Prefabricated column-foundation connection node provided with local reinforcement of ECC-stainless steel stranded wire net

Abstract

A prefabricated column-foundation connecting joint provided with an ECC-stainless steel stranded wire net for local reinforcement comprises a prefabricated column and a bearing platform. The prefabricated column is composed of prefabricated concrete, prefabricated ECC and post-cast UHPC. The prefabricated ECC is arranged on the column bottom section of the prefabricated column; a common concrete prefabricated column core column is arranged in the central area of the hollow part of the prefabricated ECC, and a prefabricated column longitudinal bar penetrates through the top wall; the bearing platform is provided with a bearing platform connecting steel bar and a bearing platform core column corresponding to the prefabricated column core column; the prefabricated concrete, the prefabricated ECC and the bearing platform are connected through the lap joint steel bars and the post-pouring UHPC. In addition, a steel strand net is arranged on the column bottom section of the prefabricated column and surrounds the prefabricated ECC. The problems of poor ductility, cracking, durability and anti-seismic performance of an assembly type foundation column component can be effectively solved, the defects that the splicing part of an assembly integral type column foundation node prefabricated component is poor in performance and prone to cracking are overcome, and the early-stage rigidity and energy dissipation capacity of the assembly integral type column foundation node prefabricated component are improved.

Description

Technical Field

[0001] The invention relates to the technical field of building structure engineering, and in particular to a column foundation node for assembled buildings. Background Art

[0002] Cast-in-place concrete construction relies on site conditions and is susceptible to factors such as weather and construction techniques, which can lead to longer construction periods and higher costs. While precast concrete components can reduce on-site construction time, the complexity of their connections often requires more materials and labor, increasing overall costs.

[0003] In order to solve these problems, 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 research hotspots due to their excellent mechanical properties and durability. ECC has high toughness and crack resistance, and can maintain the integrity of the structure when stretched, while UHPC is known for its ultra-high strength and durability. UHPC has relatively high strength, which can improve the damage state, failure mode and energy dissipation capacity of the column bottom, and greatly reduce the lap length of steel bars, saving materials and simplifying construction.

[0004] The invention with application number 202110241319.3 discloses a grouting sleeve connected with an ECC tube, and the prefabricated concrete component includes a prefabricated RC concrete component A, a prefabricated ECC tube, and a prefabricated RC concrete component B. The prefabricated RC concrete component A is a variable cross-section, and the plastic hinge end is an embedded tenon-type section adapted to the prefabricated ECC tube, and the embedded tenon is used to insert into the prefabricated ECC tube. The connection between the prefabricated RC concrete component A and the prefabricated RC concrete component B is achieved by a grouting sleeve pre-buried in the prefabricated ECC tube, and the prefabricated joints between the three are connected by grouting sleeves and joint materials such as high-strength structural adhesives, UHPC, and high-strength grouting materials. This technology can effectively improve the durability and seismic performance of prefabricated concrete components, and give full play to the excellent crack resistance and crack control capabilities of ECC materials. It is suitable for prefabricated concrete components of building structures, and also suitable for prefabricated concrete components such as prefabricated piers and tie beams in bridge structures.

[0005] However, the main focus of this invention is on the improvement of grouting process and sleeve connection, and emphasizes the connection of prefabricated components through grouting sleeves. Although it involves grouting sleeve connections, it does not give full play to the innovative application of the combination of cement-based composite materials (ECC) and ultra-high performance concrete (UHPC) materials, and has significant differences in structural form and effect compared with the steel bar lap method. Summary of the invention

[0006] In view of the shortcomings of the existing technology, the present invention proposes a prefabricated column-foundation connection node with ECC-stainless steel stranded wire mesh local reinforcement based on steel bar overlap, and proposes a new type of assembled column foundation node connection method, which can solve the problems of long construction period, high cost, low material utilization rate and so on in the existing technology. By adopting engineered cement-based composite materials (ECC), ultra-high performance concrete (UHPC) and steel strand reinforcement, the seismic performance of the node is improved.

[0007] The technical solution adopted by the present invention is: A prefabricated column-foundation connection node with ECC-stainless steel stranded wire mesh local reinforcement, comprising a prefabricated column (1) and a cap (2); the prefabricated column (1) is composed of prefabricated concrete (101), prefabricated ECC (102) and post-cast UHPC (103); the prefabricated ECC (102) is arranged at the column bottom section of the prefabricated column (1); wherein a common concrete prefabricated column core column (104) is arranged in the central area of ​​the hollow part of the prefabricated ECC (102), and the top wall of the hollow part has prefabricated column longitudinal reinforcement passing through; the cap (2) is provided with a cap connection steel bar (202) and a prefabricated column connection steel bar (202) connected to the prefabricated column A cap core column (201) corresponding to the core column (104); the precast concrete (101), the precast ECC (102) and the cap (2) are connected by overlapping steel bars; after the precast ECC (102) and the cap (2) are butt-jointed, UHPC is poured into the hollow part thereof; the precast concrete (101), the precast ECC (102) and the cap (2) are connected by overlapping steel bars and post-cast UHPC (103); and a steel strand mesh (3) is provided in the column bottom section of the precast column (1) surrounding the connection section between the precast ECC (102) and the common concrete precast column core column (104).

[0008] The prefabricated column-foundation connection node with local reinforcement of ECC-stainless steel stranded wire mesh is provided, and the height of the prefabricated ECC (102) part is 1.5-2 times the side length of the foundation column section. A high-strength stainless steel stranded wire mesh is provided while casting the ECC part. The thickness of the prefabricated ECC is 10-15d and not less than 40mm; d is the diameter of the steel strand.

[0009] The prefabricated column-foundation connection node with ECC-stainless steel stranded wire mesh local reinforcement is provided with grouting channels at the top and bottom of the prefabricated ECC (102), and a square hole is provided at the bottom, and the side length of the square hole is not greater than the spacing between the steel strands.

[0010] In the prefabricated column-foundation connection node with ECC-stainless steel strand mesh for local reinforcement, the steel strand mesh (3) is arranged within 100-150 mm of the ordinary concrete of the ECC portion of the column bottom segment and the upper portion of the top wall, one end of the high-strength steel strand extends and is anchored in the ordinary concrete of the prefabricated column to a depth of 20 times the steel strand diameter and not less than 100 mm, and the other end of the high-strength steel strand is anchored in the prefabricated ECC at the column bottom.

[0011] The prefabricated column-foundation connection node with partial reinforcement of ECC-stainless steel strand mesh is provided, and the steel strand mesh includes transverse steel strands and vertical steel strands, and the diameter of the steel strands is 3.6mm-6mm; the spacing between the steel strands is 60-100mm; the transverse steel strands are closed loops, and the two ends of the transverse steel strands are overlapped and anchored by aluminum buckles; the anchorage length of the longitudinal steel strands is 20d (d is the diameter of the steel strand) and not less than 100mm, and the ends are anchored to the prefabricated column stirrups with aluminum buckles and wire ties.

[0012] The prefabricated column-foundation connection node with ECC-stainless steel stranded wire mesh local reinforcement can be overlapped by direct overlap of vertical steel bars or U-shaped steel bar overlap, and the overlap length is 5-10D (D is the steel bar diameter).

[0013] The prefabricated column-foundation connection node with ECC-stainless steel stranded wire mesh local reinforcement is provided, and the height of the cap core column (201) is H u , take 100mm≤H u ≤150mm, prefabricated column core column (104) height H b , take 300mm≤H b ≤500mm, a gap of 50-80mm is reserved between the core column of the precast column and the core column of the pedestal, and the cross-sectional length of the core column of the precast column and the core column of the pedestal is 150-200mm and not more than 1 / 3 of the cross-sectional length of the precast column.

[0014] A construction method of the prefabricated column-foundation connection node as described above comprises the following steps: Step 1: Before pouring the precast column, a hollow core mold is first set in the hollow part of the ECC section of the precast column reinforcement cage, and then a high-strength stainless steel strand mesh is set within 100-150mm of the ordinary concrete of the ECC section of the precast column reinforcement cage and the upper part of the top wall. One end of the high-strength steel strand is extended and anchored to the stirrup at the ordinary concrete position of the precast column, and the other end of the high-strength steel strand is temporarily tied to the bottom of the hollow core mold with a wire tie; wooden blocks of the same size are placed at the corresponding positions of the grouting channel and the square hole, and then a template is set at the precast column; Step 2: During the casting of the precast column, vertical casting is adopted, first casting the full-section ordinary concrete, then casting the ECC top wall at the column bottom segment, and finally casting the ECC shell and the precast column core column at the same time; Step 3: Then carry out the hoisting construction of the prefabricated column. After the prefabricated column is hoisted into place, check whether the position of the prefabricated column in three directions is accurate; Step 4: Use the tie wire to tie the steel bars at the overlapped parts through the square holes on the side of the column. The tie points should be evenly distributed and tied firmly to ensure that the steel bars will 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 grouting hole and then stop the grouting operation. After the grouting is completed, close the grouting hole until the grouting material solidifies and hardens.

[0015] After pouring, UHPC needs to be properly cured, including covering and moist curing, to ensure that it reaches the designed strength.

[0016] Beneficial effects of the invention: Based on the prefabricated column-foundation connection node with ECC-stainless steel strand mesh local reinforcement, this invention proposes a new type of assembled column foundation node connection method, which combines ECC and UHPC materials and steel strands to improve node performance. 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 projects.

[0017] The novel assembled column foundation node connection method provided by the present invention shows unique innovation and advantages in material selection, node connection method, construction efficiency and improvement of seismic performance, especially in improving the connection performance of prefabricated components and construction economy.

[0018] 1. In the prefabricated column foundation node of the present invention, ECC and UHPC are only used in the core area of ​​the plastic hinge of the structure, and the design of using ordinary concrete for the core column has good economic benefits and improves the overall performance of the structure. More materials are used in the key parts of the structure, while reducing the use of materials in other parts, thereby maximizing cost-effectiveness while ensuring the safety of the structure, which is conducive to the promotion and large-scale application of this type of combined structure. Concrete is used in the core column (center of the cross section) to reduce costs, and gaps are left in the upper and lower core columns for UHPC filling to improve integrity. The present invention improves the bearing capacity and durability of the node through a connection method that combines UHPC and engineered cement-based composite materials (ECC) with steel strands. The local reinforcement is cast together with ordinary concrete, and a steel strand mesh is provided at the contact position to enhance integrity.

[0019] 2. The prefabricated column foundation node of the present invention can effectively solve the problems of poor ductility, cracking, durability and seismic performance of prefabricated foundation column components, make up for the shortcomings of poor performance and easy cracks in the splicing parts of prefabricated components of the assembled integral column foundation node, and improve its early stiffness and energy consumption capacity. There is a certain gap between the prefabricated column core column and the pedestal core column in the prefabricated column, and the hollow area and the gap are filled with UHPC, which not only saves materials but also solves the shortcomings of poor performance of the prefabricated component splicing parts of the assembled integral column foundation node. At the same time, steel strands are provided to increase the tensile strength of the column foundation node connection, which greatly improves the seismic resistance of the node. Through these beneficial effects, the present invention can not only meet the multiple requirements of modern construction projects for efficiency, cost, quality and environment, but also bring long-term technological innovation and economic benefits to the construction industry.

[0020] 3. The present invention uses engineered cement-based composites (ECC) and ultra-high performance concrete (UHPC) combined with stainless steel strand mesh for local reinforcement to improve the seismic performance and durability of precast column foundation nodes. ECC and post-cast UHPC are used only in the plastic hinge core area of ​​the structure, while ordinary concrete is used in other non-critical areas, taking into account both performance and economy; and according to the specifications, post-cast UHPC can reduce the lap length of steel bars accordingly, simplifying construction, saving materials and reducing construction difficulty. ECC-steel strand mesh is used as the shell of the core section, which minimizes the use of ECC and is more economical.

[0021] 4. The present invention uses a combined connection method based on steel bar lap joints, ECC, and stainless steel stranded wire mesh, aiming to improve the comprehensive performance of the node, and significantly improve the tensile strength and seismic performance of the node. The ductility of the core area is improved through the local reinforcement design of the ECC-stainless steel stranded wire mesh shell; the post-cast UHPC reduces the length of the steel bar lap joint, which is convenient for construction and reduces costs; the core column (center of the cross section) is set up with concrete to reduce costs; the upper and lower core columns leave gaps for UHPC filling, which improves the integrity. At the same time, steel strands are set to increase the tensile strength of the column foundation node connection, which greatly improves the seismic resistance of the node.

[0022] The present invention uses ECC, stainless steel stranded wire mesh and UHPC, which can significantly improve the seismic performance and durability of the assembled integral prefabricated column foundation node, especially enhance the performance of the splicing part, effectively solve the problems of poor ductility, cracking, durability and seismic performance of the assembled foundation column components, make up for the shortcomings of poor performance and easy cracks in the splicing part of the assembled integral column foundation node prefabricated components, and improve its early stiffness and energy consumption capacity. It has good crack control and dispersion capabilities, high toughness and ductility, and makes the damage distribution of the beam-column node area and the key area of ​​the plastic hinge of the beam end more uniform.

[0023] 5. The present invention reduces the lap length of steel bars and optimizes the use of materials by using UHPC, which not only improves the node performance, but also greatly saves materials, simplifies construction, and has better construction efficiency, cost-effectiveness, and economic benefits. Within a certain height at the bottom of the prefabricated column, ECC is used to replace ordinary concrete for a certain thickness of the prefabricated outer shell. A high-strength stainless steel stranded wire mesh is set at the same time when the ECC is cast. An ordinary concrete core column is set in the central area of ​​the hollow part, and the remaining space is cast with UHPC. The bottom of the column is connected by steel bar lap connection, and the pedestal is set with a pedestal core column corresponding to the core column. Setting an ordinary concrete core column where the center of the column section is subjected to less force can save costs. This is more economical in selecting different materials according to the force conditions, and also highlights local reinforcement. In addition, setting gaps between the upper and lower core columns and between the upper and lower core columns can improve the integrity of the node area. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic diagram of the structural decomposition of the assembled column foundation node of the present invention; Figure 2 For the overall picture; Figure 3 It is a structural schematic diagram of the present invention; Figure 4 It is a schematic diagram of the arrangement of the steel strand mesh of the present invention; Figure 5 It is a front view of the present invention; Figure 6 It is the layout diagram of the steel cage, steel strand mesh and hollow core mold of the present invention; Figure 7 Schematic diagram of different visible spaces of the hollow core mold of the present invention Figure 1 ; Figure 8 Schematic diagram of different visible spaces of the hollow core mold of the present invention Figure 2 ; Fig. 9 The following are shown: Figure 3 Section views at different section positions; Fig.10 Rebar lap joint Figure 1 ; Fig.11 Rebar lap joint Figure 2 .

[0025] Among them: 1-precast column, 2-cap, 3-steel strand mesh, 4-hollow core mold, 101-precast concrete, 102-precast ECC, 103-post-cast UHPC, 104-precast column core column, 105-column longitudinal reinforcement, 106-grouting channel, 107-square hole, 108-column stirrups, 201-cap core column, 202-cap connecting steel bars, 301-transverse steel strand, 302-longitudinal steel strand, 303-aluminum buckle, 401-core mold outer shell, 402-core mold inner shell, 403-longitudinal reinforcement hole. DETAILED DESCRIPTION

[0026] In order to make the technical concept and advantages of the invention more clearly understood, the technical solution of the invention is further described in detail below in conjunction with the accompanying drawings. It should be understood that the following embodiments are only used to explain and illustrate the preferred implementation of the invention and should not constitute a limitation on the scope of protection of the patent claim of the invention. Example

[0027] like Figure 1 , Figure 2 , Figure 3 As shown, the present invention provides a precast column-foundation connection node partially reinforced with an ECC-stainless steel stranded wire mesh, including a precast column 1 and a cap 2, wherein the precast column is composed of a precast concrete 101, a precast ECC 102, a precast column core column 104, a steel stranded wire mesh 3 and a post-cast UHPC 103; the cap 2 is provided with a cap connection steel bar 202 and a cap core column 201 corresponding to the precast column core column, and the precast column and the cap are connected by steel bar overlap.

[0028] The precast column 1 is provided with the precast column core column 104 and the pedestal core column 201 in positions corresponding to each other with a certain gap between the two, 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 integral column foundation node at the splicing part of the precast components. The shell of the column bottom section of the precast column uses ECC to replace ordinary concrete, and a high-strength stainless steel stranded wire mesh is set at the same time when the ECC is cast. An ordinary concrete core column is set in the central area of ​​the hollow part, and the remaining hollow areas are post-cast with UHPC. The cast UHPC should have good fluidity, and the strength should not be lower than 85MPa. The post-cast UHPC greatly reduces the lap length of the steel bars, saves materials and simplifies the construction. In addition, UHPC has a relatively high strength, which can improve the damage state, failure mode and energy consumption capacity of the column bottom; The height of the core column 201 is H u , take 100mm≤H u ≤150mm, prefabricated column core column 104 height H b , take 300mm≤H b≤500mm, and a gap of 50-80mm is reserved between the core column of the precast column and the core column of the pedestal. The cross-sectional length of the core column of the precast column and the core column of the pedestal is 150-200mm and not more than 1 / 3 of the cross-sectional length of the precast column.

[0029] like Figure 4 As shown, a high-strength stainless steel strand mesh is arranged within 100-150mm of the ordinary concrete of the ECC part of the column bottom segment and the upper part of the top wall, and the rest of the prefabricated column is cast with ordinary concrete. One end of the high-strength steel strand extends and is anchored in the ordinary concrete of the prefabricated column by 20 (d is 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 ECC at the bottom of the column; the steel strand mesh includes transverse steel strands and vertical steel strands, and the diameter of the steel strands is 3.6mm-6mm; the spacing between the steel strands is 60-100mm; the transverse steel strands are closed loops, and the two ends of the transverse steel strands are overlapped and anchored by aluminum buckles; the anchorage length of the longitudinal steel strand is 20d (d is the diameter of the steel strand) and is not less than 100mm, and the ends are anchored to the prefabricated column stirrups with aluminum buckles and wire ties.

[0030] like Fig.10 , Fig.11 As shown, the precast column and the pedestal are connected by overlapping steel bars. There are two overlapping methods for overlapping steel bars. One is direct overlapping of vertical steel bars, and the other is U-shaped steel bar overlapping method. The overlapping lengths of the two are the same. The U-shaped overlapping method increases the contact area of ​​the steel bars, improves the bonding force and bearing capacity. By adjusting the bending angle of the U-shaped steel bars, it can flexibly cope with different construction environments. The overlapping length is 5-10D (D is the diameter of the steel bar).

[0031] like Figure 5-6 As shown, grouting holes are provided at the top and bottom of the prefabricated ECC 102, and square holes are provided at the bottom, the side length of the square holes being no greater than the spacing between the steel strands. During pouring, wooden blocks of the same size are placed and fixed at the corresponding positions of the grouting holes and the square holes of the steel cage, and the wooden blocks are removed after the ECC has a certain strength after initial setting.

[0032] The height of the prefabricated ECC is 1.5-2 times the side length of the foundation 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.

[0033] like Figure 7 , Figure 8 As shown, the hollow core mold includes an outer shell, an inner shell, and longitudinal reinforcement holes. The bottom of the outer shell is connected to the inner shell and longitudinal reinforcement holes are arranged at the corresponding positions of the column longitudinal reinforcements around it. The top of the outer shell is open; the inner shell is a rectangular tube with openings on the upper and lower sides, which is used for casting to form a prefabricated column core column.

[0034] like Fig. 9As shown, section AA is the section of the concrete area of ​​the precast column, section BB is the section of the concrete area with tied steel wire mesh, section CC is the section of the ECC top wall, section DD is the section at the core column of the precast column, section EE is the section at the gap between the core column of the precast column and the core column of the pedestal, and section FF is the section at the core column of the pedestal. Example

[0035] This embodiment is a construction method for an assembled integral prefabricated column foundation node with local reinforcement of ECC-stainless steel stranded wire mesh based on steel bar overlap, comprising the following steps: Step 1: Before pouring the precast column, a hollow core mold is first set in the hollow part of the ECC section of the precast column reinforcement cage, and then a high-strength stainless steel strand mesh is set within 100-150mm of the ordinary concrete of the ECC section of the precast column reinforcement cage and the upper part of the top wall. One end of the high-strength steel strand is extended and anchored to the stirrup at the ordinary concrete position of the precast column, and the other end of the high-strength steel strand is temporarily tied to the bottom of the hollow core mold with a wire tie; wooden blocks of the same size are placed at the corresponding positions of the grouting channel and the square hole, and then a template is set at the precast column; Step 2: During the casting of the precast column, vertical casting is adopted, first casting the full-section ordinary concrete, then casting the ECC top wall at the column bottom segment, and finally casting the ECC shell and the precast column core column at the same time; Step 3: Then carry out the hoisting construction of the prefabricated column. After the prefabricated column is hoisted into place, check whether the position of the prefabricated column in three directions is accurate; Step 4: Use the tie wire to tie the steel bars at the overlapped parts through the square holes on the side of the column. The tie points should be evenly distributed and tied firmly to ensure that the steel bars will 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 grouting hole and then stop the grouting operation. After the grouting is completed, the grouting hole is closed until the grouting material solidifies and hardens. After the pouring is completed, the UHPC is properly maintained, including covering and moistening maintenance, to ensure that it reaches the designed strength.

[0036] The present invention is based on the setting of ECC-stainless steel stranded wire mesh local reinforcement prefabricated column-foundation connection node and construction method of steel bar overlap, ECC is used to replace ordinary concrete at the bottom of the prefabricated column, high-strength stainless steel stranded wire mesh is set at the same time in the part where ECC is cast, ordinary concrete core column is set in the central area of ​​the hollow part, and the remaining space is cast with UHPC, the bottom of the column is connected by steel bar overlap, and the pedestal is set with the pedestal core column corresponding to the core column. The post-cast UHPC greatly reduces the steel bar overlap length, saves materials and simplifies the construction. The design that ECC and UHPC are only used in the plastic hinge core area of ​​the structure and the core column adopts ordinary concrete has good economic benefits, which is conducive to the promotion and large-scale application of this kind of combined structure. At the same time, the setting of steel stranded wire mesh increases the tensile strength of the column foundation node connection, which greatly improves the seismic resistance of the node. Therefore, the present invention can effectively solve the problems of poor ductility, cracking, durability and seismic resistance of assembled foundation column components, make up for the shortcomings of poor performance and easy cracks in the splicing parts of the prefabricated components of the assembled integral column foundation node, and improve its early stiffness and energy consumption capacity.

[0037] The above description is only a preferred embodiment of the present invention and does not constitute a limitation of the present invention. Under the guidance of the prior art, those skilled in the art can make other modifications to the implementation of the present invention without creative work. Any modification made within the spirit and principle of the present invention or simple replacement or equivalent substitution using conventional technical means in the field should be included in the protection scope of the present invention.

Claims

1. A prefabricated column-foundation connection node with ECC-stainless steel stranded wire mesh local reinforcement, comprising a prefabricated column (1) and a cap (2); characterized in that: The precast column (1) is composed of precast concrete (101), precast ECC (102) and post-cast UHPC (103); the precast ECC (102) is arranged at the column bottom section of the precast column (1); wherein: A common concrete precast column core column (104) is arranged in the central area of ​​the hollow portion of the precast ECC (102), and a precast column longitudinal reinforcement passes through the top wall of the hollow portion; The cap (2) is provided with a cap connecting steel bar (202) and a cap core column (201) corresponding to the prefabricated column core column (104); The precast concrete (101), the precast ECC (102) and the cap (2) are connected by overlapping steel bars; after the precast ECC (102) and the cap (2) are butt-jointed, UHPC is poured into the hollow part thereof; the precast concrete (101), the precast ECC (102) and the cap (2) are connected by overlapping steel bars and post-cast UHPC (103); Furthermore, a steel strand mesh (3) is provided in the column bottom section of the prefabricated column (1), surrounding the connection section of the prefabricated ECC (102) and the common concrete prefabricated column core column (104).

2. The prefabricated column-foundation connection node with ECC-stainless steel stranded wire mesh local reinforcement according to claim 1 is characterized in that: The height of the prefabricated ECC (102) part is 1.5-2 times the side length of the foundation column section. A high-strength stainless steel strand mesh is provided while casting the ECC part. The thickness of the prefabricated ECC is 10-15d and not less than 40mm; d is the diameter of the steel strand.

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

4. The prefabricated column-foundation connection node with ECC-stainless steel stranded wire mesh local reinforcement according to claim 1, 2 or 3, characterized in that: The steel strand mesh (3) is arranged within 100-150 mm of the ordinary concrete of the ECC part of the column bottom segment and the upper part of the top wall. One end of the high-strength steel strand is extended and anchored in the ordinary concrete of the precast column to a depth of 20 times the steel strand diameter and not less than 100 mm. The other end of the high-strength steel strand is anchored in the precast ECC at the column bottom.

5. The prefabricated column-foundation connection node with ECC-stainless steel stranded wire mesh local reinforcement according to claim 4 is characterized in that: The steel strand mesh includes transverse steel strands and vertical steel strands. The diameter of the steel strands is 3.6mm-6mm; the spacing between the steel strands is 60-100mm; the transverse steel strands are closed loops, and the two ends of the transverse steel strands are overlapped and anchored by aluminum buckles; the anchorage length of the longitudinal steel strands is 20d, where d is the diameter of the steel strand and is not less than 100mm, and the ends are anchored to the prefabricated column stirrups with aluminum buckles and wire ties.

6. The prefabricated column-foundation connection node with ECC-stainless steel stranded wire mesh local reinforcement according to claim 1 is characterized in that: The steel bar lap can be directly overlapped by vertical steel bars or by U-shaped steel bar lap, and the lap length is 5-10D, where D is the steel bar diameter.

7. The prefabricated column-foundation connection node with ECC-stainless steel stranded wire mesh local reinforcement according to claim 1, 2, 3, 5 or 6, characterized in that: The height of the core column (201) of the support platform is H u , take 100mm≤H u ≤150mm, prefabricated column core column (104) height H b , take 300mm≤H b ≤500mm, a gap of 50-80mm is reserved between the core column of the precast column and the core column of the pedestal, and the cross-sectional length of the core column of the precast column and the core column of the pedestal is 150-200mm and not more than 1 / 3 of the cross-sectional length of the precast column.

8. A construction method for a prefabricated column-foundation connection node as claimed in claim 1, characterized in that: The following steps are involved: Step 1: Before pouring the precast column, a hollow core mold is first set in the hollow part of the ECC section of the precast column reinforcement cage, and then a high-strength stainless steel strand mesh is set within 100-150mm of the ordinary concrete of the ECC section of the precast column reinforcement cage and the upper part of the top wall. One end of the high-strength steel strand is extended and anchored to the stirrup at the ordinary concrete position of the precast column, and the other end of the high-strength steel strand is temporarily tied to the bottom of the hollow core mold with a wire tie; wooden blocks of the same size are placed at the corresponding positions of the grouting channel and the square hole, and then a template is set at the precast column; Step 2: During the casting of the precast column, vertical casting is adopted, first casting the full-section ordinary concrete, then casting the ECC top wall at the column bottom segment, and finally casting the ECC shell and the precast column core column at the same time; Step 3: Then carry out the hoisting construction of the prefabricated column. After the prefabricated column is hoisted into place, check whether the position of the prefabricated column in three directions is accurate; Step 4: Use the tie wire to tie the steel bars at the overlapped parts through the square holes on the side of the column. The tie points should be evenly distributed and tied firmly to ensure that the steel bars will 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 grouting hole and then stop the grouting operation. After the grouting is completed, close the grouting hole until the grouting material solidifies and hardens.

9. The construction method of the prefabricated column-foundation connection node according to claim 8, characterized in that: After pouring, UHPC is properly cured, including covering and wet curing, to ensure that it reaches the designed strength.

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