CN102425231A - Reinforcement lightweight aggregate concrete flat beam structure - Google Patents

Abstract

The invention relates to a reinforced lightweight aggregate concrete flat beam structure, which comprises a column, a beam and a plate, wherein the beam is a flat beam made of steel bars and lightweight aggregate concrete, and the beam width of the flat beam is greater than or equal to the beam height; the column is a reinforced lightweight aggregate concrete column. The reinforced lightweight aggregate concrete flat beam structure has the advantages of being capable of reducing the floor height, avoiding a pipeline from penetrating a beam and the like, has the excellent performances of light weight, energy conservation, environmental protection, good durability and the like of lightweight aggregate concrete, greatly reduces the dead weight of the whole building structure while ensuring the bearing capacity, improves the anti-seismic performance of the structure, and has remarkable economic and social benefits.

Description

A reinforced lightweight aggregate concrete flat beam structure

technical field

The invention relates to a building structure in the building field, in particular to a light-weight aggregate concrete flat beam structure with reinforcement.

Background technique

With the development of high-rise buildings in our country, more and more buildings are now restricted by the height limit of urban planning. The floor height is low and the column network is large. Appropriate stiffness and ductility. In this case, the conventional beam-slab structure can no longer meet the requirements, and the flat beam structure is one of the effective methods to solve such problems.

Over the years, experts and scholars at home and abroad have conducted various studies on flat beam structural systems, such as the flexural and shear performance of flat beams under load, the beneficial effects of floors on beam-column joints, the internal and external cores of flat beam and column joints The mechanical mechanism of the area, as well as the mechanical performance and seismic characteristics of flat beams and columns. Because of some mechanical characteristics and advantages of the flat beam structure, it is easier to realize the seismic design concept of "strong column and weak beam, strong shear and weak bending, strong node and weak member" in structural design, plus the current national restrictions on building height , so flat beams have been widely used in building structures as a new structural system in recent years.

There are many theoretical research results and rich engineering application experience of lightweight aggregate concrete at home and abroad, and have achieved remarkable environmental benefits, economic benefits and social benefits. Lightweight aggregate concrete has many advantages and special functions, such as light weight, environmental protection, and energy saving of lightweight aggregate concrete. Although the unit price is high, it reduces the weight of the building, reduces the reinforcement of beams, columns, and foundations, and improves construction Excellent seismic performance, in the case of reasonable design, can obtain better comprehensive economic benefits. The production of ceramsite in lightweight aggregate can also utilize natural waste to promote the recycling of resources. For example, the raw materials for producing ceramsite can be shale, industrial waste, fuel waste, and silt in rivers and lakes. The sources are very wide. Effectively slow down the excessive exploitation and utilization of natural resources by humans.

Among the current patents related to flat beams, CN 201292607Y Liu Qiusheng and others provide a utility model patent for a wide flat beam structure used in buildings. This patent introduces the structural form and reinforcement of the wide flat beam structure, including intersecting longitudinal And horizontal wide flat beam, reinforcement includes longitudinal bar, stirrup and waist bar, but this flat beam structure is not made with light aggregate concrete; Beam floor, the floor in this patent includes floor slabs, frame beams and densely ribbed beams, wherein the frame beams and densely ribbed beams are both wide flat beams, and at least one partial section steel is arranged axially in at least one frame beam, but the The flat beam floor is not made of light aggregate concrete either; all the other patents have their own advantages, but light aggregate concrete and flat beams are not combined and applied in construction.

Among the current patents on lightweight aggregate concrete, CN 101078283A Li Guochang introduced a corrosion-resistant and fatigue-resistant lightweight aggregate concrete beam, which is composed of fiber-reinforced plastic bars, steel bars, and light aggregate wrapped by fiber-reinforced plastic bars The concrete layer is composed of lightweight aggregate concrete, but it is not a flat beam structure; CN 201050127Y Wan Guoliang and others proposed a composite floor slab of cast-in-place lightweight aggregate reinforced concrete, which includes a prefabricated formwork made of lightweight aggregate reinforced concrete The floor body is composed of shell members, steel wire mesh sheets and cast-in-place lightweight aggregate concrete, but its beams are not flat beams; similar to the above two patents, the remaining patents using lightweight aggregate concrete floor slabs do not use flat beam structures.

Compared with the existing patents involving lightweight aggregate concrete or flat beam structure, the patent of the present invention is characterized in that the combination of light aggregate concrete and flat beam structure is applied in construction, and the light aggregate concrete and flat beam structure are fully utilized. The advantages and functions of the two can greatly reduce the building floor height or overall height, reduce the building's self-weight, and improve the earthquake resistance of the building. Its economic, social and environmental benefits are very significant.

Contents of the invention

The object of the present invention is to provide a flat beam structure of reinforced lightweight aggregate concrete, which combines the advantages and mechanical characteristics of lightweight aggregate concrete and flat beams, and greatly improves the bearing capacity while ensuring the bearing capacity. Reducing the self-weight of the entire building structure not only satisfies the requirements for the clear height of the building, but also improves the seismic performance of the structure, which has significant economic and social benefits.

The reinforced lightweight aggregate concrete flat beam structure of the present invention includes columns, beams and plates, and is characterized in that: the beam is a flat beam made of steel bars and lightweight aggregate concrete, and the beam width of the flat beam is greater than or equal to the beam height; the column is a reinforced lightweight aggregate concrete column.

The dry apparent density of the lightweight aggregate concrete is lower than 1950kg/m ³ ; the dosage of each component of the lightweight aggregate concrete per cubic meter is: cement: sand: lightweight aggregate: fly ash: silica fume: Water: superplasticizer=400～500kg: 600～800kg: 400～800kg: 0～200kg: 0～60kg: 100～200kg: 0～15kg; the light aggregate includes ceramsite, volcanic slag (pumice) , coal gangue, etc., and the ceramsite can be one or more of shale ceramsite, fly ash ceramsite and clay ceramsite.

The reinforced lightweight aggregate concrete flat beam structure of the present invention is a structural system between the beamless structure and the frame beam structure, and has some unique mechanical properties and performance:

1. The height-span ratio of flat beams should not be less than 1/20, which can effectively reduce the floor height and overall building height, reduce the adverse effects of wind load and earthquake on the internal force of the structure, and at the same time reduce the vertical components of the structure Material cost, saving cost.

2. The structure of the flat beams is mostly arranged in two directions, which can effectively improve the punching resistance of the flat beam-column joints, and can effectively solve the problem of too dense reinforcement in the joint area. The flat beam with a larger width can also reduce the clear span of the inner slab, thus reducing the stress on the inner slab, and the thickness of the slab and the amount of reinforcement can be reduced.

3. The flat beam structure can bring good effects to the building space. Compared with ordinary reinforced concrete beams, the flat beam has a lower beam height, which is conducive to the arrangement and layout of the indoor space, making the building space spacious, comfortable and beautiful.

The reinforced concrete flat beam structure with reinforced lightweight aggregate of the present invention has the following advantages with respect to the common reinforced concrete flat beam structure:

1. Lightweight: The dry apparent density of lightweight aggregate concrete is 20% to 40% lighter than ordinary concrete, and its strength can reach the strength level commonly used in ordinary concrete.

2. Good seismic performance: Light aggregate concrete can reduce the total weight of the building due to its low density, light weight and low elastic modulus. The seismic load is proportional to the total weight of the building, so the reinforcement is light under the seismic load. The aggregate reinforced concrete flat beam structure bears little seismic force and has obvious seismic effect.

3. Energy saving and environmental protection: The raw materials for the production of ceramsite in lightweight aggregates can come from shale, solid waste in industrial production and construction waste, as well as silt from rivers and canals. Fly ash can also be used as raw material for ceramsite. Therefore, the sources of raw materials used to produce ceramsite are very wide, which can reduce the excessive exploitation and utilization of natural resources; in addition, the thermal conductivity of ceramsite concrete is much lower than that of ordinary concrete, which can effectively reduce building energy consumption, so it has obvious social significance. and environmental benefits.

4. Although the price of lightweight aggregate concrete is higher than that of ordinary concrete of the same grade, lightweight aggregate concrete can greatly reduce the structural weight of the building and reduce the load transmitted to beams, columns, and foundations accordingly. Therefore, beams, The size of the column and foundation section and the amount of reinforcement can be reduced; the reduction of the self-weight of the structure reduces the section of the vertically stressed member, which increases the usable area and reduces the project cost by 5-10%, which has very significant comprehensive economic benefits.

Description of drawings

Fig. 1 is the schematic plan view of the flat beam structure of reinforced lightweight aggregate concrete of the present invention.

Figure 2 is an enlarged schematic diagram of the a-a section (the width of the flat beam is smaller than the width of the column).

Figure 3 is an enlarged schematic diagram of the b-b section (the width of the flat beam is equal to the width of the column).

Figure 4 is an enlarged schematic diagram of the c-c section (the width of the flat beam is greater than the width of the column).

In the figure: 1 pillar, 2 flat beams, 3 flat beams, 4 flat beams.

Detailed ways

In order to make the above-mentioned features and advantages of the present invention more comprehensible, the following specific embodiments are described in detail together with the accompanying drawings.

The reinforced lightweight aggregate concrete flat beam structure of the present invention includes columns, beams and plates, and is characterized in that: the beam is a flat beam made of steel bars and lightweight aggregate concrete, and the beam width of the flat beam is greater than or equal to the beam height; the column is a reinforced lightweight aggregate concrete column.

In this embodiment, the dry apparent density of the lightweight aggregate concrete is lower than 1950kg/m ³ ; the amount of each component of the lightweight aggregate concrete per cubic meter is: cement: sand: lightweight aggregate: powder Coal ash: silica fume: water: superplasticizer = 425kg: 650kg: 550kg: 80kg: 35kg: 160kg: 7kg. The lightweight aggregate is shale ceramsite, its main function is to reduce the self-weight of the flat beam structure, and it has significant environmental protection benefits. The strength of lightweight aggregate is lower than that of gravel, so adding silica fume can increase the strength of lightweight aggregate concrete. This is because silica fume has a particle size of 100-200nm and a silica content of more than 98%. It has strong activity and is easily mixed with cement water. Calcium hydroxide reacts to generate CSH gel, which fills the pores inside the concrete, thereby improving the durability and strength of lightweight aggregate concrete.

This kind of reinforced light aggregate concrete flat beam structure is shown in Figure 1. Entity 1 in the figure represents the column, and Entity 2, Entity 3 and Entity 4 represent the flat beam. There are three situations for the relationship between the width of the beam and the width of the column, as shown in Figure 1 , Figure 2 and Figure 3. In Figure 1, the beam width is smaller than the column width; in Figure 2, the beam width is equal to the column width; in Figure 3, the beam width is greater than the column width. In Figure 1, the width of the flat beams around the periphery should not be larger than the cross-sectional dimension of the columns in the width direction of the supporting flat beams, so as to avoid the longitudinal reinforcement in the width of the side flat beams exceeding the range of the column section under the action of horizontal load on the flat beams in the other direction. Great torque. Although the reduction in the height of the flat beam leads to a decrease in its bearing capacity, the use of lightweight aggregate concrete reduces the self-weight of the structure and improves its seismic performance, thus reducing the force distributed to the flat beam.

During concrete construction of the present invention, its procedure is no different from common frame construction. When the width of the flat beam is greater than the width of the column, the vertical and horizontal flat beams will meet on the column to form an enlarged node area. The intersection of the flat beam and the column is the inner core area, and the intersection of the flat beam and the flat beam is the outer core area. The force of the support node area is complex. The anchoring and lapping of the flat beam reinforcement in the node area should not only be carried out in accordance with the regulations on frame beams in the "Code for Design of Concrete Structures" GB 50010-2010, but also pay attention to the arrangement of longitudinal bars and stirrups at the part where the width of the flat beam exceeds the width of the column . During construction, special attention should be paid to avoid problems such as too dense steel bars in the joint area, and difficulty in pouring and vibrating concrete.

The present invention is not limited to the above-mentioned best implementation mode, and all equivalent changes and modifications made according to the scope of the patent application of the present invention shall fall within the scope of the present invention.

Claims (3)

1. a kind of reinforcement light aggregate concrete flat beam structure, comprises column, beam and plate, it is characterized in that: described beam is the flat beam that adopts steel bar and light aggregate concrete to make, and the beam width of described flat beam is greater than or equal to the beam height; the column is a reinforced lightweight aggregate concrete column. 2. The flat beam structure of reinforced lightweight aggregate concrete according to claim 1, characterized in that: the dry apparent density of the lightweight aggregate concrete is lower than 1950kg/m ³ , each cubic meter of lightweight aggregate concrete The dosage of components is: cement: sand: lightweight aggregate: fly ash: silica fume: water: superplasticizer = 400～500kg: 600～800kg: 400～800kg: 0～200kg: 0～60kg: 100～200kg : 0~15kg. 3. The reinforced lightweight aggregate concrete flat beam structure according to claim 2, characterized in that: said lightweight aggregate mainly comprises ceramsite, volcanic slag and coal gangue, wherein ceramsite adopts shale ceramsite, powder One or more of coal ash ceramsite and clay ceramsite.

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