CN113155732A - Method for testing performance of high-strength steel strand net enhanced ECC (error correction code) and concrete interface - Google Patents
Method for testing performance of high-strength steel strand net enhanced ECC (error correction code) and concrete interface Download PDFInfo
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Abstract
The invention relates to a method for testing the interface performance of a high-strength steel strand net reinforced ECC (error correction code) and concrete.A real stress condition when a bent member is reinforced by the high-strength steel strand net reinforced ECC is simulated by two mutually hinged concrete test blocks, and under the load action above the concrete test blocks, the interface shearing action is caused by the tension of the steel member; after further load strengthening, normal stress is generated between the ECC test block and the concrete test block by the bent steel member, so that the steel member bears the tensile force under the load to generate tensile force on a connecting interface of the ECC test block and the concrete test block, and the shearing force and the tensile force on the connecting interface of the ECC test block and the concrete test block are simultaneously applied, so that the interface bonding performance of the high-strength steel strand net reinforced ECC reinforcing beam under the static load action is truly reflected, and the stress state of the reinforcing beam is truly simulated.
Description
Technical Field
The invention belongs to the field of a method for testing the bonding performance of a high-strength steel strand net reinforced ECC (error correction code) and a concrete interface, and particularly relates to the bonding performance of a concrete-based composite material for a high-strength steel strand net reinforced engineering and the concrete interface based on a concrete beam type test piece under the static load action.
Background
The engineering cement-based composite material (ECC) has excellent mechanical properties, provides a better solution for solving the problems of concrete structure durability, engineering structure crack resistance and shock resistance, old structure renovation and reinforcement and the like, is widely used for concrete structure reinforcement technical test research, and the bonding property between the ECC and a concrete interface is the key of the joint work of the ECC and the concrete. The high-strength steel strand net has high strength, the standard strength of the high-strength steel strand net is about 5 times that of a common reinforcement, the high-strength steel strand net is adopted to reinforce the bending resistance or shearing resistance of the ECC on the concrete beam, the effect is good, the rigidity of a member can be obviously improved, and the high-strength steel strand net is not provided by a carbon fiber reinforcement technology.
At present, the test methods for researching ECC and concrete interface bonding anchoring are divided into two types, one type is axial tensile test (see the reference document: handsome. research on mechanical property and durability of interface of ultra-high toughness cement-based composite material reinforced concrete structure [ D ]. southeast university, 2017); the other type is an in-plane shear test which comprises a single shear test, a double shear test and an oblique shear test (see the reference document: tremulin fly. ECC-concrete interlayer interface performance test research [ D ]. Yangzhou university, 2016.). Wherein:
as shown in fig. 1, in the method, the bonding strength is directly obtained by a tensile machine, a chuck 101 of the tensile machine is provided with steel cushion blocks 102, bolts 103 are clamped between the cushion blocks 102, two bolts 103 are provided, one head of each bolt is embedded in an ECC test piece 104, and the other head of each bolt is embedded in a concrete test piece 105, but the obtained bonding strength is difficult to evaluate the mechanical properties of the ECC and concrete bonding surface in the shearing and bending states;
as shown in fig. 2-4, in-plane shear tests such as single shear test and double shear test are all performed by bonding a concrete surface with ECC, measuring the bonding strength between the concrete and the ECC by vertical loading, and the bonding surface of the concrete and the ECC is subjected to the bonding shear stress parallel to the surface. The single shear test method shown in fig. 2 adopts two L-shaped steel molds 201 which are fastened with each other, a groove is formed in a vertical portion of each steel mold 201, an ECC test piece 202 is formed in the groove of one steel mold 201, a concrete test piece 203 is formed in the groove of the other steel mold 201, the ECC test piece 202 and the concrete test piece 203 are connected in a planar bonding manner, and the bonding plane is parallel to or coincided with the loading direction of the loading force; the double shear test method shown in fig. 3 adopts a concrete test piece 301 located in the middle and ECC test pieces 302 bonded and connected with planes on two opposite sides of the concrete test piece 301, wherein the top of the concrete test piece 301 is connected with an upper steel cushion block 303 in a propping manner, and the lower parts of the two ECC test pieces 302 are connected with a lower steel cushion block 304 in a propping manner; the oblique shear test method shown in fig. 4 adopts an ECC test piece 401 and a concrete test piece 402 which are matched in an inclined plane, the concrete test piece 402 is positioned obliquely above the ECC test piece 401, the top of the concrete test piece 402 is connected with an upper steel cushion block 403 in an abutting mode, and the bottom of the ECC test piece 401 is connected with a lower steel cushion block 404 in an abutting mode.
However, in the high-strength steel strand net reinforced ECC reinforced concrete member, the steel strand anchoring area is usually acted with bending moment and shearing force at the same time except for tension, and the test piece can not reflect the situation.
Referring to fig. 5, according to the modified beam test piece proposed by RILEM-FIP-CEB for testing the adhesion between the reinforcing bar and the concrete, the beam test is that two identical concrete test pieces 501 are connected together by a hinge point 502, a reinforcing material is adhered to the middle or bottom of the concrete beam test piece, specifically, as shown in fig. 5, a steel bar 503 is embedded in the middle of the two concrete test pieces 501, and a plastic sleeve 504 is sleeved at the penetration and penetration positions of the steel bar 503. The bonding mechanical properties were tested by beam top loading. The method has the advantages that the bending or shearing influence of the concrete beam can be considered, and the actual stress state of the reinforced concrete beam by the reinforcing material is met. However, a beam test specimen for researching the interface bonding performance of the high-strength steel strand mesh reinforced ECC as a concrete reinforcing material does not exist, so that a device suitable for testing the interface bonding performance of the high-strength steel strand mesh reinforced ECC and concrete is needed.
Disclosure of Invention
The invention aims to provide a method for testing the bonding performance of a high-strength steel strand mesh reinforced ECC (error correction code) and a concrete interface based on a beam type test piece, solves the problems and the defects of the conventional device for testing the bonding performance of the high-strength steel strand mesh reinforced ECC and the concrete interface, and meets the requirement of truly reflecting the stress state of the high-strength steel strand mesh reinforced ECC reinforced concrete beam.
The technical scheme of the method is as follows:
the method for testing the performance of the interface between the high-strength steel strand net reinforced ECC and concrete comprises the following steps:
1) pouring and forming two concrete test blocks with the same shape;
2) the two concrete test blocks are distributed oppositely at intervals, and a steel strand net formed by binding is arranged in an empty suspension manner below the two concrete test blocks;
3) the ECC test blocks are poured and formed on the bottom surfaces of the two concrete test blocks respectively, the ECC test blocks are fixedly connected with the concrete test blocks, and the two opposite sides of the steel strand net are embedded and fixed in the ECC test blocks;
4) installing a hinge at the top of an interval space between the two concrete test blocks, fixing two ends of the hinge at opposite sides of the two concrete test blocks respectively, and connecting a sensing element for detecting stress and/or displacement on at least one of the two ECC test blocks to obtain a test sample;
5) placing the test specimen on two simple supporting fulcrums which are respectively supported on the mutually far sides of the bottom surfaces of the two concrete test blocks;
6) a load is applied from above the test specimen, and the load simultaneously acts on the opposite sides of the top surfaces of the two concrete test pieces.
Preferably, the hinges are glued to the concrete test block by means of a glue and, after the test is completed, the hinges are cut from the concrete test block from the glued position.
Preferably, the sensing element comprises a resistance strain gauge attached to the ECC test block and/or the concrete test block and a displacement sensor connected between the ECC test block and the concrete test block, and the resistance strain gauge and the displacement sensor are connected with the multi-channel dynamic strain recorder.
Preferably, one of the two concrete test blocks is provided with a reinforcing structure for enabling the connection strength of the one concrete test block and the ECC test block on the side to be larger than that of the other concrete test block and the other concrete test block on the other side, and the other concrete test block is provided with a sensing element for detecting deformation and/or displacement of the ECC test block on the other side.
The invention has the beneficial effects that:
according to the method, two mutually hinged concrete test blocks are used for simulating the real stress condition of a high-strength steel strand net reinforced ECC reinforced flexural member, and under the load action above the concrete test blocks, the interface shearing action is caused by the tension of the steel member; after further load strengthening, normal stress is generated between the ECC test block and the concrete test block by the bent steel member, so that the steel member bears the tensile force under the load to generate tensile force on a connecting interface of the ECC test block and the concrete test block, and the shearing force and the tensile force on the connecting interface of the ECC test block and the concrete test block are simultaneously applied, so that the interface bonding performance of the high-strength steel strand net reinforced ECC reinforcing beam under the static load action is truly reflected, and the stress state of the reinforcing beam is truly simulated.
Furthermore, the L-shaped concrete test block with the installation notch is adopted, so that the concrete test block can be prevented from generating bending shear or bending cracks in the loading process, the consumption of concrete is saved, and the self weight of the concrete is reduced.
Furthermore, compared with the existing in-plane shear test method for ECC and concrete interface bonding test, the in-plane shear test method provided by the invention can effectively avoid the influence of asymmetric loading, ensure the reliability of data and improve the credibility of the detection result by using a high-precision test result.
Furthermore, the hinge designed by the invention can be repeatedly used, so that the cost is saved, and the uniform stress of the concrete test blocks on two sides is ensured. The test block is convenient to manufacture, the test operation is simple, and the test problem of the bonding mechanical property of the large-batch high-strength steel strand net reinforced ECC and concrete interface is solved.
Drawings
FIG. 1 is a schematic representation of a prior art axial tensile test method;
FIG. 2 is a schematic diagram of a prior art single shear test method;
FIG. 3 is a schematic diagram of a prior art double shear test method;
FIG. 4 is a schematic diagram of a prior art skew shear test method;
FIG. 5 is a schematic view of a beam test specimen for performance of an interface between a steel bar and concrete in the prior art;
FIG. 6 is a schematic view of a test apparatus according to example 1 of the present invention;
FIG. 7 is a sectional view A-A of FIG. 6;
FIG. 8 is a cross-sectional view B-B of FIG. 6;
FIG. 9 is a bottom view of FIG. 6;
FIG. 10 is a schematic diagram of an ECC block anchoring structure of a test apparatus according to embodiment 1 of the present invention;
FIG. 11 is a schematic view of the hinge mount of FIG. 6;
FIG. 12 is a schematic view of a test apparatus according to example 2 of the present invention;
FIG. 13 is a bottom view of FIG. 11;
FIG. 14 is a schematic diagram of the ECC block of FIG. 13;
FIG. 15 is a schematic view of a test apparatus according to example 3 of the present invention.
Detailed Description
Example 1:
the method for testing the performance of the interface between the high-strength steel strand net reinforced ECC and concrete mainly comprises the following steps:
in order to ensure the smooth performance of the method for testing the bonding performance of the high-strength steel strand net reinforced ECC and concrete interface and the accurate and reliable test result, the test method comprises the following steps:
1) pouring concrete test blocks according to the size design requirement, and performing standard maintenance for 28 days generally;
2) after the concrete test blocks reach the expected strength, performing interface treatment on the bottoms of the two concrete test blocks, and then fixing and binding a steel strand net;
3) pouring ECC, and performing standard maintenance for 28 days generally;
4) and after the ECC reaches the expected strength, bonding a hinge between the two concrete test blocks by using the adhesive steel glue, and waiting for the adhesive steel glue to be hardened.
5) After the test piece is well maintained, adhering resistance strain gauges to the side faces of the ECC block test piece and the bottom face of the concrete test piece according to design requirements, mounting displacement sensors on two sides of the test piece, and connecting the multichannel dynamic strain recorder.
6) And (4) carrying out loading test by adopting a hydraulic universal testing machine according to the loading design requirement.
Specifically, referring to fig. 6 to 11, the high-strength steel strand net reinforced ECC and concrete interface performance testing device mainly comprises a test specimen and a testing device.
The test specimen comprises two L-shaped concrete test blocks which are identical in left and right and are symmetrically arranged, a hinge is bonded between the two concrete test blocks, the hinge comprises two hinge bases which are mutually overlapped and are identical and a hinge shaft which is rotatably connected between the two hinge bases, and a hinge joint 603 which is positioned below the hinge 604 is further arranged between the two concrete test blocks. For convenience of explaining the structure below the two concrete test blocks, the concrete test block on the left side is defined as a left concrete test block 601, and the concrete test block on the right side is defined as a right concrete test block 602. A bonding measurement area is defined at the center and the left of the bottom of the right concrete test block 602, the bonding measurement area and the bonding non-measurement area are symmetrical to each other, a bonding non-measurement area is defined at the center and the right of the bottom of the left concrete test block 601, the bonding measurement area and the bonding non-measurement area are identical in size, the thickness, the length and the width of an ECC (error correction code) are determined according to test requirements, and the width of the bonding measurement area and the width of the bonding non-measurement area are 90mm, the length of the bonding measurement area is 120mm, and the height of the bonding measurement area and the bonding non-measurement area is 25 mm. And (3) forming an ECC test block in a bonding measurement area and a bonding non-measurement area in a cast-in-place mode, and anchoring a high-strength steel strand 620 net in ECC to serve as an embedded steel member. The ECC test blocks in the bonding non-measurement area and the bonding measurement area are both rectangular, the longitudinal steel strand 620 spans the hinge joint 603 to connect the ECC test blocks on the left side and the right side, and the transverse steel strand 620 and the longitudinal steel strand 620 are fixed in the ECC in a binding mode. The right concrete test block 602 and the left concrete test block 601 have the same size value, and are respectively 150mm wide at the bottom, 350mm long at the top, 300 mm long at the top, 70mm long from the top to the step, 50mm high at the step and 50mm wide at the step. As shown in fig. 11, the hinge base 605 includes a base adhered and fixed on the concrete test block and a wing plate protruded thereon, the wing plates of the two hinge bases 605 are overlapped with each other and provided with hinge holes for the hinge shaft to pass through, and the base is made of stainless steel. The hinge seat 605 is assembled by a steel block as shown in fig. 11, has a rotation capacity of more than or equal to 10 degrees, and the hinge seat 605 is divided into two parts which are symmetrical left and right and is formed by connecting steel hinge shafts with the diameter of 8mm in series. As shown in fig. 6, the upper parts of the two concrete test blocks (the left concrete test block 601 and the right concrete test block 602) are connected by a hinge 604, and both side surfaces of the hinge 604 are bonded to the corresponding two concrete blocks by a bonding agent.
The testing device comprises a lower fulcrum 606 supported below the left concrete test block 601 and the right concrete test block 602 respectively, and upper fulcrums 607 supported between the two concrete test blocks and the distribution beam 611 and symmetrically arranged, wherein the upper fulcrum 607 and the lower fulcrum 606 both adopt simple fulcrums, 100KN loading equipment is arranged above the distribution beam 611, and a pressure sensor is used for recording the magnitude of a loading measurement value. The distance between the lower supporting point 606 and the end part of one end of the inner side of the concrete test block above the corresponding lower supporting point is not less than 50 mm. The distance between the upper supporting point 607 and the end part of one end of the inner side of the concrete test block below the upper supporting point is not less than 30 mm. Two rows of resistance strain gauges 616 are uniformly bonded along the edges at the smooth positions of the two side edges of the ECC test block in the bonding measurement area, and one row of resistance strain gauges 616 is bonded at the bottom side of the corresponding concrete test block.
Example 2:
as shown in fig. 12 and 13, this embodiment adds a structure for measuring the displacement change of the ECC block to the test pieces in embodiment 1. And an iron sheet 615 is adhered to one side of the right ECC test block, which is close to the hinge joint 603, so that a displacement sensor 617 fixed on the left concrete test block 601 is in contact with the iron sheet 615, and the displacement change of the right bonding measurement area ECC is recorded.
When the test device is used, the test device mainly comprises three steps of test piece manufacturing, test point arrangement and test loading, which are explained one by one.
1. Test piece manufacture
As shown in fig. 6-9, the test specimen is a beam type test specimen, and includes two symmetrically placed concrete test blocks with the same shape, a left concrete test block 601 and a right concrete test block 602, the cross sections of the two concrete test blocks are rectangles with the length of 150mm and the width of 120mm, a high-strength steel strand 620 net and an ECC test block manufactured by cast-in-place are bound at the bottoms of the left concrete test block 601 and the right concrete test block 602, and the diameter and the distribution method of the high-strength steel strand 620, and the width, the thickness and the length of the ECC test block are determined according to test requirements. Hinge joints 603 are arranged at the lower parts of the left concrete test block 601 and the right concrete test block 602, and the upper parts are connected by hinges 604. The left concrete test block 601 and the right concrete test block 602 have the same size value, and are respectively 150mm wide at the bottom, 350mm long at the top, 300 mm long at the top, 70mm long from the top to the step, 50mm high at the step and 50mm wide at the step.
The bonding non-measurement area is arranged in the middle of the bottom of the left concrete test block 601, and the bonding measurement area is arranged in the middle of the bottom of the right concrete test block 602. And a longitudinal high-strength steel strand 620 is connected between the bonding non-measurement area and the bonding measurement area, spans the hinge joint 603, and the width of the hinge joint 603 is 5 mm. The width of the bonding non-measuring area is the same as that of the bonding measuring area, and the bonding width H and the bonding length of the bonding measuring area are determined according to the test requirementsL. And pouring ECC test blocks (defined as a left ECC test block 609 and a right ECC test block 608) in corresponding areas of the bonding non-measurement area and the bonding measurement area, and determining the thickness of the ECC test blocks according to test requirements. And binding the steel strand 620 net before pouring the ECC test block.The L-shaped angle iron 613 shown in figure 3 is punched, two hole sites are arranged on the contact surface of the L-shaped angle iron 613 and the concrete test block, the number and the size of the hole sites on the other surface are determined according to the test requirements, holes are drilled on the corresponding positions of the left concrete test block 601 and the right concrete test block 602 according to the hole sites of the angle iron, the angle iron is installed and fixed at the positions which are 20mm away from the bonding non-measurement area and the bonding measurement area respectively, and fixing tools are screws. Two ends of a longitudinal steel strand 620 respectively penetrate through the angle iron hole positions on two sides, but only the steel strand 620 on one side of a bonding measurement area is fixed by an aluminum ring 618, namely a high-strength steel strand 620 net for reinforcing the right ECC test block 608 is fixed with the angle iron by the aluminum ring 618, a high-strength steel strand 620 net for reinforcing the left ECC test block 609 in a non-bonding measurement area is sleeved with the angle iron by a bolt 619, and a nut is screwed after the aluminum ring 618 is fixed. The transverse steel strands 620 are connected with the longitudinal steel strands 620 in a wire binding manner.
By applying downward load to the top steel base plate 612 of the beam test piece to generate the interface stress of the bonding surface of the ECC and the concrete, the stress performance of the bonding layer at the middle bending crack of the ECC reinforced beam can be truly simulated. And the left concrete test block 601 of the test beam is reinforced with the same ECC to ensure that the peel failure occurs in the designated bond measurement zone. The hinge 604 can be recycled, after a test specimen is loaded, the hinge 604 can be cut off along the adhesive layer by a cutting machine, and after the residual adhesive layer on the side surface of the hinge seat 605 is removed by grinding, the hinge 604 can be continuously used in the subsequent test specimen.
2. Measuring point arrangement
The station placement was performed as shown in FIGS. 13-14: the strain of the right ECC test block 608 is measured by using the resistance strain gauges 616, two rows of the resistance strain gauges 616 are arranged from dense to sparse along the upper edge and the lower edge of the side surface of the right ECC test block 608 respectively, the distance between the resistance strain gauges 616 can be set according to the test requirement, and in the embodiment, the resistance strain gauges 616 have 5-6 pieces and are symmetrically distributed from dense to sparse from left to right. The same strain gage as the lower edge of the ECC block is placed on the outer edge of the right concrete block 602 parallel to the length of the right ECC block 608 to measure the strain on the bottom surface of the right concrete block 602. And acquiring strain data by using a multi-channel dynamic strain recorder. In order to measure the relative slippage between the left concrete test block 601, the right concrete test block 602 and the ECC test block, square L-shaped angle irons 614 are respectively stuck on the two side surfaces of the left concrete test block 601 near the hinge joint 603, a linear variable displacement sensor 617 is fixed on the angle irons and contacts with an iron sheet 615 at the bottom of the right concrete test block 602, and the iron sheet 615 is stuck on the left side of the right ECC test block 608.
3. Test loading
The test loading was carried out as shown in FIG. 11: the test specimen is simply supported on the two supports 610, the distance L3 between the lower support point 606 and the beam end of the test specimen is more than or equal to 50mm, the clear span L4 is determined according to the test requirement, and L4 in the example is 605 mm; the distance L5 between the upper supporting point 607 and the end of the concrete test block near the inner side is more than or equal to 30 mm. And applying a load P on the top surface of the span of the test piece through a distribution beam 611 by using a loading device, and placing a base plate 612 at each branch point in order to avoid local crushing of concrete. The load loading (test loading device) adopts a hydraulic testing machine. The load frequency borne by a general engineering structure is between 1 Hz and 5Hz, and the loading frequency can be set according to the requirement.
The test result shows that: the test data measured based on the proposed beam type interface bonding test scheme is different from the results measured by the traditional tensile and shear interface bonding test. The cause of the difference: compared with the traditional interface bonding tensile and shear tests, the stress state at the interface of the beam type interface bonding test piece is more complex, so that errors are generated.
Example 3:
as shown in fig. 15, in this embodiment, on the basis of embodiment 2, the connection strength between the left ECC block 609 and the left concrete block 601 is enhanced, that is, a reinforcing structure is arranged between the left ECC block 609 and the left concrete block 601, the reinforcing structure includes a vertically arranged reinforcing bolt 621, a lower section of the reinforcing bolt 621 is embedded in the left ECC block, and an upper section of the reinforcing bolt 621 is embedded and fixed in the left concrete block. The upper end of the reinforcing bolt 621 is connected to the angle steel type upper connecting piece 622 fixed above the concrete test block, and the lower end is connected to the angle steel type lower connecting piece 623 fixed on the bottom surface of the ECC test block on one side. Under the action of load, the normal stress in the steel strand 620 is respectively transmitted to the interface of the bonding measurement area and the bonding non-measurement area. In order to prevent the bonding non-measuring area from peeling and damaging before the bonding measuring area, the test model is fixed by using angle steel in advance before loading. Relative slippage will not occur at the interface of the bonded non-measurement areas during loading. For the reinforcing member, the peeling failure of the interface between the reinforcing material and the base material under load is mostly caused by the bonding normal stress and shear stress between the reinforcing layer and the base layer, which generate stress higher than the ultimate tensile strength of the concrete/reinforcing material. However, the traditional tensile and shear test can only determine the interface bonding and anchoring characteristics under the shear stress, so the result obtained based on the scheme is not consistent with the actual situation. The stress characteristics of the interface of the lifting beam type interface bonding loading test model are high in matching degree with the actual condition, and the stress state of the interface bonding between the novel composite material and the concrete in a bending state can be accurately reflected. Therefore, the proposed test model is used as a basis to carry out test research on the bonding performance of the enhanced ECC of the high-strength steel strand 620 net and the concrete interface, and further provide a theoretical basis for applying the enhanced ECC of the high-strength steel strand 620 net to RC structure reinforcement.
The above description is only about the preferred embodiment of the present invention, but it should not be understood as limiting the claims, and the present invention may be modified in other structures, not limited to the above structures. In general, all changes which come within the scope of the invention are intended to be embraced therein.
Claims (4)
1. The method for testing the performance of the interface between the high-strength steel strand net reinforced ECC and concrete is characterized by comprising the following steps of:
1) pouring and forming two concrete test blocks with the same shape;
2) the two concrete test blocks are distributed oppositely at intervals, and a steel strand net is fixed below the two concrete test blocks;
3) the ECC test blocks are poured and formed on the bottom surfaces of the two concrete test blocks respectively, the ECC test blocks are fixedly connected with the concrete test blocks, and the two opposite sides of the steel strand net are embedded and fixed in the ECC test blocks;
4) installing a hinge at the top of an interval space between the two concrete test blocks, fixing two ends of the hinge at opposite sides of the two concrete test blocks respectively, and connecting a sensing element for detecting stress and/or displacement on at least one of the two ECC test blocks to obtain a test sample;
5) placing the test specimen on two simple supporting fulcrums which are respectively supported on the mutually far sides of the bottom surfaces of the two concrete test blocks;
6) a load is applied from above the test specimen, and the load simultaneously acts on the opposite sides of the top surfaces of the two concrete test pieces.
2. The method for testing the performance of the high-strength steel strand net reinforced ECC-concrete interface according to claim 1, wherein the hinge is bonded to the concrete test block by the adhesive steel glue, and after the test is completed, the hinge is cut from the concrete test block from the bonding position.
3. The method for testing the performance of the interface between the high-strength steel strand mesh reinforced ECC and the concrete as claimed in claim 1, wherein the sensing elements comprise a resistance strain gauge attached to the ECC test block and/or the concrete test block and a displacement sensor connected between the ECC test block and the concrete test block, and the resistance strain gauge and the displacement sensor are connected with a multi-channel dynamic strain recorder.
4. The method for testing the performance of the interface between the high-strength steel strand mesh reinforced ECC and the concrete as claimed in any one of claims 1 to 3, wherein one of the two concrete test blocks is provided with a reinforcing structure for enabling the connection strength of the one concrete test block and the ECC test block on the side to be greater than that of the other concrete test block and the other concrete test block on the other side, and the other concrete test block is provided with a sensing element for detecting the deformation and/or displacement of the ECC test block on the other side.
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| CN113959942A (en) * | 2021-10-28 | 2022-01-21 | 中铁建工集团有限公司 | Device and method for testing bending bonding strength between reinforcing material and concrete on site |
| CN113959942B (en) * | 2021-10-28 | 2023-08-15 | 中铁建工集团有限公司 | Device and method for testing bending bonding strength between reinforcing material and concrete on site |
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