Fabricated section steel high-ductility concrete anti-seismic short column and preparation method thereof

Abstract

The invention belongs to the technical field of building materials, and relates to a fabricated section steel high-ductility concrete anti-seismic short column and a preparation method thereof. The anti-seismic short column comprises a base body, profile steel is fixed to the top face of the base body in an inserted mode, profile steel limiting screw holes are formed in flanges and webs of the profile steel, an H-shaped groove is formed in the bottom face of the base body, a concrete limiting screw hole is formed in the side face, close to one end of the H-shaped groove, of the base body, and the profile steel is matched with the H-shaped groove in structure. The profile steel limiting screw holes are matched with the concrete limiting screw holes in position; the preparation method of the anti-seismic short column comprises the steps of manufacturing an anti-seismic short column mold, preparing cement mortar, filling the mold and forming, maintaining and demolding, manufacturing a waterproof layer coating and smearing a waterproof layer. According to a base body of the anti-seismic short column, river sand serves as aggregate, cement, coal ash and silica fume serve as binding materials, profile steel serves as a framework, PVA fibers serve as bridging fibers in the base body, the anti-seismic short column adopts the ECC base body and the profile steel framework which are high in ductility, the assembled prefabricated column can absorb and dissipate earthquake energy, and the high anti-seismic level is achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of building materials, and particularly relates to an assembled steel-shaped high-ductility concrete seismic short column and a preparation method thereof. Background Art

[0002] With the continuous advancement of my country's urbanization process, traditional construction methods are facing problems such as long construction period, serious waste of resources, and environmental pollution. People are actively seeking to solve the above problems by changing the construction method; prefabricated buildings can effectively respond to the urgency of building supply and meet the growing demand for housing and infrastructure through engineering prefabrication and rapid on-site assembly, and have received widespread attention; with the rapid development of prefabricated buildings in my country, prefabricated columns, as one of the basic components, their performance has also become a hot topic discussed by architectural designers.

[0003] Existing prefabricated columns usually adopt reinforced concrete structure, and their base adopts ordinary concrete which is easy to produce brittle failure during the manufacturing process. The overall seismic performance of reinforced concrete prefabricated columns is poor, and the steel bars such as internal steel cage and steel skeleton increase the deadweight of prefabricated columns. In high-rise buildings, reinforced concrete structures have strict requirements on the thickness of protective layer. As the thickness of protective layer increases, the deadweight of the structure also increases, and the seismic performance also decreases. In addition, due to its large volume, prefabricated whole columns have high requirements on technology and safety during transportation and installation.

[0004] In the prior art, the invention with the patent publication number CN 114232897 A and the name of “A precast concrete column steel-ECC composite connection node and its construction method” discloses a precast concrete column vertical connection node structure with convenient positioning, simple construction process and good structural reliability, which is of great practical significance. The connection of the main structure is completed by steel sections, specifically, the steel sections are respectively connected with the precast concrete column and the concrete foundation bolts, and then the steel sections are sealed with ECC to form a column end steel-ECC composite connection node, thereby improving the overall construction efficiency, having a relatively simple structure and good reliability, high overall construction efficiency and convenient positioning. However, since it only uses ECC materials with higher ductility than ordinary concrete to seal the steel sections at the connection, the upper connecting column still uses concrete that is prone to brittle failure as the matrix of the precast column, which has the problem of poor seismic performance.

[0005] In the prior art, the utility model with patent publication number CN 221855962 U and titled “A box-type steel column for assembled building steel structure” discloses a steel column A, a bracket B, a connecting frame and a steel column B. The outer side of the connecting frame is symmetrically welded with a clamping plate A and a clamping plate B for fixing the steel column A and the steel column B respectively. The outer side of the connecting frame is symmetrically rotatably connected with a support plate A and a support plate B for driving the positioning plate A and the positioning plate B to rotate respectively. The surfaces of the positioning plate A and the clamping plate A are provided with a limiting screw hole A for enabling the limiting screw A to fix the positioning plate A and the clamping plate A to the outside of the steel column A. The utility model solves the poor stability of the existing steel columns by arranging the clamping plate A, the clamping plate B, the positioning plate A, the positioning plate B, the connecting frame, the bracket A, the bracket B, the groove and the rubber pad. However, it only uses the connecting frame to connect the two steel columns, which has the problem of poor integrity. Summary of the invention

[0006] In order to overcome the problems existing in the above-mentioned prior art, the purpose of the present invention is to propose an assembled steel-shaped high-ductility concrete seismic short column and a preparation method thereof, by selecting steel-shaped to replace steel bars to improve the ductility of the prefabricated column, selecting river sand as the matrix aggregate of the engineering cement-based composite material (ECC) to increase the density of the matrix, selecting fly ash and silica fume to replace part of the cement, changing the cementitious material component, and using polyethylene (PVA) fiber as a bridging fiber to provide bridging stress inside the matrix; in the present invention, the short column uses steel-shaped as the skeleton, which is usually simpler in the assembly and connection process, and the connection node is more firm, which can effectively improve the integrity of the prefabricated column, and the prepared high-ductility concrete matrix has high ductility and durability, which can effectively increase the seismic performance of the prefabricated column.

[0007] In order to achieve the above object, the present invention is implemented by the following technical solutions:

[0008] In the first aspect, an assembled steel section high-ductility concrete seismic short column comprises a base 1, a steel section 2 is inserted and fixed on the top surface of the base 1, and steel section limiting screw holes 3 are respectively provided on the flange and web of the steel section 2, an H-shaped groove 5 is provided on the bottom surface of the base 1, and a concrete limiting screw hole 4 is provided on the side surface of the base 1 close to one end of the H-shaped groove 5, the steel section 2 and the H-shaped groove 5 are matched in structure and used for the insert connection of two sections of concrete seismic short columns, and the steel section limiting screw hole 3 and the concrete limiting screw hole 4 are matched in position and used for the bolt connection of the concrete seismic short columns after the two sections are inserted and connected.

[0009] Furthermore, the matrix 1 includes cement, fly ash, silica ash, river sand, polyethylene (PVA) fiber, water reducer and water, wherein, by mass, cement: fly ash: silica ash: river sand: water = 1: (0.8-1.2): (0.4-0.8): (2.6-3.2): (0.5-1.0); based on the total volume of cement, fly ash, silica ash, river sand and water mixed evenly, the volume content of polyethylene (PVA) fiber is 0.5%-1.5%; the amount of water reducer added is 0.6%-1.0% of the total mass of cement, fly ash and silica ash; the matrix 1 is a rectangular parallelepiped with a length, width and height of 200-500mm, 200-500mm and 800-1500mm respectively; preferably, the length and width of the matrix 1 are 240mm and 240mm respectively.

[0010] Furthermore, the particle size of the river sand in the matrix 1 is 0.5-1.5 mm; the cement is any one of ordinary Portland cement, slag Portland cement or pozzolanic Portland cement.

[0011] Furthermore, the length ratio of the exposed part of the steel section 2 and the part inserted into the base 1 is 1:8, the steel section 2 is made of any one of Q235 steel, Q345 steel, Q390 steel or Q420 steel, the length of the steel section 2 is 900-1690mm, the width of the flange and web of the steel section 2 is 100-120mm, and the thickness of the flange and web of the steel section 2 is 6-8mm and 8-10mm respectively.

[0012] Furthermore, the radius of the steel limiting screw hole 3 is 5-10 mm; the number and position of the concrete limiting screw hole 4 correspond to the steel limiting screw hole 3, and the radius of the concrete limiting screw hole 4 is 5-10 mm.

[0013] Furthermore, the depth of the H-shaped groove 5 matches the length of the portion of the steel section 2 inserted into the base 1, and the H-shaped groove 5 comprises a flange groove 501 and a web groove 502, and the width and thickness of the flange groove 501 and the web groove 502 are respectively increased by 5-10 mm than the width and thickness of the flange and web of the steel section 2.

[0014] Furthermore, the concrete seismic short column also includes a waterproof layer 6 applied to the outer surface of the substrate 1, and the waterproof layer 6 includes cement, river sand, a waterproofing agent, a filler and water, wherein, by mass, cement: river sand: waterproofing agent: filler: water = 1: (0.8-1.2): (0.05-0.1): (0.4-0.8): (0.5-0.7); the filler in the waterproof layer 6 is composed of one or more of expanded perlite, polystyrene particles, barite powder or mineral powder in any proportion; the cement in the waterproof layer 6 is any one of ordinary Portland cement, slag Portland cement or pozzolanic Portland cement, and the river sand particle size in the waterproof layer 6 is 0.5-1.5 mm.

[0015] In the second aspect, a method for preparing an assembled steel high-ductility concrete seismic short column:

[0016] S1. Making concrete earthquake-resistant short column mold:

[0017] First, a base 1 mold is made, and then a concrete limiting screw hole 4 is opened on the side of one end of the base 1 mold, and a pipe with a radius of 8-15mm is pre-buried in the base 1 mold according to the position of the concrete limiting screw hole 4. Finally, an H-shaped groove 5 is opened at the other end of the base 1 mold, and the steel 2 provided with the steel limiting screw hole 3 is inserted into the base 1 mold along the H-shaped groove 5 while maintaining the length ratio between the exposed part of the steel 2 and the part inserted into the base 1, so as to obtain a concrete seismic short column mold;

[0018] S2. Preparation of cement mortar:

[0019] First, cement, fly ash and silica fume are mixed and dry-mixed for 1-3 minutes to form a dry mixture; then river sand is added to the dry mixture and dry-mixed for 1-3 minutes to form a dry mortar; then the mixture of water reducer and water is slowly added to the dry mortar and stirred for 2-4 minutes to form a wet mixture; finally, polyethylene (PVA) fibers are dispersed and sprinkled into the wet mixture and stirred for 2-4 minutes to form a cement mortar;

[0020] S3, molding:

[0021] The cement mortar in step S2 is placed in the concrete seismic short column mold obtained in step S1, vibrated and compacted, and left for 24-36 hours to prepare a semi-finished concrete seismic short column;

[0022] S4, curing and demoulding:

[0023] The semi-finished concrete seismic short column in step S3 is naturally cured, demoulded after 24-36 hours, and then cured for 60-65 days according to the standard curing method. After ensuring that the strength of the matrix is ​​qualified, the embedded pipes are removed to obtain the concrete seismic short column.

[0024] Furthermore, the method for preparing the concrete seismic short column, based on the concrete seismic short column prepared in step S4, further includes the following processing steps:

[0025] M1. Making waterproof coating:

[0026] First, dry-mix the cement for 1-3 minutes, add river sand and filler to the dry-mixed cement, and dry-mix for 1-3 minutes to form a waterproof layer dry mix; then add the waterproofing agent to the waterproof layer dry mix and stir for 2-5 minutes, and slowly add all the water during the stirring process to form a waterproof layer wet mix; finally, stir the waterproof layer wet mix for 2-4 minutes to form a waterproof layer coating;

[0027] M2. Apply waterproof layer:

[0028] After cleaning the surface of the concrete seismic short column described in step S4, start applying the waterproof layer coating described in step M1, and use a brush to evenly apply the waterproof layer coating to the surface of the concrete seismic short column. After the first layer of waterproof layer coating is applied, wait for 4-12 hours, and then repeat the operation to complete the application of the second and third layers of waterproof layer coating. The thickness of the first, second and third waterproof layers are all 2mm-5mm.

[0029] Compared with the prior art, the present invention has the following beneficial effects:

[0030] 1. The matrix of the present invention uses river sand as aggregate, cement, fly ash and silica fume as cementitious materials, steel as a skeleton, and polyethylene (PVA) fiber as a bridging fiber inside the matrix. It is a new type of combined structure. Compared with ordinary concrete matrix, river sand with smaller particle size can better fill the matrix densely, and fly ash and silica fume replace part of cement not only to fill the gaps between particles but also to achieve green and environmental protection effects. Polyethylene (PVA) fiber can better control the development of cracks inside the matrix, and the matrix has higher ductility and seismic resistance.

[0031] 2. The assembled steel high-ductility concrete seismic short columns of the present invention are assembled into whole columns by bolts, which avoids the risk of damage during transportation and installation due to the large volume. At the same time, the steel is used as a connecting medium. During the installation process, it is only necessary to align the steel and insert it into the H-shaped groove of the short column base to be connected, insert the bolts, and tighten the bolts with pliers to complete the installation process. The process is simple and convenient.

[0032] In summary, the present invention adopts high-ductility concrete as the base material and splits the prefabricated whole column into prefabricated short columns, thereby improving the seismic resistance and avoiding the risk of damage during transportation and installation. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 This is the structural diagram of the prefabricated steel high-ductility concrete seismic short column.

[0034] Figure 2 This is the bottom cross-section of the prefabricated steel high-ductility concrete seismic short column.

[0035] In the figure, 1, base, 2, steel section, 3, steel section limiting screw hole, 4, concrete limiting screw hole, 5, H-shaped groove, 501, flange groove, 502, web groove, 6, waterproof layer. DETAILED DESCRIPTION

[0036] Combine the following Figure 1 and Figure 2 The present invention is described in further detail:

[0037] First, as Figure 1 As shown, an assembled steel-shaped high-ductility concrete seismic short column includes a base 1, a steel-shaped steel 2 is inserted and fixed on the top surface of the base 1, and steel-shaped limit screw holes 3 are respectively arranged on the flange and the web of the steel-shaped steel 2, an H-shaped groove 5 is arranged on the bottom surface of the base 1, and a concrete limit screw hole 4 is arranged on the side of the base 1 close to one end of the H-shaped groove 5, the steel-shaped steel 2 and the H-shaped groove 5 are matched in structure, and are used for the insert connection of two sections of concrete seismic short columns, the steel-shaped limit screw hole 3 and the concrete limit screw hole 4 are matched in position, and are used for the bolt connection of the concrete seismic short columns after the two sections are inserted and connected.

[0038] In actual installation, one section of concrete seismic short column is connected by inserting the steel section 2 into the H-shaped groove 5 of another section of concrete seismic short column. By utilizing the matching characteristics of the steel section limiting screw holes 3 and the concrete limiting screw holes 4 between the two sections of concrete seismic short columns after the insertion connection is completed, screws are further passed through the concrete limiting screw holes 4 and the steel section limiting screw holes 3 and tightened with nuts to complete the bolt connection between the two sections of concrete seismic short columns.

[0039] Furthermore, the matrix 1 includes cement, fly ash, silica ash, river sand, polyethylene (PVA) fiber, water reducer and water, wherein, by mass, cement: fly ash: silica ash: river sand: water = 1: (0.8-1.2): (0.4-0.8): (2.6-3.2): (0.5-1.0); based on the total volume of cement, fly ash, silica ash, river sand and water mixed evenly, the volume content of polyethylene (PVA) fiber is 0.5%-1.5%; the amount of water reducer added is 0.6%-1.0% of the total mass of cement, fly ash and silica ash; the matrix 1 is a rectangular parallelepiped with a length, width and height of 200-500mm, 200-500mm and 800-1500mm respectively; preferably, the length and width of the matrix 1 are 240mm and 240mm respectively.

[0040] Furthermore, the river sand in the matrix 1 has a particle size of 0.5-1.5 mm; the cement is any one of ordinary silicate cement, slag silicate cement or pozzolanic silicate cement; the fly ash is grade I fly ash; the silica ash has a loss on ignition of more than 3%, a silicon dioxide content of more than 80%, and a specific surface area of ​​15000m 2 / kg or more; PVA fiber length is more than 6mm, diameter is more than 30μm, tensile strength is more than 1500MPa, and elastic modulus is more than 30GPa.

[0041] Furthermore, the length ratio of the exposed part of the steel section 2 and the part inserted into the base 1 is 1:8, the steel section 2 is made of any one of Q235 steel, Q345 steel, Q390 steel or Q420 steel, the length of the steel section 2 is 900-1690mm, the width of the flange and web of the steel section 2 is 100-120mm, and the thickness of the flange and web of the steel section 2 is 6-8mm and 8-10mm respectively.

[0042] Furthermore, the radius of the steel limit screw hole 3 is 5-10mm, the flange of the steel section 2 and the steel limit screw hole 3 on the web are staggered, and the steel limit screw hole 3 is set to a circle; the number and position of the concrete limit screw hole 4 correspond to the steel limit screw hole 3, the radius of the concrete limit screw hole 4 is 5-10mm, and the concrete limit screw hole 4 is set to a circle.

[0043] Furthermore, the depth of the H-shaped groove 5 matches the length of the portion of the profile steel 2 inserted into the base 1. Figure 2 As shown, the H-shaped groove 5 includes a flange groove 501 and a web groove 502. To ensure that the steel section 2 can be normally inserted into the H-shaped groove 5, the width and thickness of the flange groove 501 and the web groove 502 are respectively increased by 5-10 mm than the width and thickness of the flange and web of the steel section 2.

[0044] Furthermore, the concrete seismic short column also includes a waterproof layer 6 applied to the outer surface of the substrate 1, and the waterproof layer 6 includes cement, river sand, a waterproofing agent, a filler and water, wherein, by mass, cement: river sand: waterproofing agent: filler: water = 1: (0.8-1.2): (0.05-0.1): (0.4-0.8): (0.5-0.7); the filler in the waterproof layer 6 is composed of one or more of expanded perlite, polystyrene particles, barite powder or mineral powder in any proportion; the cement in the waterproof layer 6 is any one of ordinary Portland cement, slag Portland cement or pozzolanic Portland cement, and the river sand particle size in the waterproof layer 6 is 0.5-1.5 mm.

[0045] In the second aspect, a method for preparing an assembled steel high-ductility concrete seismic short column:

[0046] S1. Making concrete earthquake-resistant short column mold:

[0047] First, a base 1 mold is made, and then a concrete limiting screw hole 4 is opened on the side of one end of the base 1 mold, and a pipe with a radius of 8-15mm is pre-buried in the base 1 mold according to the position of the concrete limiting screw hole 4. Finally, an H-shaped groove 5 is opened at the other end of the base 1 mold, and the steel 2 provided with the steel limiting screw hole 3 is inserted into the base 1 mold along the H-shaped groove 5 while maintaining the length ratio between the exposed part of the steel 2 and the part inserted into the base 1, so as to obtain a concrete seismic short column mold;

[0048] S2. Preparation of cement mortar:

[0049] First, cement, fly ash and silica fume are mixed and dry-mixed for 1-3 minutes to form a dry mixture; then river sand is added to the dry mixture and dry-mixed for 1-3 minutes to form a dry mortar; then the mixture of water reducer and water is slowly added to the dry mortar and stirred for 2-4 minutes to form a wet mixture; finally, PVA fibers are dispersed and sprinkled into the wet mixture and stirred for 2-4 minutes to form a cement mortar;

[0050] S3, molding:

[0051] The cement mortar in step S2 is placed in the concrete seismic short column mold obtained in step S1, vibrated and compacted, and left for 24-36 hours to prepare a semi-finished concrete seismic short column;

[0052] S4, curing and demoulding:

[0053] The semi-finished concrete seismic short column in step S3 is naturally cured, demoulded after 24-36 hours, and then cured for 60-65 days according to the standard curing method. After ensuring that the matrix strength is qualified and the pre-buried pipes are correctly positioned, the pre-buried pipes are removed to obtain the concrete seismic short column.

[0054] Furthermore, the method for preparing the concrete seismic short column, based on the concrete seismic short column prepared in step S4, further includes the following processing steps:

[0055] M1. Making waterproof coating:

[0056] First, dry mix the cement for 1-3 minutes, add river sand and filler to the dry-mixed cement, and dry mix for 1-3 minutes to form a waterproof layer dry mix; then add the waterproofing agent to the waterproof layer dry mix and stir for 2-5 minutes to ensure uniform dispersion, and slowly add all the water during the stirring process to form a waterproof layer wet mix; finally, stir the waterproof layer wet mix for 2-4 minutes to form a waterproof layer coating;

[0057] M2. Apply waterproof layer:

[0058] After cleaning the surface of the concrete seismic short column described in step S4, start applying the waterproof layer coating described in step M1. Use a brush to evenly apply the waterproof layer coating to the surface of the concrete seismic short column. When applying, pay attention to evenly applying the edges and corners of the specimen. After the first layer of waterproof layer coating is applied, wait 4-12 hours, and then repeat the operation to complete the application of the second and third layers of waterproof layer coating. The thickness of the first, second and third waterproof layers are all 2mm-5mm, and an assembled steel section high-ductility concrete seismic short column is prepared.

[0059] Example 1

[0060] The dimensions of the length×width×height of the assembled steel high-ductility concrete seismic short column matrix 1 in this embodiment 1 are 240 mm×240 mm×800 mm; the matrix 1 comprises cement, fly ash, silica fume, river sand, PVA fiber, water reducer and water, wherein, by mass, cement: fly ash: silica fume: river sand: water=1:0.8:0.4:3.2:0.9; based on the total volume of cement, fly ash, silica fume, sand and water mixed evenly, PVA fiber, water reducer and water are used as the base. The volume content of A fiber is 0.5%; the amount of water reducer added is 0.6% of the total amount of cement, fly ash and silica fume; the cement in matrix 1 is volcanic ash silicate cement, the PVA fiber is Toray's T-300PVA fiber, the water reducer is Bayset series water reducer of Bayer Building Materials, and the river sand particle size is 1.5mm; the fly ash is Class I fly ash; the ignition loss of silica fume is 3%, the silicon dioxide content is 80%, and the specific surface area is 15000m 2 / kg; the PVA fiber length is 6mm, the diameter is 30μm, the tensile strength is 1500MPa, and the elastic modulus is 30GPa.

[0061] The steel section 2 is made of Q235 steel, the thickness of the flange and web of the steel section 2 are 6mm and 8mm respectively, the width of the flange and web of the steel section 2 are 100mm respectively, and the length of the steel section 2 is 900mm.

[0062] The steel limiting screw hole 3 is arranged on the surface of the steel, and the steel limiting screw hole 3 is arranged in a circle with a radius of 5 mm.

[0063] The concrete limiting screw hole 4 is arranged on the side surface of the steel high-ductility concrete seismic short column close to one end of the H-shaped groove 5, and the concrete limiting screw hole 4 is arranged in a circle with a radius of 5 mm.

[0064] The H-shaped groove 5 is arranged on the bottom surface of the steel high-ductility concrete seismic short column. To ensure that the connecting steel 2 can enter normally, the size of the H-shaped groove 5 is 5 mm larger than the width and thickness of the flange and web of the steel 2.

[0065] The waterproof layer 6 includes cement, river sand, waterproofing agent, filler and water, wherein, by mass, cement: river sand: waterproofing agent: filler: water = 1: 0.8: 0.05: 0.4: 0.7; the filler is expanded perlite; the cement is P.O42.5 silicate cement in ordinary silicate cement, the waterproofing agent is BASF's MasterSeal series products, and the river sand particle size is 1.5 mm.

[0066] The method for preparing the concrete seismic short column involved in Example 1 is as follows:

[0067] S1. Making concrete earthquake-resistant short column mold:

[0068] First, a base 1 mold with a length×width×height size of 240mm×240mm×800mm is made, and then a concrete limiting screw hole 4 is opened on the side of one end of the base 1 mold, and a pipe with a radius of 8mm is pre-buried in the base 1 mold according to the position of the concrete limiting screw hole 4, and finally an H-shaped groove 5 is opened at the other end of the base 1 mold, and the steel 2 provided with the steel limiting screw hole 3 is inserted into the base 1 mold along the H-shaped groove 5 while maintaining the length ratio between the exposed part of the steel 2 and the part inserted into the base 1, so as to obtain a concrete seismic short column mold;

[0069] S2. Preparation of cement mortar:

[0070] First, cement, fly ash and silica fume are mixed and dry-mixed for 2 minutes to form a dry mixture; then river sand is added to the dry mixture and dry-mixed for 2 minutes to form a dry mortar; then the mixture of water reducer and water is slowly added to the dry mortar and stirred for 2 minutes to form a wet mixture; finally, PVA fibers are dispersed in the wet mixture and stirred for 3 minutes to form a cement mortar;

[0071] S3, molding:

[0072] The cement mortar in step S2 is placed in the concrete seismic short column mold obtained in step S1, vibrated and compacted, and left for 24 hours to prepare a semi-finished concrete seismic short column;

[0073] S4, curing and demoulding:

[0074] The semi-finished concrete seismic short column in step S3 is naturally cured, demoulded after 24 hours, and then cured for 65 days according to the standard curing method. After ensuring that the strength of the matrix is ​​qualified and the position of the embedded pipes is correct, the embedded pipes are removed to obtain the concrete seismic short column.

[0075] The method for preparing an assembled steel-type high-ductility concrete seismic short column including a waterproof layer is based on the concrete seismic short column obtained in step S4, and further comprises the following steps:

[0076] M1. Making waterproof coating:

[0077] First, dry mix the cement for 2 minutes, add river sand and filler to the dry-mixed cement, and dry mix for 2 minutes to form a waterproof layer dry mix; then add the waterproofing agent to the waterproof layer dry mix and stir for 3 minutes to ensure uniform dispersion, and slowly add all the water during the stirring process to form a waterproof layer wet mix; finally, stir the waterproof layer wet mix for another 3 minutes to form a waterproof layer coating;

[0078] M2. Apply waterproof layer:

[0079] After cleaning the surface of the concrete seismic short column described in step S4, start applying the waterproof layer coating described in step M1. Use a brush to evenly apply the waterproof layer coating to the surface of the concrete seismic short column specimen. When applying, pay attention to evenly apply the coating on the corners of the specimen. After the first layer of waterproof layer coating is applied, wait for 12 hours, and then repeat the operation to complete the application of the second and third layers of waterproof layer coating. The thickness of the first, second and third waterproof layers is 2 mm, and an assembled steel high-ductility concrete seismic short column is prepared.

[0080] After connecting two 240mm×240mm×800mm prefabricated steel high-ductility concrete seismic short columns (i.e., test blocks made by test molds) of Example 1, static load tests and dynamic tests were carried out. The specific results of the tests are shown in Table 1.

[0081] Table 1 Test results of seismic short columns of prefabricated steel high ductility concrete in Example 1

[0082]

[0083] It can be seen from Table 1 that the average compressive strength of the assembled steel high-ductility concrete seismic short column test block is 48MPa, the maximum displacement is 35mm, the elastic modulus is 35000MPa, the energy consumption ratio is 0.1, and the failure mode is ductile failure. The assembled steel high-ductility concrete seismic short column of the present invention can make the prepared short column have excellent seismic performance by combining reasonable materials and a specific preparation method.

[0084] Example 2

[0085] The length×width×height cross-sectional dimensions of the assembled steel high-ductility concrete seismic short column base 1 in this embodiment 2 are 240 mm×240 mm×900 mm. Except for the following parameters, the other parameters are consistent with those in embodiment 1:

[0086] Calculated by mass, the cement: fly ash: silica fume: river sand: water in matrix 1 is 1:0.9:0.5:3.1:0.8; based on the total volume of cement, fly ash, silica fume, sand and water mixed evenly, the volume content of PVA fiber is 0.7%; the amount of water reducer added is 0.8% of the total amount of cement, fly ash and silica fume; cement uses slag silicate cement; and the particle size of river sand is 1.2 mm.

[0087] The steel section 2 is made of Q345 steel, and the length of the steel section 2 is 1012.5 mm.

[0088] Calculated by mass, the cement: river sand: waterproofing agent: filler: water in the waterproof layer 6 is 1:0.7:0.05:0.4:0.6; the filler is polystyrene particles, and the river sand particle size is 1.2 mm.

[0089] In the method for preparing concrete seismic short columns involved in this embodiment 2, except that the relevant parameters of the base 1, the steel 2 and the waterproof layer 6 are consistent with those of the concrete seismic short columns in embodiment 2, the remaining steps are the same as the corresponding steps in embodiment 1.

[0090] After connecting two 240mm×240mm×900mm prefabricated steel high-ductility concrete seismic short columns (i.e., test blocks made by the test mold) of Example 2, static load tests and dynamic tests were carried out. The specific results of the tests are shown in Table 2.

[0091] Table 2 Test results of seismic short columns of prefabricated steel high ductility concrete in Example 2

[0092]

[0093] It can be seen from Table 2 that the average compressive strength of the prefabricated steel high-ductility concrete seismic short column specimen is 54MPa, the maximum displacement is 30mm, the elastic modulus is 40000MPa, the energy consumption ratio is 0.09, and the failure mode is ductile failure.

[0094] Example 3

[0095] The length×width×height cross-sectional dimensions of the assembled steel high-ductility concrete seismic short column base 1 in this embodiment 3 are 240 mm×240 mm×1100 mm. Except for the following parameters, the other parameters are consistent with those in embodiment 1:

[0096] Calculated by mass, the cement: fly ash: silica fume: river sand: water in the matrix 1 is 1:1.0:0.6:2.9:0.7; based on the total volume of cement, fly ash, silica fume, sand and water mixed evenly, the volume content of PVA fiber is 1.0%; the amount of water reducer added is 0.9% of the total amount of cement, fly ash and silica fume; cement uses slag silicate cement; and the particle size of river sand is 1.2 mm.

[0097] The steel section 2 is made of Q390 steel, the thickness of the flange and web of the steel section 2 are 8 mm and 10 mm respectively, the width of the flange and web of the steel section 2 are both 120 mm, and the length of the steel section 2 is 1237.5 mm.

[0098] The radius of the steel limiting screw hole 3 is 10 mm, and the radius of the concrete limiting screw hole 4 is 10 mm.

[0099] The size of the H-shaped groove 5 is 10 mm larger than the width and thickness of the flange and web of the steel section 2.

[0100] Calculated by mass, the cement: river sand: waterproofing agent: filler: water in the waterproof layer 6 is 1:0.7:0.05:0.4:0.6; the filler is polystyrene particles, and the river sand particle size is 1.2 mm.

[0101] In the method for preparing concrete seismic short columns involved in this embodiment 3, except that the relevant parameters of the base 1, the steel 2 and the waterproof layer 6 are consistent with the concrete seismic short columns in embodiment 3, and the thickness of the first, second and third waterproof layers are all 4 mm, the remaining steps are the same as the corresponding steps in embodiment 1.

[0102] After connecting two 240mm×240mm×1100mm prefabricated steel high ductility concrete seismic short columns (i.e., test blocks made by test molds) of Example 3, static load tests and dynamic tests were carried out. The specific results of the tests are shown in Table 3.

[0103] Table 3 Test results of seismic short columns of prefabricated steel high ductility concrete in Example 3

[0104]

[0105] It can be seen from Table 3 that the average compressive strength of the prefabricated steel high-ductility concrete seismic short test block is 64MPa, the maximum displacement is 28mm, the elastic modulus is 50000kN / mm, the energy consumption ratio is 0.06, and the failure mode is ductile failure.

[0106] Example 4

[0107] The length×width×height cross-sectional dimensions of the assembled steel high-ductility concrete seismic short column base 1 in this embodiment 4 are 240 mm×240 mm×1500 mm. Except for the following parameters, the other parameters are consistent with those in embodiment 1:

[0108] Calculated by mass, the cement: fly ash: silica fume: river sand: water in matrix 1 is 1:1.1:0.7:2.7:0.6; based on the total volume of cement, fly ash, silica fume, sand and water mixed evenly, the volume content of PVA fiber is 1.5%; the amount of water reducer added is 1.0% of the total amount of cement, fly ash and silica fume; the cement used is P.O42.5 silicate cement among the silicate cement; the particle size of the river sand is 1.0 mm.

[0109] The steel section 2 is made of Q420 steel, the thickness of the flange and web of the steel section 2 are 8 mm and 10 mm respectively, the width of the flange and web of the steel section 2 are both 120 mm, and the length of the steel section 2 is 1687.5 mm.

[0110] The radius of the steel limiting screw hole 3 is 10 mm, and the radius of the concrete limiting screw hole 4 is 10 mm.

[0111] The size of the H-shaped groove 5 is 10 mm larger than the width and thickness of the flange and web of the steel section 2.

[0112] Calculated by mass, the cement: river sand: waterproofing agent: filler: water in the waterproof layer 6 is 1:0.7:0.05:0.4:0.6; the filler is polystyrene particles, and the river sand particle size is 1.0 mm.

[0113] In the method for preparing concrete seismic short columns involved in this embodiment 4, except that the relevant parameters of the base 1, the steel 2 and the waterproof layer 6 are consistent with those of the concrete seismic short columns in embodiment 4, and the thickness of the first, second and third waterproof layers are all 4 mm, the remaining steps are the same as the corresponding steps in embodiment 1.

[0114] After connecting two 240mm×240mm×1500mm prefabricated steel high-ductility concrete seismic short columns of Example 4 (i.e., test blocks made by test molds), static load tests and dynamic tests were carried out. The specific results of the tests are shown in Table 4.

[0115] Table 4 Test results of seismic short columns of prefabricated steel high ductility concrete in Example 4

[0116]

[0117] It can be seen from Table 4 that the average compressive strength of the prefabricated steel high-ductility concrete seismic short column specimen is 78MPa, the maximum displacement is 28mm, the elastic modulus is 50000kN / mm, the energy consumption ratio is 0.05, and the failure mode is ductile failure.

[0118] The working principle of the present invention is as follows: in the present invention, during the installation of the assembled steel high-ductility concrete seismic short column, two short columns are connected by the steel, and the steel limiting screw hole coincides with the position of the concrete limiting screw hole at the bottom of the base. When the two short columns are connected, high-strength bolts are used to pass through the concrete limiting screw hole and the steel limiting screw hole for fixing. This connection method greatly improves the stability of the connection node; the ability of the prefabricated column to maintain good integrity is a prerequisite for the seismic performance. Since the present invention adopts the two short column plug-in connection method, the vibrations of the two short columns can be kept synchronized during the earthquake to ensure their integrity; the assembled steel high-ductility concrete seismic short column adopts an ECC matrix and a steel skeleton with high ductility. When an earthquake occurs, the column undergoes plastic deformation to absorb and dissipate seismic energy, so that when an earthquake occurs, the column can undergo plastic deformation without sudden destruction, thereby absorbing and dissipating seismic energy and achieving a higher seismic resistance level; in addition, the detachable assembled short column is also more convenient during transportation and installation, which enhances the flexibility of construction.

Claims

1. An assembled steel high-ductility concrete seismic short column, comprising a base (1), characterized in that: A steel section (2) is inserted and fixed on the top surface of the base (1); the flange and web of the steel section (2) are respectively provided with steel section limit screw holes (3); an H-shaped groove (5) is provided on the bottom surface of the base (1); a concrete steel section limit screw hole (4) is provided on the side surface of the base (1) close to one end of the H-shaped groove (5); the steel section (2) and the H-shaped groove (5) are matched in structure and are used for the insertion connection of two sections of concrete seismic short columns; the steel section limit screw hole (3) and the concrete steel section limit screw hole (4) are matched in position and are used for the bolt connection of the two sections of concrete seismic short columns after the insertion connection.

2. The concrete seismic short column according to claim 1, characterized in that: The matrix (1) comprises cement, fly ash, silica fume, river sand, polyethylene (PVA) fiber, water reducer and water, wherein, by mass, cement: fly ash: silica fume: river sand: water = 1: (0.8-1.2): (0.4-0.8): (2.6-3.2): (0.5-1.0); based on the total volume of cement, fly ash, silica fume, river sand and water mixed evenly, the volume content of polyethylene (PVA) fiber is 0.5%-1.5%; the amount of water reducer added is 0.6%-1.0% of the total mass of cement, fly ash and silica fume; the matrix (1) is a rectangular parallelepiped with a length, width and height of 200-500 mm, 200-500 mm and 800-1500 mm respectively; preferably, the length and width of the matrix (1) are 240 mm and 240 mm respectively.

3. The concrete seismic short column according to claim 1, characterized in that: The particle size of the river sand in the matrix (1) is 0.5-1.5 mm; the cement is any one of ordinary silicate cement, slag silicate cement or pozzolanic silicate cement.

4. The concrete seismic short column according to claim 1, characterized in that: The length ratio of the exposed part of the steel section (2) and the part inserted into the base (1) is 1:

8. The steel section (2) is made of any one of Q235 steel, Q345 steel, Q390 steel or Q420 steel. The length of the steel section (2) is 900-1690 mm. The widths of the flange and web of the steel section (2) are both 100-120 mm. The thicknesses of the flange and web of the steel section (2) are 6-8 mm and 8-10 mm respectively.

5. The concrete seismic short column according to claim 1, characterized in that: The radius of the steel limiting screw hole (3) is 5-10 mm; the number and position of the concrete steel limiting screw hole (4) correspond to the steel limiting screw hole (3), and the radius of the concrete steel limiting screw hole (4) is 5-10 mm.

6. The concrete seismic short column according to claim 1, characterized in that: The depth of the H-shaped groove (5) matches the length of the portion of the section steel (2) inserted into the base (1). The H-shaped groove (5) comprises a flange groove (501) and a web groove (502). The width and thickness of the flange groove (501) and the web groove (502) are 5-10 mm greater than the width and thickness of the flange and web of the section steel (2).

7. The concrete seismic short column according to claim 1, characterized in that: The invention also comprises a waterproof layer (6) applied to the outer surface of the substrate (1), wherein the waterproof layer (6) comprises cement, river sand, a waterproofing agent, a filler and water, wherein, by weight, cement: river sand: waterproofing agent: filler: water = 1: (0.8-1.2): (0.05-0.1): (0.4-0.8): (0.5-0.7); the filler in the waterproof layer (6) is composed of one or more of expanded perlite, polystyrene particles, barite powder or mineral powder in any proportion; the cement in the waterproof layer (6) is any one of ordinary silicate cement, slag silicate cement or pozzolanic silicate cement, and the river sand in the waterproof layer (6) has a particle size of 0.5-1.5 mm.

8. A method for preparing a concrete seismic short column according to any one of claims 1 to 6, characterized in that: The following steps are involved: S1. Making concrete earthquake-resistant short column mold: First, a base (1) mold is manufactured, and then a concrete steel limiting screw hole (4) is opened on the side of one end of the base (1) mold, and a pipe with a radius of 8-15 mm is pre-buried in the base (1) mold according to the position of the concrete steel limiting screw hole (4), and finally an H-shaped groove (5) is opened at the other end of the base (1) mold, and a steel (2) provided with the steel limiting screw hole (3) is inserted into the base (1) mold along the H-shaped groove (5) while maintaining the length ratio between the exposed part of the steel (2) and the part inserted into the base (1), so as to manufacture a concrete earthquake-resistant short column mold; S2. Preparation of cement mortar: First, cement, fly ash and silica fume are mixed and dry-mixed for 1-3 minutes to form a dry mixture; then river sand is added to the dry mixture and dry-mixed for 1-3 minutes to form a dry mortar; then the mixture of water reducer and water is slowly added to the dry mortar and stirred for 2-4 minutes to form a wet mixture; finally, polyethylene (PVA) fibers are dispersed and sprinkled into the wet mixture and stirred for 2-4 minutes to form a cement mortar; S3, molding: The cement mortar in step S2 is placed in the concrete seismic short column mold obtained in step S1, vibrated and compacted, and left for 24-36 hours to prepare a semi-finished concrete seismic short column; S4, curing and demoulding: The semi-finished concrete seismic short column in step S3 is naturally cured, demoulded after 24-36 hours, and then cured for 60-65 days according to standard curing methods. After ensuring that the strength of the matrix is ​​qualified (and the position of the embedded pipes is correct), the embedded pipes are removed to obtain the concrete seismic short column.

9. The method for preparing a concrete seismic short column according to claim 8, characterized in that: The concrete seismic short column prepared in step S4 further includes the following processing steps: M1. Making waterproof coating: First, dry-mix the cement for 1-3 minutes, add river sand and filler to the dry-mixed cement, and dry-mix for 1-3 minutes to form a waterproof layer dry mix; then add the waterproofing agent to the waterproof layer dry mix and stir for 2-5 minutes, and slowly add all the water during the stirring process to form a waterproof layer wet mix; finally, stir the waterproof layer wet mix for 2-4 minutes to form a waterproof layer coating; M2. Apply waterproof layer: After cleaning the surface of the concrete seismic short column described in step S4, start applying the waterproof layer coating described in step M1, and use a brush to evenly apply the waterproof layer coating to the surface of the concrete seismic short column. After the first layer of waterproof layer coating is applied, wait for 4-12 hours, and then repeat the operation to complete the application of the second and third layers of waterproof layer coating. The thickness of the first, second and third waterproof layers are all 2mm-5mm.

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