Reinforcement method and reinforcement structure for uneven joints on the exterior facade of a concrete frame structure

Abstract

The present invention discloses a reinforcement method for the uneven facade joints of a concrete frame structure and a reinforcement structure corresponding to the reinforcement method. The reinforcement method comprises the following steps: S1: A main channel is chiseled on the concrete protective layer in the joint core area, where the joint core area is the area where the beam and the column intersect; S2: Holes are chiseled on the surrounding beams; S3: A UHPC precast slab is installed on the surrounding beams, and an extension channel preset on the UHPC precast slab cooperates with the main channel to form a channel, and a through hole preset on the UHPC precast slab corresponds to the hole and cooperates to form a hole channel; S4: A fiber composite strip is installed in the channel; S5: An anchor is installed, the implanting limb of the anchor is inserted into the hole channel, and the overlapping limb of the anchor is installed in the channel. The reinforcement method and the reinforcement structure provided by the present invention solve the problem that the seismic reinforcement methods and structures in the prior art have low practicability when used for the case of unequal widths of beams and columns at the uneven facade joints.

Description

Technical Field

[0001] The present invention belongs to the field of concrete reinforcement engineering in civil engineering, and particularly relates to a reinforcement method and a reinforcement structure for uneven external wall nodes of a concrete frame structure. Background Art

[0002] Reinforced concrete (RC) frame structure is one of the most common building structural forms in industrial and civil buildings. Among them, the joints play a role in distributing internal forces, coordinating member deformations, and maintaining the integrity of the structure. Under seismic action, the core areas of RC frame joints are prone to shear failure, and the external wall joints are more likely to occur. Moreover, many existing buildings do not meet the current seismic design codes and have deficiencies in seismic performance, and urgent reinforcement and improvement are needed.

[0003] Regarding the seismic reinforcement of RC frame joints, many scholars have conducted a lot of research, proposed many reinforcement methods, and achieved good seismic reinforcement effects in practical engineering applications. Currently, the main methods for seismic reinforcement of RC frame joints include increasing the cross-section of concrete, steel jacket, and externally bonded fiber composite materials, etc. However, considering the characteristics of unequal widths of beam and column at the uneven external wall joints, the applicability and practical application value of the above reinforcement methods have certain deficiencies to a certain extent. Summary of the Invention

[0004] The purpose of the present invention is to provide a reinforcement method and a reinforcement structure for uneven external wall nodes of a concrete frame structure, so as to solve the problem of low practicability of the existing concrete frame joint seismic reinforcement methods and reinforcement structures when used for beam-column with unequal widths at uneven external wall joints.

[0005] The technical solution of the present invention is as follows:

[0006] A reinforcement method for uneven external wall nodes of a concrete frame structure, comprising the following steps:

[0007] S1: Chisel a main channel on the concrete protective layer of the joint core area;

[0008] S2: Chisel holes on the surrounding beams;

[0009] S3: Install the UHPC precast slab on the surrounding beams, and a preset extension channel on the UHPC precast slab cooperates with the main channel to form a channel, and a preset through hole on the UHPC precast slab corresponds to the hole and cooperates to form a hole channel;

[0010] S4: Install the fiber composite strip in the channel;

[0011] S5: Install the anchor, insert the implanting limb of the anchor into the hole channel, and install the lapping limb of the anchor in the channel.

[0012] A reinforcement method for an uneven joint on the outer facade of a concrete frame structure provided by an embodiment of the present invention, the size of the fiber composite strip is determined according to the size of the joint to be reinforced:

[0013] The length of the fiber composite strip matches the length of the channel;

[0014] The cross-section of the fiber composite strip is selected as a rectangle, the width of the rectangle is 16 - 20 mm, and the thickness is 4 - 6 mm. When the thickness of a single fiber composite strip does not meet the requirement, multiple fiber composite strips are laminated and bonded with structural adhesive to reach the required total thickness.

[0015] A reinforcement method for an uneven joint on the outer facade of a concrete frame structure provided by an embodiment of the present invention, the manufacturing steps of the UHPC precast slab are as follows:

[0016] A1: Determine the shape and size of the UHPC precast slab according to the size of the joint to be reinforced;

[0017] A2: Reserve the size and position of the extension channel and the through hole according to the size of the joint to be reinforced, the position and size of the main channel;

[0018] A3: Manufacture the corresponding mold, and place foam bodies with corresponding sizes at the extension channel and the through hole;

[0019] A4: Pour the evenly stirred UHPC material until it is formed;

[0020] The method for determining the shape and size of the UHPC precast slab is as follows:

[0021] The length of the extension channel is taken as the effective height of the beam section of the surrounding beam where it is located, and the through hole is a circular hole with a diameter of 8 mm;

[0022] The UHPC precast slab is selected as a rectangular slab, the length is 50 mm larger than the length of the extension channel, the height is taken as the beam section height of the corresponding surrounding beam, and the thickness is taken as the distance between the outer facade of the corresponding surrounding beam and the outer facade of the column.

[0023] The UHPC precast slab provided by an embodiment of the present invention is prepared by uniformly stirring cement, silica fume, quartz sand, quartz powder, water, water reducer and steel fiber; the material mix ratio of the UHPC precast slab is that for every 1 kg of cement, 0.2 - 0.22 kg of silica fume, 0.18 - 0.22 kg of quartz powder and 1.5% water reducer are incorporated, wherein the sand - binder ratio is 1.0 - 1.2, the water - binder ratio is 0.18 - 0.22, and the volume fraction of steel fiber is 2%.

[0024] A reinforcement method for an uneven node on the facade of a concrete frame structure provided by an embodiment of the present invention. The anchor includes a fiber cloth and the steel bar, and the length of the fiber cloth is greater than the length of the steel bar;

[0025] The manufacturing process of the anchor is as follows: first apply structural adhesive on the fiber cloth, then wrap the steel bar with a diameter of 6 mm, and then squeeze the unwrapped part into a sheet shape; among them, the part wrapping the steel bar is used as the implanted limb, and the unwrapped part is used as the lapping limb.

[0026] A reinforcement method for an uneven node on the facade of a concrete frame structure provided by an embodiment of the present invention. The size of the anchor is determined according to the size of the node to be reinforced and the thickness of the UHPC precast slab:

[0027] The width of the fiber cloth is taken as 40 mm;

[0028] The length of the lapping limb is taken as half of the length of the extension channel;

[0029] The length of the implanted limb is taken as the sum of the thickness of the UHPC precast slab and half of the beam section width of the corresponding peripheral beam.

[0030] A reinforcement method for an uneven node on the facade of a concrete frame structure provided by an embodiment of the present invention. In S1, according to the size and reinforcement condition of the node to be reinforced, determine the position and size of the main channel:

[0031] The position of the main channel is determined as follows: a main channel is drilled along the beam axis, and the remaining main channels are arranged parallel to the beam height, and the center distance between adjacent main channels is taken as 80 - 100 mm;

[0032] The size of the main channel is determined as follows: the length of the main channel is taken as the cross-sectional height of the column at its corresponding position, the depth is taken as 1.5 times the width of the fiber composite board strip, and the width is taken as the larger value between twice the thickness of the fiber composite board strip and the sum of the single thickness and 6 mm.

[0033] A reinforcement method for an uneven node on the facade of a concrete frame structure provided by an embodiment of the present invention. In S2, according to the hole size and position on the UHPC precast slab, drill holes at the corresponding positions on the peripheral beam,

[0034] The holes are circular holes with a diameter of 8 mm, and the depth of the holes is taken as half of the beam section width of the corresponding peripheral beam;

[0035] In S3, clean the concrete surface of the peripheral beam in the area for installing the UHPC precast slab, brush and apply epoxy resin structural adhesive, and firmly paste the UHPC precast slab to the peripheral beam.

[0036] In a reinforcement method for an uneven node on the outer facade of a concrete frame structure provided by an embodiment of the present invention, in the step S4, the fiber composite strip is centrally installed in the channel, with its width in the same direction as the depth of the channel, and structural adhesive is poured for bonding.

[0037] In a reinforcement method for an uneven node on the outer facade of a concrete frame structure provided by an embodiment of the present invention, in the step S5, the implanted limb is implanted into the hole through structural adhesive, and the overlapping limb is adhesively overlapped with the fiber composite strip.

[0038] A reinforcement structure for an uneven node on the outer facade of a concrete frame structure, where the outer facade of the column protrudes beyond the surrounding beams. The reinforcement structure includes:

[0039] A plurality of main channels, which are opened in the node core area;

[0040] UHPC precast slabs, which are installed on the surrounding beams and have a first surface, a second surface opposite to the first surface, and a contact surface located between the first surface and the second surface. The first surface is connected to the outer facade of the surrounding beam, the second surface is in the same plane as the node core area, and the contact surface is in contact with the side surface of the column where the outer facade protrudes beyond the surrounding beam; a plurality of extension channels are provided on the second surface, and the extension channels correspond to the main channels one by one and cooperate to form channels;

[0041] A plurality of fiber composite strips, which correspond to the channels one by one, and the fiber composite strips are installed in the corresponding channels;

[0042] A plurality of anchor fittings, which are used to anchor the connection between the UHPC precast slab and the surrounding beam.

[0043] In the reinforcement structure for an uneven node on the outer facade of a concrete frame structure provided by an embodiment of the present invention, each channel is parallel to the beam axis of the surrounding beam, and the center distance between adjacent channels is 80 - 100 mm.

[0044] In the reinforcement structure for an uneven node on the outer facade of a concrete frame structure provided by an embodiment of the present invention, the depth of the channel is 1.4 - 1.6 times the width of the fiber composite strip, and the width of the channel is the larger of twice the thickness of the fiber composite strip plus the single thickness plus 6 mm.

[0045] In the reinforcement structure for an uneven node on the outer facade of a concrete frame structure provided by an embodiment of the present invention, the length of the extension channel is equal to the effective height of the beam section of the corresponding surrounding beam, and the length of the UHPC precast slab in the length direction of the extension channel is 50 mm larger than the length of the extension channel.

[0046] For the reinforcement structure of the uneven facade joints of the concrete frame structure provided by an embodiment of the present invention, the length of the fiber composite strip is equal to the length of the corresponding channel, and the width of the fiber composite strip ranges from 16 to 20 mm, and the thickness ranges from 4 to 6 mm.

[0047] For the reinforcement structure of the uneven facade joints of the concrete frame structure provided by an embodiment of the present invention, the extension channel has a first end communicating with the corresponding main channel and a second end opposite to the first end. A through hole communicating the first surface and the second surface is provided at the second end of the extension channel, and holes are also correspondingly provided on the peripheral beam at the corresponding position of the through hole. The through hole and the corresponding hole cooperate to form a hole channel; the hole channels correspond to the anchor bolts one by one;

[0048] The anchor bolt includes a fiber cloth strip and a steel bar. The fiber cloth strip is a strip formed by wrapping a steel bar with fiber cloth and rolling and flattening it. The length of the steel bar is less than the length of the fiber cloth strip, and the diameter of the steel bar is 6 mm;

[0049] The part of the fiber cloth strip wrapped with the steel bar is the implanted limb, and the part not wrapped with the steel bar is the lapping limb. The lapping limb is located in the corresponding channel and is connected to the fiber composite strip located in the channel. The implanted limb is inserted into the corresponding hole channel; the length of the lapping limb is half of the length of the extension channel; the length of the implanted limb is the sum of the thickness of the UHPC precast slab and 0.5 times the cross-sectional width of the corresponding peripheral beam.

[0050] Due to the adoption of the above technical solutions, the present invention has the following advantages and positive effects compared with the prior art:

[0051] (1) The present invention is directed to the uneven facade joints of the concrete frame structure. By pasting UHPC precast slabs at the beam ends, the facades of the beams and columns are made flush, and the fiber composite strips are embedded in the channels by combining the embedding method technology. The embedded fiber composite strips improve the shear strength of the joint core area. The UHPC precast slabs and the fiber composite strips embedded therein improve the flexural performance of the beam ends, realizing the outward movement of the plastic hinge and enhancing the seismic performance of the joints. Compared with externally bonded fiber composite materials and steel plates, it has stronger applicability, safety and durability, and the construction is convenient. It can be applied to various uneven facade joints by controlling the thickness of the UHPC precast slab, and is also applicable to the reinforcement of the joints with flush facades of the concrete frame structure. Therefore, the problem of low practicability of the existing concrete frame joint seismic reinforcement methods and structures when used for the case of unequal widths of beams and columns at uneven facade joints is solved.

[0052] (2) In an embodiment of the present invention, the fiber composite strip is effectively anchored and constrained by the anchor, which can effectively improve the seismic performance of the joint, inhibit the peeling phenomenon in the later stage of loading on the side protective layer at the beam end, and also has an anchoring effect on the UHPC precast slab; compared with mechanical anchoring and U-shaped rigid anchoring, it has better durability and economy, and a wider application range. Description of the Drawings

[0053] The following further details the specific embodiments of the present invention in conjunction with the drawings, where:

[0054] Figure 1 It is a schematic diagram of the reinforcement structure of the cross-shaped joint in the out-of-plane uneven joint of the concrete frame structure of the present invention;

[0055] Figure 2 It is a schematic diagram of the structure of a fiber composite strip of the present invention;

[0056] Figure 3 It is a schematic diagram of the structure of the UHPC precast slab from the front view of the present invention;

[0057] Figure 4 It is a schematic diagram of the structure of the UHPC precast slab from the reverse view of the present invention;

[0058] Figure 5 It is a schematic diagram of the structure of the anchor when the steel bar is not wrapped with fiber cloth in the present invention;

[0059] Figure 6 It is a schematic diagram of the structure of an anchor of the present invention;

[0060] Figure 7 It is a schematic diagram of the joint at step S1 of the present invention;

[0061] Figure 8 It is a schematic diagram of the joint at step S2 of the present invention;

[0062] Figure 9 It is a schematic diagram of the joint at step S3 of the present invention;

[0063] Figure 10 It is a schematic diagram of the joint at step S4 of the present invention;

[0064] Figure 11 It is a schematic diagram of the cross-section of the surrounding beam at step S4 of the present invention;

[0065] Figure 12 It is a schematic diagram of the reinforcement structure of the T-shaped joint in the out-of-plane uneven joint of the concrete frame structure of the present invention.

[0066] Description of the Reference Numerals:

[0067] 1: Fiber composite slats; 2: UHPC precast slab; 21: Extension channel; 22: Through hole; 3: Anchor; 31: Fiber cloth; 32: Steel bar; 4: Column; 41: Main channel; 5: Peripheral beam; 51: Hole. Detailed implementation mode

[0068] The following further elaborates in detail on a reinforcement method and a reinforcement structure for an uneven node on the outer facade of a concrete frame structure proposed by the present invention in conjunction with the accompanying drawings and specific embodiments. According to the following description and the claims, the advantages and features of the present invention will be clearer. It should be noted that the accompanying drawings are all in a very simplified form and use non-precise ratios, only for the purpose of conveniently and clearly assisting in explaining the objectives of the embodiments of the present invention.

[0069] At the same time, expressions such as "first" and "second" are only used for the purpose of distinguishing multiple configurations, rather than restricting the order between configurations or other features.

[0070] In addition, the expression of "including" an element is an "open-ended" expression, and this "open-ended" expression only means that there is a corresponding component, and should not be construed as excluding additional components.

[0071] Refer to Figures 1 to 12 , this embodiment provides a reinforcement structure for an uneven node on the outer facade of a concrete frame structure. The outer facade of column 4 protrudes from the peripheral beam 5. The reinforcement structure includes a plurality of main channels 41, UHPC precast slabs 2, a plurality of fiber composite slats 1, and a plurality of anchors 3. The main channels 41 are opened in the joint core area. The UHPC precast slab 2 is installed on the peripheral beam 5, having a first surface, a second surface opposite to the first surface, and a contact surface between the first surface and the second surface. The first surface is connected to the outer facade of the peripheral beam 5, the second surface is in the same plane as the joint core area, and the contact surface and the outer facade of column 4 protrude from the side surface of the peripheral beam 5 and are attached. A plurality of extension channels 21 are provided on the second surface, and the extension channels 21 correspond to the main channels 41 one by one and cooperate to form channels. The fiber composite slats 1 correspond to the channels one by one, and the fiber composite slats 1 are installed in the corresponding channels. The anchor 3 is used to anchor the connection between the UHPC precast slab 2 and the peripheral beam 5.

[0072] This embodiment focuses on the uneven joints on the outer facade of a concrete frame structure. By pasting a UHPC precast slab 2 at the beam end, the outer facades of the beam and column 4 are made flush. Combining with the embedding method technology, the fiber composite strip 1 is embedded into the channel. The embedded fiber composite strip 1 improves the shear strength of the joint core area. The UHPC precast slab 2 and the fiber composite strip 1 embedded therein improve the flexural performance of the beam end, realizing the outward displacement of the plastic hinge and enhancing the seismic performance of the joint. Compared with externally bonded fiber composite materials and steel plates, it has stronger applicability, safety and durability, and the construction is convenient. It can be applied to various uneven joints on the outer facade by controlling the thickness of the UHPC precast slab 2, and is also applicable to the reinforcement of joints with flush outer facades in a concrete frame structure. Therefore, it solves the problem of low practicability of the existing seismic reinforcement structure for concrete frame joints when used in the case of unequal widths of beams and columns 4 with uneven outer facades.

[0073] Now, the structure, manufacturing and installation methods of this embodiment will be described. There is a sequence in the installation process, but there is no sequence in manufacturing each component. As long as the manufacturing of the component is completed when it is used in the installation process. For the convenience of understanding the following text, the following explanations are made: The joint core area is the area where the beam and column 4 intersect, and the beam is the surrounding beam 5; there is a main channel 41 on the outer facade of the column 4, and an extended channel 21 is provided on the UHPC precast slab 2. The main channel 41 and the corresponding extended channel 21 cooperate to form a channel; there is a through hole 22 on the UHPC precast slab 2, and a hole 51 is formed on the surrounding beam 5. The through hole 22 and the corresponding hole 51 cooperate to form a hole channel.

[0074] In this embodiment, the anchor 3 has an implanting limb and a lapping limb. The lapping limb is connected to the fiber composite strip 1, and the implanting limb passes through the UHPC precast slab 2 and then extends into the surrounding beam 5 for anchoring. Of course, in other embodiments, other types of anchors 3 can also be used, and the type of the anchor 3 is not limited.

[0075] The reinforcement method corresponding to the reinforcement structure of the uneven joints on the outer facade of the concrete frame structure provided by this embodiment includes the following steps:

[0076] S1: Cut a main channel 41 on the concrete protective layer in the joint core area;

[0077] S2: Cut a hole 51 on the surrounding beam 5;

[0078] S3: Install the UHPC precast slab 2 on the surrounding beam 5, and the preset extended channel 21 on the UHPC precast slab 2 cooperates with the main channel 41 to form a channel. The preset through hole 22 on the UHPC precast slab 2 corresponds to the hole 51 and cooperates to form a hole channel;

[0079] S4: Install the fiber composite strip 1 in the channel;

[0080] S5: Install the anchor fitting 3, insert the implanting limb of the anchor fitting 3 into the hole, and install the lapping limb of the anchor fitting 3 in the slot.

[0081] The specific process is as follows:

[0082] In S1, according to the size and reinforcement condition of the node to be strengthened, determine the position and size of the main slot 41: Cut a main slot 41 along the beam axis, and the remaining main slots 41 are arranged in parallel along the beam height. The center distance between adjacent main slots 41 is taken as 80 - 100 mm. The length of the main slot 41 is taken as the cross-sectional height of the column 4 at its corresponding position, the depth is taken as 1.4 - 1.6 times the width of the fiber composite strip 1, and the width is taken as the larger value between twice the thickness of the fiber composite strip 1 and the single thickness plus 6 mm. Preferably, the depth of the main slot 41 can be taken as 1.5 times the width of the fiber composite strip 1.

[0083] The method of cutting the main slot 41 is as follows: First, determine the slot position manually, then use relevant tools such as a cutting machine to cut a slot on the surface of the node core area, and roughen the inside of the slot so that the concrete can fully bite with the structural adhesive.

[0084] Clean the slot: First, use an air pump to remove all the crushed stones and floating ash, then use clean water to repeatedly wash the inner wall of the slot, especially the uneven parts of the inner wall, and completely remove the floating ash until the water dries up.

[0085] In S2, according to the size and position of the holes 51 on the UHPC precast slab 2, drill holes at the corresponding positions on the surrounding beam 5. The holes 51 are circular holes with a diameter of 8 mm, and the depth of the holes 51 is taken as 1 / 2 of the beam cross-sectional width of the corresponding surrounding beam 5, and then it can be cleaned with an air pump.

[0086] In S3, clean the concrete surface of the surrounding beam 5 in the area for installing the UHPC precast slab 2, and brush the epoxy resin structural adhesive to firmly paste the UHPC precast slab 2 to the surrounding beam 5.

[0087] In S4, center the fiber composite strip 1 and install it in the slot. Its length is in the same direction as the length of the slot, and its width is in the same direction as the slot depth of the slot. Then pour the structural adhesive until the entire slot is filled, and use a spatula to wipe off the excess adhesive.

[0088] In S5, implant the implanting limb into the hole 51 through the structural adhesive, paste and lap the lapping limb with the fiber composite strip 1 to effectively anchor and restrain the UHPC precast slab 2 and the fiber composite strip 1.

[0089] The reinforcement method for the uneven node on the outer facade of the concrete frame structure provided in this embodiment is also applicable to the reinforcement of the nodes with a flat outer facade of the concrete frame structure. It only needs to paste and cover the node core area with the UHPC precast slab 2 as well.

[0090] The manufacturing methods of the fiber composite strip 1, the UHPC precast slab 2, and the anchor 3 can be as follows:

[0091] (1) Manufacturing the fiber composite strip 1:

[0092] In this embodiment, the fiber composite strip 1 is preferably made of carbon fiber composite strip (CFRP). However, in other embodiments, the fiber composite strip 1 can also be made of other fiber materials, such as glass fiber, basalt fiber, or aramid fiber, etc., but the requirements for strength, workability, durability, etc. must be ensured.

[0093] The size of the fiber composite strip 1 can be determined according to the size of the node to be strengthened: the length of the fiber composite strip 1 matches the length of the groove, and the length of the groove is equal to the length of the main groove 41 plus the length of the extended groove 21. The node in this embodiment is a cross-shaped node, but it is also applicable to other nodes with uneven outer facades (such as T-shaped nodes), and there is no limitation on this. Therefore, the length of the fiber composite material board along the beam axis also has two cases:

[0094] ① When the node is a cross-shaped node, as Figure 1 shown, the UHPC precast slabs 2 are respectively installed on the peripheral beams 5 on both sides of the column 4. So at this time, the reinforcement structure includes two UHPC precast slabs 2. The length of the fiber composite material board along the beam axis is the length of the main groove 41 (i.e., the width of the core area of the cross-shaped node) plus the lengths of the extended grooves 21 on the two UHPC precast slabs 2. ② When the node is a T-shaped node, as Figure 12 shown, the peripheral beam 5 is located on one side of the column 4. So at this time, the reinforcement structure includes one UHPC precast slab 2. The length of the fiber composite material board along the beam axis is the length of the main groove 41 (i.e., the width of the core area of the T-shaped node) plus the length of the extended groove 21 on one UHPC precast slab 2. Among them, the length of the extended groove 21 on the UHPC precast slab 2 is taken as the effective height of the beam section of the peripheral beam 5 where it is located.

[0095] The cross-section of the fiber composite strip 1 is selected as a rectangle. The width of the rectangle is 16 - 20 mm, and the thickness is 4 - 6 mm. When the thickness of a single fiber composite strip 1 does not meet the requirement, multiple fiber composite strips 1 are laminated and bonded with structural adhesive to reach the required total thickness.

[0096] When multiple fiber composite strips are needed to reach the required thickness, thin strips of corresponding lengths are cut according to the size of the required fiber composite strip 1, and the thin strips are bonded with structural adhesive to make the fiber composite material strip with the required thickness.

[0097] (2) Manufacturing the UHPC precast slab 2:

[0098] Preferably, in this embodiment, the UHPC precast slab 2 is prepared by uniformly mixing cement, silica fume, quartz sand, quartz powder, water, water reducer and steel fibers. The material mix ratio is that for every 1 kg of cement, 0.2 - 0.22 kg of silica fume, 0.18 - 0.22 kg of quartz powder and 1.5% water reducer are incorporated. Among them, the sand-to-binder ratio is 1.0 - 1.2, the water-to-binder ratio is 0.18 - 0.22, and the volume fraction of steel fibers is 2%. However, the materials for making the UHPC precast slab 2 are not limited to the above materials and mix ratios, as long as the requirements such as strength, workability during construction, and durability are ensured, and no restrictions are imposed here.

[0099] The determination methods for the dimensions and positions of the extension channels 21 and through holes 22 on the UHPC precast slab 2 are as follows: The length of the extension channel 21 is taken as the effective height of the beam cross-section of the surrounding beam 5 where it is located (i.e., the length of the fiber composite strip 1 located in the extension channel 21). A through hole 22 is provided at the end point of the extension channel 21 far from the column 4. The through hole 22 is a circular hole with a diameter of 8 mm that communicates the first surface and the second surface of the UHPC precast slab 2.

[0100] The determination methods for the shape and dimensions of the UHPC precast slab 2 are as follows: The length of the UHPC precast slab 2 is taken as the effective height of the beam cross-section of the surrounding beam 5 where it is located (i.e., the length of the fiber composite strip 1 in the extension channel 21) plus 50 mm; the height is taken as the beam cross-section height; the thickness is taken as the distance between the outer surfaces of the corresponding surrounding beam 5 and the column 4, ensuring that after the UHPC precast slab 2 is installed, the outer surfaces of the beam and the column 4 are flush.

[0101] The manufacturing steps of the UHPC precast slab 2 are as follows:

[0102] A1: Determine the shape and dimensions of the UHPC precast slab 2 according to the dimensions of the node to be strengthened;

[0103] A2: Reserve the dimensions and positions of the extension channels 21 and through holes 22 according to the dimensions of the node to be strengthened, the position and dimensions of the main channel 41;

[0104] A3: Manufacture the corresponding molds and place foam bodies with corresponding dimensions at the extension channels 21 and through holes 22;

[0105] A4: Pour the uniformly mixed UHPC material until it is formed.

[0106] (3) Manufacture the anchor fixture 3

[0107] The anchor fixture 3 is mainly made of fiber cloth 31, steel bars 32 and structural adhesive. Among them, the length of the fiber cloth 31 is greater than that of the steel bars 32. The fiber cloth 31 used preferably selects carbon fiber cloth 31 (CFRP), but in other embodiments, other fiber materials such as glass fiber, basalt fiber or aramid fiber can also be used, as long as the requirements such as strength, workability during construction, and durability are ensured, and no restrictions are imposed here.

[0108] The manufacturing method of the anchor 3 is as follows: First, apply structural adhesive on the fiber cloth 31, then wrap the steel bar 32 with a diameter of 6 mm, and then extrude the unwrapped part into a sheet. The part wrapped with the steel bar 32 serves as the implanted limb of the anchor 3, and the unwrapped part serves as the lapping limb.

[0109] The size of the anchor 3 is determined according to the size of the node to be strengthened and the thickness of the UHPC precast slab 2: The length of the lapping limb is taken as half of the length of the corresponding extended channel 21, and the length of the implanted limb is taken as the sum of the thickness of the UHPC precast slab 2 and half of the beam cross-section width of the corresponding peripheral beam 5. Among them, the length of the steel bar 32 is taken as the length of the implanted limb; the length of the fiber cloth 31 is taken as the sum of the lengths of the implanted limb and the lapping limb of the anchor 3, and the width of the fiber cloth 31 is taken as 40 mm.

[0110] The manufacturing method, shape of the anchor 3, and the connection method with the peripheral beam 5, UHPC precast slab 2, and fiber composite strip 1 enable: The anchor 3 effectively anchors and restrains the fiber composite strip 1, can effectively improve the seismic performance of the node, inhibit the peeling phenomenon in the later stage of loading on the side protective layer of the beam end, and at the same time also has an anchoring effect on the UHPC precast slab 2; compared with mechanical anchoring and U-shaped rigid anchoring, it has better durability and economy, and a wider application range.

[0111] To better illustrate and understand the reinforcement structure and reinforcement method of the concrete frame structure facade non-aligned node provided in this embodiment, a specific size and manufacturing and installation process of a reinforcement structure are given below for detailed description. It should be understood that the specific size and manufacturing and installation process of this reinforcement structure are only for illustration and not for limiting the protection scope of the present invention.

[0112] Taking a cross-shaped node on the facade of a certain frame as an example:

[0113] Node size: The cross-sectional size of the peripheral beam 5 is 300×500 mm, the cross-sectional size of the column 4 is 400×400 mm, and the beam and column 4 are centered. Then, the facades of the beam and column 4 are not aligned, with a difference of 50 mm.

[0114] Node seismic performance: This node has the problem of "weak node and strong component" (such as insufficient stirrup configuration in the core area), does not meet the requirements of the current seismic design code, and has insufficient seismic performance.

[0115] Reinforcement plan:

[0116] As Figure 2 described, according to the size and reinforcement configuration of the node to be strengthened, it is determined that 3 fiber composite strips 1 are required, and their sizes need to be: 1300 mm in length, 16 mm in width, 6 mm in thickness, and a cross-sectional area of 96 mm 2The thickness of the single fiber composite strip 1 used is 2 mm and the width is 16 mm. Therefore, three single fiber composite strips 1 are adhesively bonded to form the required fiber composite strip 1. The fiber composite strip 1 is a carbon fiber composite strip 1.

[0117] As Figure 7 described, according to the number of strips, it is required to cut three main channels 41 along the beam axis direction in the joint core area. The main channel 41 is 24 mm deep and 12 mm wide. Cut a channel along the beam axis, and the remaining channels are arranged in parallel. The spacing of the center lines of the channels along the beam height direction is 100 mm. Use relevant tools such as a cutting machine to cut the channels, roughen the inner walls of the channels, and clean them up.

[0118] As Figure 3 and Figure 4 described, according to the size of the member to be strengthened and the reinforcement distribution, the UHPC precast slab 2 used is a rectangular slab with dimensions of 500×500×50 mm. In addition, according to the size and position of the main channel 41, three extension channels 21 should be reserved for each UHPC precast slab 2. The extension channels 21 are 450 mm long, 24 mm deep, and 12 mm wide, and the channel spacing is 100 mm; the diameter of the through holes 22 reserved on the UHPC precast slab 2 is 8 mm, which are located at the endpoints of the extension channels 21 far from the column 4. Make the corresponding templates, place the 450×24×12 mm cube foam and the 8 mm diameter cylindrical foam in the designated positions, and pour the evenly stirred UHPC material until it is formed.

[0119] As Figure 8 and Figure 9 described, at the corresponding position of the beam end and the through hole 22 on the UHPC precast slab 2, drill a hole 51 with the same cross-sectional size as the through hole 22 and a depth of 150 mm, and use an air pump to clean the floating slag. After a 28-day curing period, take out the UHPC precast slab 2, remove the foam in the extension channels 21 and the through holes 22, and clean the concrete surface where the UHPC precast slab 2 is to be installed to make it flat and dust-free, brush the epoxy resin structural adhesive, and paste the UHPC precast slab 2.

[0120] As Figure 10 described, first inject 2 / 3 of the required volume of the structural colloid into the channel, then insert the fiber composite strip into the center of the channel (the width of the strip is along the depth direction of the channel), and finally fill up the structural adhesive.

[0121] As Figure 5 and Figure 6As described above, according to the size and reinforcement configuration of the node to be strengthened, 6 anchor members 3 are required for the cruciform node. The fiber cloth 31 is a rectangular cloth with dimensions of 425×40 mm, and the steel bars 32 are plain round steel bars with a diameter of 6 mm and a length of 200 mm. Structural adhesive is brushed on the surface of the fiber cloth 31, and the steel bars 32 are placed along the length direction of the fiber cloth 31 at one end of the fiber cloth 31, and then the fiber cloth 31 is rolled along the width direction to wrap the steel bars 32; then, the part of the fiber cloth 31 that does not wrap the steel bars 32 is extruded into a sheet shape to make the fiber cloth 31 fully bonded and overlapped with each other, and thus the anchor member 3 can be obtained, with a lapping limb of 225 mm and an implanting limb of 200 mm.

[0122] As Figure 1 and Figure 11 As described above, structural adhesive is brushed on the surface of the area where the fiber composite strip 1 is used to lap with the lapping limb, and at the same time, the hole is filled with structural adhesive. Then, the implanting limb of the anchor member 3 is implanted into the hole 51, the lapping limb is adhesively lapped with the fiber composite strip 1, and the overflowing structural adhesive in the hole is wiped off with a spatula.

[0123] The embodiments of the present invention have been described in detail above in conjunction with the accompanying drawings, but the present invention is not limited to the above embodiments. Even if various changes are made to the present invention, provided that these changes fall within the scope of the claims of the present invention and their equivalent technologies, they still fall within the protection scope of the present invention.

Claims

1. A reinforcement method for the uneven joint of the outer facade of a concrete frame structure, characterized in that, It includes the following steps: S1: Cut the main channel on the concrete protective layer of the node core area; S2: Cut holes on the surrounding beams; S3: Install the UHPC precast slab on the surrounding beams, and preset an extension channel on the UHPC precast slab to cooperate with the main channel to form a channel. The through holes preset on the UHPC precast slab correspond to the holes and cooperate to form a pore channel; S4: Install fiber composite strips in the channel; S5: Install the anchor, insert the implanting limb of the anchor into the pore channel, and install the lapping limb of the anchor in the channel and lap with the fiber composite strip; Wherein, the anchor includes a fiber cloth and a steel bar, and the length of the fiber cloth is greater than the length of the steel bar; The manufacturing process of the anchor is as follows: First, apply structural adhesive on the fiber cloth, then wrap the steel bar with a diameter of 6 mm, and then squeeze the unwrapped part into a sheet shape; wherein, the part wrapping the steel bar serves as the implanting limb, and the unwrapped part serves as the lapping limb.

2. The reinforcement method for the uneven joint of the outer facade of the concrete frame structure according to claim 1, characterized in that, The size of the fiber composite strip is determined according to the size of the node to be strengthened: The length of the fiber composite strip matches the length of the channel; The cross-section of the fiber composite strip is selected as a rectangle, the width of the rectangle is 16 - 20 mm, and the thickness is 4 - 6 mm. When the thickness of a single fiber composite strip does not meet the requirement, multiple fiber composite strips are pasted and laminated with structural adhesive to reach the required total thickness.

3. The reinforcement method for the uneven node on the outer facade of the concrete frame structure according to claim 1, characterized in that The manufacturing steps of the UHPC precast slab are as follows: A1: Determine the shape and size of the UHPC precast slab according to the size of the node to be strengthened; A2: Reserve the size and position of the extension channel and the through hole according to the size of the node to be strengthened, the position and size of the main channel; A3: Make the corresponding mold, and place foam bodies with corresponding sizes at the extension channel and the through hole; A4: Pour the evenly stirred UHPC material until it is formed; The determination method of the shape and size of the UHPC precast slab is as follows: The length of the extension channel takes the effective height of the beam section of the surrounding beam where it is located, and the through hole is a circular hole with a diameter of 8 mm; The UHPC precast slab is selected as a rectangular slab, the length is 50 mm larger than the length of the extension channel, the height takes the beam section height of the corresponding surrounding beam, and the thickness takes the distance between the outer facade of the corresponding surrounding beam and the outer facade of the column.

4. The reinforcement method for the uneven node on the facade of the concrete frame structure according to claim 1, wherein, The UHPC precast slab is made by uniformly stirring cement, silica fume, quartz sand, quartz powder, water, water reducing agent and steel fiber; the material mixing ratio of the UHPC precast slab is that 0.2 - 0.22 kg of silica fume, 0.18 - 0.22 kg of quartz powder and 1.5% water reducing agent are incorporated per 1 kg of cement, wherein the sand - binder ratio is 1.0 - 1.2, the water - binder ratio is 0.18 - 0.22, and the volume fraction of steel fiber is 2%.

5. The reinforcement method for the uneven node on the outer facade of the concrete frame structure according to claim 1, characterized in that, The size of the anchor is determined according to the size of the node to be strengthened and the thickness of the UHPC precast slab: The width of the fiber cloth is taken as 40 mm; The length of the lapping limb takes half of the length of the extension channel The length of the implanted limb is the sum of the thickness of the UHPC precast slab and half of the beam cross-sectional width of the corresponding peripheral beam.

6. The reinforcement method for the uneven joint on the outer facade of the concrete frame structure according to claim 1, characterized in that, In the step S1, according to the size and reinforcement conditions of the node to be strengthened, determine the position and size of the main channels: The method for determining the position of the main channels is as follows: a main channel is excavated along the beam axis, and the remaining main channels are arranged parallel to the beam height, and the center distance between adjacent main channels is 80-100 mm; The method for determining the size of the main channels is as follows: the length of the main channel is the cross-sectional height of the column at its corresponding position, the depth is 1.5 times the width of the fiber composite strip, and the width is the larger of twice the thickness of the fiber composite strip and the single thickness plus 6 mm.

7. The reinforcement method for the uneven node on the outer facade of a concrete frame structure according to claim 1, characterized in that In the step S2, according to the hole size and position on the UHPC precast slab, drill holes at the corresponding positions on the peripheral beam, The holes are circular holes with a diameter of 8 mm, and the depth of the holes is half of the beam cross-sectional width of the corresponding peripheral beam; In the step S3, clean the concrete surface of the peripheral beam in the area for installing the UHPC precast slab, and brush and apply epoxy resin structural adhesive to firmly paste the UHPC precast slab to the peripheral beam.

8. The reinforcement method for the uneven node on the facade of the concrete frame structure according to claim 1, characterized in that, In the step S4, center the fiber composite strip in the channel, with its width in the same direction as the depth of the channel, and pour structural adhesive for bonding.

9. The reinforcement method for the uneven node on the outer facade of the concrete frame structure according to claim 1, characterized in that, In the step S5, implant the implanted limb into the hole through the structural adhesive, and paste and lap the lapping limb with the fiber composite strip.

10. A reinforcement structure for an uneven joint on the outer facade of a concrete frame structure, characterized in that, The outer facade of the column protrudes from the peripheral beam, and the reinforcement structure includes: A number of main channels, which are opened in the node core area; A UHPC precast slab, which is installed on the peripheral beam, has a first surface, a second surface opposite to the first surface, and a contact surface between the first surface and the second surface. The first surface is connected to the outer facade of the peripheral beam, the second surface is in the same plane as the node core area, and the contact surface and the outer facade of the column protrude and fit with the side surface of the peripheral beam; a number of extension channels are provided on the second surface, and the extension channels correspond to the main channels one by one and cooperate to form channels; A number of fiber composite strips, which correspond to the channels one by one, and the fiber composite strips are installed in the corresponding channels; A number of anchor fittings, which are used to anchor the connection between the UHPC precast slab and the peripheral beam; Among them, the anchor fitting includes a fiber cloth strip and a steel bar. The fiber cloth strip is a strip formed by wrapping a steel bar with fiber cloth and rolling and flattening it. The length of the steel bar is less than the length of the fiber cloth strip, and the diameter of the steel bar is 6 mm; The part of the fiber cloth strip wrapped with the steel bar is the implanted limb, and the part not wrapped with the steel bar is the lapping limb. The lapping limb is located in the corresponding channel and is connected to the fiber composite strip located in the channel, and the implanted limb is inserted into the corresponding hole.

11. The reinforcement structure for the uneven joint on the facade of the concrete frame structure according to claim 10, characterized in that, Each of the said channels is parallel to the beam axis of the peripheral beam, and the center distance between adjacent channels is 80 - 100 mm.

12. The reinforcement structure for the uneven joint on the outer facade of the concrete frame structure according to claim 10, characterized in that, The depth of the channel is 1.4 - 1.6 times the width of the fiber composite strip, and the width of the channel is the larger value of twice the thickness and single thickness of the fiber composite strip plus 6 mm.

13. The reinforcement structure for the uneven node on the outer facade of the concrete frame structure according to claim 10 is characterized in that, The length of the extended channel is equal to the effective height of the beam cross-section of the corresponding peripheral beam, and the length of the UHPC precast slab in the length direction of the extended channel is 50 mm larger than the length of the extended channel.

14. The reinforcement structure of the uneven node on the outer facade of the concrete frame structure according to claim 10, characterized in that, The length of the fiber composite strip is equal to the length of the corresponding channel, and the width of the fiber composite strip ranges from 16 to 20 mm, and the thickness ranges from 4 to 6 mm.

Images