A precast column-foundation connection node with local reinforcement of the ECC-stainless steel wire mesh

Abstract

A prefabricated column-base connection node with local reinforcement of ECC-stainless steel wire mesh, comprising a prefabricated column, a bearing platform; the prefabricated column is composed of prefabricated concrete, prefabricated ECC and post-poured UHPC; the prefabricated ECC is arranged at the column bottom segment of the prefabricated column; a common concrete prefabricated column core is arranged in the central area of the hollow part of the prefabricated ECC, and the longitudinal reinforcement of the prefabricated column passes through the top wall; the bearing platform is provided with bearing platform connecting reinforcement and bearing platform core corresponding to the prefabricated column core; the prefabricated concrete, the prefabricated ECC and the bearing platform are connected through lap joint reinforcement and post-poured UHPC; and the prefabricated column is provided with a steel wire mesh around the prefabricated ECC at the column bottom segment. The application can effectively solve the problems of poor ductility, cracking, durability and seismic performance of the prefabricated column component, make up for the poor performance and easy cracking of the prefabricated component splicing part of the prefabricated monolithic column base node, and improve the early stage stiffness and energy dissipation capacity.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of building structure engineering, and in particular to a column foundation node for fabricated buildings. BACKGROUND

[0002] Cast-in-place concrete construction relies on site conditions and is susceptible to weather and construction technology factors, which can lead to extended construction periods and increased costs. While precast concrete components can reduce on-site construction time, the complexity of their connecting parts often requires more materials and labor, thereby increasing overall costs.

[0003] To address these issues, the industry has begun to explore the use of new materials and technologies to optimize the connection method of column foundation nodes. Engineered cementitious composites (ECC) and ultra-high performance concrete (UHPC) have become a hot topic of research due to their excellent mechanical properties and durability. ECC has high toughness and crack resistance, enabling it to maintain the integrity of the structure when subjected to tension, while UHPC is known for its ultra-high strength and durability. UHPC has a higher strength, which can improve the damage state, failure mode, and energy dissipation capacity of the column bottom, significantly reduce the lap length of steel bars, save materials, and simplify construction.

[0004] The invention with application number 202110241319.3 discloses a grouting sleeve connection fabricated concrete component with an ECC pipe. The fabricated concrete component includes a precast RC concrete component A, a precast ECC pipe, and a precast RC concrete component B. The precast RC concrete component A has a variable cross-section, with the plastic hinge end being an embedded tenon-type cross-section that is compatible with the precast ECC pipe. The embedded tenon is used to insert into the precast ECC pipe. The connection between the precast RC concrete component A and the precast RC concrete component B is achieved through a grouting sleeve embedded in the precast ECC pipe. The fabricated joint between the three components is connected by grouting sleeve, high-strength structural adhesive, UHPC, high-strength grouting material, and other joint materials. This technology effectively improves the durability and seismic performance of fabricated concrete components and fully utilizes the excellent crack resistance and crack control ability of ECC material. It is suitable for fabricated concrete components of building structures and also suitable for fabricated concrete components such as fabricated piers and tie beams in bridge structures.

[0005] However, this invention mainly focuses on the improvement of grouting process and sleeve connection, emphasizing the connection of precast components through grouting sleeves. Although it involves grouting sleeve connection, it does not utilize the innovative application of engineered cementitious composites (ECC) and ultra-high performance concrete (UHPC) material combinations. There is a significant difference in structure and effect compared to the steel bar lap joint method. SUMMARY

[0006] The present application aims at the prior art deficiencies, and provides a prefabricated column-base connecting node provided with ECC-stainless steel strand net local reinforcement based on steel bar lap joint, a novel fabricated column base node connecting mode, which can solve the problems of long construction period, high cost, low material utilization and the like in the prior art.

[0007] The technical scheme adopted by the present application is as follows:

[0008] A prefabricated column-base connecting node provided with ECC-stainless steel strand net local reinforcement, comprising a prefabricated column (1) and a bearing platform (2); the prefabricated column (1) is composed of prefabricated concrete (101), prefabricated ECC (102) and post-poured UHPC (103); the prefabricated ECC (102) is arranged at a column bottom segment of the prefabricated column (1); a common concrete prefabricated column core column (104) is arranged in a central area of a hollow part of the prefabricated ECC (102), and a prefabricated column longitudinal reinforcement passes through a top wall of the hollow part; the bearing platform (2) is provided with bearing platform connecting steel bars (202) and bearing platform core columns (201) corresponding to the prefabricated column core column (104); the prefabricated concrete (101) and the bearing platform (2) are connected through steel bar lap joint; the prefabricated ECC (102) and the bearing platform (2) are butted, and the hollow part is poured with UHPC; the prefabricated concrete (101), the prefabricated ECC (102) and the bearing platform (2) are connected through lap joint steel bars and post-poured UHPC (103); and a steel strand net (3) is arranged at a connecting segment of the prefabricated ECC (102) and the common concrete prefabricated column core column (104) surrounding the column bottom segment of the prefabricated column (1).

[0009] The prefabricated column-base connecting node provided with ECC-stainless steel strand net local reinforcement, the height of the prefabricated ECC (102) part is 1.5-2 times of the side length of the base column section, a high-strength stainless steel strand net is arranged while pouring the ECC part, the thickness of the prefabricated ECC is 10-15d and is not less than 40mm; d is the diameter of the steel strand.

[0010] The prefabricated column-base connecting node provided with ECC-stainless steel strand net local reinforcement, grouting holes are arranged at the top and the bottom of the prefabricated ECC (102), and a square hole is arranged at the bottom, and the side length of the square hole is not greater than the spacing of the steel strands.

[0011] The setting ECC-stainless steel wire mesh local enhancement of the precast column-foundation connection node, the steel wire mesh (3) is arranged in the column bottom segment ECC part and the ordinary concrete 100-150mm range of the upper part of the top wall, one end of the high-strength steel wire is extended and anchored in the ordinary concrete inside the precast column 20 times the steel wire diameter depth, and is not less than 100mm, and the other end of the high-strength steel wire is anchored in the column bottom precast ECC.

[0012] The setting ECC-stainless steel wire mesh local enhancement of the precast column-foundation connection node, the steel wire mesh includes transverse steel wire and vertical steel wire, the diameter of the steel wire is 3.6mm-6mm; the steel wire spacing is 60-100mm; the transverse steel wire is closed loop, and the two ends are overlapped and anchored by aluminum buckles; the longitudinal steel wire anchoring length is 20d (d is the steel wire diameter), and is not less than 100mm, and the end is anchored on the precast column stirrup by aluminum buckles and wire binding.

[0013] The setting ECC-stainless steel wire mesh local enhancement of the precast column-foundation connection node, the steel wire overlap can adopt vertical steel wire direct overlap or U-shaped steel wire overlap method, and the overlap length is 5-10D (D is the steel wire diameter).

[0014] The setting ECC-stainless steel wire mesh local enhancement of the precast column-foundation connection node, the core column (201) height of the bearing platform is H u , 100mm≤H u ≤150mm, the core column (104) height of the precast column is H b , 300mm≤H b ≤500mm, the gap of 50-80mm is reserved between the precast column core column and the bearing platform core column, the section side length of the precast column core column and the bearing platform core column is 150-200mm and is not greater than 1 / 3 of the precast column section side length.

[0015] A construction method of the precast column-foundation connection node, comprising the following steps:

[0016] Step 1: before pouring the precast column, first, hollow core mold is arranged in the hollow part of the precast column steel reinforcement cage column bottom segment ECC, then high-strength stainless steel wire mesh is arranged in the column bottom segment ECC part of the precast column steel reinforcement cage and the ordinary concrete 100-150mm range of the upper part of the top wall, one end of the high-strength steel wire is extended and anchored on the stirrup at the ordinary concrete position of the precast column, and the other end of the high-strength steel wire is temporarily bound on the bottom of the hollow core mold by wire binding; the wood block with the same size as the grouting hole and the square hole is placed at the corresponding position, and then the formwork is arranged at the precast column;

[0017] Step 2: During the precast column pouring process, vertical pouring is adopted, ordinary concrete is poured first, then ECC top wall at the column bottom segment is poured, and finally ECC shell and precast column core column are poured simultaneously;

[0018] Step 3: Then the precast column hoisting construction is carried out, and after the precast column is hoisted in place, it is checked whether the positions of the precast column in three directions are accurate;

[0019] Step 4: The steel bars at the lap joint part are bound by using wire through the square hole on the side of the column, the binding points should be uniformly distributed and firmly bound to ensure that the steel bars will not be displaced during the pouring of concrete;

[0020] Step 5: Inject grouting material: inject UHPC through the grouting hole, stop grouting operation after the grouting material overflows from the upper grouting hole, and close the grouting hole after grouting is completed until the grouting material solidifies and hardens.

[0021] After pouring is completed, the UHPC needs to be properly maintained, including covering and wet curing, to ensure that it reaches the designed strength.

[0022] Inventive beneficial effects:

[0023] The present application provides a new type of prefabricated column foundation node connection method based on the setting of ECC-stainless steel wire mesh local reinforcement of the steel lap joint, which combines ECC and UHPC materials and steel wire to improve the performance of the node. Through this innovative connection method, it aims to provide a solution with better structural performance, higher construction efficiency and lower cost to meet the growing demand for economy, efficiency and sustainability in modern construction engineering.

[0024] The new type of prefabricated column foundation node connection method provided by the present application has unique innovation and advantages in material selection, node connection method, construction efficiency and seismic performance improvement, especially in improving the connection performance of prefabricated components and construction economy.

[0025] 1. The prefabricated column foundation node of the present application, ECC and UHPC are only used in the plastic hinge core area of the structure, the design of the core column using ordinary concrete has good economic benefits and improves the overall performance of the structure, more materials are used in the key parts of the structure, and materials are reduced in other parts, so as to maximize the cost-effectiveness while ensuring the safety of the structure, which is conducive to the promotion and large-scale application of the combined structure. The core column (section center) uses concrete, which reduces the cost, and the upper and lower core columns have gaps for UHPC filling to improve the integrity. The present application improves the bearing capacity and durability of the node by combining the connection mode of UHPC and engineering cement-based composite material (ECC) with steel wire. The local reinforcement is co-cast with ordinary concrete and the contact position is reinforced with a steel wire mesh to improve the integrity.

[0026] 2. The prefabricated column foundation node of the present application can effectively solve the problems of poor ductility, cracking, durability and seismic performance of the prefabricated foundation column component, make up for the poor performance and easy cracking of the prefabricated component splicing part of the prefabricated monolithic column foundation node, and improve the early stage stiffness and energy dissipation capacity. The prefabricated column is provided with a certain gap between the prefabricated column core column and the pile cap core column, and the hollow area and the gap are filled with UHPC, which not only saves materials but also solves the problem of poor performance of the prefabricated monolithic column foundation node at the prefabricated component splicing part. At the same time, steel wire is arranged to increase the tensile capacity of the column foundation node connection, which greatly improves the seismic capacity of the node. Through these beneficial effects, the present application not only meets the multiple requirements of efficiency, cost, quality and environment of modern building engineering, but also brings long-term technological innovation and economic benefits to the building industry.

[0027] 3. The present application uses engineering cement-based composite material (ECC) and ultra-high performance concrete (UHPC) combined with stainless steel wire mesh for local reinforcement to improve the seismic performance and durability of the prefabricated column foundation node. Only ECC and post-cast UHPC are used in the plastic hinge core area of the structure, and ordinary concrete is used in other non-key areas, which takes into account performance and economy; and according to the specification, the post-cast UHPC can correspondingly reduce the lap length of the steel bar, simplify the construction, save materials and reduce the construction difficulty. ECC-steel wire mesh as the shell of the core section maximizes the use of ECC, which is more economical.

[0028] 4, The application uses a combined connection mode based on steel bar lap joint, ECC and stainless steel wire mesh, aims to improve the comprehensive performance of the node, and significantly improves the tensile capacity and seismic performance of the node. The local reinforcement design of the ECC-stainless steel wire mesh shell improves the ductility of the core area; the post-cast UHPC reduces the length of the steel bar lap joint, facilitates construction and reduces cost; the core column (section center) is made of concrete to reduce cost; the gap between the upper and lower core columns is filled with UHPC to improve the integrity. At the same time, the steel wire is arranged to increase the tensile capacity of the column foundation node connection, which greatly improves the seismic capacity of the node.

[0029] The application can significantly improve the seismic performance and durability of the assembled monolithic prefabricated column foundation node, especially the performance of the splicing part, which can effectively solve the problems of poor ductility, cracking, durability and seismic performance of the assembled foundation column component, make up for the poor performance and easy cracking of the splicing part of the prefabricated component of the assembled monolithic column foundation node, and improve the early stage stiffness and energy dissipation capacity. It has good crack control and dispersion ability, high toughness and ductility, and makes the damage distribution of the beam-column node area and the plastic hinge key area more uniform.

[0030] 5, The application uses UHPC to reduce the length of steel bar lap joint and optimize material use, which not only improves the node performance, but also greatly saves materials, simplifies construction, has better construction efficiency and cost benefit, and economic benefit. The column bottom of the prefabricated column is within a certain height, the prefabricated shell is within a certain thickness, ECC is used to replace ordinary concrete, high-strength stainless steel wire mesh is arranged in the part of pouring ECC, ordinary concrete core column is arranged in the center area of the hollow part, the rest space is filled with post-cast UHPC, the column bottom is connected by steel bar lap joint, and the pile cap is provided with a pile cap core column corresponding to the core column. The column section center is under small stress, and the ordinary concrete core column can save cost, which selects different materials according to the stress condition, is more economical, highlights local reinforcement, and the gap between the upper and lower core columns can improve the integrity of the node area. BRIEF DESCRIPTION OF DRAWINGS

[0031] Figure 1 It is a structural exploded view of the assembled column foundation node of the application; Figure 2 It is an overall view;

[0032] Figure 3 It is a structural view of the application;

[0033] Figure 4 It is a schematic view of the steel wire mesh arrangement of the application;

[0034] Figure 5 It is a front view of the application;

[0035] Figure 6 Arrangement of the hollow core form, steel strand net and steel reinforcement cage of the present application;

[0036] Figure 7 、 Figure 8 Respectively, the different visible space stereographic view of the hollow core form of the present application;

[0037] Figure 9 Respectively, the different cross-sectional position view of the hollow core form of the present application; Figure 3

[0038] Figure 10 、 Figure 11 Respectively, the two kinds of steel reinforcement lap joint schematic diagram.

[0039] Wherein: 1-prefabricated column, 2-pile cap, 3-steel strand net, 4-hollow core form, 101-prefabricated concrete, 102-prefabricated ECC, 103-prefabricated UHPC, 104-prefabricated column core column, 105-column longitudinal reinforcement, 106-grouting duct, 107-square hole, 108-column stirrup, 201-pile cap core column, 202-pile cap connecting reinforcement, 301-transverse steel strand, 302-longitudinal steel strand, 303-aluminum buckle, 401-core form outer shell, 402-core form inner shell, 403-longitudinal reinforcement hole. DETAILED DESCRIPTION

[0040] In order to make the technical concept and advantages of the invention to achieve its purpose more clear and obvious, the technical scheme of the present application is further described in detail below in combination with the drawings. It should be understood that the following examples are only used to explain and illustrate the preferred embodiments of the present application, and should not be construed as limiting the scope of protection of the present application.

[0041] Example 1

[0042] As shown in Figure 1 、 Figure 2 、 Figure 3 The ECC-stainless steel strand net local reinforcement prefabricated column-foundation connection node of the present application is set, which comprises a prefabricated column 1 and a pile cap 2, the prefabricated column is composed of prefabricated concrete 101, prefabricated ECC 102, prefabricated column core column 104, steel strand net 3 and post-poured UHPC 103; the pile cap 2 is provided with pile cap connecting reinforcement 202 and pile cap core column 201 corresponding to the prefabricated column core column, and the prefabricated column and the pile cap are connected by steel reinforcement lap joint.

[0043] ​The precast column 1 is provided with a precast column core column 104 and a cap core column 201 corresponding to the positions and having a certain gap therebetween, and then the hollow area and the gap are filled with UHPC, which not only saves materials but also solves the problem of poor performance of the assembled monolithic column foundation node at the splicing part of the prefabricated component. The column bottom segment of the precast column uses ECC to replace ordinary concrete, high-strength stainless steel wire mesh is arranged in the part poured with ECC, an ordinary concrete core column is arranged in the central area of the hollow part, and UHPC is post-poured in the remaining hollow area. The poured UHPC should have good fluidity and a strength not less than 85 MPa. The post-poured UHPC greatly reduces the lap length of the steel bars, saves materials and simplifies the construction. In addition, the UHPC has relatively high strength, which can improve the damage state, failure mode and energy dissipation capacity of the column bottom.

[0044] The height of the cap core column 201 is H u , and 100 mm≤H u ≤150 mm is taken. The height of the precast column core column 104 is H b , and 300 mm≤H b ≤500 mm is taken. The precast column core column and the cap core column are provided with a gap of 50-80 mm therebetween, and the cross-sectional side length of the precast column core column and the cap core column is taken to be 150-200 mm and not greater than 1 / 3 of the cross-sectional side length of the precast column.

[0045] As shown in Figure 4 , the high-strength stainless steel wire mesh is arranged in the ECC part of the column bottom segment and the upper ordinary concrete 100-150 mm of the top wall thereof, the remaining part of the precast column is poured with ordinary concrete, one end of the high-strength steel wire extends and is anchored in the interior of the ordinary concrete of the precast column by 20d (d is the diameter of the steel wire), and is not less than 100 mm, and the other end of the high-strength steel wire is anchored in the ECC of the column bottom; the steel wire mesh comprises horizontal steel wires and vertical steel wires, the diameter of the steel wire is 3.6 mm-6 mm, and the spacing between the steel wires is 60-100 mm; the horizontal steel wires are closed loops and are lap-anchored at both ends by aluminum buckles; the anchoring length of the vertical steel wires is 20d (d is the diameter of the steel wire), and is not less than 100 mm, and the end portions are anchored on the stirrups of the precast column by aluminum buckles and wire ties.

[0046] As shown in Figures 10-11 , the precast column and the cap are connected by lap joint of steel bars. When the steel bars are lap-jointed, two lap joint methods can be used. One is direct lap joint of vertical steel bars, and the other is U-shaped lap joint method. The lap joint lengths of the two methods are the same. The U-shaped lap joint method increases the contact area of the steel bars, improves the bonding force and the bearing capacity, and can flexibly cope with different construction environments by adjusting the bending angle of the U-shaped steel bars. The lap joint length is taken to be 5-10D (D is the diameter of the steel bar).

[0047] As shown in Figures 5-6As shown, grouting channels are arranged at the top and bottom of the prefabricated ECC 102, and a square hole is arranged at the bottom, with the side length of the square hole not greater than the spacing between the steel strands. During pouring, wood blocks with the same size as the grouting channels and the square hole are placed and fixed at the corresponding positions of the steel reinforcement cage and the square hole, and the wood blocks are removed after the ECC has a certain strength after initial setting.

[0048] The height of the prefabricated ECC is 1.5-2 times the side length of the base column section, and the thickness of the prefabricated ECC is 10-15d (d is the diameter of the steel strand) and not less than 30mm.

[0049] As shown in Figure 7 , Figure 8 The hollow core mold includes an outer shell, an inner shell, and longitudinal reinforcement holes, the outer shell is connected with the inner shell at the bottom and is provided with longitudinal reinforcement holes at the corresponding positions of the column longitudinal reinforcement around the periphery, and the top of the outer shell is open; the inner shell is an open rectangular tube with upper and lower faces, which is used for pouring to form a prefabricated column core column.

[0050] As shown in Figure 9 , A-A section is the cross section of the prefabricated column concrete area, B-B section is the cross section of the concrete area provided with the steel strand mesh, C-C section is the cross section of the ECC top wall, D-D section is the cross section at the prefabricated column core column, E-E section is the cross section at the gap between the prefabricated column core column and the pile cap core column, and F-F section is the cross section at the pile cap core column.

[0051] Example 2

[0052] The present embodiment is a construction method of an assembly monolithic prefabricated column foundation node based on the setting of ECC-stainless steel strand mesh local reinforcement, which comprises the following steps:

[0053] Step 1: Before pouring the prefabricated column, a hollow core mold is arranged in the hollow part of the ECC at the bottom segment of the prefabricated column reinforcement cage, and then a high-strength stainless steel strand mesh is arranged in the ECC part at the bottom segment of the prefabricated column reinforcement cage and the upper part of the ordinary concrete 100-150mm of the top wall of the prefabricated column, one end of the high-strength steel strand is extended and anchored to the stirrup at the position of the ordinary concrete of the prefabricated column, and the other end of the high-strength steel strand is temporarily bound to the bottom of the hollow core mold with a binding wire; wood blocks with the same size as the grouting channels and the square hole are placed at the corresponding positions of the grouting channels and the square hole, and then a formwork is arranged at the prefabricated column.

[0054] Step 2: During the pouring process of the prefabricated column, vertical pouring is adopted, the full-section ordinary concrete is poured first, then the ECC top wall at the bottom segment is poured, and finally the ECC shell and the prefabricated column core column are poured simultaneously.

[0055] Step 3: Then the hoisting construction of the prefabricated column is carried out, and after the prefabricated column is hoisted and positioned, it is checked whether the positions of the prefabricated column in three directions are accurate.

[0056] Step 4: The lap joint of the steel bars is bound by using a wire through the square hole on the side of the column, and the binding points are uniformly distributed and firmly bound to ensure that the steel bars are not displaced during the concrete pouring process;

[0057] Step 5: Inject grouting material. Inject UHPC through the grouting hole until the grouting material overflows from the upper outlet hole, then stop the grouting operation. After the grouting is completed, the grouting hole is closed until the grouting material hardens. After pouring, the UHPC is properly maintained, including covering and wet curing, to ensure that it reaches the designed strength.

[0058] The present application is based on the setting of ECC-stainless steel wire mesh local reinforcement of prefabricated column-base connection node and construction method. ECC is used to replace ordinary concrete at the bottom of the prefabricated column, high-strength stainless steel wire mesh is set at the same time of pouring ECC in the part, ordinary concrete core column is set in the center area of the hollow part, and the remaining space is used for post-cast UHPC. The column bottom is connected by steel bar lap joint, and the pile cap is provided with a pile cap core column corresponding to the core column. The post-cast UHPC greatly reduces the length of the steel bar lap joint, saves materials and simplifies the construction. ECC and UHPC are only used in the plastic hinge core area of the structure, and the design of the core column using ordinary concrete has good economic benefits, which is conducive to the popularization and large-scale application of the combined structure. At the same time, the setting of the steel wire mesh increases the tensile capacity of the column base node connection, greatly improving the seismic capacity of the node. Therefore, the present application can effectively solve the problems of poor ductility, cracking, durability and seismic performance of prefabricated column components, make up for the poor performance of the prefabricated component splicing part of the prefabricated column base node, and improve the early stage stiffness and energy dissipation capacity.

[0059] The above only describes the preferred embodiments of the present application and does not constitute a limitation on the present application. Those skilled in the art can make other modifications to the implementation of the present application without creative labor under the guidance of the prior art, and any modification or simple replacement or equivalent replacement made within the spirit and principles of the present application by using conventional technical means in the art shall be included in the protection scope of the present application.

Claims

1. A prefabricated column-foundation connection joint provided with local reinforcement of the ECC-stainless steel wire mesh, comprising a prefabricated column (1), a bearing platform (2); characterized in that: The prefabricated column (1) is composed of prefabricated concrete (101), prefabricated ECC (102) and post-poured UHPC (103); the prefabricated ECC (102) is arranged in the column bottom section of the prefabricated column (1); wherein, The central area of the hollow part of the prefabricated ECC (102) is provided with a common concrete prefabricated column core column (104), and the top wall of the hollow part has prefabricated column longitudinal reinforcement passing through; The bearing platform (2) is provided with bearing platform connecting steel bars (202) and bearing platform core columns (201) corresponding to the prefabricated column core column (104); the prefabricated concrete (101) and the bearing platform (2) are connected by steel bar lap joint; the prefabricated ECC (102) and the bearing platform (2) are butted, and the hollow part is poured with UHPC after the butting; the prefabricated concrete (101), the prefabricated ECC (102) and the bearing platform (2) are connected by lap joint steel bars and post-poured UHPC (103); the prefabricated column core column (104) and the bearing platform core column (201) are in corresponding positions and have a certain gap therebetween, and then the hollow area and the gap are filled with UHPC; And, in the column bottom section of the prefabricated column (1), the connecting section surrounding the prefabricated ECC (102) and the common concrete prefabricated column core column (104) is provided with a steel strand net (3); the steel strand net (3) is arranged in the prefabricated ECC part of the column bottom section and the common concrete 100-150mm range of the upper part of the top wall thereof, one end of the high-strength steel strand extends and is anchored in the common concrete inside the prefabricated column to a depth of 20 times the diameter of the steel strand and is not less than 100mm, and the other end of the high-strength steel strand is anchored in the column bottom prefabricated ECC.

2. The precast column-to-foundation connection node locally reinforced with a mesh of ECC-stainless steel strands according to claim 1, characterized in that: The height of the prefabricated ECC (102) part is 1.5-2 times the side length of the base column section, and the thickness of the prefabricated ECC is 10-15d and is not less than 40mm; d is the diameter of the steel strand.

3. The precast column-to-foundation connection node with local reinforcement of the ECC- stainless steel wire mesh according to claim 2, characterized in that: Grouting holes are arranged at the top and bottom of the prefabricated ECC (102), and a square hole is arranged at the bottom, and the side length of the square hole is not greater than the spacing of the steel strands.

4. The precast column-to-foundation connection node locally reinforced with a mesh of ECC-stainless steel strands according to claim 1, 2 or 3, characterized in that: The steel strand net includes horizontal steel strands and vertical steel strands, the diameter of the steel strands is 3.6mm-6mm, and the spacing of the steel strands is 60-100mm; the horizontal steel strands are closed loops, and the two ends are lap-jointed and anchored by aluminum buckles; the anchoring length of the vertical steel strands is 20d, and d is the diameter of the steel strand and is not less than 100mm, and the end part is anchored on the stirrup of the prefabricated column by aluminum buckles and wire binding.

5. The precast column-to-foundation connection node locally reinforced with a mesh of ECC-stainless steel strands according to claim 1, 2 or 3, characterized in that: The steel bar lap joint can adopt vertical steel bar direct lap joint or U-shaped steel bar lap joint method, and the lap joint length is 5-10D, and D is the diameter of the steel bar.

6. The precast column-to-foundation connection node locally reinforced with a mesh of ECC-stainless steel strands according to claim 1, 2 or 3, characterized in that: The height of the core column (201) of the bearing platform is H u , 100mm≤H u ≤150mm, the height of the core column (104) of the prefabricated column is H b , 300mm≤H b ≤500mm, a gap of 50-80mm is reserved between the core column of the prefabricated column and the core column of the bearing platform, and the cross-sectional side length of the core column of the prefabricated column and the core column of the bearing platform is 150-200mm and not greater than 1 / 3 of the cross-sectional side length of the prefabricated column.

7. A method of constructing a precast column-to-foundation connection node locally reinforced with a mesh of ECC-stainless steel strands according to any one of claims 1-6, characterized in that, The method comprises the following steps: Step 1: before pouring the prefabricated column, first arrange a hollow core mold in the hollow part of the prefabricated ECC of the column bottom section of the prefabricated column steel reinforcement cage, then arrange a high-strength stainless steel strand net in the prefabricated ECC part of the column bottom section of the prefabricated column steel reinforcement cage and the common concrete 100-150mm range of the upper part of the top wall thereof, one end of the high-strength steel strand extends and is anchored on the stirrup at the position of the common concrete of the prefabricated column, and the other end of the high-strength steel strand is temporarily bound by wire at the bottom of the hollow core mold; wood blocks with the same size as the grouting holes and the square hole are placed at the corresponding positions of the grouting holes and the square hole, and then a formwork is arranged at the prefabricated column; Step 2: During the precast column pouring process, vertical pouring is used. First, the entire cross-section of ordinary concrete is poured, then the precast ECC top wall at the column bottom segment is poured, and finally the precast ECC shell and precast column core column are poured simultaneously; Step 3: Then the precast column hoisting construction is carried out. After the precast column is hoisted into place, check whether the position of the precast column in three directions is accurate; Step 4: Use wire binding to bind the steel bars at the lapping part through the square holes on the side of the column. The binding points should be evenly distributed and firmly bound to ensure that the steel bars do not shift during the concrete pouring process; Step 5: Inject grouting material: Inject UHPC through the grouting hole until the grouting material overflows from the upper outlet hole, then stop the grouting operation. After grouting is completed, the grouting hole is sealed until the grouting material hardens.

8. The method of constructing a precast column-foundation joint according to claim 7, wherein: After pouring is completed, appropriate curing of UHPC is carried out, including covering and wet curing, to ensure that it reaches the designed strength.

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