CN206352357U - A kind of prestressed concrete overlapped slab with steel truss - Google Patents

Abstract

The utility model discloses a prestressed concrete laminated slab with a steel truss, which belongs to the technical field of construction engineering. Inclined surface, wedge-shaped joints are formed between adjacent prefabricated floor plates, and high-strength grouting materials are filled in the wedge-shaped joints, longitudinal prestressed steel bars are arranged along the length direction inside the precast floor plates, and transversely distributed steel bars are arranged along the width direction. Set up at least one steel truss, the steel truss is interspersed with transverse reinforcement along the width direction of the prefabricated floor, and the transverse reinforcement is located on the upper surface of the prefabricated floor, which can connect multiple prefabricated floors together. Laminated layer transverse reinforcement and laminated layer longitudinal reinforcement. The utility model has the characteristics of good overall stress performance, large applicable span, excellent fire prevention effect, high factory production efficiency, and convenient on-site construction.

Description

A prestressed concrete laminated slab with steel trusses

technical field

The utility model relates to the technical field of construction engineering, in particular to a prestressed concrete composite slab with a steel truss.

Background technique

In recent years, with the improvement of my country's requirements for green construction, energy conservation and emission reduction, and the substantial increase in labor market prices, prefabricated construction technology has been vigorously promoted and applied. Floor slabs, as important force-transmitting components in building structures, are changing from traditional integral cast-in-place or integral prefabrication to laminated floors with factory prefabricated lower floors and cast-in-place upper laminated floors. Compared with the traditional integral cast-in-place slab, the laminated slab avoids construction procedures such as formwork on the construction site and lower steel bar binding, saves building materials, shortens the construction period, is green and environmentally friendly, and meets the country's development requirements for building industrialization; compared with traditional integral prefabricated slabs , The laminated slab has good integrity, superior seismic performance, no leakage and cracks, etc., and meets the requirements of building safety and usability. Based on the above advantages, in recent years, laminated panels have been applied in new industrial and civil buildings.

The laminated slabs used in construction projects mainly include flat laminated slabs, reinforced truss laminated slabs and prefabricated ribbed prestressed concrete laminated slabs.

A certain degree of problems or defects were found in the production, transportation, construction and use of flat plate laminated slabs, reinforced truss laminated slabs and prefabricated ribbed prestressed concrete laminated slabs.

(1) The prefabricated floor of the flat laminated slab has low flexural and flexural rigidity, and is easy to break during transportation and hoisting. During construction, it is necessary to set up dense temporary supports, and the bonding force between the old and new concrete is low. When the surface load is large, it is easy to crack between the superimposed surfaces.

(2) Reinforced truss laminated slabs are divided into common reinforced truss laminated slabs and prestressed steel truss laminated slabs. The thickness of the prefabricated bottom slabs of ordinary reinforced truss laminated slabs reaches 60mm to 80mm, resulting in a large dead weight, which is difficult to apply to the situation of large spans, and during installation and construction, multiple temporary supports need to be arranged under the prefabricated slabs; prestressed steel truss laminated slabs The thickness of the prefabricated bottom slab is small, and the prefabricated bottom slab is prone to reverse arching after prestressing, and the concrete on the slab surface is easy to crack during hoisting, transportation and installation.

(3) The prefabricated ribbed prestressed concrete composite slab is to add concrete ribs or steel plate ribs on the upper part of the prefabricated floor. Concrete ribs or steel plate ribs improve the out-of-plane stiffness of the prefabricated floor, but when concrete ribs are used, the formwork is complicated, the ribs and the floor need to be constructed twice, the production efficiency is low, and there are construction joints between the ribs and the floor, resulting in precast The integrity of the bottom plate is poor; when steel plate ribs are used, the steel web is easy to cut the prefabricated bottom plate during hoisting, transportation and installation, resulting in a short service life of the product. In addition, the holes on the two types of ribs are discontinuous. During actual construction, it is difficult to penetrate the pipelines in the corner areas of the building.

In addition, the design value of the prefabricated floor reinforcement cover thickness of the above three kinds of laminated slabs is 15mm. When a fire breaks out in a building, the high temperature will easily cause the peeling of the bottom surface concrete and the fracture of the lower steel bars, so that the fire resistance of the floor structure does not meet the design requirements of the code, and there are certain safety hazards. Therefore, at this stage, it is necessary to develop a new type of precast concrete composite slab, which can meet the requirements of good overall mechanical performance, large applicable span, high factory production efficiency, and simple on-site construction. At the same time, it has excellent fire prevention effect and meets the requirements of national fire resistance regulations Require.

Utility model content

The technical task of the present utility model is to provide a prestressed concrete laminated slab with steel truss for the deficiencies in the prior art above. , Excellent fire prevention effect, high factory production efficiency, and easy on-site construction.

The technical solution adopted by the utility model to solve its technical problems is: it includes a prefabricated bottom plate, transverse steel bars and laminated layers, the prefabricated bottom plate includes a plurality of pieces, and the two sides of each prefabricated bottom plate along the length direction are inclined planes , wedge-shaped joints are formed between adjacent prefabricated floor plates, and high-strength grouting materials are filled in the wedge-shaped joints to the upper surface of the prefabricated floor plates. The longitudinal prestressed steel bars are arranged along the length direction inside the prefabricated floor plates, and the transversely distributed steel bars are arranged along the width direction. The distributed steel bars are located above the longitudinal prestressed steel bars, and at least one steel truss is arranged on the upper part of each prefabricated floor along the length direction, and the horizontal steel bars are interspersed along the width direction of the prefabricated floor below the steel truss, and the transverse steel bars are located on the upper surface of the prefabricated floor. A plurality of prefabricated base plates can be connected together, and a laminated layer is poured above the prefabricated base plate, and a laminated layer transverse reinforcement and a laminated layer longitudinal reinforcement are arranged inside the laminated layer, and the laminated layer transverse reinforcement is fixed on the upper surface of the steel truss, Laminated layer longitudinal reinforcement should avoid steel truss arrangement.

The steel truss includes an upper chord steel plate, two lower chord steel bars and two bent web bars, the bent web bars are bent in a wave shape, and the upper bending points of each bent web bar are It is welded with the upper chord steel plate, and the lower bending points are all welded with the lower chord steel bar. The upper chord steel plate is located outside the prefabricated bottom plate, and the lower chord steel bar is located in the prefabricated bottom plate and fixed on the horizontally distributed steel bars inside the prefabricated bottom plate. The upper surface of the prefabricated base plate is lower than the height of the lamination layer.

The bending angle of the bent web bars is 30-60 degrees.

The lower chord steel bars of the steel truss are fixed above the transversely distributed steel bars inside the prefabricated bottom plate by binding or welding.

The interior of each prefabricated bottom plate is arranged at equal intervals along the length direction. ^Longitudinal prestressed steel bars are arranged at equal intervals along the width direction. The horizontally distributed steel bars are arranged at equal intervals along the width direction. Steel bars adopt Φ ^b 4 cold-drawn low-carbon steel wires. The spacing of longitudinal prestressed steel bars is determined according to the requirements of design and construction conditions, and should meet the structural requirements of 80mm-250mm. The spacing of horizontally distributed steel bars is 250mm.

The concrete strength grade of the prefabricated floor is C40, and the concrete strength grade of the laminated layer is C30 or C40; the length of the prefabricated floor is 1200mm-7200mm, the width is 600mm-1200mm, and the thickness is 50-70mm.

The distance between the outer side of the longitudinal prestressed reinforcement and the lower edge of the prefabricated floor is 25mm, and the length of the protruding end is 150mm. The longitudinal prestressed reinforcement may not protrude from the end face of the prefabricated bottom slab according to the engineering needs, but the structural measures of adding short steel bars shall be adopted to strengthen the connection at the end of the prefabricated bottom slab.

The upper surface of the prefabricated bottom plate is a natural rough surface or an indented rough surface that meets the standard roughness requirement that the concave-convex depth is not less than 4mm.

A method for manufacturing a prestressed concrete composite slab with a steel truss, comprising the following steps:

(1) Manufacture and fix steel molds according to the dimensions of the prefabricated floor, and reserve end holes in the steel molds for inserting longitudinal prestressed steel bars;

(2) Put the longitudinal prestressed steel bar into the mold and stretch it;

(3) Binding and fixing the transversely distributed steel bars and steel trusses of the prefabricated floor in sequence;

(4) Concrete is poured into the steel mold and vibrated for maintenance. The upper surface retains a natural rough surface or is treated as an indentation rough surface. When the compressive strength of the poured concrete reaches 75% of the standard value of the designed compressive strength, loosen the longitudinal pre-stressing. Stress reinforcement, when the compressive strength of the poured concrete reaches 100% of the design value, it can be demoulded and lifted;

(5) Hoist the prefabricated bottom plate in place, and consider whether temporary support needs to be erected according to the needs;

(6) Use high-strength grouting materials to fill the wedge-shaped joints between adjacent prefabricated floor plates, and the filling height reaches the upper surface of the precast floor plates;

(7) Equipment pipelines and transverse steel bars are interspersed under the steel truss;

(8) Binding the laminated layer transverse reinforcement and laminated layer longitudinal reinforcement inside the laminated layer;

(9) Pour the composite layer concrete to the design thickness.

Compared with the prior art, a prestressed concrete composite slab with steel truss of the present utility model has the following outstanding beneficial effects:

The prefabricated bottom slab is arranged with longitudinal prestressed steel bars along the length direction. By applying prestress to the prefabricated bottom slab, its out-of-plane rigidity can be effectively improved, the thickness of the slab can be reduced, the self-weight can be reduced, and the net height of the building can be increased;

The inclined sides between adjacent prefabricated floor plates can form wedge-shaped joints, and the interior of the joints is filled with high-strength grouting materials, which improves the crack resistance of the joints;

The steel truss can significantly improve the out-of-plane stiffness and bearing capacity of the prefabricated floor, and increase the applicable span of the laminated slab. At the same time, it can reduce the anti-arch caused by the prestress, and avoid cracking of the slab concrete during hoisting, transportation and installation. At the same time, the temporary support of the lower part can be reduced or avoided during the construction stage, and the installation speed and construction efficiency of the prefabricated floor can be significantly improved;

The steel truss increases the bonding force between the prefabricated floor and the concrete of the upper laminated layer, effectively avoiding cracking between the new and old concrete of the laminated slab;

The upper chord steel plate of the steel truss can be used as the support for the transverse reinforcement of the laminated layer in the post-cast laminated layer, and at the same time, the force can be considered simultaneously with the longitudinal reinforcement of the upper laminated layer, which reduces the stress of the longitudinal reinforcement of the upper laminated layer of the post-cast laminated layer configuration;

The bent steel bars of the web members of the steel truss adopt wave-shaped bent steel bars, which are convenient for interspersing the lower horizontal steel bars and equipment pipelines. By arranging the lower horizontal steel bars and pouring the laminated layer concrete, the two-way force transmission of the laminated slab can be realized, and the force of the laminated slab can be improved. performance;

The thickness of the protective layer of steel bars at the lower part of the prefabricated floor is 25mm. When a fire breaks out in the building, it can delay the spalling of the concrete on the lower surface of the floor and the fracture of the lower steel bars, increasing the time for evacuation and rescue, and improving the fire safety of the building;

The processing mold of the prefabricated floor is simple, the steel truss can be automatically processed and welded by the machine, and the steel truss and the prefabricated floor concrete can be poured into shape at one time, completely realizing the factory assembly line production, and the production efficiency is high. There is no construction joint between the steel truss and the prefabricated floor, and it is not easy to be broken or damaged during demoulding, hoisting, transportation and installation, and the product qualification rate is high.

Description of drawings

Accompanying drawing 1 is the structural representation of the prestressed concrete laminated slab with a steel truss on the upper part of each prefabricated bottom slab formed by splicing four prefabricated bottom slabs;

Accompanying drawing 2 is the structural representation of the prefabricated floor shown in Fig. 1;

Accompanying drawing 3 is the sectional view of the prefabricated floor shown in Fig. 1;

Accompanying drawing 4 is the structural representation of the prestressed concrete laminated slab with two steel trusses on the upper part of each prefabricated bottom slab formed by splicing three prefabricated bottom slabs;

Accompanying drawing 5 is the structural representation of the prefabricated floor shown in Fig. 4;

Accompanying drawing 6 is the sectional view of the prefabricated floor shown in Fig. 4;

Accompanying drawing 7 is the structural representation of steel truss;

Accompanying drawing 8 is the side view of steel truss;

Accompanying drawing 9 is the front view of steel truss;

Explanation of reference signs: 1. Prefabricated floor, 2. Wedge joint, 3. Transverse reinforcement, 4. Lamination layer, 5. Longitudinal prestressed reinforcement, 6. Horizontal distributed reinforcement, 7. Steel truss, 8. Lamination layer Transverse reinforcement, 9, longitudinal reinforcement of laminated layer, 10, upper surface of prefabricated bottom plate, 11, inclined plane, 12, upper chord steel plate, 13, lower chord reinforcement, 14, web bending reinforcement, 15, upper bending point, 16, lower bending point.

detailed description

Referring to accompanying drawings 1 to 9 of the specification, a prestressed concrete composite slab with steel truss of the present invention will be described in detail below.

A prestressed concrete laminated slab with steel truss of the utility model has a structure comprising a prefabricated bottom slab 1, a transverse steel bar 3 and a laminated layer 4, and the prefabricated bottom slab 1 includes a plurality of pieces, and each prefabricated bottom slab 1 is along the length direction The two side surfaces on the top are slopes 11, and wedge-shaped joints 2 are formed between adjacent prefabricated bottom plates 1. The wedge-shaped joints 2 are filled with high-strength grouting material to the upper surface 10 of the prefabricated bottom plate. The interior of the prefabricated bottom plate 1 is arranged along the length direction Longitudinal prestressed steel bars 5, horizontally distributed steel bars 6 are arranged along the width direction, and the horizontally distributed steel bars 6 are located above the longitudinal prestressed steel bars 5, and at least one steel truss 7 is arranged on the upper part of each prefabricated bottom plate 1 along the length direction, stacked on the upper part of the pouring Before lamination 4, horizontal steel bars 3 are interspersed under the steel truss 7 along the width direction of the prefabricated floor 1, and the transverse steel bars 3 are located on the upper surface of the prefabricated floor 1, which can connect multiple prefabricated floor 1 together and realize the two-way integration of the laminated slab For force transmission, the laminated layer 4 is poured above the prefabricated floor 1, and the laminated layer transverse reinforcement 8 and the laminated layer longitudinal reinforcement 9 that resist negative bending moments are arranged inside the laminated layer 4, and the laminated layer transverse reinforcement 8 is fixed on the steel On the upper surface of the truss 7, the laminated layer longitudinal reinforcement 9 should be arranged away from the steel truss 7, and the diameter and spacing of the laminated layer transverse reinforcement 8 and laminated layer longitudinal reinforcement 9 in the laminated layer 4 should be determined according to the design requirements. Laminated longitudinal steel bar 9 can consider the beneficial effect of the upper chord steel plate of steel truss 7 to reduce the reinforcement area.

The steel truss 7 includes an upper chord steel plate 12, two lower chord steel bars 13 and two web bar bent bars 14, the web bar bent bars 14 are wave-shaped bent, and each web bar bent bar 14 The upper bending points 15 are welded with the upper chord steel plate 12, and the lower bending points 16 are welded with the lower chord steel bar 13. The upper chord steel plate 12 is located outside the prefabricated bottom plate 1, and the lower chord steel bar 13 is located in the prefabricated bottom plate 1 and fixed on the prefabricated bottom plate. 1. On the transversely distributed steel bars 6 inside, the upper chord steel plate 12 is higher than the upper surface of the prefabricated floor 1 and lower than the height of the laminated layer 4. The longitudinal steel bars 9 of the laminated layer should avoid the upper chord steel plate 12 of the steel truss 7. The number of steel trusses 7 can be determined according to the span and width of the prefabricated floor 1 and the design and construction requirements. It should be noted that multiple steel trusses 7 can increase the rigidity of the prefabricated floor 1, reduce or avoid the temporary support of the lower part, increase the applicable span, and improve the construction efficiency. speed.

The upper part of each prefabricated base plate 1 is provided with two steel trusses 7 along the length direction. Compared with the arrangement of one steel truss 7, the out-of-plane rigidity of the prefabricated base plate 1 is greatly increased, which can be applied to the situation of a larger span (above 6m).

The bending angle of the bent web bars 14 is 30°-60°.

The lower chord steel bars 13 of the steel truss 7 are fixed above the horizontally distributed steel bars 6 inside the prefabricated floor 1 by binding or welding.

Each prefabricated bottom plate 1 is arranged with longitudinal prestressed steel bars 5 at equal intervals along the length direction, and horizontally distributed steel bars 6 are arranged at equal intervals along the width direction. The longitudinal prestressed steel bars 5 adopt 1570 grade Φ ^H 4.8 stress-relieving spiral ribs Steel wires, horizontally distributed steel bars 6 adopt Φ ^b 4 cold-drawn low-carbon steel wires, the spacing of longitudinal prestressed steel bars 5 is determined according to design and construction conditions, and should meet the structural requirements of 80mm-250mm, and the spacing of horizontally distributed steel bars 6 is 250mm.

The concrete strength grade of the prefabricated floor 1 is C40, and the concrete strength grade of the superimposed layer 4 is C30 or C40; the length of the prefabricated floor 1 is 1200mm-7200mm, the width is 600mm-1200mm, and the thickness is 50-70mm. Requirements should be determined according to usage and design requirements.

The distance between the outer side of the longitudinal prestressed steel bar 5 and the lower edge of the prefabricated floor 1 is 25 mm, and the length of the protruding end is 150 mm. The longitudinal prestressed steel bar can also not protrude from the end face of the prefabricated bottom plate 1 according to the engineering needs, but the structural measures of adding short steel bars should be adopted to strengthen the connection of the end of the prefabricated bottom plate 1.

The upper surface 10 of the prefabricated base plate is a natural rough surface or an indented rough surface that meets the standard roughness requirement that the depth of concavities and convexities is not less than 4mm.

A method for manufacturing a prestressed concrete composite slab with a steel truss, comprising the following steps:

(1) Manufacture and fix a steel mold according to the size specification of the prefabricated bottom plate 1, and reserve end holes in the steel mold for interspersing the longitudinal prestressed steel bars 5;

(2) Put the longitudinal prestressed steel bar 5 into the mold and stretch it;

(3) Binding and fixing the transversely distributed steel bars 6 and steel trusses 7 of the prefabricated floor 1 in sequence;

(4) Concrete is poured into the steel mold and vibrated for maintenance. The upper surface retains a natural rough surface or is treated as an indentation rough surface. When the compressive strength of the poured concrete reaches 75% of the standard value of the designed compressive strength, loosen the longitudinal pre-stressing. Stress reinforcement 5, when the poured concrete compressive strength reaches 100% of the design value, it can be demoulded and lifted;

(5) Hoist the prefabricated bottom plate 1 in place, and consider whether it is necessary to set up temporary supports as needed;

(6) Use high-strength grouting material to fill the wedge-shaped joints 2 between adjacent prefabricated bottom plates 1, and the filling height reaches the upper surface of the prefabricated bottom plate 1;

(7) Equipment pipelines and transverse steel bars 3 are interspersed under the steel truss 7;

(8) Binding the laminated layer transverse reinforcement 8 and the laminated layer longitudinal reinforcement 9 inside the laminated layer 4;

(9) Pour the concrete of the composite layer 4 to the design thickness.

The implementation methods listed above are only for understanding the utility model, and are not intended to limit the technical solutions described in the utility model. Those of ordinary skill in the relevant field can also make many modifications on the basis of the technical solutions described in the claims. All equivalent changes or modifications shall fall within the protection scope of the claims of the present utility model. The parts of the utility model that are not described in detail are the known techniques of those skilled in the art.

Claims (8)

1. a prestressed concrete laminated slab with steel truss, is characterized in that: comprise prefabricated base plate, transverse reinforcing bar and laminated layer, described prefabricated base plate comprises many pieces, each prefabricated base plate along two sides on the length direction They are all inclined surfaces, and wedge-shaped joints are formed between adjacent prefabricated floor plates. The wedge-shaped joints are filled with high-strength grouting materials to the upper surface of the prefabricated floor plates. The prefabricated floor is arranged with longitudinal prestressed steel bars along the length direction and horizontally distributed along the width direction. Reinforcing bars, horizontally distributed reinforcing bars are located above the longitudinal prestressed reinforcing bars, and at least one steel truss is arranged on the upper part of each prefabricated floor along the length direction, and transverse reinforcing bars are interspersed below the steel truss along the width direction of the prefabricated floor, and the transverse reinforcing bars are located at the prefabricated floor. On the upper surface, a plurality of prefabricated base plates can be connected together, and a laminated layer is poured above the prefabricated base plate, and the laminated layer transverse reinforcement and the laminated layer longitudinal reinforcement are arranged inside the laminated layer, and the laminated layer transverse reinforcement is fixed on the steel truss On the upper surface, the longitudinal reinforcement of the laminated layer shall avoid the layout of the steel truss. 2. A prestressed concrete composite slab with steel truss according to claim 1, characterized in that: said steel truss comprises an upper chord steel plate, two lower chord steel bars and two bent web bars, said The bent web bar is bent in a wave shape, the upper bending point of each web bar bent steel bar is welded with the upper chord steel bar, and the lower bent point is welded with the lower chord steel bar, and the upper chord steel plate is located outside the prefabricated floor. The lower chord steel bars are located in the prefabricated bottom slab and fixed on the horizontally distributed steel bars inside the prefabricated bottom slab. The upper chord steel plate is higher than the upper surface of the prefabricated bottom slab and lower than the height of the laminated layer. 3. A prestressed concrete laminated slab with steel truss according to claim 2, characterized in that: the bending angle of the bent web bars is 30-60 degrees. 4. A prestressed concrete composite slab with steel truss according to claim 2, characterized in that: the lower chord reinforcement of the steel truss is fixed above the horizontally distributed reinforcement inside the prefabricated floor by binding or welding. 5. A kind of prestressed concrete composite slab with steel truss according to claim 1, characterized in that: the longitudinal prestressed steel bars are arranged at equal intervals along the length direction inside each prefabricated bottom plate, and are arranged at equal intervals along the width direction Horizontally distributed reinforcement, the longitudinal prestressed reinforcement adopts 1570 grade Φ ^H 4.8 stress-relieving spiral rib steel wire, and the lateral distribution reinforced adopts Φ ^b 4 cold-drawn low-carbon steel wire, and the spacing of the longitudinal prestressed reinforcement is determined according to design and construction conditions. And it should meet the structural requirements of 80mm ~ 250mm, and the spacing of horizontally distributed steel bars is 250mm. 6. The prestressed concrete laminated slab of a kind of band steel truss according to claim 1, is characterized in that: the concrete strength grade of described prefabricated floor is C40, and the concrete strength grade of laminated layer is C30 or C40; The length of the bottom plate is 1200mm-7200mm, the width is 600mm-1200mm, and the thickness is 50-70mm. 7. A prestressed concrete composite slab with steel truss according to claim 6, characterized in that: the distance between the outer side of the longitudinal prestressed reinforcement and the lower edge of the prefabricated floor is 25mm, and the length of the protruding end is 150mm , the longitudinal prestressed reinforcement may not protrude from the end face of the precast floor, but the structure of additional short steel bars shall be adopted to strengthen the connection at the end of the precast floor. 8. A prestressed concrete composite slab with steel truss according to claim 1, characterized in that: the upper surface of the prefabricated base plate is a natural rough surface or a pressed surface that meets the standard roughness requirements with a concave-convex depth of not less than 4mm. rough surface.