KR101682203B1 - Construction method for filling material of modular bridge formed by slab module assembly and filling material for use in same - Google Patents

Abstract

 The present invention relates to a method of manufacturing a single slab module, comprising the steps of: (S10) attaching a bottom surface and a side mold substitute to a rim portion of a single slab module; (S20) of pressing the bottom surface and side mold substitute while allowing the other slab module to approach the one slab module so that a filling space is formed between the one slab module and the other slab module; And filling the filling space with a filling material (S30). The filling material filling method of the modular bridge is formed by assembling a plurality of slab modules.

Description

Field of the Invention [0001] The present invention relates to a modular bridge construction method for filling a modular bridge formed by assembling a plurality of slab modules,

In a modular bridge formed by assembling a plurality of slab modules, it is possible to assemble a slab module manufactured by a factory with a filler material and to install the filler material without installing a separate formwork, In the case of the filler material used, sufficient compressive strength is exhibited at the time of introducing the tensile force at the time of assembly so as to shorten the air and prevent various cracks at the joint portion, thereby ensuring durability. Thereby improving the workability and structural integrity of the modular bridge by allowing a clear filling between the slab modules.

The bridge top plate is a structure that transmits the traffic load to the main girder or the bridge, causing traffic accidents and traffic congestion, and frequent maintenance and reinforcement. These bridges can be installed by field casting, and recently, they have been made into precast at the factory. transit. It is installed more economically, shortening the air and ensuring quality.

It is important to construct the connection between the slab modules that form the top plate when modularizing the bridge top plate. In the case of integrated bridges, bridges can have continuity in load transfer, but in modular bridges, there is no continuity of load transfer, so the connection can act as a weak part. Therefore, in order to have the same continuity of load transfer as in the case of a single-type spot-placed bridge top plate, the treatment of the connection portion is the most important.

In other words, in the case of modular bridges, the longitudinal and transverse behavior are significantly different from the monolithic cast-in-place bridge deck when the vertical load acts on the connections of each slab module after construction. That is, when a vertical load is applied, the vertical load is transmitted to the adjacent member due to the vertical shear force and the bending of the connection portion in the case of the modular bridge, and the bending stiffness of the connection portion greatly affects the load distribution.

On the other hand, in the case of the integral type spot-placed bridge top plate, the load is distributed in the lateral direction mainly because the length is long in the longitudinal direction, but the lateral direction and the longitudinal direction bending stiffness are fixed. Therefore, it is very important to secure the shear stiffness and flexural stiffness of these joints in the case of modular bridges.

On the other hand, in case of horizontal load, since the warpage rate due to the length of the upper plate block is small in the case of the top-mounted bridge top plate, the continuity of the connecting portion is very important because the modular bridge is different depending on the module size.

Conventionally, in the case of a modular bridge, since the connection between the modules is formed by installing the mold between the modules and filling the filling material, it is not easy to install the form at a high place and there is a problem of safety accident Since the formwork has to be removed after the filler material is laid, it is cumbersome and also has a problem of safety accident.

In general, concrete or non-shrinking mortar is used as a filler material. Since the initial strength is low when general concrete or shrinkage mortar is used, cracks due to vibration or displacement due to vibration or traffic during construction of the bridge top plate before full curing Lt; / RTI > Such cracks are already cracked even if they are not subjected to re-vibration or impact, which leads to a decrease in durability of the entire bridge over time.

Korean Patent Publication No. 10-2014-0031583

In order to solve the above problems, in the present invention, it is possible to construct the connecting portion between the slab modules without the need for a separate formwork installation, and it is possible to shorten the air by expressing the compressive strength early, And it is an object of the present invention to provide a construction method capable of securing filling property and controlling various cracks by early curing.

According to another aspect of the present invention, there is provided a method of manufacturing a filler material for a modular bridge formed by assembling a plurality of slab modules according to the present invention, comprising the steps of: (S10) attaching a bottom surface and a side mold substitute to a rim of a single slab module; (S20) of pressing the bottom surface and side mold substitute while allowing the other slab module to approach the one slab module so that a filling space is formed between the one slab module and the other slab module; Filling the filling space with a filler (S30).

As an example, a step S40 of placing a top surface formwork substitute in the edge portion between the slab modules may be further included.

As an example, the side and top surface formwork alternatives may be coated with a hydrophobic surfactant on the side contacting the filler.

For example, in step S30, the filler composition is filled between the slab modules by an injection port formed of an upper body having a shape of increasing diameter in the upward direction and an injection body integrally formed at the lower end of the upper body and the lower end being disposed between the slab modules. .

The present invention also discloses a filler, wherein the filler comprises 20 to 80 parts by weight of sand, 3 to 5 parts by weight of an expanding agent, and 1 to 3 parts by weight of a shrinkage reducing agent based on 100 parts by weight of cement, (Strength at 28 days of age) of 80 MPa or more and the strength at the time of introduction of the tensile force (7 days strength at the time of the year) is 80% or more of the design standard strength .

Preferably, a calcium sulfaaluminate (CSA) based expansion agent is used as the expansion agent.

Preferably, the shrinkage reducing agent comprises 50 to 100 parts by weight of glycol ether, 20 to 30 parts by weight of urea, and 5 to 10 parts by weight of a defoaming agent based on 100 parts by weight of the polyoxyalkylene alkyl ether.

Preferably, the filler composition of the present invention further contains 0.1 to 0.5 parts by weight of a polysaccharide-based thickener in addition to the above-mentioned compositions.

In addition, 0.01 to 0.05 parts by weight of triethanolamine is further added.

According to the present invention, there is no need for a separate formwork construction when the filler material is installed between the slab modules, thereby facilitating construction and preventing safety problems.

Further, in the present invention, a connection part is formed between the slab modules by a filler composition during the assembly of a modular bridge, and the connection part is provided with a compressive strength sufficiently early in design standards, .

In addition, the filler composition of the present invention has an advantage in that filling strength is improved while improving the initial strength, workability is improved, and filling between the slab modules is possible, thereby providing a solid connection part.

Further, the filler composition of the present invention is capable of controlling various kinds of cracks even in early curing, thereby improving durability.

1 is an exploded perspective view showing a slab module to which a filler composition of the present invention is applied,
2 is a block diagram showing a construction method of the present invention,
3 is a schematic view showing an example in which the construction method of the present invention is applied,
4 is a schematic view showing an embodiment of the construction method of the present invention.

Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

As shown in FIG. 2, according to the present invention, a method of installing a filler material of a modular bridge formed by assembling a plurality of slab modules is disclosed. In the method of the present invention, (S10); (S20) of pressing the bottom surface and side mold substitute while allowing the other slab module to approach the one slab module so that a filling space is formed between the one slab module and the other slab module; Filling the filling space with a filler (S30).

As shown in FIG. 3, the construction method of the present invention includes a step S10 of attaching a bottom surface and a side mold substitute to a rim portion of the one-sided module 10. The formwork substitute 30 is made of an elastic material so that the formwork substitute 31 and the side mold substitute 32 are attached to the bottom and side surfaces of the one slab module 10, respectively.

Next, the other slab module is brought close to the one slab module to press the bottom and side mold substitute, thereby forming a filling space between the one slab module and the other slab module (S20). In other words, the other slab module is disposed on one slab module to which the formwork substitute 30 is attached while pressing the formwork substitute 30 when the other slab module is placed, thereby forming a sealed space between the slab modules.

(S30) filling the filling space with the filler material, and it is not necessary to install a separate formwork between the slab modules by such a construction method, so that the construction method becomes easy, .

If the filler material is hardened after the step S30, the form replacement material 30 can be removed from the slab module 10 between the mold substitute material 31 and the side mold substitute material 32, So that a modular bridge can be formed.

When the formwork substitute 30 is completed between the slab modules 10, the bridges are completed due to the difference in composition between the slab module 10 and the connecting portion 20 Therefore, even if cracks are generated between the slab module 10 and the connecting portion 20 due to the difference in thermal expansion coefficient, water tightness can be ensured and defects can be prevented from increasing due to the inflow of rainwater or the like from the outside.

In the construction method of the present invention, as shown in FIG. 4, an example is shown in which the upper surface formwork substitute material 33 is further placed on the upper surface of the rim portion between the slab modules 10 after steps S10 and S30.

As a result, the entire frame is closed by the formwork substitute 30 in the state where the filler composition is filled between the slab modules 10. That is, even if cracks are generated between the slab module 10 and the connecting portion 20 due to the difference of the thermal expansion coefficient, the formwork substitute 30 seals the entire rim between the slab modules 10, To block the durability deterioration factors such as cracking, cracking, and deterioration due to moisture at cracks.

More preferably, it is appropriate that the coating layer 34 is coated with a hydrophobic surfactant on the side of the side and top mold substitutes 31, 32, 33 which is in contact with the filler composition.

The reason why the coating layer 34 is formed is that when filling the filler composition with the formwork substitute 30 in place, the filler composition reacts with the formwork substitute 30 in the hydrogen bonding process of the filler composition, Is attached.

The reason for preventing the filling material composition and the formwork substitute 30 from adhering is to prevent the integral behavior of the formwork substitute 30 and the filler composition. In other words, when the filler composition and the formwork substitute 30 are attached to each other to perform an integrated behavior, cracks are generated between the slab module 10 and the connecting portion 20 due to the difference in thermal expansion coefficient, This is because a gap 30 may also be generated between the slab module 10 and the sealing mold 30. That is, the structure of the coating layer 34 is to block any chemical action between the formwork substitute 30 and the filler composition that creates an adhesive force.

On the other hand, the hydrophobic surfactant may be selected from among polyoxyethylene stearyl ether derivatives, polyoxyethylene stearyl ether derivatives, sorbitan fatty acid ester derivatives and polyoxyethylene oleylamine derivatives. It is preferable to use a mixture.

In step S30, an upper body 41 having a larger diameter in the upward direction and an injection body 42 integrally formed in the lower end of the upper body 41 and having a lower end disposed between the slab modules 10 The filler composition can be filled between the slab modules 10 by means of the injection port 40.

In the present invention, as shown in FIG. 1, fillers used for assembling a plurality of slab modules 10 are also presented. The connection part 20 is formed between the slab modules 10 by the filling material.

The slab module 10 is formed in a rectangular shape and is assembled in the field by factory production. The side wall of the slab module 10 is formed with a groove (not shown). The filler composition of the present invention is filled with the groove between the slab modules 10 to hold the slab module 10 and the slab module 10 10 to prevent deformation of the modular bridge upper plate.

The slab module 10 generally has a strength of 50 MPa or more. Further, after the filling of the filler composition according to the present invention between the slab modules 10, it is appropriate to introduce a tensile force in the lateral direction (lateral direction of the slab module 10).

Here, the filler of the present invention includes cement, sand, an expansion material, and a shrinkage reducing agent. The polyamide fiber is blended with reinforcing fiber to prevent the shrinkage of the cured body by the expansion agent and the shrinkage reducing agent, To prevent cracks caused by various cracks due to cracking control by cross-linking action.

Here, the blend of the filler of the present invention will be described in more detail. The blend includes 20 to 80 parts by weight of sand, 3 to 5 parts by weight of the expanding agent, and 1 to 3 parts by weight of the shrinkage reducing agent per 100 parts by weight of the cement, (Strength at the age of 28 days) of 80 MPa or more and the strength at the time of introduction of the tensile force (7 days strength at the time of the year) is 80% or more of the design standard strength .

The blend ratio of these materials is blended according to Remyrout-HP800 of Hanil Cement High Strength Grout so that the W / B ratio is about 16% while containing 20 to 80 parts by weight of sand relative to 100 parts by weight of cement. Day strength) is preferably 80 MPa or more.

That is, strength of 80 MPa or more is expressed in the connecting portion 20 between the slab modules 10, thereby facilitating the distribution of the forces to the vertical load and the horizontal load.

Meanwhile, a calcium sulfaaluminate (CSA) based expansion material can be used as a constituent of the filler of the present invention. The calcium sulfaaluminate (CSA) based expansion material is a mineral material including 4CaO.3Al2O3CaSO4 Lt; / RTI >

That is, in order to prevent premature shrinkage by premature curing by proper blending ratio, a calcium sulfaaluminate (CSA) type expansion agent is added to control shrinkage cracking.

In addition, the shrinkage reducing agent is further added to the filler of the present invention to control shrinkage cracking of the connecting portion 20. The shrinkage reducing agent is preferably a shrinkage reducing agent containing an ether compound, It is appropriate to control various shrinkage before and after curing by constituting the composition including urea, antifoaming agent and water so as to prevent deterioration of early strength without deteriorating workability.

That is, it is possible to prevent a decrease in early strength and to prevent cracks from occurring due to cyclic loading of the vehicle or the like in the initial stage of curing after application to the connecting portion 20 between the slab modules 10. The blending ratio of the shrinkage reducing agent is preferably 50 to 100 parts by weight of glycol ether, 20 to 30 parts by weight of urea and 5 to 10 parts by weight of a defoaming agent based on 100 parts by weight of the polyoxyalkylene alkyl ether.

The polyoxyalkylene alkyl ether is a type of surfactant that reduces the capillary tension when water evaporates in the voids of cement paste, thereby reducing the internal tensile tension, thereby inducing drying shrinkage reduction in the mortar after curing, Addition is required. However, if the addition amount of the polyoxyalkylene alkyl ether exceeds the above mixing range, the strength of the cured body due to the mortar may be sharply lowered due to the occurrence of an excessive amount of air, so that the content thereof should be limited to the above-mentioned blending range.

The glycol ether functions to control the drying shrinkage by reducing the capillary tension of the cement paste by polyoxyalkylene alkyl ether. That is, by adding polyoxyalkylene alkyl ether, shrinkage reduction rate due to drying shrinkage can be reduced to some extent. However, when a certain amount or more of polyoxyalkylene alkyl ether is blended, the compressive strength is excessively lowered in the amount of air, By adding the glycol ether to the polyoxyalkylene alkyl ether, the shrinkage reduction rate can be increased while preventing the compression strength from being lowered.

The glycol ether is required to be added in an amount of 50 parts by weight or more. However, if it exceeds 100 parts by weight, the strength of the cured product may be abruptly lowered due to excessive air amount, so that the content of the glycol ether is preferably limited to 50 to 100 parts by weight.

The glycol ether is not limited in its kind but is preferably selected from the group consisting of dipropylene glycol dimethyl ether (DMFDG), propylene glycol monopropyl ether (PEG), ethylene glycol monoisopropyl ether (IPG), ethylene glycol monoisobutyl Ether (IBG) may be used alone or in combination of two or more.

By such a combination, drying shrinkage of the cured body by the filler can be controlled as mentioned above. However, due to such a structure, it is impossible to control plastic contraction and autogenous shrinkage at the initial stage of curing, Bar, a composition that complements this function, is further compounded with urea.

The urea is a moisturizing agent that reacts with water. In the hydration reaction, the compound water reacts with the cement, and the surplus water remaining therein is prevented from being rapidly evaporated to dryness, thereby controlling the autogenous shrinkage. And it is possible to prevent the initial strength from being lowered by the use of the ether compound.

In order to achieve the plastic shrinkage control, the autogenous shrinkage control and the initial strength enhancement effect, the urea is required to be added in an amount of 5 wt% or more. However, when the amount is more than 20% by weight, the long-term strength may be lowered due to over-moisturizing, so that the proper amount of urea is limited to 20 to 30 parts by weight so as to control the plastic contraction and autogenous shrinkage while preventing initial strength and long- .

Although the type of the urea is not limited, it may preferably be a mixture of at least one member selected from the group consisting of formal urea, hydroxyethyl urea and urea-d-gluconic acid.

 On the other hand, the antifoaming agent is preferably blended in an amount of 5 parts by weight or more to control an excessively large amount of air due to the use of a surfactant. When the amount of the antifoaming agent is more than 10 parts by weight, To 10 parts by weight.

In the filler of the present invention, the effect of preventing cracking due to shrinkage control is doubled by adding the reinforcing fiber. As described above, the compounding ratio of 0.05 to 0.25 vol% based on the total volume is suggested at a suitable blending ratio. When the reinforcing fiber is added in an amount less than 0.05 vol% based on the total volume, reinforcing fibers have little effect of strengthening the toughness and impact resistance in the cement paste. When the reinforcing fiber is added in an amount exceeding 0.25 vol%, the economic efficiency is lowered, The strength is lowered, and it is preferable to limit the strength as described above.

In addition, if the filler is blended with the polyamide fiber and the adhesion strength between the cement paste and the polyamide fiber is not ensured, crack resistance due to the addition of the reinforcing fiber can not be guaranteed. In addition to the above composition, Series thickener is further included, it is proper that the composition is further blended with 0.1 to 0.5 parts by weight based on 100 parts by weight of the cement.

Generally, it is advantageous to use a thickening agent having a high molecular weight such as a water-soluble polymer for viscosity, but there is a problem in stable construction due to a change in viscosity depending on a site condition, that is, temperature and time elapsed. It is intended to use a thickener having properties of preventing effective material separation (between cement paste and reinforcing fiber).

In the case of the water-soluble polymer, the polysaccharide-based thickener has a linear structure. On the other hand, the polyurethane-based thickener has a feature of preventing the separation of materials structurally due to the development of numerous side chains. So that stable construction can be performed.

The reason why the polysaccharide-based thickener is limited to the above-mentioned mixing range is as described above in consideration of the problem of the thickening effect and the lowering of the fluidity.

In addition, in the composition of the present invention, triethanolamine is added in an amount of 0.01 to 0.05 parts by weight based on 100 parts by weight of the cement, so that the flowability is developed as a stabilizer while improving the initial water retention and securing the initial strength . That is, the filling material of the present invention is easily filled between the slab modules 10, and the initial strength is developed so that at least 80% of the design reference strength of the filler material is exhibited at the time of introducing the tensional material (for example, seven days).

Meanwhile, in the present invention, reinforcing fibers are added, but they are made of hydrophilic fibers so as to generate a strong bonding force with cement, thereby improving the crack resistance by the crosslinking action. By coating the surface of the reinforcing fiber with a hydrophobic surfactant, The present invention is characterized in that the problem of fiber cutting is solved to improve the impact resistance.

That is, reinforcing fibers composed of hydrophilic fibers are added to strengthen the toughness by increasing the hydrogen bonding force with the cement paste. If the hydrogen bonding force is too large, the cement paste is deformed by repetitive external impact such as vehicle load (Polyamide) composed of such a hydrophilic fiber is coated with a hydrophobic surfactant so that the surface of the reinforcing fiber composed of the hydrophilic fiber is treated with a hydrophilic treatment to form a reinforcing fiber So as to enhance the impact resistance by allowing the inherent elasticity to be exhibited as it is, and to be pulled out when a deformation due to a certain impact is generated.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention. Therefore, the technical scope of the present invention should not be limited to the contents described in the detailed description of the specification, but should be defined by the claims.

10: Slab module 20: Connection
30: Formwork Alternative 31: Formwork Alternative
32: side mold substitute material 33: top mold substitute material
34: Coating layer

Claims (9)

(S10) attaching a bottom surface and a side mold substitute to a rim of the one slave module;
(S20) of pressing the bottom surface and side mold substitute while making the other slab module approach the one slab module so that a filling space is formed between the one slab module and the other slab module;
Filling the filling space with a filling material (S30);
(S40) of placing an upper surface formwork substitute in the edge portion between the slab modules,
Characterized in that the filler comprises 20 to 80 parts by weight of sand, 3 to 5 parts by weight of an expansion agent and 1 to 3 parts by weight of shrinkage reducing agent per 100 parts by weight of cement. Way.
delete The method according to claim 1,
The method of claim 1, wherein the side and top formwork alternatives are coated with a hydrophobic surfactant on the side contacting the filler material, wherein the filler material is formed by assembling a plurality of slab modules.
The method according to claim 1,
In step S30,
Characterized in that the filler composition is filled between the slab modules by means of an injection body consisting of an upper body having a shape whose diameter increases upwardly and an injection body integrally formed at the lower end of the upper body and the lower end being disposed between the slab modules. A method of constructing a filler material of a modular bridge formed by module assembly.
The method according to claim 1,
In fillers,
Wherein the polyamide fibers are blended with 0.05 to 0.20% by volume of the total volume of the slab module.
6. The method of claim 5,
(CSA) -based expansion material is used as the expansion material, and a calcium sulfaaluminate (CSA) expansion material is used as the expansion material.
6. The method of claim 5,
The shrinkage-
Characterized in that it comprises 50 to 100 parts by weight of a glycol ether, 20 to 30 parts by weight of urea and 5 to 10 parts by weight of a defoaming agent based on 100 parts by weight of a polyoxyalkylene alkyl ether. Filler construction method.
6. The method of claim 5,
And 0.1 to 0.5 parts by weight of a thickener of a polysaccharide series is further added to the slab module.
9. The method of claim 8,
Wherein the amount of triethanolamine is 0.01 to 0.05 part by weight based on the total weight of the slab module.

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