CN111677007A - Comprehensive pipe gallery using sprayed ultra-high toughness cement-based composite material and its construction method - Google Patents

Abstract

The invention discloses a comprehensive pipe gallery by spraying ultra-high toughness cement-based composite materials and a construction method thereof. The comprehensive pipe gallery structure is composed of corrugated steel plate, fiber mesh reinforced cement-based composite material with ultra-high toughness, and concrete base. The corrugated steel plate is cold-formed to form an arched section, and the fiber woven mesh is arranged on the surface, and the effective connection between the corrugated steel plate and the fiber woven mesh is ensured by connecting parts; the ultra-high toughness cement-based composite material is sprayed on the corrugated steel plate by a spray device. Fiber woven mesh is made of carbon fiber, glass fiber or fine steel wire criss-cross woven. The comprehensive pipe gallery structure proposed by the invention can ensure the synergistic stress between the ultra-high toughness material and the steel plate, and obtain superior bearing performance; when the ultra-high toughness material is stretched, many fine cracks can be generated, which can effectively block the internal steel plate and soil. The complex environment plays the role of steel rust prevention; the construction process is simple and efficient, which can shorten the construction period and reduce the cost.

Description

Comprehensive pipe gallery using sprayed ultra-high toughness cement-based composite material and its construction method

technical field

The invention relates to the technical field of structural engineering, in particular to a comprehensive pipe gallery using sprayed ultra-high toughness cement-based composite material and a construction method thereof.

Background technique

Urban underground integrated pipe gallery (referred to as integrated pipe gallery) refers to the public tunnels used for centralized layout of municipal pipelines such as electric power, communication, radio and television, water supply, drainage, heat, gas, etc. in the city underground. Intensive urban infrastructure. The integrated pipe gallery solves the problems of dense overhead line network, repeated road excavation, and frequent pipeline accidents, which is conducive to ensuring the functions of urban infrastructure, beautifying the urban environment, and improving the quality of urban development and comprehensive carrying capacity. With the deepening of my country's urbanization process and the improvement of urban construction standards, based on the advantages of comprehensive pipe corridors, the promotion and support of comprehensive pipe corridors at the national level have been increasing. In recent years, many cities in China have begun to lay comprehensive pipe corridor networks. .

Reinforced concrete integrated pipe gallery is relatively common in practical projects, and the main structure of arched reinforced concrete pipe gallery is usually formed by prefabrication or cast-in-place. Due to the heavy weight of concrete and the tendency to crack on the tensile side under bending loads, it has been gradually replaced by the integrated pipe gallery with steel plates as the main body in recent years. Using steel plate as the main structure of the pipe gallery can significantly reduce the weight of the structure, facilitate construction, shorten the construction period and reduce labor costs. However, due to the complex underground environment where the integrated pipe gallery is located, it is easy to cause corrosion of the steel; in order to prevent the corrosion of the steel, electroplating the steel or laying waterproof materials will increase the structural cost. On the other hand, smaller thickness steel plates are prone to buckling failure, increasing the risk of structural failure.

SUMMARY OF THE INVENTION

In order to improve the problems that the steel plate integrated pipe gallery is easy to corrode and buckling under pressure, the present invention proposes a comprehensive pipe gallery and a construction method thereof using sprayed ultra-high toughness cement-based composite material.

A comprehensive pipe gallery using sprayed ultra-high toughness cement-based composite material, comprising a concrete base; further comprising:

Corrugated steel plate, the corrugated steel plate is formed into an arch by cold bending, and the end of the corrugated steel plate is supported on the concrete base;

Fiber woven mesh, fixed on the corrugated steel plate;

The ultra-high toughness cement-based composite material is sprayed on the corrugated steel plate on which the fiber woven mesh 4 is arranged to form a reinforcement layer.

In the integrated pipe gallery structure, the corrugated steel plate is formed into an arched section by cold bending, and the ends are supported on the concrete base.

In the integrated pipe gallery structure, the corrugated steel plate includes two forms of sinusoidal corrugated steel plate and trapezoidal corrugated steel plate. During use, one of these structures can be used, or two structures can be used at the same time.

A construction method for a comprehensive pipe gallery, comprising the following steps:

1) The corrugated steel plate is formed into an arch by cold bending, and the end of the corrugated steel plate is supported on the concrete base;

2) Arrange the fiber woven mesh on the outer surface of the corrugated steel plate, and fix the fiber woven mesh on the outer surface of the corrugated steel plate by spot welding through the connector to realize the connection between the fiber woven mesh and the corrugated steel plate; The matrix composite material is sprayed on the corrugated steel plate arranged with the fiber woven mesh, and the comprehensive pipe gallery using the sprayed ultra-high toughness cement-based composite material is obtained;

The fiber woven mesh is made of carbon fiber, glass fiber or thin steel wire crisscrossed.

The ultra-high toughness cement-based composite material can be sprayed, and specifically includes: ordinary Portland cement, aluminate cement, water, fine aggregate, fly ash, silica fume, metakaolin, redispersible latex powder, modified Bentonite, hydroxypropyl methylcellulose, polycarboxylate water reducer and polyvinyl alcohol fiber. The ultra-high toughness cement-based composite material is made of the following raw materials by mass percentage:

The comprehensive pipe gallery structure and its construction method proposed by the present invention have the following advantages:

(1) The ultra-high toughness cement-based composite material used has high compressive bearing capacity, exhibits strain hardening characteristics when in tension, and the ultimate tensile strain can stably reach more than 3%, so it can ensure the synergy between it and the corrugated steel plate Force.

(2) By arranging the fiber woven mesh on the surface of the corrugated steel plate, not only the mechanical properties of the ultra-high toughness cement-based composite material can be significantly improved, but also the bonding effect between the concrete and the steel plate can be improved. The corrugated steel plate and the outer fiber mesh reinforced ultra-high toughness cement-based composite material form a steel-concrete composite cross-section. Using the synergistic working mechanism and combined effect between the two, the structural bearing performance of "1+1>2" is produced. The steel plate is less prone to buckling under the constraints of the concrete, and the steel plate provides the support and permanent formwork for the woven fiber mesh and the concrete.

(3) When the ultra-high toughness cement-based composite material is stretched, it can produce many fine cracks, which can effectively block the internal steel plate and the complex environment of the soil, and play the role of steel rust prevention.

(4) Using the existing relatively mature injection technology and equipment of ultra-high toughness cement-based composite materials, a simple and efficient construction process can be realized, the construction period of the structure can be shortened, and the construction cost can be reduced.

(5) The comprehensive pipe gallery structure proposed by the present invention can ensure the synergistic force between the ultra-high toughness material and the steel plate, and obtain superior bearing performance; when the ultra-high toughness material is stretched, a number of fine cracks can be generated, which can effectively block the internal The complex environment of steel plate and soil plays the role of steel rust prevention; the construction process is simple and efficient, which can shorten the construction period and reduce the cost.

Description of drawings

Figure 1 is a schematic structural diagram of a comprehensive pipe gallery;

Figure 2-1 is the A-A sectional view of the integrated pipe gallery structure: the steel plate waveform adopts a sine wave;

Figure 2-2 is the A-A sectional view of the integrated pipe gallery structure: the steel plate waveform adopts trapezoidal twists and turns;

Figure 3-1 is a schematic diagram of the construction method of the integrated pipe gallery: before spraying the ultra-high toughness cement-based composite material;

Figure 3-2 is a schematic diagram of the construction method of the integrated pipe gallery: after spraying the ultra-high toughness cement-based composite material.

Detailed ways

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

As shown in Figure 1, a comprehensive pipe gallery using sprayed ultra-high toughness cement-based composite material includes the following components: corrugated steel plate 1, including two forms: sinusoidal corrugated steel plate 1-1, trapezoidal corrugated steel plate 1-2; Fiber mesh reinforced ultra-high toughness cement-based composite material 2; concrete base 3.

As shown in Figure 1, the integrated pipe gallery structure includes corrugated steel plate 1, fiber mesh reinforced ultra-high toughness cement-based composite material 2, and concrete base 3; On the base 3 , the fiber mesh reinforced ultra-high toughness cement-based composite material 2 is arranged outside the corrugated steel plate 1 .

As shown in Figures 2-1 and 2-2, the corrugated steel plate 1 includes two forms of a sinusoidal corrugated steel plate 1-1 and a trapezoidal corrugated steel plate 1-2.

As shown in Figures 3-1 and 3-2, during the construction of the integrated pipe gallery structure, the fiber woven mesh 4 is first arranged on the outer surface of the corrugated steel plate 1, and then spot welded on the outer surface of the corrugated steel plate 1 through the connecting piece 5. The connection between the fiber woven mesh 4 and the corrugated steel plate 1 is realized, and finally the ultra-high toughness cement-based composite material is sprayed on the corrugated steel plate 1 on which the fiber woven mesh 4 is arranged by using the spray device 6 .

The composition of the sprayable ultra-high toughness cementitious composite material includes: ordinary portland cement, aluminate cement, water, fine aggregate, fly ash, silica fume, metakaolin, dispersible latex powder, modified bentonite, hydroxypropyl methylcellulose, polycarboxylate superplasticizer and polyvinyl alcohol fiber.

The mass ratio of the components of the mixture is:

The maximum particle size of the fine aggregate is not more than 0.5mm, the length of the polyvinyl alcohol fiber is 8-12mm, and the content of the polyvinyl alcohol fiber is 1.0%-2.5% of the total volume of the ultra-high toughness cement-based composite material; Polyvinyl alcohol fiber, its diameter is 0.039mm, its tensile strength is 1620MPa, its elastic modulus is 42.8GPa, and its ultimate elongation is 6%; for polyvinyl alcohol fiber with a length of 12mm, its diameter is 0.026mm, and its tensile strength is 6%. The strength is 1560MPa, the elastic modulus is 36.3GPa, and the ultimate elongation is 7%.

The sprayable ultra-high toughness cement-based composite material obtained by the above combination has good rheological properties, the slump is 120mm-200mm, the viscous resistance in the sprayer pipeline is small, and the nozzle will not be blocked; and the spraying process It can be misty in the middle, and the consistency increases rapidly after spraying to the surface to be sprayed, so as to ensure that there is basically no rebound during the spraying process; after the material is sprayed to the surface to be sprayed, it can harden quickly, without the need to spray another accelerator.

The fiber woven mesh 4 is made of carbon fiber, glass fiber or thin steel wire criss-cross woven. Among them, the tensile strength of carbon fiber is 3500MPa, the elastic modulus is 190GPa, and the elongation at break is 1.8%; the tensile strength of glass fiber is 3200MPa, the elastic modulus is 65GPa, and the elongation at break is 4.5%; the tensile strength of steel wire is About 400MPa, the elastic modulus is 200GPa, and the elongation at break is 8.0%. Specifically, a fiber woven mesh 4 formed by crisscrossing glass fibers can be used.

The test shows that the fiber mesh reinforced ultra-high toughness cement-based composite material can achieve sufficient connection with the steel plate, effectively preventing the structural damage caused by the interface slip between the two; the tensile limit of the fiber mesh reinforced ultra-high toughness cement-based composite material The strain is greater than 3% (more than 300 times that of ordinary concrete, and more than 15 times that of the yield strain of steel bars).

The comprehensive pipe gallery using the sprayed ultra-high-toughness cement-based composite material proposed by the present invention, wherein the ultra-high-toughness cement-based composite material not only has the function of anti-cracking and anti-seepage, but also acts as a structural component to improve the bearing performance of the overall structure. . The research shows that for the 2mm thick corrugated steel plate integrated pipe gallery commonly used in engineering, the bending stiffness per unit width of the plate around the strong axis is 30.8 kN m, and the bending stiffness around the weak axis is 0.14 kN m; For the ultra-high toughness cement-based composite material with a thickness of 10mm, the bending stiffness of the plate per unit width around the strong axis can be increased to about 107kN m (more than 3 times higher), and the bending stiffness around the weak axis can be increased to about 5.9kN m ( increased by more than 40 times). Therefore, the comprehensive pipe gallery system proposed by the present invention can improve the anti-corrosion performance of the structure and at the same time significantly improve the rigidity, strength and stability of the structure under out-of-plane loads.

Claims (4)

1. A comprehensive pipe gallery adopting a sprayed ultrahigh-toughness cement-based composite material comprises a concrete base; it is characterized by also comprising:

the corrugated steel plate is formed into an arch shape through cold bending forming, and the end part of the corrugated steel plate is supported on the concrete base;

the fiber woven mesh is fixed on the corrugated steel plate;

and the ultrahigh-toughness cement-based composite material is sprayed on the corrugated steel plate on which the fiber woven net is arranged to form a reinforcing layer.

2. The utility tunnel according to claim 1, wherein the corrugated steel plate is one or both of a sine-shaped corrugated steel plate and a trapezoid-shaped corrugated steel plate.

3. A construction method of a comprehensive pipe gallery adopting a sprayed ultrahigh-toughness cement-based composite material is characterized by comprising the following steps:

1) forming the corrugated steel plate into an arch through cold bending, and supporting the end part of the corrugated steel plate on a concrete base;

2) arranging the fiber woven mesh on the outer surface of the corrugated steel plate, and fixing the fiber woven mesh on the outer surface of the corrugated steel plate through a connecting piece in a spot welding manner to realize the connection between the fiber woven mesh and the corrugated steel plate; and (3) spraying the ultrahigh-toughness cement-based composite material on the corrugated steel plate with the fiber woven net by using a spraying device to obtain the comprehensive pipe gallery adopting the sprayed ultrahigh-toughness cement-based composite material.

4. The construction method of the utility tunnel sprayed with the ultra-high toughness cement-based composite material as claimed in claim 3, wherein the fiber mesh grid is woven by carbon fibers, glass fibers or thin steel wires in a criss-cross manner.

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