CN112227200B - Non-stud toughness combined bridge deck system - Google Patents

Abstract

The invention discloses a stud-free toughness composite bridge deck system, which comprises L-shaped curled steel, longitudinal steel bars and ultra-high toughness concrete. The L-shaped rolled-edge sections are continuously placed side by side along the longitudinal direction of the bridge deck, and the adjacent sections are welded by two fillet welds to form the bridge deck steel skeleton. A row of circular holes is opened on the flange plate of the L-shaped curled-shaped steel, and the longitudinal reinforcement bars pass through each of the L-shaped curled-shaped steel flange plates through the circular holes. The ultra-high toughness concrete is poured on the bridge deck steel frame to protect the bridge deck steel frame. In the composite bridge deck system proposed by the present invention, the ultra-high toughness concrete can ensure that no or only tiny cracks below 100 microns are generated under various loads, and the toughness and durability of the structure are improved; L-shaped curled steel and longitudinal steel bars The combined construction method plays an effective shear and pullout resistance, replacing the role of studs and transverse reinforcement, thus greatly reducing the material cost and construction complexity, and has superior fatigue performance.

Description

A stud-free ductile composite bridge deck system

technical field

The invention relates to the technical field of structural engineering, in particular to a stud-free ductile composite bridge deck system.

Background technique

With the continuous advancement of my country's infrastructure construction process, people realize that the convenience of intra-city and inter-city transportation greatly affects the development of the national economy and social progress; therefore, the country has achieved great development of road and bridge engineering in recent decades. . Among them, bridge structures are not only widely used in urban overpasses, subway light rails, high-speed railways, etc., but also in cross-river and sea-crossing structures. In recent years, with the construction of super-large bridge projects such as the Hong Kong-Zhuhai-Macao Bridge and the Hangzhou Bay Bridge, bridge structures at home and abroad are facing unprecedented development opportunities. In the construction of bridge structures, the bridge deck not only plays the role of carrying the load of the superstructure and passing vehicles, but also faces long-term effects such as wheel friction, driving vibration, water and ion erosion, and thus affects the bearing capacity of the bridge deck. Durability and toughness put forward higher requirements.

Reinforced concrete bridge decks are widely used in practical engineering, but due to the large self-weight of concrete and the poor tensile properties of concrete materials, they cannot be applied to bridge structures with large spans. In order to solve this problem, the orthotropic steel bridge deck came into being; the orthotropic bridge deck system formed by arranging longitudinal and transverse stiffeners outside the steel deck deck can significantly improve the bearing efficiency of the bridge deck and improve the structural economy. However, considering that the steel is easily corroded when exposed to the air for a long time, the durability of the orthotropic bridge deck has become an urgent problem to be solved in the project.

In order to solve the above problems, steel and concrete materials are combined to form a composite bridge deck system in the project, so as to give full play to the tensile performance of steel and the compressive performance of concrete, and further improve the bearing performance of the structure. However, the existing steel-concrete composite bridge deck still has some problems: First, in order to ensure sufficient shear connection between steel and concrete and prevent the separation of the interface between the two, usually more bolts are arranged between the two. Nails (playing the dual role of anti-shear + anti-pull), which greatly increases the construction workload, and affects the fatigue performance of the structure due to the existence of welds; second, the steel deck part of the composite deck usually needs to be welded out-of-plane Multiple stiffeners, which also increase the amount of construction and affect the fatigue performance of the structure; third, ordinary concrete materials are prone to cracking under tension, and are sensitive to local defects. The corrosion resistance and durability of the bridge deck significantly increase the repair and maintenance costs of the bridge structure, resulting in a huge waste of manpower and material resources.

SUMMARY OF THE INVENTION

In order to improve the problems existing in the traditional steel-concrete composite bridge deck system, the present invention proposes a stud-free ductile composite bridge deck system.

A stud-free ductile composite bridge deck system, comprising:

A plurality of L-shaped crimping steels continuously placed side by side along the longitudinal direction of the bridge deck, the L-shaped crimping steel includes: an L-shaped structure formed by a bottom plate and a flange plate, and the end of the L-shaped structure where the bottom plate is formed by crimping the connecting end, the end where the L-shaped structural flange plate is located is rolled to form a reinforcement end;

Rebars passing through each L-shaped crimped steel;

And the concrete poured on the bridge deck steel skeleton formed by the L-shaped crimped steel and steel bars.

In the present invention, the L-shaped crimping section steels are continuously placed side by side along the longitudinal direction of the bridge deck, and the adjacent section steels are welded by two fillet welds to form the bridge deck steel frame. A row of circular holes is opened on the flange plate of the L-shaped curled-shaped steel, and the longitudinal reinforcement bars pass through each of the L-shaped curled-shaped steel flange plates through the circular holes. The ultra-high toughness concrete is poured on the bridge deck steel frame to protect the bridge deck steel frame. In the composite bridge deck system proposed by the present invention, the ultra-high toughness concrete can ensure that no or only tiny cracks below 100 microns are generated under various loads, and the toughness and durability of the structure are improved; L-shaped curled steel and longitudinal steel bars The combined construction method plays an effective shear and pullout resistance, replacing the role of studs and transverse reinforcement, thus greatly reducing the material cost and construction complexity, and has superior fatigue performance.

The following are the preferred technical solutions of the present invention:

The connecting end of the L-shaped structure bead is arranged parallel to the flange plate. Each L-shaped curling section steel is connected in turn by welding the flange plate of the former L-shaped curling section steel and the connecting end of the latter L-shaped curling section steel.

The reinforced end of the L-shaped structural hemming is formed by first hemming parallel to the direction of the bottom plate and then parallel to the direction of the flange plate for a second hemming.

A row of circular holes is opened on the L-shaped crimped steel, and the steel bars pass through the circular holes on each of the L-shaped crimped steels. The reinforcing bars are arranged longitudinally along the bridge deck. That is, the steel bars pass through the circular holes on each L-shaped crimping steel in the longitudinal direction of the bridge deck.

The concrete is ultra-high-toughness concrete, and the thickness of the ultra-high-toughness concrete layer is slightly higher than the height of the bridge deck steel skeleton, so as to protect the bridge deck steel skeleton.

In the studless ductile composite bridge deck system, the L-shaped rolled-edge steels are continuously placed side by side along the longitudinal direction of the bridge deck, and the adjacent shaped steels are welded by two fillet welds to form a bridge deck steel skeleton.

In the non-bolt toughness composite bridge deck system, a row of circular holes is opened on the L-shaped crimped steel flange plate, and the longitudinal reinforcing bars pass through each L-shaped crimped steel flange plate through the circular holes.

In the non-bolt toughness composite bridge deck system, the ultra-high toughness concrete is poured on the bridge deck steel frame; the thickness of the ultra-high toughness concrete layer is slightly higher than the height of the bridge deck steel frame, which plays a role of protecting the bridge deck steel frame. . The thickness of the ultra-high toughness concrete layer is 10% to 30% higher than the height of the bridge deck steel frame.

The ultra-high toughness concrete adopted by the present invention includes cement, active mineral admixture, aggregate, reinforcing fiber and water, wherein the cement and active mineral admixture adopt the following raw materials by weight:

Most preferably, the ultra-high toughness concrete adopts the following raw materials by weight:

The stud-free toughness composite bridge deck system proposed by the present invention is composed of a steel skeleton formed by welding cold-formed steel, longitudinal steel bars and ultra-high toughness concrete, and has the following advantages:

(1) The ultra-high ductile concrete used has high compressive bearing capacity, exhibits strain hardening characteristics in tension, and the ultimate tensile strain can be stabilized to more than 3%, and only densely distributed multiple fine cracks appear under the ultimate tensile strain. It can effectively block the steel and the external environment, prevent the steel from rusting, and improve the toughness, corrosion resistance and durability of the bridge deck structure.

(2) The steel skeleton of the bridge deck is welded by L-shaped crimped steel. The processing process is simple and efficient, and it can be combined with industrial welding robots to industrialize the processing process; the parameters of the bridge deck can be flexibly changed by changing the size of the shaped steel, which is convenient for design. , At the same time of construction, the modularity of the bridge deck system should be improved.

(3) The combination of profiled steel flanges and longitudinally traversing steel bars is used to ensure the shear connection effect between the steel skeleton and the ultra-high-toughness concrete; Detachment of the steel-concrete interface; the system avoids the use of studs, significantly reducing construction complexity and cost, while significantly improving the fatigue performance of the structure.

(4) The profiled steel flange plays the role of transverse reinforcement in the transverse direction of the bridge deck, so the use of transverse reinforcement can be avoided by properly adjusting the size of the profiled steel, reducing the amount of steel and avoiding binding the reinforcement mesh, thereby significantly improving construction efficiency and reducing costs.

Description of drawings

Figure 1 is a cross-sectional view of a stud-free ductile composite bridge deck system;

Figure 2 is a longitudinal sectional view of a stud-free ductile composite bridge deck system;

Figure 3 is a schematic diagram of the bridge deck steel frame;

FIG. 4 is a schematic diagram of an L-shaped crimped section steel.

Detailed ways

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

As shown in Figures 1 and 2, a stud-free toughness composite bridge deck system includes the following components: L-shaped crimping steel 1, longitudinal steel bars 2, and ultra-high toughness concrete 4.

As shown in Figure 3, the L-shaped crimping steel 1 is continuously placed side by side along the longitudinal direction of the bridge deck, and the adjacent shaped steels 1 are welded by two fillet welds 3 to form the bridge deck steel frame, of which 5 is the longitudinal direction of the bridge deck.

As shown in FIG. 4 , a row of circular holes is opened on the flange plate of the L-shaped curled steel 1 , and the longitudinal reinforcement bars 2 pass through the flanges of each L-shaped curled steel 1 through the circular holes.

As shown in Figures 1 and 2, the ultra-high toughness concrete 4 is poured on the bridge deck steel frame; the thickness of the ultra-high toughness concrete 4 is slightly higher than the height of the bridge deck steel frame, which plays a role in protecting the bridge deck steel frame.

The ultra-high toughness concrete adopted in the present invention comprises cement, active mineral admixture, aggregate, fiber and water, and the active mineral admixture comprises fly ash, silica fume, granulated blast furnace slag, metakaolin, aggregate The maximum particle size is not more than 0.5mm, and the fiber adopts one or more combinations of polyvinyl alcohol fiber, polyethylene fiber, and aramid fiber, the fiber length is 5mm~25mm, and the diameter is 0.015mm~0.055mm, The elastic modulus is 30GPa～150GPa, the tensile strength is 1000MPa～3500MPa, the ultimate elongation is 2%～15%, and the weight ratio of each component of cement and active mineral admixture is:

The performance test of the ultra-high toughness concrete obtained under the above mix ratio shows that its ultimate tensile strain can reach 3.2% (about 320 times that of concrete), and the corresponding crack width at the ultimate tensile strain is 0.049mm; the flexural strength It is 12.8MPa (about 2 times that of concrete), the uniaxial compressive strength is 48MPa, and the compressive strain corresponding to the peak load is 0.55% (about 2 times that of concrete).

The stud-free ductile composite bridge deck system proposed by the present invention adopts ultra-high ductility concrete to ensure that it does not generate or only generates tiny cracks below 100 microns under the action of tension, compression, bending and other various loads, which plays a role in The functions of anti-crack, anti-seepage and corrosion resistance significantly improve the toughness and durability of the structure. The structure of the combination of the open-hole L-shaped crimping steel and the longitudinally traversing steel bar adopted in the present invention can effectively resist shearing and pulling out, thereby effectively replacing the role of the stud in the combined structure. Studies have shown that in the traditional steel-concrete composite bridge deck, in order to achieve a complete shear connection effect, the number of studs per square meter of the bridge deck varies from 20 to 100, and the number of studs varies with the thickness of the concrete layer, Concrete strength, external load and other factors are improved; the present invention can effectively eliminate the material cost, construction cost and negative influence of welding on fatigue performance of these studs. In addition, the present invention effectively avoids the need for the use of transverse steel bars, reduces material costs and shortens construction period. Therefore, the stud-free ductile composite bridge deck system proposed by the present invention can greatly reduce the material cost and construction complexity while improving the structural toughness and durability, and has the potential to be popularized and applied in bridge structures.

Claims (4)

1. A studless malleable composite decking system, comprising:

a plurality of L shape turn-up shaped steel that place side by side along the bridge floor is vertical in succession, L shape turn-up shaped steel include: the L-shaped structure is formed by the bottom plate and the flange plates, one end of the L-shaped structure where the bottom plate is located is curled to form a connecting end, and one end of the L-shaped structure where the flange plates are located is curled to form a reinforcing end;

reinforcing steel bars penetrating through the L-shaped curled profile steels;

concrete poured on a bridge deck steel framework formed by the L-shaped curled steel and the steel bars;

the connecting end is arranged in parallel to the flange plate;

each L-shaped curled profile steel is welded with the connecting end of the next L-shaped curled profile steel through the flange plate of the previous L-shaped curled profile steel and is connected in sequence;

the reinforcing end is formed by firstly curling in a direction parallel to the bottom plate and then curling in a direction parallel to the flange plate through secondary curling;

the concrete is ultra-high toughness concrete and is prepared from the following raw materials in percentage by weight:

cement: 12% -55%;

fly ash: 45% -85%;

silica fume: 0 to 15 percent;

granulated blast furnace slag: 0 to 10 percent;

metakaolin: 0 to 20 percent.

2. The studless flexible composite decking system defined in claim 1 wherein the L-section profiled sections are formed with a row of circular holes and the reinforcing steel is passed through each circular hole in the L-section profiled section.

3. The studless flexible composite decking system defined in claim 1 wherein the reinforcing steel bars extend longitudinally along the deck through circular holes in each of the L-shaped roll-formed sections.

4. The boltless flexible combined bridge deck slab system according to claim 1, wherein the thickness of the ultra-high flexible concrete layer is 10% -30% higher than the height of the bridge deck steel framework.

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