A semi-rigid connection precast concrete frame structure

Abstract

The present invention discloses a semi-rigid connection precast concrete frame structure, which has the following characteristics: precast concrete columns, precast concrete beams, precast concrete node core areas and post-cast concrete superimposed layers, wherein the upper precast concrete columns and the lower precast concrete columns are connected by screw connectors and high-strength screws, and no reinforcement is provided at the column ends; the precast concrete columns and precast concrete beams are connected by convex connectors and concave connectors, and no reinforcement is provided at the beam ends; UHPC grouting is used in the connector cavity, and the post-cast concrete superimposed layer is on the precast concrete beam. The present invention has convenient construction and controllable quality, can reduce on-site wet work, increase assembly rate, and has a high bearing capacity level. At the same time, it has obvious semi-rigid characteristics and greatly improves the deformation capacity of the nodes. The present invention is of great significance for improving the construction efficiency and engineering quality of precast concrete structures, and has broad application prospects in the field of construction engineering.

Description

Technical Field

[0001] The present invention relates to the technical field of civil engineering, and in particular to a semi-rigid connection precast concrete frame structure. Background Art

[0002] Precast concrete structures are fast to construct, have good quality, can save a lot of formwork and support, have significant energy-saving and emission-reduction characteristics, and are a structural type that meets the development needs of industrialized buildings. In precast concrete frame structures, there are a large number of joints between the precast components. The reliable connection of beam and column components is the key to ensuring that the precast concrete frame structure has good seismic performance. At present, the post-cast integral connection is the most commonly used precast concrete beam-column node connection form in China. The post-cast integral connection has a simple structure and good overall performance, and it is easy to achieve seismic performance equivalent to cast-in-place. However, the post-cast integral connection requires a large amount of on-site wet work, and reserved steel bars need to be set at the beam ends and column ends, and the problem of dense steel bars in the core area of ​​the node is prominent.

[0003] Compared with post-cast integral connections, prestressed connections, welded connections or bolted connections can significantly reduce on-site wet work, increase prefabrication rate and construction speed. In fact, these connections usually show obvious semi-rigid characteristics. Semi-rigidity combines the advantages of rigid connections and hinged connections. It can transmit part of the bending moment and has a certain rotation capacity. However, at present, although the PRESS system and prestressed assembled concrete frame system have good deformation capacity under earthquake action, their energy consumption capacity is poor, so they are less used. In addition, the longitudinal reinforcement in existing precast concrete columns is mostly connected by sleeve grouting. Although the technology is mature, the grouting quality is difficult to detect. For a few bolt connection forms, the bolt connectors are all constrained by dense stirrups, the operating space is small, and it is not easy to construct. Summary of the Invention

[0004] The present invention is made to solve the above problems, and its purpose is to provide a semi-rigid connection precast concrete frame structure.

[0005] The present invention provides a semi-rigid connection precast concrete frame structure having the following characteristics: comprising: precast concrete columns, precast concrete beams, precast concrete node core areas and post-cast concrete superimposed layers, wherein the upper precast concrete columns and the lower precast concrete columns are connected by screw connectors and high-strength screws, and no reinforcement is provided at the column ends; the precast concrete columns and the precast concrete beams are connected by convex connectors and concave connectors, and no reinforcement is provided at the beam ends.

[0006] The semi-rigid connection precast concrete frame structure provided by the present invention may also have the following features: a high-strength screw is embedded in the upper end of the lower precast concrete column, and a screw connector is provided at the lower end of the upper precast concrete column. The high-strength screw and the screw connector are connected, thereby connecting the upper and lower precast concrete columns.

[0007] The semi-rigid connection precast concrete frame structure provided by the present invention may also have the following features: wherein the high-strength screw is overlapped with the longitudinal reinforcement in the precast concrete column, the overlap length is not less than 50d, d is the diameter of the longitudinal reinforcement, and the overlap section is constrained by additional steel bars.

[0008] The semi-rigid connection precast concrete frame structure provided by the present invention may also have the following features: wherein the vertical rod of the screw connector overlaps the longitudinal reinforcement in the precast concrete column, the overlap length is not less than 50d, and the bottom overlap area is constrained by ultra-high performance concrete (UHPC), and the length of the constrained area is not less than 15d.

[0009] The semi-rigid connection precast concrete frame structure provided by the present invention may also have the following features: a male connector is provided at the upper end of the precast concrete column, and a female connector is provided at the left and right ends of the precast concrete beam, and the male connector is connected to the female connector, thereby connecting the precast concrete column and the precast concrete beam.

[0010] The semi-rigid connection precast concrete frame structure provided by the present invention may also have the following features: wherein, the lap lengths of the upper horizontal bars and the lower horizontal bars of the concave connector and the longitudinal reinforcement in the precast concrete beam are not less than 25d and 40d, respectively; the additional stirrups in the lap area are staggered with the stirrups in the precast concrete beam, with a spacing of less than 15cm; and UHPC is used for grouting in the cavity of the concave connector.

[0011] The semi-rigid connection precast concrete frame structure provided by the present invention may also have the following features: a convex connector is provided in the core area of ​​the precast concrete node, the anchorage length of the horizontal rod with the end in the convex connector is not less than 1 / 3 of the width of the core area of ​​the precast concrete node, the lap length of the vertical rod in the convex connector and the longitudinal reinforcement in the precast concrete column is not less than 50d, the lap area is constrained by additional steel bars, and the length and height of the exposed part of the convex end are not less than 1 / 4 and 1 / 2 of the height of the precast concrete beam, respectively.

[0012] Functions and effects of the invention

[0013] The semi-rigid connection precast concrete frame structure involved in the present invention includes: precast concrete columns, precast concrete beams, precast concrete node core areas and post-cast concrete superposition layers, wherein the upper precast concrete columns and the lower precast concrete columns are connected by screw connectors and high-strength screws, and no reinforcement is provided at the column ends; the precast concrete columns and precast concrete beams are connected by convex connectors and concave connectors, and no reinforcement is provided at the beam ends, and UHPC is used for restraint or grouting, which greatly improves the transportation and installation efficiency of precast components, and has important significance and role in promoting the process of construction industrialization in my country, promoting industrial structure adjustment, and achieving energy conservation and emission reduction.

[0014] In addition, the semi-rigid connection of the precast concrete frame structure of the present invention uses UHPC to constrain the column bottom, which improves the bearing capacity. The beams and columns transmit force through connectors, which greatly improves the deformation capacity of the nodes. It has obvious semi-rigid characteristics, and the energy consumption capacity is not significantly reduced, thereby effectively improving the overall seismic performance of the precast concrete frame structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 Schematic diagram of a two-story, two-span semi-rigidly connected precast concrete frame structure according to an embodiment of the present invention;

[0016] Figure 2 Schematic diagram of a beam-column node in an embodiment of the present invention;

[0017] Figure 3 is a schematic cross-sectional view of a precast concrete beam in an embodiment of the present invention;

[0018] Figure 4 is a schematic diagram of the bottom cross-section of a precast concrete column in an embodiment of the present invention;

[0019] Figure 5 Schematic diagram of a high-strength screw, a screw connector, a male connector, and a female connector in an embodiment of the present invention;

[0020] Figure 6 1 is a hysteresis curve of the semi-rigid connection precast concrete frame structure under a pseudo-static test in an embodiment of the present invention. DETAILED DESCRIPTION

[0021] In order to make the technical means, creative features, objectives and effects of the present invention easier to understand, the following embodiments and accompanying drawings specifically illustrate the semi-rigid connection precast concrete frame structure of the present invention.

[0022] This embodiment provides a semi-rigid connection precast concrete frame structure 100 .

[0023] Figure 1Schematic diagram of a semi-rigid connected precast concrete frame structure in an embodiment of the present invention.

[0024] like Figure 1 As shown, the two-span semi-rigid precast concrete frame includes multiple precast concrete columns 1, multiple precast concrete beams 2, multiple precast concrete joint cores 3, and a post-cast concrete overlay layer 4. The upper and lower precast concrete columns 1 are connected via screw connectors 6 and high-strength screws 5, with no reinforcement at the column ends. The precast concrete columns 1 and precast concrete beams 2 are connected via male connectors 7 and female connectors 8, with no reinforcement at the beam ends.

[0025] A high-strength screw 5 is embedded in the upper end of the precast concrete column 1, and a screw connector 6 is provided at the lower end of the upper precast concrete column 1. The high-strength screw 5 and the screw connector 6 are connected, thereby connecting the upper and lower precast concrete columns 1.

[0026] The upper end of the precast concrete column 1 is provided with a male connector 7, and the left and right ends of the precast concrete beam 2 are provided with female connectors 8. The male connector 7 is connected to the female connector 8, so that the precast concrete column 1 and the precast concrete beam 2 are connected.

[0027] Figure 2 Schematic diagram of a beam-column node in an embodiment of the present invention.

[0028] Figure 3 2 is a schematic cross-sectional view of a precast concrete beam in an embodiment of the present invention.

[0029] Figure 4 2 is a schematic diagram of the cross-section of the bottom of a precast concrete column in an embodiment of the present invention.

[0030] Figure 5 Schematic diagram of a high-strength screw, a screw connector, a male connector, and a female connector in an embodiment of the present invention.

[0031] like Figures 2 to 5 As shown, four high-strength screws 5 are embedded in the upper end of the lower precast concrete column 1. The embedded sections of the high-strength screws 5 are connected to the longitudinal reinforcement in the precast concrete column 1 by overlapping. The overlapping length is 50d, where d is the diameter of the longitudinal reinforcement. The overlapping section is constrained by additional reinforcement 10.

[0032] Four screw connectors 6 are provided at the lower end of the precast concrete column 1. The vertical rod 6a is connected to the longitudinal reinforcement in the precast concrete column 1 by overlap, and the overlap length is 50d. UHPC9 is used to replace the dense stirrups for constraint in the bottom overlap area. The length of the constraint area is 15d. UHPC has high tensile strength, high ductility, and contains organic fibers.

[0033] The upper horizontal rod 8a and the lower horizontal rod 8b of the concave connector 8 are overlapped and connected with the longitudinal reinforcement in the precast concrete beam 2, with overlap lengths of 25d and 40d respectively. The overlap area is constrained by additional stirrups 11. The additional stirrups 11 are staggered with the stirrups in the precast concrete beam 2 with a spacing of 10 cm. UHPC is used for grouting in the cavity of the concave connector.

[0034] The core area 3 of the precast concrete node is located at the upper part of the precast concrete column 1. The exposed end 7a of the convex connector 7 is 1 / 4 of the height of the precast concrete beam 2 and 1 / 2 of the height of the precast concrete beam 2. Two horizontal rods 7b with ends are anchored in the core area 3 of the precast concrete node, and the anchorage length is 1 / 3 of the width of the core area 3 of the precast concrete node. The two vertical rods 7c are overlapped and connected with the longitudinal reinforcement in the precast concrete column 1, and the overlap length is 50d. The overlap area is constrained by additional steel bars 10.

[0035] The beam in this embodiment is composed of a precast concrete beam 2 and a post-cast concrete laminated layer 4 .

[0036] The manufacturing process of the semi-rigid connection precast concrete frame structure 100 in this embodiment is as follows:

[0037] Step 1: First, precast concrete columns 1, precast concrete beams 2 and foundations are prefabricated in the factory, and each component is numbered and transported to the construction site after curing.

[0038] Step 2: Hoist the first layer of precast concrete columns 1 onto the foundation, form a preliminary connection with the high-strength screws 5 embedded in the foundation through the screw connector 6, straighten the precast concrete columns 1, tighten the high-strength bolts with a torque wrench, and use UHPC to cast the column bottom connection area.

[0039] Step 3: hoist the precast concrete beam 2 and set up temporary support. Hang the concave connector 8 set at the beam end directly on the convex connector 7 set at the core area 3 of the precast concrete node, and use UHPC to grout the cavity of the concave connector 8.

[0040] Step 4: After the beam-column connection is completed, the longitudinal reinforcement at the top of the beam is tied, the formwork is set, and the concrete superposition layer 4 is poured on site.

[0041] Step 5: After the concrete strength of the composite layer 4 reaches 50% of the design strength, the second-layer precast concrete columns 1 are hoisted and connected to the high-strength screws 5 embedded in the upper ends of the first-layer precast concrete columns 1 through the screw connectors 6 set at the bottom of the second-layer precast concrete columns 1. After the upper and lower columns are aligned, the high-strength bolts are tightened, and the column bottom connection area is cast using UHPC.

[0042] Step 6: Repeat steps 3 and 4 to complete the construction of this embodiment.

[0043] Figure 6 1 is a hysteresis curve of the semi-rigid connection precast concrete frame structure under a pseudo-static test in an embodiment of the present invention.

[0044] like Figure 6 As shown, pseudo-static tests were conducted on this embodiment under a high axial compression ratio. The results show that this embodiment implements a beam-column hybrid hinge failure mechanism, with a ductility coefficient of 6.1 and a relatively full hysteresis curve, indicating good energy dissipation capacity. Furthermore, this embodiment exhibits good relative rotational capacity between the beam and column, demonstrating certain semi-rigid characteristics.

[0045] Functions and Effects of the Embodiments

[0046] The semi-rigid connection precast concrete frame structure involved in this embodiment includes: precast concrete columns, precast concrete beams, precast concrete node core areas and post-cast concrete superposition layers. Among them, the upper precast concrete columns and the lower precast concrete columns are connected by screw connectors and high-strength screws, and no reinforcement is provided at the column ends. The precast concrete columns and precast concrete beams are connected by convex connectors and concave connectors, and no reinforcement is provided at the beam ends. UHPC is used for restraint or grouting, which greatly improves the transportation and installation efficiency of precast components. It has important significance and role in promoting the process of building industrialization in my country, promoting industrial structure adjustment, and achieving energy conservation and emission reduction.

[0047] In addition, the column bottoms of the semi-rigidly connected precast concrete frame structure of this embodiment are constrained by UHPC, which improves the bearing capacity. The beams and columns transmit force through connectors, which greatly improves the deformation capacity of the nodes. It has obvious semi-rigid characteristics, and the energy consumption capacity is not significantly reduced, thereby effectively improving the overall seismic performance of the precast concrete frame structure.

[0048] The above embodiments are preferred examples of the present invention and are not intended to limit the scope of protection of the present invention.

Claims

1. A semi-rigid connection precast concrete frame structure, characterized in that: include: Precast concrete columns, precast concrete beams, precast concrete node core areas and post-cast concrete superimposed layers, The upper precast concrete column and the lower precast concrete column are connected by screw connectors and high-strength screws, and no reinforcement is provided at the column ends. The vertical rod of the screw connector overlaps the longitudinal reinforcement in the precast concrete column, and the overlap length is not less than 50d. The bottom overlap area is restrained by ultra-high performance concrete, and the length of the restrained area is not less than 15d. The precast concrete column and the precast concrete beam are connected by a male connector and a female connector, and no reinforcement is provided at the beam end. The upper and lower horizontal bars of the concave connector overlap with the longitudinal bars in the precast concrete beam by a length of not less than 25d and 40d respectively, where d is the diameter of the longitudinal bar. The additional stirrups in the overlap area are staggered with the stirrups in the precast concrete beam, with a spacing of less than 15cm. The cavity of the concave connector is grouted with ultra-high performance concrete. The core area of ​​the precast concrete node is provided with a male connector, and the anchoring length of the horizontal rod with the end in the male connector is not less than 1 / 3 of the width of the core area of ​​the precast concrete node. The lap length between the vertical rod in the male connector and the longitudinal reinforcement in the precast concrete column shall not be less than 50d, and the lap area shall be restrained by additional steel bars. The length and height of the exposed part of the male end shall not be less than 1 / 4 and 1 / 2 of the height of the precast concrete beam respectively.

2. The semi-rigid connection precast concrete frame structure according to claim 1, characterized in that: in, The upper end of the lower precast concrete column is pre-embedded with a high-strength screw, and the lower end of the upper precast concrete column is provided with the screw connector. The high-strength screw and the screw connector are connected, so that the upper and lower precast concrete columns are connected.

3. The semi-rigid connection precast concrete frame structure according to claim 1, characterized in that: in, The high-strength screw is overlapped with the longitudinal reinforcement in the precast concrete column. The overlap length is not less than 50d, and the overlap section is restrained by additional steel bars.

4. The semi-rigid connection precast concrete frame structure according to claim 1, characterized in that: in, The upper end of the precast concrete column is provided with the male connector, and the left and right ends of the precast concrete beam are provided with the female connector. The male connector is connected to the female connector, thereby connecting the precast concrete column and the precast concrete beam.

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