LU501971B1 - A Kind of engineered cementitious composite seamless bridge and construction method thereof - Google Patents

Abstract

This invention comprises abutment, foundation beam and structural layer, which are respectively located on both sides of the bridge; the structural layer on the side of the abutment near the road surface comprises a first asphalt concrete layer, a leveling layer and a hollow floor. The first layer is above the abutment; the structural layer on the side of the foundation beam near the road surface is the road surface base. The structural layer between the first layer and the foundation beam is a composite material layer; the structural layer between the abutment and the foundation beam is a concrete base layer; the composite material layer is above the concrete base layer; the structural layer on the bridge is a second asphalt concrete layer; the middle of the composite layer comprises a carbon-fiber mesh which is located below the horizontal line at the top of the foundation beam.

Description

Description 10501977 A Kind of engineegred cementitious composite seamiess bridge and construction method thereof

Technical Neid

The invention belongs to the technical field of bridge construction, particularly relates to a kind of enginesred cementitious composite seamiass bridge and construction method thereof

Background in order to solve the deformation problem caused by temperature, small and medium size bridges usually set expansion joints in the bridges.

However, due io the long-term impact of external vehicle load and external erosion, bridgs expansion joints are very vulnerable to damage, In order to overcome these problems, the continuous reinforced concrets pavement is allowed to be used with cracks, and the two ends of the lap plate are cormacied to the main beam and the concrete pavement respectively 19 form a semi-integrated fully seamless bridge system.

At present, the pavement materials used in semi-integral seamless bridges ars generally ordinary continuously reinforced concrete.

Due to is own defects, such as low tensile strength, poor crack resistance, high Orithiensss and so on, the surface of ordinary concrets is easily damaged under long-term vehicle load.

Because of the pavement in use is allowed with cracks, the internal reinforcement of concrete is easily corroded by external water, carbon dioxide and other corrosive substances.

However, the flatness of ordinary concrete is relatively poor, and it is easy to cause problems such as bridgehead jumps when it is damaged, which endangers the safety of vehicles and people.

Therefore, itis the key to find a seamless bridge connection cavement material with good pavement performance and strong durability as solution to the problem described above,

Summary

In view of the above-mentioned problems in the prior art, an object of the present invention is to provide a kind of engineered cementitious composite seamiess bridge and construction method thereof.

it aims ai soiving the problems that the existing seamless bridge connesion 97 pavement is easily damaged under the action of vehicle load and easily invaded by harmful substances after cracks appear, so as to prolong the service life of the wiring pavement.

in order to solve the above problems, this invention provides technical solution described as following: À seamiess bridge made of engineered cementitious composite includes abutments, foundation beams and structural layers. The abutments and foundation beams are respectively located on both sides of the bridge; the structural layer of the abuiment near the side of the road surface is provided with the first asphalt concrete layer, leveling layer and hollow floor from top to bottom; the first asphalt concrete layer is located above the horizontal line at the top of the abutment, and the structural layer of the foundation beam that is near road surface is the road surface base. The structural laver between the first asphalt concrete layer and the foundation beam is a composite material layer, the structural laver between the sbutment and the foundation beam is concrets base; the composis maternal layer is located above the concrete base layer, the structural layer on the bridge surface is a bridge deck layer, the middle of the composite material layer is horizontally provided with a carbon fiber mesh; and the carbon fiber mesh is located below the horizontal ine at the top of the foundation beam.

Compared with the bridge structure in the prior art, the application introduces the engineered cementitious composite(ECC) and carbon fiber mesh, Compared with the bridge approach slab structure in the existing bridge structure, the cracks will affect the normal driving of vehicles under the action of extemal forces due to gaps between the bridge approach slabs of the existing bridge structure, the combination of the carbon fiber mesh and ECC material in this application saves the complicated steps of installing the butt strap on the pavement. When the temperature changes, the deformation of the beam is transmitied to the ECG pavement material with the carbon fiber mesh through the bul strap, the hardened ECC composite should have obvious strain hardening characteristics, and fine cracks can be produced under tensile load, and the ultimate tensile strain can stably reach more than 3%. Therefore, ECC connection pavement has the ability to completely absorb the deformation of the beam and reduce the tension of the main beam, it solves the problem that the gap of the bridge has bad influence on the normal Eh a the vehicle, Preferably, carbon fiber mesh adopts a plain weave structure of warp and weft fiber bundles, The tensile force from the bridge is mainly supported by the fiber bundle, The type of carbon fiber mesh is T7008, the fiber model is 12K, the tensile strength of warp fiber bundle is 4900MPa, the tensile modulus is 220GPa, and the elongation at break is 2.1%.

Preferably, two rows of anchoring bars are horizontally arranged between the bottom edge of the composite material layer and the concrets base layer The function of anchoring reinforcement is to transfer the tensile force on the beam to the pavement.

More preferably, a part of the anchoring reinforcement above the abutment is located inside the first agphalt concrete layer, and the other part is located in the composite materia laver. The stress of the two parts is mutually restricted, which improves the stress resistance of this part of the structural layer.

Preferably, a rubber bearing is arranged between the bottom of the hollow floor and the abutment.

Preferably, the thickness of the first asphalt concrets layer is 5-7om.

Preferably, the leveling layer consisis of cement concrete with a thickness of 9-1 term, The main function of the leveling layer is to ensure that it is flush with the top of the abutment, so that the anchoring reinforcement can be well located at the bottom of the first asphalt concrete layer and the composite materia! laver.

Freferably, the composite material layer IS composed of enginesred cementitious composite, and the thickness of the composite material layer is 5-7om.

The thickness of the composite laver has a certain influence on the tensile strain force. IF itis too thick and exceeds the suitable distance between the surface of the composite layer and the carbon fiber mesh, and the carbon fiber mesh could not form a relative reaction to the force transmitted from the surface of the composite layer, thus the bearing capacity could cause some damage to the composite layer.

Preferably, an SBS modified asphalt synchronous macadam seal layer is arranged 9 between the composite material layer and the concrete base layer, and the thickness of the SBS modified asphalt synchronous macadam seal layer is 1-3om.

The SES modified asphalt synchronous crushed stone seal coat is used to prevent water seepage, and its overall mechanical characteristics are flexible, which can increase the pavement crack resistance.

Freferably, the thickness of the concrete base layer is 28-320m.

Preferably, the thickness of the bridge deck layer is 3-5om.

The construction method of a kind of enginesred cementitious composite seamless bridge comprises the following steps: 1) pouring the abuiment back and building the roadbed, wherein the roadbed is a concrets base, a SBS modified asphalt synchronous surface dressing base and a pavement bass; I) prepanng enginsersd cementitious composite: 3) pouring foundation beams and erecting anchor bars, 4) erecting carbon fiber mesh, 5) casting engineered cementitious composite; 8) paving the upper layer of asphalt concrete; 7) maintaining the road surface.

Preferably, the installation method of the carbon fiber mesh in step 4 comprises the following steps: installing a guide rail on the bridge deck as a walking track of paving equipment to ensure the smoothness of the carbon fiber mesh; in the construction process of the second asphalt concrete layer, the temperature of the asphalt concrete mixture is greater than 130°C, and ensure that the density of the asphalt concrete mibidure of the road surface is greater than 80%.

The beneficial effects of this invention is described as followings:

1. ECC is used as the pavement material of seamless bridge connection pavement, and carbon fiber mesh is embedded in ECC instead of steel mesh, it meets the requirements of semi-integrai fully seamless bridge to absorb temperature deformation by working with cracks.

2. ECC can fransform the macroscopic cracking mode of single crack of traditional cement-based materials under the action of tensile force into microscopic cracking mode of multiple fine cracks, which improves the flexurai-tensile resistance of pavement jointing parts and is safer and more reliabis.

3. ECC has a strong crack control ability. Compared with manual sawing on the oi 9 parts of pavement, the cracks are more evenly distributed, and the pulling force of the jointing paris on the beam is more even, which not only simplifies the project, but also reduces the damage io the jointing parts of pavement.

à The carbon fiber material has high tensile strength, and the longitudinal and transverse fiber bundies of the carbon fiber mesh are mainly arranged along the main bending and tensile directions in the concrete slab, so that the use of carbon fiber mesh to arthance the bending and tensile strength of ECC can often play a role in obtaining higher bending and tensile strength with iower mesh distribution ratio,

5. Replacing the traditional steel mesh with carbon fiber mesh can overcome the shortcomings of traditional steel mesh corrosion caused by working with cracks and harmful substances intruded into the structure,

5. The bottom of the composite material layer is flushed with the bottom of the first asphalt concrets layer, the bottom of the composite material layer is provided with anchoring reinforcing bars, and the first asphalt concrete layer and the composite material layer form anti-stress cooperation, so that the acting force of the application is weakened and the anti-stress ability is improved through the transmission of the acting force beiween the first asphalt concrete laver and the composite material layer.

Brief Description Of The Figures The Figures in the specification, which form a part of this application, are used to provide a further understanding of this application. The illustrative embodiments of this application and their descriptions are used fo explain this application and do not constitute undue restrictions on this application.

Fig. 1 is a structural schematic diagram of a novel seamiess bridge made of enginesred cementitious composite prepared by the method of the present invention; Wherein, 1. bridge deck 2. composite material layer, 3. anchoring reinforcement; 4. carbon fiber mesh, 5. the first asphalt concrete layer, 6. leveling layer; 7. hollow floor; 8. abutment; 9. pavement base, 10. foundation beam; 11. 555 modified asphalt synchronous crushed stone seal cost 12. concrets base, 13. rubber bearing.

Description of the present invention 10501977 it should be noted that the following detailed description is exemplary and intended Io provide further explanation for this application. Unisss otherwise specified, ail technical and scientific terms used herein have the same meanings as commonly understood by ordinary people in the technical field to which this application belongs.

i should be noted thai the terminology used here is only for desonbing specific embodiments, and is not intended to limit the embodiments according to this application. As used herein, unless the context clearly indicaies otherwise, the singular form is also intended to include the plural form, in addition, it should be understood that when the terms “containing” and/or “comprising” are used in this specification, they indicate the presence of features, steps, operations, devices, components and/or combinations thereof. The present invention will be further explained with examples below, Embodiment 1 The construction method of a kind of enginesred cementitious composite seamless bridge 1) Pouring the abutment back and building the roadbed, wherein the roadbed is a concrete bass, a SBS modified asphalt synchronous surface dressing base and a payement base Concrele base: clean up dirt in the base, Template, Pouring C15 concrete base, Vibrate and level the poured concrete, SBS modified asphalt synchronous macadam seal coat: SBE modified asphalt and macadam are evenly distributed by synchronous macadam seal coat truck, and the rubber-tyred roller is used to roll closely; Pavement base: the pavement base is paved by cement stabilized macadam; After the stabilized macadam Is mixed, it is transported by dump truck; Paving and shaping of the mixture shall be done by manually cooperating with paver for paving and leveling.

2) Preparation of engineered cementitious composite 1 The mass of cement, fly ash, quartz sand, water, admixiure and PVA fiber per cubic mater is 583kg, /12kg, 473kg, 339kg, 56 09kg and 26kg respectively, and the raw materials arg weighed according to the above proportions,

2 The weighed solid components including cement, fly ash, quartz sand and niche 0 are put into a mixer for dry mixing for 2 minutes untit uniform; 3 Add water and water reducing agent and stir for 3-5 minutes until the slurry is uniform and has good fluidity, 4 Add PVA fiber and stir for 5 minutes until there is no fiber agglomeration phenomenon in the hand-knsaded mixture, 3} Building foundation beams and erecting anchor steel bars, Anchorage reinforcement is erected to connect the joints of pavement with the foundation, and the foundation beam is mainly used as the foundation of the supsrstruciure to transfer the upper load to the foundation.

4) Installation of fiber web.

The carbon fiber mesh is made of high tensile strength carbon fiber, Clean the bridge deck before construction, remove dirt from the bridge deck, and keep the working face clean and dry, Install the guide rad on the bridge deck as the walking track of paving equipment When installing the carbon fiber mesh, ensure that the carbon fiber mesh is flat, and place the carbon fiber mesh in the middie of the engineered cementitious compositeiayer.

Casting of enginesred cementitious composite enginesred cementitious composite can be mixed in factory or on site; Pour the enginesred cementitious composite from the hopper into the paving equipment, and when the enginesred cementitious composite in the hopper is piled up to hall the height of the hopper, tum on the motor to make the equipment move slowly on the guide rail. find a flat plate to smooth the surface of the material with the advancement of the equipment, in order to realize the paving of the engineered cementitious composite: the compaction plais is pressed on the smoothed surface of the engineersd cementitious composite to prevent extrusion and uplift, Strictly control the slump flow of engineered cementitious composite to ensure seif-compacingss.

Determination of ine surface length The length of the joining pavement should be comprehensively considered in combination with factors such as interlayer friction, slab thickness, reinforcement ratio,

temperature difference, etc. Generally, 20m jointing pavement should be arranged Tor 9 bridges with à total span of 80m.

5) Paving construction of asphalt concrete upper layer.

During paving construction of asphalt pavement, pavers should be used for the construction of hot-mixed asphall mixture, and different pavers and methods should be used according to different highway grades. Before paving, check the temperature of the mixture car by car to ensure that is temperature is above 130°C. The vibrating frequency and amplitude of the paver should be properly adjusted, so as to promote the high compactness of asphalt concrete after paving, which is generally controlled above 80%. Strictly follow the production capacity, transportation distance, equipped transport vehicle and compaction capacity of the mixing equipment Io determine the paving speed, 50 as to ensure that the paver can travel at a uniform spesd during the construction process and avoid damage to the road surface. The mixture must be laid evenly. Construction personnel shall timely check the paving thickness, etc, If there is any deviation, they should use paver to construct it, so as to ensure the paving quality of highway asphalt concrete pavement.

5} Maintain the road surface, Embodiment 2 A seamiess bridge made of engineered cementitious composite comprises an abutment 8 and a foundation beam 10, wherein the abutment & and the foundation beam are respectively located on both sides of the bridge, a first asphalt concrete layer 5, a leveling layer 6 and a hollow floor 7 are arranged on the side of the abutment 8 that is near the road surface from top to bottom; and the first asphalt concrete laver 5 is located above the horizontal line at the top of the abutment. The side of the foundation beam 10 near the road surface is the pavement base layer 4, the first asphall concrete layer 5 and the foundation beam 10 are provided with a composite material layer 2, and the concrete basse laver 12 is provided between the abutment 8 and the foundation beam 10. The composite material layer 2 is located above the concrete base layer 12, and the surface layer of the bridge deck is provided with an upper laver 1. The carbon fiber mesh 4 is horizontally arranged in the middie of the composite material layer 2, and the carbon fiber mesh 4 is located below the horizontal line at the top of the foundation beam 10.

Two rows of anchoring bars 3 are horizontally arranged between the bottom edge 9 the composite material layer 2 and the concrets base layer 12.

Part of the anchoring steel bar 3 above the shutment 8 is located inside the first asphalt concrete layer 5.

A rubber support is arranged between the bottom of the hollow ficor 7 and the abutment 8.

The thickness of the first asphalt concrete layer 5 is Som, The leveling layer 5 is composed of cement concrete with a thickness of 10cm.

The composite material layer 2 is composed of engineered cementitious composite, and the thickness of the composite material layer 2 is Bom.

À 555 modified asphall synchronous crushed stone seal layer 11 is arranged between the composite material layer 2 and the concrete base layer 12, and the thickness of the SBS modified asphalt synchronous crushed stone seal layer 11 is Jom.

The thickness of the concrets base layer 12 15 300m.

The upper layer 1 has a thickness of dom, Embodiment 3 Enginesred cementitious composite (ECC) is a kind of cement composite with high performance, 1 is found that this kind of composite material shows obvious strain hardening characteristics under tensile or bending load. Because it can transform the macroscopic cracking mode of single crack of traditional cement-based material under tensile force into rhicroscapic cracking mode of multiple fine cracks, this kind of material can still maintain a large bearing capacity and work with cracks after cracks appear. ECC material has high ductility, high toughness and high energy absorption capacity. The maximum Crack width at ultimate load is about Soum. The ultimate tensile strain measured by tensile test and bending test is above 3%, and the average crack spacing is about 1mm. ECC has strong toughness and durability, and can mest the long-term vehicle load.

Carbon fiber mesh has the characteristics of high strength, low density, thin thickness, basically not increasing the self-weighi and cross-sectional size of reinforcement members, eic., It is used io replace the steel mesh in wiring pavement, and has the advantages of convenient construction, no need of large-scale machines and equipment, simple operation, no need of on-site fixed facibtes, less construction space and high construction efficiency, it also has high durability, and can be used normally ne 7 environment of high acid, alkali, salt and atmospheric corrosion without worrying about rust when used in bridges.

The deformation of seamless bridge caused by temperature can be absorbed by the performance of ECC with cracks, and the tensile capacity and durability of the bridge can be enhanced by reinforcing ECC material with carbon fiber mash. What has been described above 1s only the preferred embodiment of this application, and i is not intended to Hmit this application.

For those skilled in the art, this application can be subject to various modifications and changes. Any modification, equivalent replacement, improvement, ele. made within the spirit and principle of this application should be included in the scope of protection of this application.

Claims (10)

1. Claims LU501971

   1. À kind of enginesred cementitious composite seamiess bridge and construction method thereof is characterized in comprising an abutment, a foundation beam and a structural layer, wherein the abutment and the foundation beam are respectively located at two sides of the bridge; the structural layer on ons side of the abutment near the bridge deck is provided with a first asphalt concrete layer, a leveling layer and a hollow floor from top to bottom; the first asphalt concrate layer is located above the horizontal ing at the top of the abutment, the structural layer on the side of the foundation beam near the road surface is the road base, the structural layer between the first asphalt concrete layer and the foundation beam is the composite material layer, the structural layer between the abutment and the foundation beam is the concrete base, the composite material layer is located above the concrete base, the structural layer on the bridge surface is the bridge deck layer, and the middle of the composite material layer is horizontally provided with a carbon fiber mesh, which is located below the horizontal line at the top of the foundation beam; two rows of anchoring steel bars are horizonially arranged between the bottom edge of the composite material layer and the concrets base layer, wo rows of anchoring steel bars are arranged horizontally between the bottom edges of the composite material layer and the concrata base.

   2. The seamless bridge, according to claim 1, is characterized in that the carbon fiber mesh adopts a plain weave structure of warp and weft fiber bundles à The seamless bridge, according to claim 1, is characterized in that a part of the anchoring steel bars above the bridge abutment is located inside the first asphalt concrete layer.

   4, The seamless bridge, according to claim 1, is characterized in that a rubber bearing is arranged between the bottom of the hollow ficor and the abutment.

   5. The seamless bridge, according to claim 1, is characterized in that the thickness of the first asphail concrets layer is 5-7 om, the leveling layer is composed of cement concrete, and the thickness of the cement concrete is 9-11 om.

   5. The seamless bridge, according to claim 1, is characterized in that the composite material layer is composed of an enginesred cementitious composite, and the thickness of the composite material layer is 5-7 om.

   7. The seamisss bridge, according to claim 1, is characterized in that a SBS TE 9 asphalt synchronous crushed stone seal layer is arranged between the composite material layer and the concrete base layer, and the thickness of the SBS modified asphalt synchronous crushed stone seal laver is 1-3om.

   & The seamless bridge, according to claim 1, is characterized in that the thickness of the concrets base layer is 28-320m, the thickness of the bridge deck layer is 3-&om.

   9. The construction method of a kind of enginesred cementitious composite seamless bridge, is characterized in comprising the following steps: 1) pouring the abuiment back and building the roadbed, wherein the roadbed is a concrete base, a SBS modified asphalt synchronous crushed sions seal coat and a pavement base, 2} preparing engineerec cementitious composite material, 3) pouring foundation beams and erecting anchor Gars; 4) arecting carbon fiber mesh: 5) casting enginesred cementitious composite material, 6) paving the upper layer of asphalt concrete; 7} maintaining the road surface.

   10. The construction method, according to claim 9 is characterized in that the installation method of the carbon fiber mesh in step 4 comprises the following steps: installing a guide rail on the bridge deck as a walking track of paving equipment to ensure the smocthness of the carbon fiber mesh; in the paving construction process of the asphalt concrete upper layer in step 8, the temperature of the asphalt concrete mixture is greater than 130°C, and ensuring the compactness of the asphalt concrete mixture on the road surface 10 be greater than 20%.