Regenerated brick aggregate lightweight concrete and application thereof in preparation of fabricated steel structure joints

Abstract

The invention relates to the technical field of civil engineering, and discloses recycled brick aggregate lightweight concrete and application thereof in preparation of fabricated steel structure nodes, the recycled brick aggregate lightweight concrete comprises the following raw materials: P.I. 42.5 cement, river sand, natural coarse aggregate, recycled brick aggregate, a polyhydroxy acid water reducing agent, a defoaming agent and water; wherein the water-cement ratio of the water to the cement is 0.5-0.6, the substitution rate of the recycled brick aggregate and the total aggregate is 0.35-0.4, and the total aggregate comprises natural coarse aggregate and the recycled brick aggregate. According to the recycled brick aggregate lightweight concrete disclosed by the invention, the proportioning mode of the concrete is changed, so that the strength of the finally formed recycled brick aggregate lightweight concrete can be effectively improved, the cost of the concrete is reduced, and the lateral buckling rigidity of a node adopting the recycled brick aggregate lightweight concrete is further improved; and the strength of the node is effectively improved.

Description

Technical Field

[0001] The present invention relates to the technical field of civil engineering, and in particular to a recycled brick aggregate lightweight concrete and application thereof in preparing assembled steel structure nodes. Background Art

[0002] Traditional prefabricated steel structure nodes are mostly connected by welding. During construction, vertical welds and longitudinal welds are often involved, which are more complicated to weld, making welding difficult and inefficient. At the same time, when subjected to lateral loads such as earthquakes and strong winds, the steel at the nodes is prone to buckling failure, leading to structural failure.

[0003] Nowadays, prefabricated steel structures are mainly used in high-rise and small-high-rise residential buildings. They have the advantages of high industrialization, controllable cost, high degree of prefabrication, and faster construction speed than cast-in-place concrete structures. However, at the same time, the current modular nodes of prefabricated steel structures still have many shortcomings, such as poor bearing capacity and lateral stiffness, complex welding connection of connection nodes, large amount of engineering at the nodes, low construction efficiency, etc. At the same time, there are many defects in the force of modular node structures of prefabricated steel structures: 1. Traditional steel structure nodes are connected by welding, and the welding quality cannot be guaranteed, especially at the nodes where the upper and lower components are spliced, the stiffness is prone to sudden changes, resulting in cracking of the welds and damage to the overall failure of the structure. 2. When the axial pressure on the upper part of the steel structure column is relatively large, the steel plate at the node is prone to buckling failure. At this time, the steel plate is unstable and the effective bearing capacity of the structure decreases rapidly. 3. The construction period of nodes connected by welding is long, the construction process is complex, and it involves high voltage and high current work, which has certain safety hazards. Local high temperatures generated during welding can easily lead to changes in the internal structure of the steel and a decrease in the steel's material properties. At the same time, the material undergoes thermal expansion during welding, which can easily produce residual stress.

[0004] Therefore, it is necessary to provide a lightweight concrete made of recycled brick aggregate and its application in the preparation of prefabricated steel structure nodes to solve the problems of low concrete strength, high cost and poor lateral buckling stiffness and strength of concrete nodes in the prior art. Summary of the invention

[0005] In view of this, the present invention proposes a lightweight concrete with recycled brick aggregate and its application in the preparation of prefabricated steel structure nodes, aiming to solve the problems of low concrete strength, high cost and poor lateral buckling stiffness and strength of concrete nodes in the prior art.

[0006] In one aspect, the present invention provides a recycled brick aggregate lightweight concrete, wherein the raw materials of the recycled brick aggregate lightweight concrete include:

[0007] PI I.42.5 cement, river sand, natural coarse aggregate, recycled brick aggregate, polyhydroxy acid water reducer, defoamer and water;

[0008] The water-cement ratio of water to cement is 0.5-0.6, the replacement rate of recycled brick aggregate to total aggregate is 0.35-0.4, and the total aggregate includes natural coarse aggregate and recycled brick aggregate.

[0009] Furthermore, the weight ratio of the PI I.42.5 cement, river sand, natural coarse aggregate, recycled brick aggregate, polyhydroxy acid water reducer, defoamer and water is 350-370 kg / m 3 :600~650kg / m 3 :720~770kg / m 3 :400~430kg / m 3 :20~40kg / m 3 :0.15~0.25kg / m 3 :190~210kg / m 3 .

[0010] Furthermore, the weight ratio of PI I.42.5 cement, river sand, natural coarse aggregate, recycled brick aggregate, polyhydroxy acid water reducer, defoamer and water is 360 kg / m 3 :625kg / m 3 :750kg / m 3 :410kg / m 3 : 35kg / m 3 :0.2kg / m 3 : 200kg / m 3 .

[0011] Furthermore, the method for preparing the recycled brick aggregate lightweight concrete comprises:

[0012] Mix cement and river sand;

[0013] After cement and river sand are mixed, add water, polyhydroxy acid water reducer and defoamer and stir to mix;

[0014] After mixing and fusion, recycled brick aggregate and natural coarse aggregate are added and mixed, and then poured into a mold for curing to obtain a concrete sample.

[0015] Furthermore, the mixing and fusing of cement and river sand includes: mixing by dry mixing, the dry mixing time is at least 3 minutes, and the mixing speed is 60-70 rpm.

[0016] Furthermore, after the cement and river sand are fused, water, polyhydroxy acid water reducer and defoamer are added and then stirred for fusion, including: stirring is wet mixing, the stirring time is 10 minutes, and the stirring speed is 60-70 rpm.

[0017] Furthermore, the recycled brick aggregate and the natural coarse aggregate are added to the mixed and stirred mixture, and then poured into a mold for curing to obtain a concrete sample, which includes: the curing time is at least 28 days, the curing temperature is 20±2° C., and the curing environment humidity is 95%.

[0018] On the other hand, the present application also provides an application of recycled brick aggregate lightweight concrete in preparing assembled steel structure nodes, including:

[0019] Furthermore, the prefabricated steel structure node includes:

[0020] Node steel pipe;

[0021] Lightweight concrete with recycled brick aggregate is filled in the node steel tube;

[0022] Ear plates are arranged on two opposite sides of the node steel pipe;

[0023] A steel column, one end of which is provided with an ear plate, wherein the ear plate of the steel column is connected to the ear plate of the node steel pipe;

[0024] A steel tube beam is connected to one side of the node steel tube, and the steel tube beam is perpendicular to the steel column.

[0025] Furthermore, the steel column includes a steel pipe column and a cross-shaped steel, and the ear plate on the steel column and the ear plate on the node steel pipe are connected by using a self-locking single-sided expansion bolt.

[0026] Furthermore, the fabricated steel structure node also includes:

[0027] A stiffening rib is connected to the steel column on one side and connected to the ear plate on the steel column on the other side.

[0028] Compared with the prior art, the beneficial effect of the present invention is that the recycled brick aggregate lightweight concrete of the present invention can effectively improve the strength of the final recycled brick aggregate lightweight concrete by changing the concrete mix ratio, reduce the concrete cost, and further improve the lateral buckling stiffness of the node using the recycled brick aggregate lightweight concrete, and effectively improve the strength of the node. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present invention. Moreover, the same reference symbols are used throughout the accompanying drawings to represent the same components. In the accompanying drawings:

[0030] Figure 1 One of the structural schematic diagrams of the assembled steel structure node provided by the embodiment of the present invention;

[0031] Figure 2 One of the structural schematic diagrams of the assembled steel structure node provided by the embodiment of the present invention;

[0032] Figure 3 One of the structural schematic diagrams of the assembled steel structure node provided by the embodiment of the present invention;

[0033] In the figure, 100, node steel pipe; 200, recycled brick aggregate lightweight concrete; 300, ear plate; 400, steel column; 410, steel pipe column; 420, cross steel; 500, steel pipe beam; 600, stiffening rib. DETAILED DESCRIPTION

[0034] The specific implementation of the present invention is further described in detail below in conjunction with the accompanying drawings and examples. The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0035] In the description of the present application, it should be understood that the terms "center", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0036] The terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, unless otherwise specified, "plurality" means two or more.

[0037] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be a communication between the inner sides of two components. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0038] In some embodiments of the present application, this embodiment provides a recycled brick aggregate lightweight concrete 200, including: the raw materials of the recycled brick aggregate lightweight concrete 200 include:

[0039] PI I.42.5 cement, river sand, natural coarse aggregate, recycled brick aggregate, polyhydroxy acid water reducer, defoamer and water;

[0040] Among them, the water-cement ratio of water to cement is 0.5-0.6, the replacement rate of recycled brick aggregate to total aggregate is 0.35-0.4, and the total aggregate includes natural coarse aggregate and recycled brick aggregate.

[0041] In some embodiments of the present application, the weight ratio of PI I.42.5 cement, river sand, natural coarse aggregate, recycled brick aggregate, polyhydroxy acid water reducer, defoamer and water is 350-370 kg / m 3 :600~650kg / m 3 :720~770kg / m 3 :400~430kg / m 3 :20~40kg / m 3 :0.15~0.25kg / m 3 :190~210kg / m 3 .

[0042] It can be understood that recycled brick aggregate refers to the aggregate obtained by crushing, screening and processing waste materials such as waste building bricks, tiles, masonry, etc. These wastes usually come from demolition and construction waste, and are an environmentally friendly aggregate. Through scientific process flow, it can not only efficiently recycle construction waste, but also provide standard aggregates for projects such as concrete and roads, which helps to reduce the consumption of natural resources and the pressure of construction waste treatment.

[0043] In some embodiments of the present application, the weight ratio of PI I.42.5 cement, river sand, natural coarse aggregate, recycled brick aggregate, polyhydroxy acid water reducer, defoamer and water is 360 kg / m 3 :625kg / m 3 :750kg / m 3 :410kg / m 3 : 35kg / m 3 :0.2kg / m 3 : 200kg / m 3 .

[0044] In some embodiments of the present application, the method for preparing the recycled brick aggregate lightweight concrete 200 includes:

[0045] Mix cement and river sand;

[0046] After cement and river sand are mixed, add water, polyhydroxy acid water reducer and defoamer and stir to mix;

[0047] After mixing and fusion, recycled brick aggregate and natural coarse aggregate are added and mixed, and then poured into a mold for curing to obtain a concrete sample.

[0048] In some embodiments of the present application, when cement and river sand are mixed and blended, the mixing includes: mixing by dry mixing, the dry mixing time is at least 3 minutes, and the mixing speed is 60-70 rpm.

[0049] In some embodiments of the present application, after cement and river sand are completely blended, water, polyhydroxy acid water reducer and defoamer are added and then stirred for fusion, including: wet mixing, stirring time is 10 minutes, and stirring speed is 60-70 rpm.

[0050] In some embodiments of the present application, after stirring and fusing, recycled brick aggregate and natural coarse aggregate are added and mixed, and poured into a mold for curing to obtain a concrete sample, including: the curing time is at least 28 days, the curing temperature is 20±2°C, and the curing environment humidity is 95%.

[0051] On the other hand, see Figure 1-3 As shown, the present application also provides an application of recycled brick aggregate lightweight concrete 200 in preparing assembled steel structure nodes, which is used to apply the recycled brick aggregate lightweight concrete 200, including:

[0052] In some embodiments of the present application, the fabricated steel structure node includes:

[0053] Node steel pipe 100;

[0054] Recycled brick aggregate lightweight concrete 200 is filled in the node steel pipe 100;

[0055] Ear plates 300 are arranged on two opposite sides of the node steel pipe 100;

[0056] A steel column 400 is provided with an ear plate 300 at one end, and the ear plate 300 of the steel column 400 is connected to the ear plate 300 of the node steel pipe 100;

[0057] The steel tube beam 500 is connected to one side of the node steel tube 100 , and the steel tube beam 500 is perpendicular to the steel column 400 .

[0058] In some embodiments of the present application, the steel column 400 includes a steel pipe column 410 and a cross-shaped steel 420 , and the ear plate 300 on the steel column 400 is connected to the ear plate 300 on the node steel pipe 100 by using a self-locking single-side expansion bolt.

[0059] In some embodiments of the present application, the assembled steel structure node further includes:

[0060] The reinforcing rib 600 is connected to the steel column 400 at one side and connected to the ear plate 300 on the steel column 400 at the other side.

[0061] In summary, the recycled brick aggregate lightweight concrete 200 of the present invention can effectively improve the strength of the final recycled brick aggregate lightweight concrete 200 and reduce the cost of concrete by changing the mix ratio of concrete, thereby improving the lateral buckling stiffness of the nodes using the recycled brick aggregate lightweight concrete 200 and effectively improving the strength of the nodes.

[0062] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the relevant field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents. Any modification or equivalent replacement that does not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A recycled brick aggregate lightweight concrete, characterized in that: The raw materials of the recycled brick aggregate lightweight concrete include: PI I.42.5 cement, river sand, natural coarse aggregate, recycled brick aggregate, polyhydroxy acid water reducer, defoamer and water; The water-cement ratio of water to cement is 0.5-0.6, the replacement rate of recycled brick aggregate to total aggregate is 0.35-0.4, and the total aggregate includes natural coarse aggregate and recycled brick aggregate.

2. The recycled brick aggregate lightweight concrete according to claim 1, characterized in that: The weight ratio of the P.II.42.5 cement, river sand, natural coarse aggregate, recycled brick aggregate, polyhydroxy acid water reducer, defoamer and water is 350-370 kg / m 3 :600~650kg / m 3 :720~770kg / m 3 :400~430kg / m 3 :20~40kg / m 3 :0.15~0.25kg / m 3 :190~210kg / m 3 .

3. The recycled brick aggregate lightweight concrete according to claim 1, characterized in that: The weight ratio of the P.II.42.5 cement, river sand, natural coarse aggregate, recycled brick aggregate, polyhydroxy acid water reducer, defoamer and water is 360kg / m 3 :625kg / m 3 :750kg / m 3 :410kg / m 3 : 35kg / m 3 :0.2kg / m 3 : 200kg / m 3 .

4. The recycled brick aggregate lightweight concrete according to claim 1, characterized in that: The preparation method of the recycled brick aggregate lightweight concrete comprises: Mix cement and river sand; After cement and river sand are mixed, add water, polyhydroxy acid water reducer and defoamer and stir to mix; After mixing and fusion, recycled brick aggregate and natural coarse aggregate are added and mixed, and then poured into a mold for curing to obtain a concrete sample.

5. The recycled brick aggregate lightweight concrete according to claim 4, characterized in that: The mixing and fusing of cement and river sand includes: mixing by dry mixing, the dry mixing time is at least 3 minutes, and the mixing speed is 60-70 rpm.

6. The recycled brick aggregate lightweight concrete according to claim 5, characterized in that: After the cement and river sand are completely blended, water, polyhydroxy acid water reducing agent and defoaming agent are added and then stirred for blending, including: stirring is wet mixing, the stirring time is 10 minutes, and the stirring speed is 60-70 rpm.

7. The recycled brick aggregate lightweight concrete according to claim 6, characterized in that: The process of adding recycled brick aggregate and natural coarse aggregate to the mixed concrete after mixing and blending, and pouring the mixed concrete into a mold for curing to obtain a concrete sample includes: the curing time is at least 28 days, the curing temperature is 20±2° C., and the curing environment humidity is 95%.

8. Application of recycled brick aggregate lightweight concrete in the preparation of assembled steel structure nodes, used for applying the recycled brick aggregate lightweight concrete according to any one of claims 1 to 7, characterized in that: Prefabricated steel structure nodes include: Node steel pipe; Lightweight concrete with recycled brick aggregate is filled in the node steel tube; Ear plates are arranged on two opposite sides of the node steel pipe; A steel column, one end of which is provided with an ear plate, wherein the ear plate of the steel column is connected to the ear plate of the node steel pipe; A steel tube beam is connected to one side of the node steel tube, and the steel tube beam is perpendicular to the steel column.

9. The use of the recycled brick aggregate lightweight concrete in the preparation of assembled steel structure nodes according to claim 8, characterized in that: The steel column comprises a steel pipe column and a cross-shaped steel, and the ear plate on the steel column is connected with the ear plate on the node steel pipe by using a self-locking single-side expansion bolt.

10. The use of the recycled brick aggregate lightweight concrete in the preparation of assembled steel structure nodes according to claim 8, characterized in that: The fabricated steel structure node also includes: A stiffening rib is connected to the steel column on one side and connected to the ear plate on the steel column on the other side.

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