High-strength concrete configuration method and concrete shear wall constrained by new stirrups

Abstract

The present invention relates to the technical field of civil engineering, and discloses a high-strength concrete configuration method and a concrete shear wall under novel stirrup constraints. Based on the mass of the shear wall specimen, the shear wall comprises the following weight ratio: P.II.52.5 cement 750-900 kg / m 3 , silica fume 200~250kg / m 3 , fly ash 180~230kg / m 3 , river sand 850~1000kg / m 3 , polyhydroxy acid water reducer 20~40kg / m 3 , water 142.5~216kg / m 3 , defoaming agent 0.15~0.25kg / m 3 , basalt fiber 7.5~10kg / m 3 . The combination of corrugated stirrups and rectangular stirrups in the shear wall structure of the present invention can improve the restraint effect on the concrete and longitudinal reinforcement in the shear wall. The present invention can effectively improve the strength of the final concrete by changing the mix ratio of concrete, thereby improving the overall strength of the shear wall using the concrete and effectively improving the compressive strength of the shear wall; in addition, the combination of corrugated stirrups and rectangular stirrups can effectively improve the restraint force on the concrete in the shear wall and ensure the safety of the shear wall.

Description

Technical Field

[0001] The invention relates to the technical field of civil engineering, and in particular to a high-strength concrete configuration method and a concrete shear wall constrained by novel stirrups. Background Art

[0002] The stirrups in traditional reinforced concrete shear walls are horizontal stirrups, that is, parallel to the two engineering axes, and are closed rectangular stirrups. In applications with large forces, this type of stirrup is insufficient to restrain the longitudinal reinforcement and concrete inside the shear wall, and is prone to brittle failure. In addition, studies have shown that the shear bearing capacity and ductility of steel plate concrete walls are higher than those of ordinary concrete walls.

[0003] Nowadays, shear wall structures are mainly used in high-rise and small-high-rise residential buildings. They have the advantages of high industrialization, controllable costs, and faster construction speed than cast-in-place shear walls. However, the current shear walls still have many shortcomings, such as: the bearing capacity and lateral stiffness are worse than cast-in-place shear wall structures, the connection is more complicated, the amount of work at the nodes is more, the construction efficiency is low, the construction accuracy is poor, etc. At the same time, prefabricated shear walls and special-shaped column components also have many defects in terms of structural force:

[0004] 1. The overall stiffness of shear walls and special-shaped columns is worse than that of cast-in-place structures, especially at the nodes where the upper and lower components are spliced, where the stiffness is prone to sudden changes, resulting in shear slip failure that is prone to occur at the location where the stiffness of the shear wall changes suddenly.

[0005] 2. When the axial pressure of the shear wall component is relatively large, the shear wall component may suffer from compression failure. At this time, the compressive steel bars are buckled and the concrete is crushed, eventually leading to structural failure.

[0006] 3. When the shear wall is low, under the action of horizontal force, diagonal cracks or cross-diagonal cracks appear on the wall, causing the concrete to be crushed and peel off in pieces, the stirrups to bulge out or break, and finally the component to suffer shear and diagonal compression failure. Summary of the invention

[0007] The technical problem to be solved by the first aspect of the present invention is to provide a high-strength concrete configuration method, which can improve the performance of concrete for casting walls, thereby improving the overall strength of the wall.

[0008] In order to solve the above technical problems, the first aspect of the present invention provides a high-strength concrete configuration method. Based on the mass of the shear wall specimen, the shear wall comprises the following weight ratio: P.II.52.5 cement 750-900 kg / m 3 , silica fume 200~250kg / m 3 , fly ash 180~230kg / m 3, river sand 850~1000kg / m 3 , polyhydroxy acid water reducer 20~40kg / m 3 , water 142.5~216kg / m 3 , defoaming agent 0.15~0.25kg / m 3 , basalt fiber 7.5~10kg / m 3 . .

[0009] Preferably, the shear wall specimen comprises the following weight ratio: P.II.52.5 cement 850kg / m 2 , silica fume 230kg / m 2 , fly ash 230kg / m 2 , river sand 930kg / m 2 , polyhydroxy acid water reducer 35kg / m 2 , water 160kg / m 2 , defoamer 0.2kg / m 2 , basalt fiber 8kg / m 2 .

[0010] Further preferably, the water-cement ratio of water to cement is 0.19-0.24.

[0011] Preferably, the configuration method comprises:

[0012] (1) Add cement, silica fume, fly ash and river sand into a mixing pot and mix;

[0013] (2) After the fusion is completed, add water, polyhydroxy acid water reducer and defoamer and stir to blend;

[0014] (3) After the mixture has initial fluidity after being stirred and integrated, basalt fiber is added and mixed until it is completely integrated, and then it is introduced into a mold for curing to obtain a concrete sample.

[0015] Further preferably, in step (1), the mixing and stirring is performed by dry mixing, the dry mixing and stirring time is at least 3 minutes, and the stirring speed is 60 to 70 rpm.

[0016] Preferably, in step (2), the mixing and stirring is wet mixing and stirring, the stirring time is 10 minutes, and the stirring speed is 60 to 70 rpm.

[0017] Further preferably, in step (3), the curing time is at least 28 days, the curing temperature is 20±2° C., and the humidity is 95%.

[0018] A second aspect of the present invention provides a shear wall, which includes concrete and a steel bar assembly, wherein the steel bar assembly is arranged in the concrete to form the shear wall, and the steel bar assembly includes steel bars, which are arranged along the length direction of the wall and are symmetrically arranged in a corrugated shape.

[0019] Preferably, the shear wall has a plurality of wall limbs, the plurality of wall limbs are perpendicular to each other to form special-shaped shear walls of various shapes, and the intersections between the plurality of wall limbs form an intersection area, the steel bar assembly extends out of the wall body and intersects in the intersection area to connect the plurality of wall limbs.

[0020] Further preferably, the steel bar assembly includes at least corrugated stirrups, which are symmetrically arranged in the length direction of the wall, and the bent portions of the corrugated stirrups intersect in the wall to form intersections, the corrugated stirrups on both sides of the intersections are parallel to each other to form straight portions of the corrugated stirrups, and a plurality of the intersections are tightly clamped by rectangular stirrups to form a stirrup structure in the shear wall.

[0021] Through the above technical scheme, the high-strength concrete configuration method of the present invention can effectively improve the strength of the final concrete by changing the concrete mix ratio, thereby improving the overall strength of the shear wall using the concrete and effectively improving the compressive strength of the shear wall.

[0022] Other features and advantages of the present invention will be described in detail in the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 A flowchart of a high-strength concrete configuration method according to a specific embodiment of the present invention;

[0024] Figure 2 A compressive strength diagram of each test block of the high-strength concrete configuration method according to a specific embodiment of the present invention;

[0025] Figure 3 It is a structural schematic diagram of a T-shaped shear wall of a concrete shear wall constrained by a novel stirrup according to a specific implementation mode of the present invention;

[0026] Figure 4 A schematic diagram of reinforcement arrangement of a T-shaped shear wall of a concrete shear wall constrained by a novel stirrup according to a specific embodiment of the present invention;

[0027] Figure 5 It is a structural schematic diagram of a ten-type shear wall of a concrete shear wall constrained by a novel stirrup according to a specific implementation mode of the present invention;

[0028] Figure 6A schematic diagram of reinforcement arrangement of a ten-type shear wall of a concrete shear wall constrained by a novel stirrup according to a specific embodiment of the present invention;

[0029] Figure 7 It is a structural schematic diagram of an L-shaped shear wall of a concrete shear wall constrained by a novel stirrup according to a specific implementation mode of the present invention;

[0030] Figure 8 It is a schematic diagram of reinforcement of an L-shaped shear wall of a concrete shear wall constrained by a novel stirrup according to a specific implementation manner of the present invention.

[0031] Reference numerals

[0032] 1 Intersection 2 Wall

[0033] 3 longitudinal reinforcement 4 corrugated stirrups

[0034] 5 Rectangular stirrups DETAILED DESCRIPTION

[0035] The specific implementation of the present invention is described in detail below in conjunction with the accompanying drawings. It should be understood that the specific implementation described here is only used to illustrate and explain the present invention, and is not used to limit the present invention.

[0036] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "setting", and "connection" should be understood in a broad sense. For example, the term "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0037] Reference Figure 1 to Figure 2 A high-strength concrete configuration method according to a specific embodiment of the present invention is based on the mass of the shear wall specimen, wherein the shear wall comprises the following weight proportions: P.II.52.5 cement 750-900 kg / m 3 , silica fume 200~250kg / m 3 , fly ash 180~230kg / m 3 , river sand 850~1000kg / m 3 , polyhydroxy acid water reducer 20~40kg / m 3 , water 142.5~216kg / m 3 , defoaming agent 0.15~0.25kg / m 3 , basalt fiber 7.5~10kg / m 3 .

[0038] Specifically, the shear wall specimen adopts the following weight ratio composition: P.II.52.5 cement 850kg / m 2 , silica fume 230kg / m 2 , fly ash 230kg / m 2 , river sand 930kg / m 2 , polyhydroxy acid water reducer 35kg / m 2 , water 160kg / m 2 , defoamer 0.2kg / m 2 , basalt fiber 8kg / m 2 .

[0039] Among them, the water-cement ratio of water to cement is 0.19-0.24.

[0040] In addition, the specific configuration method of the shear wall specimen synthesized by the above weight ratio is as follows:

[0041] (1) Add cement, silica fume, fly ash and river sand into a mixing pot and mix;

[0042] (2) After the fusion is completed, add water, polyhydroxy acid water reducer and defoamer and stir to blend;

[0043] (3) After the mixture has initial fluidity after being stirred and integrated, basalt fiber is added and mixed until it is completely integrated, and then it is introduced into a mold for curing to obtain a concrete sample.

[0044] In step (1), cement, silica fume, fly ash and river sand are first mixed by dry mixing, and then dry mixed for at least 3 minutes at a mixing speed of 60 to 70 rpm to ensure that the cement, silica fume, fly ash and river sand can be completely mixed and fused.

[0045] In step (2), the mixing and stirring is performed by wet mixing, the wet mixing and stirring time is 10 minutes, and the stirring speed is 60 to 70 rpm.

[0046] After the above materials are mixed, preferably, they need to be cured for at least 28 days to ensure that the final strength of the concrete sample reaches the highest, and the curing temperature is 20±2°C and the humidity is 95%. During the curing process, the compressive strength stress-strain curves of each sample within 28 days are shown in the following table:

[0047] Test block number Standard 7 days Standard 14 days Standard 28 days Test block 1 64.31MPa 84.52MPa 125.43MPa Test block 2 65.26MPa 85.63MPa 124.31MPa Test block 3 67.84MPa 86.04MPa 125.67MPa Test block 4 66.91MPa 87.92MPa 122.34MPa Test block 5 67.44MPa 84.88MPa 126.31MPa

[0048] Table 1 Changes in compressive strength of samples

[0049] It can be seen that when the sample is cured for 28 days or more, the compressive strength of the sample reaches the maximum value, exceeding 126.31MPa.

[0050] A new type of concrete shear wall under stirrup restraint of the present invention adopts the configuration method of the high-strength concrete of the present invention. The shear wall includes concrete and a steel bar assembly. The steel bar assembly is arranged in the concrete to form the shear wall. The steel bar assembly includes steel bars. The steel bars are arranged along the length direction of the wall 2, and the steel bars are arranged symmetrically in a corrugated shape. By combining the steel bars and the concrete of the configuration method, the compressive strength of the concrete shear wall finally formed is higher. Due to the basic properties of the steel bars, the steel bars are composed of high-performance fibers and matrix materials. The fibers are reinforcing materials and can play the role of stiffening ribs. The matrix can play the role of bonding and transmitting shear force. Due to its low density and light weight, its density is generally 1 / 6 to 1 / 4 of that of ordinary steel bars. Therefore, it is beneficial to reduce the deadweight of the structure and facilitate construction. In addition, since it also has the effects of corrosion resistance and fatigue resistance, the combination of steel bars and concrete with a new proportion can further improve the shear bearing capacity of the wall 2 and ensure the overall ductility.

[0051] Specifically, in the shear wall, a new stirrup method is also used. The shear wall has multiple wall limbs, and the new stirrup method is used in each of the multiple wall limbs. The multiple wall limbs are perpendicular to each other so as to form special-shaped shear walls of various shapes, and the intersections between the multiple wall limbs form an intersection area 1. A steel bar assembly extends from each wall limb and intersects in the intersection area 1 to connect the multiple wall limbs.

[0052] In addition, due to the large number of special-shaped shear walls of various shapes, only three commonly used shapes of shear wall structures are listed for discussion.

[0053] Reference Figure 3 to Figure 4 , various shapes of special-shaped shear walls include T-shaped shear walls. The T-shaped shear wall structure includes three walls 2, two of which are arranged horizontally and form the same row, and the other wall 2 is arranged perpendicular to the two walls 2 in the same row, and the vertically arranged wall 2 is located at the exact center of the two walls 2 in the same row, that is, the two walls 2 in the same row are symmetrically arranged with the vertically arranged wall 2 as the symmetry axis. The three walls 2 intersect to form an intersection area 1, and the three walls 2 have steel bar assemblies extending into the overlap area and intersecting in the overlap area, and after the multiple steel bar assemblies in the overlap area intersect, rectangular stirrups 5 are also used to tighten the intersecting steel bars in the intersection area 1 to ensure the strength of the final wall 2.

[0054] Reference Figures 5 and 6, the shear wall is configured as a ten-shaped shear wall structure, wherein the ten-shaped shear wall structure includes four walls 2, the four walls 2 are perpendicular to each other to form a ten-shape, and the four walls 2 together form an intersection area 1, and a plurality of steel bar assemblies are arranged in the four walls 2, and the plurality of steel bar assemblies also include corrugated stirrups 4, rectangular stirrups 5 and longitudinal bars 3, and the plurality of rectangular stirrups 5 arranged in the same wall 2 are arranged at equal intervals, and in the intersection area 1, the plurality of corrugated stirrups 4 arranged in the same column of walls 2 all extend into the same intersection area 1 and intersect in the intersection area 1, and the connection nodes of the intersecting corrugated stirrups 4 are also fastened with rectangular stirrups 5 to ensure the structural stability of the formed shear wall 2.

[0055] Reference Figures 7 and 8 When the shear wall is set as an L-shaped shear wall structure, the L-shaped shear wall structure includes two walls 2, the ends of the two walls 2 are perpendicular and overlap to form an intersection 1. The internal reinforcement is the same as the above-mentioned T-shaped and X-shaped shear walls. The L-shaped shear wall also uses corrugated stirrups 4, rectangular stirrups 5 and longitudinal reinforcement 3. Therefore, the structure of the L-shaped shear wall formed can also ensure the bearing capacity and ductility of the shear wall.

[0056] More specifically, the steel bar assembly includes at least corrugated stirrups 4, which are symmetrically arranged in the length direction of the wall 2, and the bent parts of the corrugated stirrups 4 intersect in the wall 2 to form intersections, and rectangular stirrups 5 are arranged at each intersection. The corrugated stirrups 4 include multiple stirrup units, and the multiple stirrup units are linear structures, and the multiple stirrup units are connected in sequence. Specifically, a hook structure is also arranged at one end of the stirrup unit arranged at the end, and the hook structure and the stirrup unit located at the end have an arc transition, and the bending angle of the hook structure is 45° to 60°. Through the arrangement of the corrugated stirrups 4, the restraint effect on the longitudinal reinforcement 3 and concrete can be effectively improved. Through the coordinated arrangement of the rectangular stirrups 5 and the corrugated stirrups 4, the restraint force on the longitudinal reinforcement 3 and concrete in the shear wall can be improved to prevent it from losing stability, and the concrete strength used is relatively high, so the strength of the cast concrete can be further improved.

[0057] In the description of the present invention, the description with reference to the terms "one embodiment", "some embodiments", "an implementation method", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In the present invention, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0058] The preferred embodiments of the present invention are described in detail above in conjunction with the accompanying drawings, but the present invention is not limited thereto. Within the technical concept of the present invention, the technical solution of the present invention can be subjected to a variety of simple modifications, including the combination of various specific technical features in any appropriate manner. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations. However, these simple modifications and combinations should also be regarded as the contents disclosed by the present invention and belong to the protection scope of the present invention.

Claims

1. A concrete shear wall constrained by stirrups, characterized in that: The shear wall comprises concrete and a steel bar assembly, wherein the steel bar assembly is arranged in the concrete to form the shear wall, the steel bar assembly comprises steel bars, and the steel bars are arranged along the length direction of the wall body, and the steel bar assembly further comprises corrugated stirrups, wherein the corrugated stirrups are symmetrically arranged in the length direction of the wall body, and the bent portions of the corrugated stirrups intersect in the wall body to form intersections, the corrugated stirrups on both sides of the intersections are parallel to each other to form straight portions of the corrugated stirrups, and a plurality of the intersections are tightly bounded by rectangular stirrups to form a stirrup structure in the shear wall, The corrugated stirrups include a plurality of stirrup units, which are linear structures. The plurality of stirrup units are connected in sequence, and a hook structure is further provided at one end of the stirrup unit disposed at the end. A circular arc transition is formed between the hook structure and the stirrup unit disposed at the end, and the bending angle of the hook structure is 45° to 60°.

2. The concrete shear wall constrained by stirrups according to claim 1, characterized in that: The shear wall has a plurality of wall limbs, and the plurality of wall limbs are perpendicular to each other to form a plurality of shapes of special-shaped shear walls, and the intersections between the plurality of wall limbs form an intersection area, and the steel bar assembly extends out of the wall and intersects in the intersection area to connect the plurality of wall limbs.

3. A method for preparing high-strength concrete, characterized in that: A concrete shear wall constrained by stirrups as claimed in any one of claims 1 to 2, wherein the concrete shear wall is cast by concrete formed by the high-strength concrete configuration method. Based on the mass of the specimen of the shear wall, the shear wall comprises the following weight ratio: P.II.52.5 cement 750-900 kg / m 3 , silica fume 200~250kg / m 3 , fly ash 180~230kg / m 3 , river sand 850~1000kg / m 3 , polycarboxylate water reducer 20~40kg / m 3 , water 142.5~216kg / m 3 , defoamer 0.15~0.25kg / m 3 , basalt fiber 7.5~10kg / m 3 .

4. The high-strength concrete configuration method according to claim 3, characterized in that: The shear wall specimens include the following weight ratios: P.II.52.5 cement 850 kg / m 3 , silica fume 230kg / m 3 , fly ash 230kg / m 3 , river sand 930kg / m 3 , polycarboxylate water reducer 35kg / m 3 , water 160kg / m 3 , defoamer 0.2kg / m 3 , basalt fiber 8kg / m 3 .

5. The high-strength concrete configuration method according to claim 4, characterized in that: The water-cement ratio of water to cement is 0.19~0.

24.

6. The high-strength concrete configuration method according to claim 3, characterized in that: The configuration method comprises: (1) Add cement, silica fume, fly ash and river sand into a mixing pot and mix; (2) After the fusion is completed, add water, polycarboxylic acid water reducer and defoamer and stir to blend; (3) After the mixture has initial fluidity after being stirred and integrated, basalt fiber is added and mixed until it is completely integrated, and then it is introduced into a mold for curing to obtain a concrete sample.

7. The high-strength concrete configuration method according to claim 6, characterized in that: In step (1), the mixing and stirring is performed by dry mixing, the dry mixing and stirring time is at least 3 minutes, and the stirring speed is 60-70 rpm.

8. The high-strength concrete configuration method according to claim 6, characterized in that: In step (2), the mixing and stirring is wet mixing, the stirring time is 10 minutes, and the stirring speed is 60-70 rpm.

9. The high-strength concrete configuration method according to claim 6, characterized in that: In step (3), the curing time is at least 28 days, the curing temperature is 20±2°C, and the humidity is 95%.

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