenance;

[0016] Connect the CFRP winding layer of the SMA embedded optical fiber and the CFRP composite reinforcement with a wire to the positive electrode of the first external power source, and connect the steel bar with a wire to the negative electrode of the first external power source;

[0017] The two ends of the light-circular Fe-SMA rib with SMA embedded optical fiber and CFRP composite rib are respectively connected to the positive electrode and the negative electrode of the second external power supply by wires.

[0018] The present invention also provides a method for enhancing ICCP system degradation, comprising the following steps:

[0019] Applying an excitation current to the SMA embedded optical fiber and CFRP composite reinforcement in the CFRP-SMA smart reinforcement concrete structure described in the above technical solution or the CFRP-SMA smart reinforcement concrete structure prepared by the preparation method described in the above technical solution, so that the SMA embedded optical fiber and CFRP composite reinforcement produces a pre-tightening force, and the pre-tightening force contributes to the bearing capacity of the CFRP-SMA smart reinforcement concrete structure, namely, ΔM, thereby enhancing the degradation of the ICCP system;

[0020] The excitation current application method includes: applying the excitation current to the smooth round Fe-SMA tendon of the SMA embedded optical fiber and the CFRP composite tendon after the ICCP system is turned on and the CFRP winding layer is degraded, or directly applying the excitation current to the smooth round Fe-SMA tendon of the SMA embedded optical fiber and the CFRP composite tendon after the ICCP system is not turned on and the CFRP winding layer is not degraded;

[0021] When the normal load is applied, the strain ε of the CFRP wrapping layer f > Strain ε of CFRP wrapping layer when excitation current is applied fa , and the ICCP system power-on time T≤ the service life t of the CFRP-SMA intelligent reinforced concrete structure life When the ICCP system is turned on, an excitation current is applied to the light-circular Fe-SMA tendon of the SMA embedded optical fiber and the CFRP composite tendon after the CFRP winding layer is degraded; when ε f ≤ε fa When ε f >ε fa , and T>t life When the user fails to meet the safety requirement, the process ends;

[0022] When the excitation current is directly applied to the SMA embedded optical fiber and CFRP wrapped composite reinforcement with the ICCP system turned off and the CFRP wrapping layer not deteriorated, the bearing capacity M of the CFRP-SMA smart reinforcement concrete structure after the initial preload is applied is calculated. i1 , M i1 = the bearing capacity contribution ΔM generated by the preload force and the initial bearing capacity M of the CFRP-SMA smart reinforced concrete structure i After the excitation current is applied, the ICCP system is turned on. i1 ≥M a When M i1 <M a When monitoring the strain of the CFRP wrapping layer, if ε f >ε fa , and T≤t life When the excitation current is continuously applied to the light-circular Fe-SMA ribs of the SMA embedded optical fiber and the CFRP composite ribs;

[0023] The current value of the excitation current satisfies: after the excitation current is applied, the average strain Δε of the SMA embedded optical fiber and CFRP composite reinforcement is sp ≥Strain of CFRP wrapping layer when excitation current is appliedε fa The strain ε of the CFRP wrapping layer when the normal load is initially applied fiThe difference between the initial bearing capacity M and the initial bearing capacity M of the CFRP-SMA smart reinforced concrete structure is i The design bearing capacity M of the CFRP-SMA smart reinforced concrete structure in normal use a difference.

[0024] Preferably, the calculation formula for the service life of the CFRP-SMA smart reinforced concrete structure is obtained according to Formula I:

[0025]

[0026] In formula I, t life is the service life of the CFRP-SMA smart reinforced concrete structure, A a is the surface area per unit length of the CFRP winding layer of the SMA embedded optical fiber and the CFRP composite reinforcement, q anode The charge density passing through the CFRP wrapping layer is 1.6×10 7 C / m 2 At this time, the anode reaction system is stable and the residual strength efficiency of the CFRP winding layer anode material is 68%, i p The applied cathodic protection current density is usually 2 to 20 mA / m 2 , take 20mA / m 2 , ρ is the tensile reinforcement ratio, A c is the cross-sectional area of ​​the CFRP composite bar perpendicular to the SMA embedded optical fiber and wrapped CFRP in the CFRP-SMA smart reinforced concrete structure, and n is the number of tensile steel bars.

[0027] Preferably, the calculation formula of the initial bearing capacity of the CFRP-SMA smart reinforced concrete structure is as shown in Formula II:

[0028]

[0029] Formula II assumes that the yield strength of the round Fe-SMA bar and the steel bar in the SMA embedded optical fiber wrapped CFRP composite bar is the same as f y , A s is the total area of ​​steel bars and plain Fe-SMA bars, d is the effective height of the CFRP-SMA smart reinforced concrete structure, A f is the cross-sectional area of ​​the CFRP winding layer, E f is the elastic modulus of the CFRP wrapping layer, ε fi is the strain of the CFRP wrapping layer when the normal load is initially applied, f c ' is the concrete strength, b is the width of the CFRP-SMA smart reinforced concrete structure, M i is the initial bearing capacity of the CFRP-SMA smart reinforced concrete structure.

[0030] Preferably, the calculation formula of the bearing capacity contribution ΔM generated by the preload force is shown in Formula III:

[0031] ΔM=(σ pc -γf tk )W 0 Formula III

[0032] γ=(0.7-120 / h)γ m Formula IV

[0033]

[0034] In formula III, ΔM is the bearing capacity contribution generated by the preload force, f tk is the standard value of concrete tensile strength, W 0 is the elastic resistance moment of the tensile edge of the conversion section, γ m is the basic value of the plastic influence coefficient of the section resistance moment of the CFRP-SMA smart reinforced concrete structure, and the rectangular section is taken as 1.15. γ is the plastic influence coefficient of the section resistance moment of the CFRP-SMA smart reinforced concrete structure, which is calculated by Formula IV. σ pc is the pre-compressive stress of the round Fe-SMA rib in the SMA embedded optical fiber and wrapped CFRP composite rib, calculated by the formula V, E sp is the elastic modulus of the SMA embedded optical fiber and wrapped CFRP composite reinforcement, l is the spatial resolution of distributed optical fiber sensing acquisition, u is the total number of measurement points for distributed optical fiber acquisition, i is the measurement point for distributed optical fiber acquisition, and ε sp,i is the strain at the i-th measuring point after the excitation current is applied, l is the total length of the distributed optical fiber sensing measurement section, Δε sp is the average strain of the SMA embedded optical fiber wrapped CFRP composite reinforcement after the excitation current is applied.

[0035] Preferably, the strain ε of the CFRP winding layer when the excitation current is applied is fa The calculation formula is shown in Formula VI:

[0036]

[0037] in, B=2A s f y A f E f -1.7f c 'bd f ,

[0038] The present invention provides a CFRP-SMA intelligent reinforced concrete structure, comprising: an ICCP system and an ICCP system degradation enhancement system; the ICCP system comprises a steel cage, concrete, SMA embedded optical fiber and externally wrapped CFRP composite reinforcement material, steel bars and a first external power source; the steel cage is placed in the concrete; the SMA embedded optical fiber and externally wrapped CFRP composite reinforcement and the steel bars are dispersed in the concrete; the CFRP winding layer of the SMA embedded optical fiber and externally wrapped CFRP composite reinforcement is connected to the positive electrode of the first external power source through a wire; the steel bar is connected to the negative electrode of the first external power source through a wire; the ICCP system degradation enhancement system comprises a second external power source; the positive electrode and the negative electrode of the second external power source are respectively connected to the two ends of the light round Fe-SMA reinforcement of the SMA embedded optical fiber and externally wrapped CFRP composite reinforcement through wires; the first external power source is used to provide a DC power source for the ICCP system; the second external power source is an excitation device for the light round Fe-SMA reinforcement.

[0039] Different from the traditional ICCP concrete structure system, the SMA embedded optical fiber wrapped CFRP composite reinforcement in the present invention, which integrates cathodic protection, force perception, stress regulation and structural reinforcement, is a multifunctional intelligent reinforcement material, including being able to serve as a concrete reinforcement bar itself and an auxiliary anode of ICCP to prevent steel corrosion. At the same time, SMA has the ability to adjust stress after excitation, and the embedded optical fiber can self-sense the stress state of the reinforcement. Taking the residual strength efficiency of the outer layer CFRP of the composite reinforcement as the control index, a calculation method for determining the strain of the outer layer CFRP when the excitation current is applied is proposed. The outer layer CFRP is used as a new structural system and a method for improving performance after degradation of the ICCP technology auxiliary anode. The stress regulation ability of the reinforcement after excitation will generate prestress and anti-arch in the structure, thereby compensating for the strength degradation caused by the outer layer CFRP as an auxiliary anode; the self-sensing function can monitor the performance threshold for starting compensation; at the same time, the composite reinforcement itself can be used as a structural force-bearing component with good corrosion resistance. This structural system effectively solves the problems of durability, real-time intelligent perception and bearing capacity regulation of concrete structures in coastal environments, and solves the performance degradation caused by CFRP degradation during the service life of traditional ICCP. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 It is a schematic diagram of the structure of the sheathed optical cable in the present invention;

[0041] Figure 2 Schematic diagram of a smooth round Fe-SMA rib with grooves in the present invention;

[0042] Figure 3 It is a schematic diagram of the present invention in which the sheathed optical cable at both ends of the extended light-circular Fe-SMA ribs is sheathed with a corrugated sleeve;

[0043] Figure 4Schematic diagram of a smooth round Fe-SMA rib with a CFRP wrapping layer in the present invention;

[0044] Figure 5 This is a schematic diagram of the SMA embedded optical fiber and the CFRP composite reinforcement wrapped outside in the present invention;

[0045] Figure 6 It is a structural schematic diagram of the ICCP system in the CFRP-SMA intelligent reinforced concrete structure of the present invention;

[0046] Figure 7 It is a structural schematic diagram of the ICCP system degradation enhancement system in the CFRP-SMA smart reinforced concrete structure of the present invention;

[0047] Figure 8 A relationship diagram between the bearing capacity of the CFRP-SMA smart reinforced concrete structure and the service life of ICCP in the present invention;

[0048] Fig. 9 This is a relationship diagram between the strength and strain of the outer CCFRP and the service life of ICCP in the present invention;

[0049] Fig.10 It is a flow chart of the enhancement method of ICCP system degradation in the present invention;

[0050] Among them, 1-glass fiber inner core, 2-polyimide coating layer, 3-polyurethane sheathing layer, 4-grooving, 5-smooth round Fe-SMA ribs, 6-sheathed optical cable, 7-corrugated casing, 8-CFRP winding layer, 9-tight sheath. DETAILED DESCRIPTION

[0051] like Figures 6-7 As shown, the present invention provides a CFRP-SMA smart reinforced concrete structure, including: an ICCP system (impressed current cathodic protection system) and an ICCP system degradation enhancement system;

[0052] The ICCP system includes a steel cage, concrete, SMA (shape memory metal) embedded optical fiber and externally wrapped CFRP (carbon fiber reinforced composite material) composite reinforcement, steel bars and a first external power source; the steel cage is placed in the concrete; the SMA embedded optical fiber and externally wrapped CFRP composite reinforcement and the steel bars are dispersed in the concrete; the CFRP winding layer of the SMA embedded optical fiber and externally wrapped CFRP composite reinforcement is connected to the positive electrode of the first external power source through a wire; the steel bar is connected to the negative electrode of the first external power source through a wire;

[0053] The ICCP system degradation enhancement system includes a second external power supply;

[0054] The positive electrode and the negative electrode of the second external power supply are respectively connected to the two ends of the SMA embedded optical fiber and the CFRP composite rib (iron-based shape memory metal) through wires;

[0055] The first external power supply is used to provide a DC power supply for the ICCP system;

[0056] The second external power source is an excitation device for the smooth round Fe-SMA tendons.

[0057] Unless otherwise specified, the present invention has no special requirements on the sources of the raw materials used, and commercially available products known to those skilled in the art may be used.

[0058] The CFRP-SMA intelligent reinforced concrete structure provided by the present invention comprises: an ICCP system.

[0059] In the present invention, the ICCP system includes a steel cage, concrete, SMA (shape memory metal) embedded optical fiber and externally wrapped CFRP (carbon fiber reinforced composite material) composite reinforcement, steel bars and a first external power source; the steel cage is placed in the concrete; the SMA embedded optical fiber and externally wrapped CFRP composite reinforcement and the steel bars are dispersed in the concrete; the CFRP winding layer of the SMA embedded optical fiber and externally wrapped CFRP composite reinforcement is connected to the positive electrode of the first external power source through a wire; the steel bars are connected to the negative electrode of the first external power source through a wire.

[0060] In the present invention, the number of the steel bars is preferably 2; the steel bars are preferably placed on both sides of the SMA embedded optical fiber wrapped CFRP composite bars; the steel cage is preferably made of ribbed bars. The present invention has no special limitation on the number of the steel bars, which can be determined according to actual needs.

[0061] In the present invention, the wire is preferably a metal wire. The present invention has no special restrictions on the type and size of the metal wire, which can be selected according to actual needs.

[0062] In the present invention, the first external power supply is used to provide a DC power supply for the ICCP system; the voltage of the first external power supply is preferably 5-20V, more preferably 10-20V; the current of the first external power supply is preferably 200mA-3A, more preferably 1-3A.

[0063] The CFRP-SMA smart reinforced concrete structure provided by the present invention comprises: an ICCP system degradation enhancement system.

[0064] In the present invention, the ICCP system degradation enhancement system includes a second external power supply; the positive and negative electrodes of the second external power supply are respectively connected to the two ends of the SMA embedded optical fiber and CFRP composite ribs (iron-based shape memory metal) through wires.

[0065] In the present invention, the wire is preferably a metal wire. The present invention has no special restrictions on the type and size of the metal wire, which can be selected according to actual needs.

[0066] In the present invention, the second external power source is an excitation device for the smooth round Fe-SMA tendons; the voltage of the second external power source is preferably 5 to 20V, more preferably 10 to 20V; the current of the second external power source is preferably 200mA to 3A, more preferably 1 to 3A.

[0067] The present invention has no special limitation on the size of the CFRP-SMA smart reinforced concrete structure, the diameter and length of the steel bars, which can be determined according to actual needs.

[0068] The SMA embedded optical fiber wrapped CFRP composite reinforcement in the present invention integrates force sensing, driving stress, and structural reinforcement. It uses Fe-SMA with surface grooves and embedded optical fiber sensors as the inner core, and has the characteristics of self-resetting prestressing, self-sensing prestress loss, and structural reinforcement. The CFRP-SMA intelligent reinforcement concrete structure can effectively solve the durability of the structural system in the coastal environment and the problems of real-time intelligent sensing and bearing capacity regulation in service, and at the same time solves the performance degradation problem caused by CFRP degradation during the use of traditional ICCP.

[0069] like Figures 1 to 5 As shown, in the present invention, the SMA embedded optical fiber and CFRP composite ribs preferably include: a sheathed optical cable 6, a round Fe-SMA rib 5, a CFRP winding layer 8, a tight sheath 9 and a metal conductor; the sheathed optical cable 6 includes a glass fiber inner core 1, a polyimide coating layer 2 and a polyurethane wrapping layer 3 stacked from the inside to the outside; the round Fe-SMA rib 5 has a groove 4 along the length direction; the sheathed optical cable 6 is embedded in the groove 4 in parallel; the CFRP winding layer 8 is wound on the outer surface of the round Fe-SMA rib 5, and the material of the CFRP winding layer 8 is a carbon fiber reinforced composite material, more preferably an epoxy resin composite fiber; the tight sheath 9 includes a first tight sheath and a second tight sheath, which are respectively sheathed on the interface between the two ends of the sheathed optical cable 6 and the CFRP winding layer 8; the outer surface of the CFRP winding layer 8 has a rib structure; and a wire is led out from each end of the round Fe-SMA rib 5.

[0070] The SMA embedded optical fiber and CFRP composite reinforcement provided by the present invention preferably includes: a sheathed optical cable 6. In the present invention, the sheathed optical cable 6 includes a glass fiber inner core 1, a polyimide coating layer 2 and a polyurethane sheathing layer 3 stacked from the inside to the outside; the diameter of the sheathed optical cable 6 is preferably <1mm, more preferably <0.9mm. The present invention does not specifically limit the type of sheathed optical cable, and the sheathed optical cable well known in the art can be used. The diameter of the sheathed optical cable is within this range, which can avoid affecting the mechanical properties of the reinforcement material after the sheathed optical cable is implanted.

[0071] In the present invention, the structure of the sheathed optical cable 6 is as follows Figure 1 As shown. Figure 1 As shown, the center of the sheathed optical cable 6 is a glass fiber inner core 1 , the outer layer of the glass fiber inner core 1 is coated with a polyimide coating layer 2 , and the outer layer of the polyimide coating layer 2 is coated with a polyurethane sheathing layer 3 .

[0072] The SMA embedded optical fiber wrapped CFRP composite rib provided by the present invention preferably includes: a smooth round Fe-SMA rib 5. In the present invention, the smooth round Fe-SMA rib is a commercially available product. The present invention has no special restrictions on the diameter and strength of the smooth round Fe-SMA rib, which can be selected and produced according to actual engineering needs. The diameter of the smooth round Fe-SMA rib is preferably 8 mm, 10 mm or 14 mm.

[0073] In the present invention, the smooth round Fe-SMA rib 5 has a groove 4 along the length direction; the groove 4 is preferably a square groove of 1 mm×1 mm; the number of the grooves 4 is preferably ≥1, and more preferably 1; the sheath optical cable 6 is embedded in the groove 4 in parallel; the number of the sheath optical cables is preferably ≥1, and more preferably 1. The position and number of the grooves on the smooth round Fe-SMA rib and the number of implanted sheath optical cables can be selected according to actual needs.

[0074] In the present invention, the size of the groove 4 is preferably larger than the size of the sheathed optical cable 6 .

[0075] In the present invention, the structure of the smooth round Fe-SMA rib 5 is as follows: Figure 2 As shown. Figure 2 As shown, a groove 4 is provided along the length direction of the smooth round Fe-SMA rib 5.

[0076] In the present invention, the length of the sheathed optical cable 6 is preferably greater than the length of the smooth round Fe-SMA rib 5, and the sheathed optical cable 6 extends out of both ends of the smooth round Fe-SMA rib 5. The sheathed optical cable 6 extending out of both ends of the smooth round Fe-SMA rib 5 is preferably respectively covered with a corrugated sleeve 7.

[0077] In the present invention, the sheathed optical cable at both ends of the extended light round Fe-SMA ribs is provided with a corrugated sleeve such as Figure 3 As shown. Figure 3It can be seen that the corrugated sleeve is inserted into the sheathed optical cable at both ends of the Fe-SMA ribs extending out of the light circle, and enters a part of the groove.

[0078] The SMA embedded optical fiber wrapped CFRP composite rib provided by the present invention preferably includes: a CFRP winding layer 8. In the present invention, the CFRP winding layer 8 is wound on the outer surface of the light round Fe-SMA rib 5, and the material of the CFRP winding layer 8 is preferably a carbon fiber reinforced composite material; the thickness of the CFRP winding layer is preferably 1 to 3 mm, more preferably 2 mm. The thickness of the CFRP winding layer can be determined according to actual conditions in this field.

[0079] The structure of the smooth round Fe-SMA rib with CFRP winding layer in the present invention is as follows: Figure 4 As shown. Figure 4 It can be seen that the epoxy resin composite fiber is wound around the outer layer of the smooth round Fe-SMA tendon to form a CFRP winding layer.

[0080] The SMA embedded optical fiber wrapped CFRP composite reinforcement provided by the present invention preferably includes: a tight sheath 9. In the present invention, the tight sheath 9 includes a first tight sheath and a second tight sheath, which are respectively sleeved at the interface between the two ends of the sheathed optical cable 6 and the CFRP winding layer 8. In the present invention, the tight sheath 9 is preferably sleeved into the end of the CFRP winding layer 8 by 20 mm; the tight sheath 9 is preferably at least 50 mm shorter than the sheathed optical cable 6.

[0081] The structure of the SMA embedded optical fiber and the CFRP composite rib is as follows: Figure 5 As shown. Figure 5 It can be seen that the tight sheath is put into the two ends of the sheathed optical cable and is put on part of the winding layer.

[0082] In the present invention, the outer surface of the CFRP winding layer 8 has a rib structure; the rib structure is preferably formed by winding fiber bundles. In the present invention, the width of the rib structure is preferably 5 mm, the height of the rib structure is preferably 2 mm, and the spacing of the rib structure is preferably 5 mm. The rib structure provided on the surface of the SMA embedded optical fiber wrapped CFRP composite reinforcement has sufficient anchoring effect, which can ensure the anchoring efficiency of the reinforcement and concrete during the self-driven tensioning process and reduce the loss of prestress.

[0083] The present invention preferably further comprises: adding an anchor to replace the rib structure at the end of the SMA embedded optical fiber and wrapped CFRP composite rib, and the anchor is preferably a steel sleeve anchor.

[0084] The present invention preferably further includes: reserving a 50mm portion not wrapped with the CFRP wrapping layer 8 in the middle of the smooth round Fe-SMA rib 5, and coating the portion not wrapped with the CFRP wrapping layer 8 with a high resistance coating 10 to replace the CFRP wrapping layer 8; the thickness of the high resistance coating 10 is preferably 15 μm; the composition of the high resistance coating 10 is preferably a graphene carbon nanotube composite water-based conductive material; the model of the graphene carbon nanotube composite water-based conductive material is TF-H-001, and the manufacturer is Suzhou Tanfeng Graphene Technology Co., Ltd. The present invention has no special limitation on the coating process, and a coating process well known in the art can be used.

[0085] The function of the high resistance coating is to make the Fe-SMA tendons in the high resistance area generate a higher excitation temperature in advance when the excitation current is applied, which serves as the self-driven design elongation recovery adjustment section. The temperature of the wrapped CFRP winding layer 8 area is lower than the maximum glass transition temperature, which serves as the anchoring section.

[0086] In the present invention, the method for preparing the SMA embedded optical fiber and CFRP coated composite reinforcement preferably comprises the following steps:

[0087] Grooving along the length direction of the smooth round Fe-SMA rib 5 to form a groove 4;

[0088] After the sheathed optical cable 6 is fixed in parallel in the groove 4, the smooth round Fe-SMA tendons 5 are wound with epoxy resin composite fibers and cured to obtain the smooth round Fe-SMA tendons 5 coated with the CFRP winding layer 8;

[0089] Insert the tight sheath 9 from the sheathed optical cable 6 and put it on both ends of the CFRP winding layer 8, and finally lay a rib structure on the outer surface of the CFRP winding layer 8 to obtain SMA embedded optical fiber and CFRP composite ribs;

[0090] The sheathed optical cable 6 extends out of both ends of the optical round Fe-SMA rib 5 .

[0091] In the present invention, preferably, grooves are cut along the length direction of the smooth round Fe-SMA rib 5 to form the grooves 4 .

[0092] Before the grooving, the present invention preferably further comprises: pre-tensioning the smooth round Fe-SMA tendon 5 according to the designed pre-tensioning strain; the elongation of the smooth round Fe-SMA tendon 5 after the pre-tensioning is preferably 2-6%, more preferably 3-5%.

[0093] In the present invention, the notching is preferably performed by a metal notching machine. The present invention has no special limitation on the notching process, and any notching method known in the art can be used.

[0094] After the grooving, the present invention preferably applies insulating paint on the outer surface of the inner core of the smooth round Fe-SMA rib 5 after the grooving; the thickness of the insulating paint is preferably 0.3 mm.

[0095] After obtaining the groove 4 , the present invention preferably fixes the sheathed optical cable 6 in parallel in the groove 4 .

[0096] In the present invention, the sheathed optical cable 6 extends out of both ends of the optical round Fe-SMA rib 5 .

[0097] Before the sheathed optical cable 6 is fixed parallel to the groove 4, the present invention preferably pre-treats the surface of the smooth round Fe-SMA tendon 5; the pre-treatment preferably includes polishing, cleaning and drying in sequence; the polishing is preferably performed with sandpaper; the cleaning is preferably performed with acetone; the drying temperature is preferably 30-40°C, more preferably 35°C; the drying time is preferably 3-5h, more preferably 5h. The present invention removes rust on the surface of the smooth round Fe-SMA tendon through pre-treatment.

[0098] In the present invention, the fixing method is preferably: first fix the sheathed optical cable 6 with adhesive tape, and then encapsulate the groove 4 with glue. In the present invention, the adhesive tape is preferably a transparent tape. The present invention has no special limitation on the glue, and any glue known in the art can be used. In the present invention, the fixing is specifically: bury the sheathed optical cable 6 at the bottom of the groove 4 of the round Fe-SMA rib 5, keep it in a straight state, and fix it with a transparent tape to ensure the position of the sheathed optical cable 6, and then put glue in the groove 4 to avoid relative slippage between the sheathed optical cable 6 and the round Fe-SMA rib 5.

[0099] After the fixation, the present invention preferably leads out a wire from each end of the smooth round Fe-SMA rib 5 for applying an excitation current during later use.

[0100] The present invention preferably reserves a non-sealed glue section in the grooves 4 at both ends of the smooth round Fe-SMA rib 5, and after the glue is cured, the corrugated sleeve 7 is inserted into both ends of the sheathed optical cable 6 and placed in the grooves 4 of the non-sealed glue section. In the present invention, the length of the non-sealed glue section is preferably 10 mm.

[0101] In the present invention, the diameter of the corrugated sleeve 7 is preferably 1 mm; the length of the corrugated sleeve 7 is preferably at least 20 mm shorter than the length of the sheathed optical cable 6 .

[0102] The present invention preferably further comprises: inserting the corrugated sleeve 7 into the two ends of the sheathed optical cable 6 extending out of the two ends of the smooth round Fe-SMA rib 5 and placing it in the end of the groove 4 of the non-sealed section.

[0103] The present invention preferably inserts corrugated sleeves at both ends of the sheathed optical cable to prevent the sheathed optical cable from being damaged at a large angle at the ends of the grooved light circle Fe-SMA ribs. In addition, the corrugated tube 7 is also a conductive material and can be used to connect the wire of the excitation current.

[0104] After the sheathed optical cable 6 is fixed in parallel in the groove 4 , the present invention preferably winds the smooth round Fe-SMA tendons 5 with carbon fiber reinforced composite materials and solidifies them to obtain the smooth round Fe-SMA tendons 5 coated with the CFRP winding layer 8 .

[0105] In the present invention, the epoxy resin composite fiber preferably includes fiber cloth impregnated with epoxy resin and fiber bundles impregnated with epoxy resin; the fiber cloth is preferably carbon fiber cloth, glass fiber cloth or basalt fiber cloth, more preferably carbon fiber cloth; the fiber bundle is preferably carbon fiber, basalt fiber, glass fiber, aramid fiber or plant fiber, more preferably carbon fiber.

[0106] The present invention has no special limitation on the types and amounts of the epoxy resin, fiber cloth and fiber bundle, which can be determined according to actual needs.

[0107] In the present invention, when the carbon fiber reinforced composite material is an epoxy resin composite fiber, the winding process is preferably to wrap the light round Fe-SMA tendons 5 of the implanted sheathed optical cable 6 with a fiber cloth impregnated with epoxy resin, and then to perform circumferential winding with a fiber bundle impregnated with epoxy resin to form a CFRP winding layer 8; the circumferential winding is preferably performed along the length direction of the light round Fe-SMA tendons 5, and more preferably at 90 degrees along the length direction of the light round Fe-SMA tendons 5; the direction of the carbon fiber in the carbon fiber cloth is consistent with the direction of the light round Fe-SMA tendons. The thickness of the fiber bundle impregnated with epoxy resin in the present invention is not particularly limited and can be determined according to actual needs, such as 1mm, 2mm.

[0108] In an embodiment of the present invention, the winding process is specifically as follows: applying epoxy resin on the fiber cloth, and after the epoxy resin is fully impregnated, wrapping the fiber cloth on the outer surface of the smooth round Fe-SMA tendon 5, and after curing; winding the fiber bundle impregnated with epoxy resin in a circumferential direction along the length direction of the smooth round Fe-SMA tendon 5 to form a CFRP winding layer 8.

[0109] After obtaining the smooth round Fe-SMA ribs 5 coated with the CFRP winding layer 8 , the present invention inserts the tight sheath 9 from the sheathed optical cable 6 and sheathes it on both ends of the CFRP winding layer 8 .

[0110] In the present invention, the length of the tight sheath 9 inserted into the end of the smooth round Fe-SMA reinforcement 5 coated with the CFRP winding layer 8 is preferably at least 20 mm; the diameter of the tight sheath 9 is preferably 1 mm larger than the diameter of the reinforcement 5 coated with the CFRP winding layer 8; the sheathed optical cable 6 is preferably at least 50 mm longer than the tight sheath 9; and the corrugated tube 7 is preferably at least 30 mm longer than the tight sheath 9.

[0111] The invention allows the sheathed optical cable to extend out of the two ends of the tight sheath, leaving the sheathed optical cable longer, so as to facilitate the subsequent fusion splicing of the sheathed optical cable with the optical fiber jumper.

[0112] The present invention preferably further comprises heating the tight sheath 9; the heating is preferably performed using a hot air gun. The present invention shrinks the tight sheath by heating to tightly wrap the winding layer.

[0113] After the tight sheath 9 is inserted into the sheathed optical cable 6 , the present invention arranges a rib structure on the outer surface of the CFRP winding layer 8 to obtain SMA embedded optical fiber and CFRP wrapped composite ribs.

[0114] In the present invention, the rib structure is preferably formed by winding a fiber bundle on the outer surface of the CFRP winding layer 8; the width of the rib structure is preferably 5 mm, the height is preferably 2 mm, and the rib spacing is preferably 5 mm. The rib structure is provided in the present invention to ensure the anchoring efficiency of the reinforcement and concrete during the tensioning process and reduce the loss of prestress.

[0115] The present invention pre-grooves the surface of the smooth round Fe-SMA tendons and implants them into the sheathed optical cable, so that they have the function of self-sensing, that is, "intelligence", to ensure the control of the prestress during its tensioning process and the monitoring of the prestress loss during normal use. The obtained SMA embedded optical fiber and CFRP composite tendons are different from the traditional steel-continuous fiber intelligent tendons. The steel inner core used in the present invention is a smooth round Fe-SMA tendon, which has a shape memory effect, that is, it cannot recover by itself after pre-stretching at room temperature, and can recover to its original state after being stimulated by a specific heating temperature. This characteristic determines that the SMA embedded optical fiber and CFRP composite tendons have the characteristics of self-driving. Winding fibers on the surface of the grooved smooth round Fe-SMA tendons implanted in the sheathed optical cable can form a CFRP winding layer to prevent the inner core of the smooth round Fe-SMA tendons from rusting and prevent the sheathed optical cable from breaking, thereby improving the durability of the prestressed tendons. The rib structure on the surface of the CFRP winding layer can provide sufficient bite force and anchoring effect, so that the prestress is evenly distributed during the application process, reducing the loss of prestress due to friction and the like. Therefore, the SMA embedded optical fiber wrapped CFRP composite bar proposed by the present invention has the characteristics of self-driving, self-sensing, and low prestress loss, overcoming the shortcomings of existing steel-continuous fiber composite bars: large prestress loss, low anchoring efficiency, low tension prestress control accuracy, and complex construction. As a force-bearing material, it can be applied to prestress application and prestress loss monitoring of various complex engineering components. Moreover, the SMA embedded optical fiber wrapped CFRP composite bar provided by the present invention is corrosion-resistant, has high strength and high precision, is easy to construct, can be applied in engineering, and is suitable for large-scale promotion.

[0116] The present invention also provides a method for preparing the CFRP-SMA smart reinforced concrete structure according to the above technical solution, comprising the following steps:

[0117] Place the steel cage with built-in SMA embedded optical fiber and external CFRP composite bars and steel bars in the mold, pour concrete, and then perform maintenance;

[0118] Connect the CFRP winding layer of the SMA embedded optical fiber and the CFRP composite reinforcement with a wire to the positive electrode of the first external power source, and connect the steel bar with a wire to the negative electrode of the first external power source;

[0119] The two ends of the light-circular Fe-SMA rib with SMA embedded optical fiber and CFRP composite rib are respectively connected to the positive electrode and the negative electrode of the second external power supply by wires.

[0120] The present invention has no special limitation on the concrete and the mold, and they can be selected according to actual needs.

[0121] The present invention has no particular limitation on the curing process, and any curing process known in the art may be used.

[0122] The present invention also provides a method for enhancing ICCP system degradation, comprising the following steps:

[0123] Applying an excitation current to the light round Fe-SMA bar with SMA embedded optical fiber and CFRP composite bar outside in the CFRP-SMA smart bar concrete structure described in the above technical solution or the CFRP-SMA smart bar concrete structure prepared by the preparation method described in the above technical solution, so that the SMA embedded optical fiber and CFRP composite bar outside generates a pre-tightening force, and the pre-tightening force contributes to the bearing capacity of the CFRP-SMA smart bar concrete structure, namely, ΔM, thereby enhancing the degradation of the ICCP system;

[0124] The excitation current application method includes: applying the excitation current to the smooth round Fe-SMA tendon of the SMA embedded optical fiber and the CFRP composite tendon after the ICCP system is turned on and the CFRP winding layer is degraded, or directly applying the excitation current to the smooth round Fe-SMA tendon of the SMA embedded optical fiber and the CFRP composite tendon after the ICCP system is not turned on and the CFRP winding layer is not degraded;

[0125] When the normal load is applied, the strain ε of the CFRP wrapping layer f > Strain ε of CFRP wrapping layer when excitation current is applied fa , and the ICCP system power-on time T≤ the service life t of the CFRP-SMA intelligent reinforced concrete structure life When the ICCP system is turned on, an excitation current is applied to the light-circular Fe-SMA tendon of the SMA embedded optical fiber and the CFRP composite tendon after the CFRP winding layer is degraded; when ε f ≤ε fa When ε f >ε fa , and T>t life When the user fails to meet the safety requirement, the process ends;

[0126] When the excitation current is directly applied to the SMA embedded optical fiber and CFRP wrapped composite reinforcement with the ICCP system turned off and the CFRP wrapping layer not deteriorated, the bearing capacity M of the CFRP-SMA smart reinforcement concrete structure after the initial preload is applied is calculated. i1 , M i1 = the bearing capacity contribution ΔM generated by the preload force and the initial bearing capacity M of the CFRP-SMA smart reinforced concrete structure i After the excitation current is applied, the ICCP system is turned on. i1 ≥M a When M i1 <M a When monitoring the strain of the CFRP wrapping layer, if ε f >εfa , and T≤t life When the excitation current is continuously applied to the light-circular Fe-SMA ribs of the SMA embedded optical fiber and the CFRP composite ribs;

[0127] The current value of the excitation current satisfies: after the excitation current is applied, the average strain Δε of the SMA embedded optical fiber and CFRP composite reinforcement is sp ≥Strain of CFRP wrapping layer when excitation current is appliedε fa The strain ε of the CFRP wrapping layer when the normal load is initially applied fi The difference between the initial bearing capacity M and the initial bearing capacity M of the CFRP-SMA smart reinforced concrete structure is i The design bearing capacity M of the CFRP-SMA smart reinforced concrete structure in normal use a difference.

[0128] The present invention applies an excitation current to the light round Fe-SMA tendons with SMA embedded optical fiber and externally wrapped CFRP composite tendons in the CFRP-SMA smart tendon concrete structure described in the above technical solution or the CFRP-SMA smart tendon concrete structure prepared by the preparation method described in the above technical solution, so that the SMA embedded optical fiber and externally wrapped CFRP composite tendons generate a pre-tightening force, and the pre-tightening force contributes to the bearing capacity of the CFRP-SMA smart tendon concrete structure, namely ΔM, thereby enhancing the degradation of the ICCP system.

[0129] In the present invention, the method of applying the excitation current includes: applying the excitation current to the smooth round Fe-SMA tendons of the SMA embedded optical fiber and outer CFRP composite tendons after the ICCP system is turned on and the CFRP winding layer is degraded, or directly applying the excitation current to the smooth round Fe-SMA tendons of the SMA embedded optical fiber and outer CFRP composite tendons when the ICCP system is not turned on and the CFRP winding layer is not degraded. Preferably, the excitation current is applied to the smooth round Fe-SMA tendons of the SMA embedded optical fiber and outer CFRP composite tendons after the ICCP system is turned on and the CFRP winding layer is degraded.

[0130] In the present invention, when the normal use load is applied, the strain ε of the CFRP winding layer is f > Strain ε of CFRP wrapping layer when excitation current is applied fa , and the ICCP system power-on time T≤ the service life t of the CFRP-SMA intelligent reinforced concrete structure life When the ICCP system is turned on, an excitation current is applied to the light-circular Fe-SMA tendon of the SMA embedded optical fiber and the CFRP composite tendon after the CFRP winding layer is degraded; when ε f ≤ε faWhen ε f >ε fa , and T>t life When the usage safety is not met, the process ends.

[0131] In the present invention, when the excitation current is directly applied to the light round Fe-SMA bar of the SMA embedded optical fiber and wrapped CFRP composite bar with the ICCP system not turned on and the CFRP winding layer not deteriorated, the bearing capacity M after the initial preload force is applied to the CFRP-SMA smart bar concrete structure design is calculated. i1 , M i1 = the bearing capacity contribution ΔM generated by the preload force and the initial bearing capacity M of the CFRP-SMA smart reinforced concrete structure i After the excitation current is applied, the ICCP system is turned on. i1 ≥M a When M i1 <M a When monitoring the strain of the CFRP wrapping layer, if ε f >ε fa , and T≤t life When the excitation current is continuously applied to the light-circular Fe-SMA rib of the SMA embedded optical fiber and the CFRP composite rib.

[0132] In the present invention, the current value of the excitation current satisfies: after the excitation current is applied, the average strain Δε of the SMA embedded optical fiber and CFRP composite reinforcement is sp ≥Strain of CFRP wrapping layer when excitation current is appliedε fa The strain ε of the CFRP wrapping layer when the normal load is initially applied fi The difference between the initial bearing capacity M and the initial bearing capacity M of the CFRP-SMA smart reinforced concrete structure is i The design bearing capacity M of the CFRP-SMA smart reinforced concrete structure in normal use a difference.

[0133] like Fig.10 As shown, in the present invention, the process of the enhancement method is preferably:

[0134] Obtaining the service life of the ICCP system in the CFRP-SMA smart reinforced concrete structure described in the above technical solution or the CFRP-SMA smart reinforced concrete structure prepared by the preparation method described in the above technical solution;

[0135] Applying a normal service load to the CFRP-SMA smart reinforced concrete structure;

[0136] Obtaining the initial bearing capacity of the CFRP-SMA smart reinforced concrete structure;

[0137] Turn on the ICCP system;

[0138] The strain of the CFRP winding layer of the SMA embedded optical fiber and the CFRP composite reinforcement wrapped in the CFRP-SMA smart reinforcement concrete structure is monitored. When the normal service load is applied, the strain ε f > Strain ε of CFRP wrapping layer when excitation current is applied fa , and the ICCP system power-on time T≤ the service life t of the CFRP-SMA intelligent reinforced concrete structure life When the excitation current is applied, the SMA embedded optical fiber wrapped CFRP composite bar generates a preload, and the bearing capacity contribution ΔM generated by the preload is calculated. When the excitation current is applied, the average strain Δε of the SMA embedded optical fiber wrapped CFRP composite bar sp ≥Strain of CFRP wrapping layer when excitation current is appliedε fa The strain ε of the CFRP wrapping layer when the normal load is initially applied fi The difference between the initial bearing capacity M and the initial bearing capacity M of the CFRP-SMA smart reinforced concrete structure is i The design bearing capacity M of the CFRP-SMA smart reinforced concrete structure in normal use a When Δε is greater than Δε, the bearing capacity of the degraded CFRP-SMA smart reinforced concrete structure meets the design requirements of the bearing capacity of the CFRP-SMA smart reinforced concrete structure. sp <ε fa -ε fi , or ΔM<M i -M a When the excitation current continues to be applied, until Δε sp ≥ε fa -ε fi , and ΔM≥M i -M a ;;

[0139] When ε f ≤ε fa When the CFRP layer of the SMA embedded optical fiber and the CFRP composite reinforcement is wrapped, the strain is continuously monitored;

[0140] When ε f >ε fa , and T>t life When the user fails to meet the safety requirement, the process ends;

[0141] Alternatively, before the ICCP system is turned on, after applying a normal service load to the CFRP-SMA smart reinforced concrete structure, an excitation current is directly applied to the SMA embedded optical fiber and externally wrapped CFRP composite reinforcement that has not deteriorated, and the SMA embedded optical fiber and externally wrapped CFRP composite reinforcement generates a preload force. The bearing capacity contribution ΔM generated by the preload force is calculated. The average strain Δε of the SMA embedded optical fiber and externally wrapped CFRP composite reinforcement after the excitation current is applied is sp ≥Strain of CFRP wrapping layer when excitation current is appliedε fa The strain ε of the CFRP wrapping layer when the normal load is initially applied fi The difference between the initial bearing capacity M and the initial bearing capacity M of the CFRP-SMA smart reinforced concrete structure is i The design bearing capacity M of the CFRP-SMA smart reinforced concrete structure in normal use a When Δε is greater than Δε, the bearing capacity of the degraded CFRP-SMA smart reinforced concrete structure meets the design requirements of the bearing capacity of the CFRP-SMA smart reinforced concrete structure. sp <ε fa -ε fi , or ΔM<M i -M a When the excitation current continues to be applied, until Δε sp ≥ε fa -ε fi , and ΔM≥M i -M a ;

[0142] Calculation of the bearing capacity M of CFRP-SMA smart reinforced concrete structure after initial preload i1 , M i1 = the bearing capacity contribution ΔM generated by the preload force and the initial bearing capacity M of the CFRP-SMA smart reinforced concrete structure i When M i1 ≥M a When M i1 <M a When ε f >ε fa , and T≤t life When Δε is Δε, the excitation current is continuously applied to the light-circular Fe-SMA rib of the SMA embedded optical fiber and wrapped CFRP composite rib until Δε sp ≥ε fa -ε fi , and ΔM≥M i -M a .

[0143] In the present invention, the calculation formula for the service life of the CFRP-SMA smart reinforced concrete structure is preferably obtained according to Formula I:

[0144]

[0145] In formula I, t life is the service life of the CFRP-SMA smart reinforced concrete structure, A a is the surface area per unit length of the CFRP winding layer of the SMA embedded optical fiber and the CFRP composite reinforcement, q anode The charge density passing through the CFRP wrapping layer is 1.6×10 7 C / m 2 At this time, the anode reaction system is stable and the residual strength efficiency of the CFRP winding layer anode material is 68%, i p The applied cathodic protection current density is usually 2 to 20 mA / m 2 , take 20mA / m 2 , ρ is the tensile reinforcement ratio, A c is the cross-sectional area of ​​the CFRP composite bar perpendicular to the SMA embedded optical fiber and wrapped CFRP in the CFRP-SMA smart reinforced concrete structure, and n is the number of tensile steel bars.

[0146] In the present invention, the calculation formula of the initial bearing capacity of the CFRP-SMA smart reinforced concrete structure is preferably as shown in Formula II:

[0147]

[0148] Formula II assumes that the yield strength of the round Fe-SMA bar and the steel bar in the SMA embedded optical fiber wrapped CFRP composite bar is the same as f y , A s is the total area of ​​steel bars and plain Fe-SMA bars, d is the effective height of the CFRP-SMA smart reinforced concrete structure, A f is the cross-sectional area of ​​the CFRP winding layer, E f is the elastic modulus of the CFRP wrapping layer, ε fi is the strain of the CFRP wrapping layer when the normal load is initially applied, f c ' is the concrete strength, b is the width of the CFRP-SMA smart reinforced concrete structure, M i is the initial bearing capacity of the CFRP-SMA smart reinforced concrete structure.

[0149] like Figure 8 As shown, it is assumed that the design bearing capacity for normal use is M aAs time goes by, the strength of the CFRP wrapping layer decreases, resulting in the degradation of the bearing capacity of the CFRP-SMA smart reinforced concrete structure. In order to ensure the normal use of the CFRP-SMA smart reinforced concrete structure, the bearing capacity of the CFRP-SMA smart reinforced concrete structure should be greater than M a , so if there is T a At the moment, the bearing capacity of the CFRP-SMA smart reinforced concrete structure is monitored to be equal to M a When the excitation current is applied to heat the shape memory alloy (SMA), the SMA embedded optical fiber wrapped CFRP composite bar that integrates force sensing, driving stress and structural reinforcement can generate preload. The preload can cause the CFRP-SMA smart bar concrete structure to produce an upward arch, thereby closing cracks and improving bearing capacity. At this time, in order to ensure the safety of the structure, ΔM≥M i -M a .

[0150] In addition, the excitation current can also be applied at the initial stage of design to make the CFRP-SMA smart reinforced concrete structure meet the design bearing capacity requirements for normal use during its service life. The bearing capacity M after the preload force is applied at the initial stage of design must be i1 =M i +ΔM.

[0151] Considering that the role of the preload force is mainly to prevent concrete cracking and cause the CFRP-SMA smart reinforced concrete structure to produce an upward arch, and the CFRP wrapping layer needs to work only after the preload force is consumed and the concrete cracks, the calculation formula for the bearing capacity contribution ΔM generated by the preload force is preferably as shown in Formula III:

[0152] ΔM=(σ pc -γf tk )W 0 Formula III

[0153] γ=(0.7-120 / h)γ m Formula IV

[0154]

[0155] In formula III, ΔM is the bearing capacity contribution generated by the preload force, f tk is the standard value of concrete tensile strength, W 0 is the elastic resistance moment of the tensile edge of the conversion section, γ m is the basic value of the plastic influence coefficient of the section resistance moment of the CFRP-SMA smart reinforced concrete structure, and the rectangular section is taken as 1.15. γ is the plastic influence coefficient of the section resistance moment of the CFRP-SMA smart reinforced concrete structure, which is calculated by Formula IV. σ pcis the pre-compressive stress of the SMA embedded optical fiber and CFRP composite reinforcement, which can be calculated by the formula V, E sp is the elastic modulus of the SMA embedded optical fiber and wrapped CFRP composite reinforcement, l is the spatial resolution of distributed optical fiber sensing acquisition, u is the total number of measurement points for distributed optical fiber acquisition, i is the measurement point for distributed optical fiber acquisition, and ε sp,i is the strain at the i-th measuring point after the excitation current is applied, l is the total length of the distributed optical fiber sensing measurement section, Δε sp is the average strain of the SMA embedded optical fiber wrapped CFRP composite reinforcement after the excitation current is applied.

[0156] The design load capacity for normal use is M a Under the condition that the strength of the CFRP wrapping layer decreases due to the deterioration of the CFRP wrapping layer after the cathodic protection before the excitation current is applied, in order to ensure the safety of the CFRP-SMA smart reinforced concrete structure, the strength of the CFRP wrapping layer is usually not deteriorated by more than 0.68f. fu In addition, the deterioration of the strength of the CFRP wrapping layer will also lead to the increase of the strain of the CFRP wrapping layer. i =M a Substituting into formula II, the strain ε of the CFRP wrapping layer when the excitation current needs to be applied can be obtained: fa , the strain ε of the CFRP wrapping layer when the excitation current is applied fa The calculation formula of is preferably as shown in Formula VI:

[0157]

[0158] in, B=2A s f y A f E f -1.7f c 'bd f ,

[0159] Assuming that the axial force of the SMA embedded optical fiber wrapped CFRP composite reinforcement remains unchanged before the excitation current is applied, the stress f of the CFRP winding layer when the excitation current is applied can be obtained: fa Preferably, it is as shown in Formula VII:

[0160] f fa =ε fi (E f +E s A s / A f )-ε fa E s A s / A f Formula VII

[0161] Fig. 9 The design bearing capacity for normal use is given as M a The relationship between the strength and strain of the lower outer layer CFRP composite reinforcement and the service life. Before applying the excitation current, it is assumed that the axial force of the SMA embedded optical fiber wrapped CFRP composite reinforcement remains unchanged. Since the wrapped CFRP wrapping layer is used as an auxiliary anode for cathodic protection, the strength of the CFRP wrapping layer deteriorates, resulting in a decrease in its stress. However, the strain of the CFRP wrapping layer changes from the initial strain ε fi Assuming that the SMA core and the CFRP wrapping layer work together, it is assumed that the strain monitored by the optical fiber is equal to the strain of the CFRP wrapping layer. When the strain of the CFRP wrapping layer monitored by the optical fiber increases to ε fa The excitation current can be started when the excitation current is applied. After the excitation current is applied, the self-driving of the composite reinforcement generates pressure, which reduces the stress of the CFRP winding layer and the stress of the SMA embedded optical fiber wrapped CFRP composite reinforcement from tension to pressure. At the same time, the strain of the CFRP winding layer also decreases with the generation of pressure.

[0162] Fig.10 The flow chart of the performance improvement method after degradation of a new structural system integrating cathodic protection, force sensing, stress regulation and structural reinforcement, with SMA embedded with optical fiber and CFRP composite reinforcement wrapped with outer layer of CFRP (CFRP wrapping layer) as ICCP technology auxiliary anode. Fig.10 As shown in the figure, the design parameters of the component (CFRP-SMA smart reinforced concrete structure) are input, the service life of the ICCP system is calculated, the normal service load is applied, the initial bearing capacity is calculated, the ICCP system is turned on, and the strain of the outer CFRP (CFRP wrapping layer) is monitored. If the strain of the CFRP wrapping layer after applying the normal service load is ε f > Strain ε of CFRP wrapping layer when excitation current is applied fa , and the ICCP system power-on time T≤ the service life t of the CFRP-SMA intelligent reinforced concrete structure life , apply excitation current to generate preload, calculate the bearing capacity contribution ΔM after applying preload, if Δε sp ≥ε fa -ε fi , and ΔM≥M i -M a , the bearing capacity after deterioration meets the design requirements, and the end is, if Δε sp <ε fa -ε fi , or ΔM<M i -M a , continue to apply the excitation current until Δε sp ≥ε fa -ε fi , and ΔM≥M i-M a ; if ε f ≤ε fa , continue to monitor the outer CFRP strain, if ε f ≤ε fa And T>t life , the process ends with failure to meet the safety requirement; or, after applying the normal load and before the CFRP wrapping layer deteriorates, apply the excitation current to generate the preload, and calculate the bearing capacity contribution ΔM after the preload is applied. If Δε sp ≥ε fa -ε fi , and ΔM≥M i -M a , the bearing capacity after deterioration meets the design requirements, if Δε sp <ε fa -ε fi , or ΔM<M i -M a , continue to apply the activation excitation current until Δε sp ≥ε fa -ε fi , and ΔM≥M i -M a ; Calculate the bearing capacity M of the CFRP-SMA smart reinforced concrete structure after the initial preload is applied i1 , M i1 = the bearing capacity contribution ΔM generated by the preload force and the initial bearing capacity M of the CFRP-SMA smart reinforced concrete structure i After the excitation current is applied, the ICCP system is turned on. i1 ≥M a When M i1 <M a When ε f >ε fa , and T≤t life When Δε is Δε, the excitation current is continuously applied to the light-circular Fe-SMA rib of the SMA embedded optical fiber and wrapped CFRP composite rib until Δε sp ≥ε fa -ε fi , and ΔM≥M i -M a .

[0163] The present invention proposes a new structural system and reinforcement method using a CFRP winding layer (outer layer CFRP) of SMA embedded optical fiber and externally wrapped CFRP composite bars that integrates cathodic protection, force sensing, stress regulation and structural reinforcement as an auxiliary anode of ICCP technology. Taking a concrete beam as an example: it is mainly composed of concrete, bottom tensile steel bars, SMA embedded optical fiber and externally wrapped CFRP composite bars that integrate cathodic protection, force sensing, stress regulation and structural reinforcement, and a steel cage. Among them, the SMA embedded optical fiber and externally wrapped CFRP composite bars that integrate cathodic protection, force sensing, stress regulation and structural reinforcement use Fe-SMA with surface grooves and embedded optical fiber sensors as the inner core, and have the characteristics of self-resetting prestressing, self-sensing prestress loss, and structural reinforcement. This structural system effectively solves the problems of durability of structures in coastal environments and real-time intelligent perception and bearing capacity regulation in service, and at the same time solves the performance degradation problem caused by CFRP deterioration during the use of traditional ICCP.

[0164] The carbon fiber material in the carbon fiber CFRP composite bar has excellent mechanical, electrical conductivity and electrochemical properties. It is an auxiliary anode material with superior performance. It can stably control the polarization potential of the steel bar in the corrosion-free zone, thereby effectively controlling the corrosion of the steel bar. Compared with the commonly used metal auxiliary anodes, it has the characteristics of good electrochemical stability, strong tolerance, low working voltage, low consumption rate and long service life. In addition, the carbon fiber CFRP composite bar can also be cast in concrete as a structural reinforcement material. However, the carbon fiber CFRP will deteriorate during the process of being used as an auxiliary anode, resulting in a decrease in strength. Shape memory alloy (SMA) is a special type of metal alloy that has a special property that it can be restored to its original shape by heating or other means after undergoing a certain deformation. Using it as the inner core of the carbon fiber CFRP composite bar can generate a preload by applying an excitation current to compensate for the decrease in strength caused by the deterioration of the outer carbon fiber CFRP as an auxiliary anode, thereby improving the structural reinforcement effect.

[0165] The technical solutions of the present invention will be described clearly and completely below in conjunction with the embodiments of the present invention, but they should not be construed as limiting the protection scope of the present invention.

[0166] Example 1

[0167] The dimensions of the CFRP-SMA smart reinforced concrete structure (concrete beam) are 3000 mm long, 250 mm high, 150 mm wide, and the clear span is 2500 mm. The reinforcement configuration is shown in Figure 6. Two 14 mm diameter steel bars and one 14 mm SMA embedded optical fiber wrapped CFRP composite bar that integrates cathodic protection, force sensing, stress regulation, and structural reinforcement are used on the tension side of the bottom of the beam. The composite bar is placed in the middle and the steel bars are placed on both sides. In order to ensure that the beam has sufficient shear bearing capacity, the stirrups are 8mm diameter plain round bars with a diameter of 150mm. After the steel cage is tied, in order to cathodically protect the longitudinal steel bars, metal wires for cathodic protection are connected to the surface of the CFRP winding layer (thickness of 2mm) of the longitudinal steel bars and the SMA embedded optical fiber and externally wrapped CFRP composite bars, respectively. The CFRP winding layer of the SMA embedded optical fiber and externally wrapped CFRP composite bars is connected to the positive electrode of the first external power supply through a metal wire, and the steel bar is connected to the negative electrode of the first external power supply through a metal wire. The left end of the plain round Fe-SMA bar of the SMA embedded optical fiber and externally wrapped CFRP composite bar is connected to the negative electrode of the second power supply through a metal wire, and the right end of the plain round Fe-SMA bar is connected to the positive electrode of the second power supply through a metal wire. Concrete is poured and maintained. When the cathodic protection current is applied, the CFRP winding layer is connected to the positive electrode of the first power supply as an anode material, and the steel bar is connected to the negative electrode of the first power supply as a cathode material to form an ICCP system. The plain round Fe-SMA bar and the second power supplies connected at both ends form an ICCP system degradation enhancement system.

[0168] The preparation steps of SMA embedded optical fiber and CFRP composite reinforcement are as follows:

[0169] The smooth round Fe-SMA tendons are pre-tensioned according to the designed pre-stretching strain, and the elongation of the smooth round Fe-SMA tendons after pre-tensioning is 3%; a metal grooving machine is used to carve a 1mm×1mm square groove along the length direction of the smooth round Fe-SMA tendons; the rust on the outer surface of the inner core of the grooved smooth round Fe-SMA tendons is removed by sandpaper, and then the inner core of the grooved smooth round Fe-SMA tendons is cleaned with acetone, and then dried at 35°C for 5h, and a 0.3mm thick insulating varnish is applied to the outer surface of the inner core of the grooved smooth round Fe-SMA tendons 5, and a metal wire is connected to one end of the smooth round Fe-SMA tendons 5 for applying an excitation current during later use. The cable (diameter <0.9mm, glass fiber inner core, polyimide coating layer and polyurethane sheathing layer stacked from inside to outside) is buried in the bottom of the groove of the smooth round Fe-SMA tendon, kept in a straight state, and fixed with transparent tape to ensure the position of the sheathed optical cable, and then glue is placed in the groove to avoid relative slippage between the sheathed optical cable and the smooth round Fe-SMA tendon; after the sheathed optical cable is implanted, within 10mm of both ends of the grooved smooth round Fe-SMA tendon, without glue packaging, a corrugated tube with a diameter of 1mm and at least 20mm shorter than the sheathed optical cable is inserted into both ends of the sheathed optical cable, and placed in the grooved end of the unsealed section to prevent the sheathed optical cable from slipping at the end of the grooved smooth round Fe-SMA tendon. Large angle damage occurs on the part; epoxy resin is applied on the fiber cloth, and after the epoxy resin is fully impregnated, the carbon fiber cloth is wrapped on the outer surface of the inner core of the smooth round Fe-SMA rib to form a smooth round rib. The direction of the carbon fiber in the carbon fiber cloth is consistent with the direction of the smooth round Fe-SMA rib. After it is cured, the carbon fiber bundle impregnated with epoxy resin is circumferentially wound at 90 degrees along the length direction of the Fe-SMA rib to form a smooth round Fe-SMA rib coated with a CFRP winding layer (thickness of 2mm); the two ends of the sheathed optical cable are inserted into a tight sheath 1mm larger than the diameter of the smooth round Fe-SMA rib coated with the CFRP winding layer, and the tight sheath is inserted into the smooth round Fe-SMA rib coated with the CFRP winding layer. The end of the reinforcement is 20mm, the tight sheath is at least 50mm shorter than the sheathed optical cable, which is convenient for the later fusion of the sheathed optical cable and the optical fiber jumper. The corrugated tube is at least 30mm longer than the tight sheath, which is convenient for the later connection of the excitation current wire. Finally, the tight sheath is heated with a hot air gun to shrink the tight sheath due to heat. In order to ensure the anchoring efficiency of the reinforcement and concrete during the tensioning process and reduce the loss of prestress, a fiber bundle is wound on the outer surface of the CFRP winding layer 8 to form a rib structure. The width of the rib structure is 5mm, the height of the rib structure is 2mm, and the spacing of the rib structure is 5mm, so as to obtain an SMA embedded optical fiber wrapped CFRP composite reinforcement integrating cathodic protection, force perception, stress regulation and structural reinforcement.

[0170] Example 2

[0171] The dimensions of the CFRP-SMA smart reinforced concrete structure (concrete beam) are 3000 mm long, 250 mm high, 150 mm wide, and the clear span is 2500 mm. The reinforcement configuration is shown in Figure 6. Two 14 mm diameter steel bars and one 14 mm SMA embedded optical fiber wrapped CFRP composite bar that integrates force sensing, driving stress, and structural reinforcement are used on the tension side of the bottom of the beam. The composite bar is placed in the middle and the steel bars are placed on both sides. In order to ensure that the beam has sufficient shear bearing capacity, the stirrups are 8mm diameter plain round bars with a diameter of 150mm. After the steel cage is tied, in order to cathodically protect the longitudinal steel bars, metal wires for cathodic protection are connected to the surface of the CFRP wrapping layer (thickness of 2mm) of the longitudinal steel bars and the SMA embedded optical fiber wrapped CFRP composite bars. The CFRP wrapping layer of the SMA embedded optical fiber wrapped CFRP composite bars is connected to the positive electrode of the first external power supply through a metal wire, and the steel bar is connected to the negative electrode of the first external power supply through a metal wire. The left end of the plain round Fe-SMA bar of the SMA embedded optical fiber wrapped CFRP composite bar is connected to the negative electrode of the second power supply through a metal wire, and the right end of the plain round Fe-SMA bar is connected to the positive electrode of the second power supply through a metal wire. Concrete is poured and maintained. When the cathodic protection current is applied, the CFRP wrapping layer is connected to the positive electrode of the power supply as the anode material, and the steel bar is connected to the negative electrode of the power supply as the cathode material, thereby forming an ICCP degradation enhancement system; the normal use design bearing capacity of the concrete beam is M a It is 20kN.m.

[0172] The process of applying excitation current after the CFRP wrapping layer deteriorates:

[0173] 1. Input component design parameters including: beam height, width, material parameters and other data.

[0174] 2. Calculate the service life of the ICCP system according to Formula I

[0175] The calculation formula for the service life of the CFRP-SMA smart reinforced concrete structure is preferably obtained according to Formula I:

[0176]

[0177] In formula I, t life is the service life of the CFRP-SMA smart reinforced concrete structure, A a (0.04396) is the surface area per unit length of the CFRP winding layer of the SMA embedded optical fiber and the CFRP composite reinforcement, q anode The charge density passing through the CFRP wrapping layer is 1.6×10 7 C / m 2 At this time, the anode reaction system is stable and the residual strength efficiency of the CFRP winding layer anode material is 68%, ip The applied cathodic protection current density is usually 2 to 20 mA / m 2 , take 20mA / m 2 , ρ is the tensile reinforcement ratio, A c (0.0000785) is the cross-sectional area of ​​the CFRP composite bar perpendicular to the SMA embedded optical fiber and wrapped CFRP in the CFRP-SMA smart reinforced concrete structure, and n is the number of tensile steel bars.

[0178] 3. Apply normal load and monitor the strain (ε fi =0.002) to calculate the initial bearing capacity.

[0179] In the present invention, the calculation formula of the initial bearing capacity of the CFRP-SMA smart reinforced concrete structure is preferably as shown in Formula II:

[0180]

[0181] Formula II assumes that the yield strength of the round Fe-SMA bar and the steel bar in the SMA embedded optical fiber wrapped CFRP composite bar is the same as f y =300MPa, A s =386mm 2 is the total area of ​​the steel bar and the round Fe-SMA bar, d = 225 mm is the effective height of the CFRP-SMA smart reinforced concrete structure, A f =75.36mm 2 is the cross-sectional area of ​​the CFRP winding layer, E f =200GPa is the elastic modulus of the CFRP wrapping layer, ε fi =0.002 is the strain of the CFRP wrapping layer when the normal load is initially applied, f c ' = 30MPa is the concrete strength, b = 150mm is the width of the CFRP-SMA smart reinforced concrete structure, and the initial bearing capacity M of the CFRP-SMA smart reinforced concrete structure is calculated. i =30kN.m.

[0182] 4. Calculate the strain ε of the CFRP winding layer when the excitation current needs to be applied fa =0.016. If the strain ε monitored by the optical fiber f ≤ε fa Continue monitoring. If ε f >ε fa , and T <t life Then the excitation current can be applied to degrade it.

[0183] The deterioration of the strength of the CFRP wrapping layer will also lead to the increase of the strain of the CFRP wrapping layer. i =Ma Substituting into formula II, the strain ε of the CFRP wrapping layer when the excitation current needs to be applied can be obtained: fa =0.016, the strain ε of the CFRP winding layer when the excitation current is applied fa The calculation formula of is preferably as shown in Formula VI:

[0184]

[0185] in, B=-2A s f y A f E f -1.7f c 'bd f ,

[0186] 5. Determine whether the ICCP system has reached its service life. If the ICCP system is powered on for T <t life Deterioration enhancement can be performed, otherwise the residual strength efficiency of the CFRP wrapped layer anode material is less than 68%, the structure does not meet the safety requirements for use, and the process ends.

[0187] 6. Calculate the average strain Δε of the SMA embedded optical fiber wrapped CFRP composite reinforcement after the actual excitation current is applied sp and the bearing capacity contribution ΔM after applying the excitation current. When Δε is satisfied sp ≥ε fa -ε fi and ΔM≥M i -M a The degradation enhancement process is completed when the deterioration enhancement process is completed, otherwise, continue to apply the excitation current to adjust the preload.

[0188] The average strain Δε of SMA embedded optical fiber wrapped CFRP composite reinforcement after the actual excitation current is applied sp ≥ε fa -ε fi =0.014

[0189] The bearing capacity contribution of the preload force can be calculated according to formulas III, IV, and V.

[0190] ΔM=(σ pc -γf tk )W 0 Formula III

[0191] γ=(0.7-120 / h)γ m Formula IV

[0192]

[0193] In formula III, the bearing capacity contribution generated by the preload force is calculated to be ΔM = 14.3 kN.m, f tk is the standard value of concrete tensile strength, W 0 =0.000195 is the elastic resistance moment of the tensile edge of the converted section, γ m is the basic value of the plastic influence coefficient of the section resistance moment of the CFRP-SMA smart reinforced concrete structure, and the rectangular section is taken as 1.15. γ=0.115 is the plastic influence coefficient of the section resistance moment of the CFRP-SMA smart reinforced concrete structure, which is calculated by Formula IV. pc is the pre-compressive stress of the SMA embedded optical fiber and CFRP composite reinforcement, which can be calculated by the formula V, E sp is the elastic modulus of the SMA embedded optical fiber and wrapped CFRP composite reinforcement, l is the spatial resolution of distributed optical fiber sensing acquisition, u is the total number of measurement points for distributed optical fiber acquisition, i is the measurement point for distributed optical fiber acquisition, and ε sp,i is the strain at the i-th measuring point after the excitation current is applied, l is the total length of the distributed optical fiber sensing measurement section, Δε sp =0.014 is the average strain of the SMA embedded optical fiber wrapped CFRP composite reinforcement after the excitation current is applied.

[0194] The process of applying excitation current before the CFRP wrapping layer deteriorates:

[0195] 1. Input component design parameters including: beam height, width, material parameters and other data.

[0196] 2. Calculate the service life of the ICCP system according to Formula I

[0197] The calculation formula for the service life of the CFRP-SMA smart reinforced concrete structure is preferably obtained according to Formula I:

[0198]

[0199] In formula I, t life is the service life of the CFRP-SMA smart reinforced concrete structure, A a (0.04396) is the surface area per unit length of the CFRP winding layer of the SMA embedded optical fiber and the CFRP composite reinforcement, q anode The charge density passing through the CFRP wrapping layer is 1.6×10 7 C / m 2 At this time, the anode reaction system is stable and the residual strength efficiency of the CFRP winding layer anode material is 68%, i p The applied cathodic protection current density is usually 2 to 20 mA / m 2 , take 20mA / m 2 , ρ is the tensile reinforcement ratio, Ac (0.0000785) is the cross-sectional area of ​​the CFRP composite bar perpendicular to the SMA embedded optical fiber and wrapped CFRP in the CFRP-SMA smart reinforced concrete structure, and n is the number of tensile steel bars.

[0200] 3. Apply normal load and monitor the strain (ε fi =0.002) to calculate the initial bearing capacity.

[0201] In the present invention, the calculation formula of the initial bearing capacity of the CFRP-SMA smart reinforced concrete structure is preferably as shown in Formula II:

[0202]

[0203] Formula II assumes that the yield strength of the round Fe-SMA bar and the steel bar in the SMA embedded optical fiber wrapped CFRP composite bar is the same as f y =300MPa, A s =386mm 2 is the total area of ​​the steel bar and the round Fe-SMA bar, d = 225 mm is the effective height of the CFRP-SMA smart reinforced concrete structure, A f =75.36mm 2 is the cross-sectional area of ​​the CFRP winding layer, E f =200GPa is the elastic modulus of the CFRP wrapping layer, ε fi =0.002 is the strain of the CFRP wrapping layer when the normal load is initially applied, f c ' = 30MPa is the concrete strength, b = 150mm is the width of the CFRP-SMA smart reinforced concrete structure, and the initial bearing capacity M of the CFRP-SMA smart reinforced concrete structure is calculated. i =30kN.m.

[0204] 4. Calculate the average strain Δε of the SMA embedded optical fiber wrapped CFRP composite reinforcement after the actual excitation current is applied sp Calculate the strain ε of the CFRP wrapping layer when the excitation current is applied fa =0.016. The bearing capacity contribution ΔM after applying the excitation current. When Δε is satisfied sp ≥ε fa -ε fi and ΔM≥M i -M a The degradation enhancement process is completed when the deterioration enhancement process is completed, otherwise, continue to apply the excitation current to adjust the preload.

[0205] 5. Monitor the strain of the optical fiber. If the strain ε f <ε fa Continue monitoring. If ε f>ε fa , and T <t life , then apply the excitation current.

[0206] 6. Determine whether the ICCP system has reached its service life. If the ICCP system is powered on for T <t life Deterioration enhancement can be performed, otherwise the residual strength efficiency of the CFRP wrapped layer anode material is less than 68%, the structure does not meet the safety requirements for use, and the process ends.

[0207] 7. Calculate the bearing capacity contribution ΔM and the average strain Δε of the SMA embedded optical fiber and CFRP composite reinforcement after applying the excitation current sp When Δε is satisfied sp ≥ε fa -ε fi and ΔM≥M i -M a The degradation enhancement process is completed when the deterioration enhancement process is completed, otherwise, continue to apply the excitation current to adjust the preload.

[0208] Although the above embodiment describes the present invention in detail, it is only a part of the embodiments of the present invention rather than all the embodiments. People can also obtain other embodiments based on this embodiment without creativity, and these embodiments all fall within the protection scope of the present invention.

Claims

1. A method for enhancing ICCP system degradation, characterized in that: The following steps are involved: Applying an excitation current to the SMA embedded optical fiber and CFRP composite reinforcement in the CFRP-SMA smart reinforcement concrete structure integrating cathodic protection, force sensing and bearing capacity self-regulation, so that the SMA embedded optical fiber and CFRP composite reinforcement generates a pre-tightening force, and the pre-tightening force contributes to the bearing capacity of the CFRP-SMA smart reinforcement concrete structure, namely, ΔM, thereby enhancing the degradation of the ICCP system; The excitation current application method includes: applying the excitation current to the smooth round Fe-SMA tendon of the SMA embedded optical fiber and the CFRP composite tendon after the ICCP system is turned on and the CFRP winding layer is degraded, or directly applying the excitation current to the smooth round Fe-SMA tendon of the SMA embedded optical fiber and the CFRP composite tendon after the ICCP system is not turned on and the CFRP winding layer is not degraded; When the normal load is applied, the strain ε of the CFRP wrapping layer f > Strain ε of CFRP wrapping layer when excitation current is applied fa , and the ICCP system power-on time T≤ the service life t of the CFRP-SMA intelligent reinforced concrete structure life When the ICCP system is turned on, an excitation current is applied to the light-circular Fe-SMA tendon of the SMA embedded optical fiber and the CFRP composite tendon after the CFRP winding layer is degraded; when ε f ≤ε fa When ε f >ε fa , and T>t life When the user fails to meet the safety requirement, the process ends; When the excitation current is directly applied to the SMA embedded optical fiber and CFRP wrapped composite reinforcement with the ICCP system turned off and the CFRP wrapping layer not deteriorated, the bearing capacity M of the CFRP-SMA smart reinforcement concrete structure after the initial preload is applied is calculated. i1 , M i1 = the bearing capacity contribution ΔM generated by the preload force and the initial bearing capacity M of the CFRP-SMA smart reinforced concrete structure i After the excitation current is applied, the ICCP system is turned on. i1 ≥M a When M i1 <M a When monitoring the strain of the CFRP wrapping layer, if ε f >ε fa , and T≤t life When the excitation current is continuously applied to the light-circular Fe-SMA ribs of the SMA embedded optical fiber and the CFRP composite ribs; The current value of the excitation current satisfies: after the excitation current is applied, the average strain Δε of the SMA embedded optical fiber and CFRP composite reinforcement is sp ≥Strain of CFRP wrapping layer when excitation current is appliedε fa The strain ε of the CFRP wrapping layer when the normal load is initially applied fi The difference between the initial bearing capacity M and the initial bearing capacity M of the CFRP-SMA smart reinforced concrete structure is i The design bearing capacity M of the CFRP-SMA smart reinforced concrete structure in normal use a difference; The calculation formula for the service life of the CFRP-SMA smart reinforced concrete structure is obtained according to Formula I: In formula I, t life is the service life of the CFRP-SMA smart reinforced concrete structure, A a is the surface area per unit length of the CFRP winding layer of the SMA embedded optical fiber and the CFRP composite reinforcement, q anode The charge density passing through the CFRP wrapping layer is 1.6×10 7 C / m 2 At this time, the anode reaction system is stable and the residual strength efficiency of the CFRP winding layer anode material is 68%, i p The applied cathodic protection current density is usually 2 to 20 mA / m 2 , take 20mA / m 2 , ρ is the tensile reinforcement ratio, A c is the cross-sectional area of ​​the CFRP composite reinforcement perpendicular to the SMA embedded optical fiber and wrapped with CFRP in the CFRP-SMA smart reinforcement concrete structure, and n is the number of tensile reinforcements; The calculation formula of the initial bearing capacity of the CFRP-SMA smart reinforced concrete structure is shown in Formula II: Formula II assumes that the yield strength of the round Fe-SMA bar and the steel bar in the SMA embedded optical fiber wrapped CFRP composite bar is the same as f y , A s is the total area of ​​steel bars and plain Fe-SMA bars, d is the effective height of the CFRP-SMA smart reinforced concrete structure, A f is the cross-sectional area of ​​the CFRP winding layer, E f is the elastic modulus of the CFRP wrapping layer, ε fi is the strain of the CFRP wrapping layer when the normal load is initially applied, f c ' is the concrete strength, b is the width of the CFRP-SMA smart reinforced concrete structure, M i is the initial bearing capacity of the CFRP-SMA smart reinforced concrete structure; The calculation formula for the bearing capacity contribution ΔM generated by the preload force is shown in Formula III: ΔM=(σ pc -γf tk )W0 or III γ = (0.7 - 120 / h)γ m Formula IV In formula III, ΔM is the bearing capacity contribution generated by the preload force, f tk is the standard value of concrete tensile strength, W0 is the elastic resistance moment of the tensile edge of the conversion section, γ m is the basic value of the plastic influence coefficient of the section resistance moment of the CFRP-SMA smart reinforced concrete structure, and the rectangular section is taken as 1.

15. γ is the plastic influence coefficient of the section resistance moment of the CFRP-SMA smart reinforced concrete structure, which is calculated by Formula IV. σ pc is the pre-compressive stress of the round Fe-SMA rib in the SMA embedded optical fiber and wrapped CFRP composite rib, calculated by the formula V, E sp is the elastic modulus of the SMA embedded optical fiber and wrapped CFRP composite reinforcement, l is the spatial resolution of distributed optical fiber sensing acquisition, u is the total number of measurement points for distributed optical fiber acquisition, i is the measurement point for distributed optical fiber acquisition, and ε sp,i is the strain at the i-th measuring point after the excitation current is applied, l is the total length of the distributed optical fiber sensing measurement section, Δε sp is the average strain of the SMA embedded optical fiber wrapped CFRP composite reinforcement after the excitation current is applied; The strain ε of the CFRP winding layer when the excitation current is applied fa The calculation formula is shown in Formula VI: in, B=2A s f y A f E f -1.7f c 'bd f , The CFRP-SMA intelligent reinforced concrete structure integrating cathodic protection, force sensing and bearing capacity self-adjustment includes: an ICCP system and an ICCP system degradation enhancement system; The ICCP system includes a steel cage, concrete, SMA embedded optical fiber wrapped CFRP composite reinforcement, steel bars and a first external power source; the steel cage is placed in the concrete; the SMA embedded optical fiber wrapped CFRP composite reinforcement and the steel bars are dispersed in the concrete; the CFRP winding layer of the SMA embedded optical fiber wrapped CFRP composite reinforcement is connected to the positive electrode of the first external power source through a wire; the steel bar is connected to the negative electrode of the first external power source through a wire; The ICCP system degradation enhancement system includes a second external power supply; The positive electrode and the negative electrode of the second external power supply are respectively connected to the two ends of the SMA embedded optical fiber and the CFRP composite rib through wires; The first external power supply is used to provide a DC power supply for the ICCP system; The second external power source is an excitation device for the light round Fe-SMA tendons; The voltage of the first external power supply is 5-20V; The current of the first external power supply is 200mA to 3A; The steel cage is made of ribbed steel bars; The preparation method of the CFRP-SMA smart reinforced concrete structure comprises the following steps: Place the steel cage with built-in SMA embedded optical fiber and external CFRP composite bars and steel bars in the mold, pour concrete, and then perform maintenance; Connect the CFRP winding layer of the SMA embedded optical fiber and the CFRP composite reinforcement with a wire to the positive electrode of the first external power source, and connect the steel bar with a wire to the negative electrode of the first external power source; The two ends of the light-circular Fe-SMA rib with SMA embedded optical fiber and CFRP composite rib are respectively connected to the positive electrode and the negative electrode of the second external power supply by wires.

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