KR101313084B1 - Construction method of scenery structure comprising wet-mix shotcrete composition using wire net form - Google Patents

Abstract

The present invention is a method of constructing a landscape structure containing a high performance wet shotcrete composition using a wire mesh formwork, more specifically, install a wire mesh formwork on the front of the slope and pour concrete in the space between the landfill The present invention relates to a method of constructing a landscape structure having excellent scenery by providing a high performance wet shotcrete composition containing silica fume and an AE agent on the front of the formwork, as well as excellent strength and durability. To this end, slope stabilization step, concrete placing step, shotcrete surface construction step, shotcrete surface construction step, wet curing step, characterized in that it comprises a colorant and coating agent coating step.

Description

Construction method of landscape structure including high performance wet shotcrete composition using wire mesh formwork {CONSTRUCTION METHOD OF SCENERY STRUCTURE COMPRISING WET-MIX SHOTCRETE COMPOSITION USING WIRE NET FORM}

The present invention is a method of constructing a landscape structure containing a high performance wet shotcrete composition using a wire mesh formwork, more specifically, install a wire mesh formwork on the front of the slope and pour concrete in the space between the landfill The present invention relates to a method of constructing a landscape structure having excellent scenery by providing a high performance wet shotcrete composition containing silica fume and an AE agent on the front of the formwork, as well as excellent strength and durability.

Wet shotcrete is a concept that is distinguished from dry shotcrete. It refers to concrete that adds water to the injector when water is mixed and supplies it to the sprayer by increasing the spraying speed by applying air from the nozzle. It is roughly classified as a press method. 1 is a block diagram showing the production process and construction method of the conventional wet shotcrete.

This method has been in use for about 50 years, and the development of the equipment and materials was particularly active in the 1970s and 1980s (ACI 506R-05).

Wet shotcrete has the advantage of easy quality control and less rebound and dust generation than dry shotcrete because it sprays the pre-mixed material at a constant mixing ratio.

In addition, the construction volume is larger than dry shotcrete, which is suitable for mass construction.

On the other hand, the equipment is large and constrained by the materials used, and the transfer distance is shorter than dry shotcrete.

Recently, with the development of wet shotcrete for structure and maintenance, the research for the reduction of equipment capacity and size and the application of small diameter hoses are also in progress.

However, the necessity of research on the wet shotcrete composition for increasing the performance of the conventional wet shotcrete to be used in various applications has been highlighted, and the reason is as follows.

First, the range of shotcrete used in Korea is limited.

Shotcrete used in Korea is mainly used for slope stabilization of tunnels and underground spaces as a primary support material, and is used only for suppressing initial deformation and is not used as a main structural material. It is also used for the maintenance of all structures.

For this reason, the interest in the application of the shotcrete method to the single-shell method, construction and maintenance of the structure in Korea is increasing. That is, the development of materials is increasingly required for high strength, high durability, and high workability of shotcrete.

The second point is about poor quality control.

The shotcrete used in Korea is 21MPa, which is the quality standard, and the quality is low. Therefore, the shotcrete used in Korea currently serves only as the primary support material, and the concrete (tunnel: lining) can be overlaid to secure long-term strength and durability. As a result, the initial construction is mainly designed to prevent deformation, and thus, the efforts and recognition for the high performance of shotcrete are insufficient.

Third, the need for developing high performance shotcrete is highlighted.

Generally, high performance concrete is defined as high strength and high durability of concrete, but in case of wet shotcrete, high workability should be added to high performance. Accordingly, in recent years, studies on high strength and high durability as well as high workability (pumping performance, rebound rate, pasting performance) have been actively conducted at home and abroad for the purpose of improving the performance of wet shotcrete.

Wet shotcrete consists of a process of transferring material through a hose by a pump and a process of spraying it onto an object (object structure) .At this time, the material transfers well due to the characteristics of the material and ensures high yield stress and viscosity that does not flow down during shotcrete placement. shall. In other words, it is necessary to have a material with excellent sticking performance when pouring shotcrete while securing fluidity with excellent pumping performance.

On the other hand, concrete (shotcrete) construction materials, which are most used in civil engineering and construction, are incompatible with the surrounding natural environment due to gray color and monotonous appearance compared to natural materials, and are recognized as inhuman and unnatural materials. As a result of aging, surface degradation and cracks were generated, causing further problems in surrounding landscape. Recently, research on construction technology that can provide eco-friendly and human-friendly spaces for concrete spaces is required.

In addition, high-performance wet shotcrete with high strength and high durability has been required as an important construction condition for economic performance when constructing high-performance wet shotcrete due to the high cost of materials.

Accordingly, the present invention has been proposed to solve the conventional problems as described above, an object of the present invention is to integrate the concrete and the shotcrete surface so that the wire mesh formwork is embedded, while maintaining the high performance of the high performance wet shotcrete composition To provide a construction method of landscape structures with excellent economic efficiency by reducing the cost.

Another object of the present invention is to provide a construction method of the landscape structure to take into consideration the green environment and eco-friendliness, and to have a long-term commonality to reduce the cost of renovation by constructing the landscape structure to have a shape and color similar to natural rock. There is.

Another object of the present invention is to provide a construction method of landscape structures that improve the construction properties of the wet shotcrete, and does not easily deteriorate and cracks for a long period compared to conventional concrete, and improves the compressive strength.

It is another object of the present invention to include silica fume, an expanding material and an AE agent, which has excellent pumping performance and reduces rebounding during pouring, and improves the sticking performance after placing the shotcrete, and does not cause shrinkage cracking during the hydration reaction. To provide a method of construction of landscape structures, including.

The construction method of the landscape structure containing the high performance wet shotcrete composition using the wire mesh formwork of the present invention is a slope stabilization step for stabilizing the slope using a length-type member for the slope stability or cut surface to construct the landscape structure, the slope stabilization step After installing the wire mesh formwork to install the wire mesh formwork on the front surface of the slope, the concrete placing step of placing concrete in the inner space of the wire mesh formwork, install and attach a high performance wet shotcrete composition on the front of the wire mesh formwork Shotcrete installation surface construction step to form a shotcrete installation surface to be integrated with the concrete so that the wire mesh buried formwork is buried, finishing the shotcrete surface and carved to form a contour of the natural rock shape shotcrete sculpture surface constructionIt includes a wet step of wet curing step to prevent shrinkage cracking of the shotcrete surface, the colorant and coating agent coating step of applying a colorant and a coating agent to represent the surface texture of the natural rock after the wet curing step Is done.

The present invention is a method of integrating the concrete and shotcrete installation surface to embed the wire-filling formwork embedded there is excellent economic efficiency by reducing the amount of use while maintaining the high performance of the high-performance wet shotcrete composition.

In addition, by constructing a landscape structure to have a shape and color similar to that of natural rock, it considers the green environment and eco-friendliness, and has the commonness for a long time, thereby reducing the cost of renovation.

In addition, the construction properties of wet shotcrete is improved, and deterioration and cracking are not easily generated for a long time compared with existing concrete, and compressive strength is improved.

In addition, the use of high performance wet shotcrete composition containing silica fume, expansion material and AE agent improves pumping performance, reduces rebound during pouring, improves sticking performance after placing shotcrete, and prevents shrinkage cracking during the hydration reaction process. It works.

1 is a flow chart of the present invention.
2 to 4 is a side cross-sectional view of the landscape structure according to the construction step of the present invention.
Figure 5 is a side cross-sectional view of the landscape structure according to another embodiment of the present invention.
Figure 6 is a side cross-sectional view of the landscape structure according to another embodiment of the present invention.

When described in detail with the accompanying drawings the construction method of the landscape structure containing a high-performance wet shotcrete composition using the present invention wire mesh formwork.

In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear. It is to be understood that the following terms are defined in consideration of the functions of the present invention, and may be changed according to the intention of the user, the operator, or the precedent, and the meaning of each term should be interpreted based on the contents will be.

First, the present invention is the slope stabilization step (S1), wire mesh formwork installation step (S2), concrete placing step (S3), shotcrete laying surface construction step (S4), shotcrete engraving surface construction step (S5), wet curing step (S6) ), And the coloring and coating application step (S7) is included.

1 is a flow chart of the present invention.

The slope stabilization step (S1) stabilizes the slope 10 by using a cut-out or fill surface for stabilizing the landscape structure using a length-type member for slope stabilization.

In this case, the slope type length member is preferably any one or more of a rock bolt, earth anchor, rebar.

The wire filling form step (S2) is installed wire mesh formwork 20 to the front surface of the slope 10 after the slope stabilization step as shown in FIG.

At this time, the wire mesh buried formwork 20 is provided with a formwork plate 22 installed to face the slope 10, a lath 24 spaced apart from the formwork plate 22, and a formwork plate 22 and a lath ( Spacer 26 is connected to each other so that the 24 has a gap, and the support frame 26 is fixed to support the formwork plate 22 and the lath 24.

The lath 24 is a metal mesh formed to pour out the concrete to be described later, and any one or more of the reinforcing bars and wire mesh is fixed to the metal mesh to maintain the shape so that the metal mesh does not fall It is preferable.

The formwork plate 22 is preferably made of plywood, metal plate or the like in the form of a plate.

The concrete pouring step (S3) is to cast concrete 30 in the interior space of the wire mesh formwork 20 as shown in FIG.

At this time, a part of the concrete is poured out to the front part through the metal mesh formed in the lath 24 of the wire mesh formwork 20.

The shotcrete laying surface construction step (S4) is integrated with the concrete 30 so that the wire mesh embedded form 20 is embedded by attaching and attaching a high performance wet shotcrete composition to the front of the wire mesh embedded form 20 as shown in FIG. The shotcrete installation surface 40 is formed.

The high-performance wet shotcrete composition is prepared directly on site using a mobile mixer equipment, and then ready to install the shotcrete, and then installed by spraying the high-performance wet shotcrete composition and attached to the wire mesh formwork 20. At this time, due to the wire mesh formwork 20, the high-performance wet shotcrete composition is firmly attached to the wire mesh formwork 20, and the shotcrete surface 40 having a predetermined thickness is constructed.

Since the construction by spraying the high-performance wet shotcrete composition is embedded with the concrete 30 oozed through the metal mesh formed in the lath 24 of the wire mesh embedding form 20 while being embedded in the wire mesh formwork 20 In this way, the construction work is excellent in applicability even in areas where work accessibility is difficult, and thus the construction period is shortened.

In addition, since the amount of high performance wet shotcrete composition can be reduced by the amount of poured concrete while maintaining the high performance of the high performance wet shotcrete composition, it is economically effective.

The high-performance wet shotcrete composition is made of 80 to 85% by volume of shotcrete and 15 to 20% by volume of air before mixing, wherein the shotcrete before mixing is 18 to 28% by weight of coarse aggregate, based on 100% by weight of shotcrete before mixing. Fine aggregate 40-50% by weight, cement 12-22% by weight, water 3-13% by weight, silica fume 1.4-2.4% by weight, expander 1.6-2.6% by weight, high performance fluidizing agent 0.01-0.1% by weight AE 0.0001-0.01 weight % Is included, and the AE agent is preferably 0.0027 to 0.005 parts by weight based on 100 parts by weight of the cement.

The coarse aggregate in the shotcrete before the mixing is preferably 10 mm or less in diameter, 18 to 28% by weight, in order to reduce rebound during construction of the landscape structure using the high performance wet shotcrete composition according to the present invention, More preferably, it is 23.9 weight%.

The fine aggregate is preferably mixed at 40 to 50% by weight, more preferably 45.3% by weight for pumping and sticking performance.

The cement is usually preferably mixed at 12-22% by weight with Portland cement, more preferably 17.9% by weight.

Water-binder ratio (W / B) is a ratio used to express the amount of water to the unit binder, it is preferable to lower the value to have a value of 40% in order to prepare a wet shotcrete composition excellent in pumping performance and adhesion performance.

In this case, the binder means that the aggregate can be bonded in the concrete mixture, and in general, cement is representative, and in addition, the mixed material may be referred to as a binder when the mixed material acts as an adhesive by hydration reaction.

In the high performance wet shotcrete composition according to the present invention, cement, silica fume and expandable material are included in the binder.

The amount of unit required for the hydration in shotcrete is 15-25% of water-cement ratio, but the reason for maintaining water-cement ratio of 55 ~ 60% is that it is necessary to secure fluidity. However, in order to prepare the wet shotcrete composition of the present invention, it is necessary to lower the water-binder ratio to 40%, and for this purpose, a high performance fluidizing agent described below is used together.

The silica fume is intended to increase the pumping performance and the pumping performance of the high performance wet shotcrete composition. When the landscape structure is constructed using the high performance wet shotcrete composition containing the silica fume, the watertightness and durability are excellent. Silica fume is preferably mixed at 1.4 to 2.4% by weight, more preferably 1.9% by weight.

High-performance wet shotcrete with high unit cement content is likely to cause self-shrinkage and dry shrinkage. Therefore, it is necessary to suppress moisture evaporation and reduce shrinkage during curing. However, most of them are cured in the dry condition, causing shrinkage cracks due to water evaporation.

In addition, since the present invention requires coloring and finishing work during construction of the landscape structure, film curing is impossible.

Therefore, the use of an expansion material (Calcium Sulfoaluminate (CSA) can compensate for shrinkage after pouring and prevent cracking due to shrinkage. For this purpose, the expansion material is preferably mixed at 1.6 to 2.6% by weight, and is 2.2% by weight. It is more preferable that it is%.

The high performance fluidizing agent is preferably mixed at 0.01 to 0.1% by weight in order to secure the fluidity of the wet shotcrete, more preferably 0.05% by weight, and in the present invention, it is most preferable to use a polycarboxylic acid system.

The reason for using the polycarboxylic acid system is that the slump loss phenomenon of reading the fluidity occurs over time, the conventional naphtharene-based slump loss phenomenon increases with time, so that the change of slump after concrete mixing Although there is a problem that appears, using a polycarboxylic acid system can reduce the slump loss phenomenon and has the advantage of ensuring workability up to shotcrete work after concrete mixing.

The AE agent, which is an air entrainer, is preferably mixed in an amount of 0.0001 to 0.01 wt%, more preferably 0.0005 wt%, and mixed in an amount of 0.0027 to 0.005 parts by weight based on 100 parts by weight of the cement.

When AE agent is used, the initial excess air volume is secured to the shotcrete and the fluidity increases as the air acts as a bearing, and when the shotcrete adheres to the pouring surface at the same time as the shotcrete is placed, the air volume decreases rapidly and flows as the fluidity decreases. Bonding performance is increased by increasing yield value. It also has the effect of reducing the rebound rate during pouring.

Conventional concretes contain AE agent to increase the durability index (freeze-melting resistance) to secure 3 ~ 6% by volume of air.However, shotcrete used in Korea does not require high durability, so AE agent is included. There is no shotcrete material. In addition, the shotcrete has a problem in that the amount of air decreases due to the high-pressure injection due to the nature of the construction method, thereby reducing the amount of entrained air.

The amount of air according to the present invention has a feature of having 15 to 20% by volume before pouring, and 3 to 6% by volume after pouring, compared to the amount of air contained in conventional shotcrete.

If the construction immediately after production in the field, there is an advantage that can increase the efficiency of the construction and maintain a constant high quality.

The shotcrete engraving surface construction step (S5) finishes the shotcrete laying surface 40 to the plastering and carved the shotcrete surface by carving so that the contour appears in the natural shape of the natural rock.

The wet curing step (S6) is wet curing to prevent shrinkage cracking of the shotcrete slice.

At this time, the wet curing method covers at least one of vinyl and a curing cloth on the surface of the shotcrete and is sufficiently cured for 14 to 28 days.

The colorant and coating agent coating step (S7) is applied to the colorant and coating agent to represent the surface texture of the natural rock after the wet curing step.

The colorant used in the present invention is a product of LITHOCHROME Chemstain Classic of SCOFIELD Co., Ltd. and reacts with calcium hydroxide in concrete to give color through a neutralization reaction to give a permanent color to concrete, and the degree of expression of color depending on the amount of calcium hydroxide. Can be different.

The method for applying the colorant may be used using a general brush, sponge, spine float, cotton swab, etc., it is preferable not to use a product with a strong hair, it may be applied by spray injection method.

In Korea, colorants used in concrete have few applications, and most of them are used only for flooring. The colorant used in the flooring material is mostly using a water-soluble colorant, there is a problem that it is not easy to express the color to penetrate the concrete.

Meanwhile, a space may be formed between the shotcrete laying surface 40 integrated with the concrete 30 and the slope 10 so that the wire mesh formwork 20 is embedded according to the construction site and conditions, and at this time, a coloring agent and a coating agent After the coating step or between the shotcrete surface construction step to any one of the colorant and coating agent coating step, a backfill layer 50 filled with any one or more of sand, gravel and crushed stone is constructed.

The construction of the landscape structure of the present invention is completed through the above construction step.

According to another embodiment of the present invention, when there is a limit in constructing the landscape structure because the height of the slope is high according to the place and condition to construct the landscape structure, the landscape structure according to the present invention as shown in FIG. By repeating the slope stabilization step to the application of the colorant and coating agent may be constructed by forming a plurality of layers to correspond to the staircase shape landscape structure.

In another embodiment of the present invention when the slope of the slope 10 is urgent in accordance with the place and conditions to construct the landscape structure as shown in Figure 6 the wire mesh formwork 20 according to the present invention slope 10 It can be installed to be in close contact with the construction. At this time, the formwork plate 22 of the wire mesh buried formwork 20 may be omitted as necessary.

Hereinafter, the test results for determining the effect of the high performance wet shotcrete composition according to the present invention will be described.

Table 1 is a compounding table showing a preferred blending ratio of one embodiment of the high performance wet shotcrete composition according to the present invention.

In the compounding table, the unit binder including the cement, the silica fume, and the expanding material of the shotcrete before blending preferably has a value of 440 to 480 kg / m 3 for the pumping performance and the sticking performance of the high performance wet shotcrete composition. More preferably, it is 460 kg / m <3>.

The Gmax means the maximum dimension of the coarse aggregate, the maximum dimension of 10mm aggregate is made of aggregates of 10mm inner pack.

The S / a means the aggregate aggregate rate, the total aggregate volume used when producing 1000L (1㎥) of concrete is a, and the aggregate aggregate volume is S.

In domestic concrete (shotcrete) mixing design, each material is divided by density and calculated by volume to calculate the volume ratio that can produce 1000ℓ (1㎥), and then convert it to weight and convert the compounding ratio to the weight ratio of the material used for 1㎥ production. Decide

Table 2 shows the strength characteristics, workability and durability of the landscape structure constructed using a high performance wet shotcrete composition according to the formulation table of Table 1.

Through Table 2, it can be seen that the landscape structure constructed using the high performance wet shotcrete composition according to the present invention has excellent compressive strength, adhesion strength and crack resistance, excellent workability and sufficient air volume, freeze-thawing resistance, It can be seen that the surface peeling resistance and waterproof performance is excellent.

As described above, although the present invention has been described by limited embodiments, the terms or words used in the present specification and claims should not be construed as being limited to ordinary or dictionary meanings, and are meant to meet the technical spirit of the present invention. It must be interpreted as a concept. Therefore, the embodiments described in the specification and the drawings shown in the drawings are only one example of the present invention and do not represent all of the technical idea of the present invention, various equivalents that may be substituted for them at the time of the present application It should be understood that there may be variations and variations.

10: slope
20: wire mesh formwork
30: Concrete
40: high performance wet shotcrete laying surface

Claims (6)

Slope stabilization step of stabilizing slope by using cut-out length member for slope stabilization
Wire mesh embedded form installation step of installing the wire mesh formwork on the front surface of the slope after the slope stabilization step,
Concrete placing step of placing concrete in the inner space of the wire mesh formwork,
Shotcrete laying surface construction step of forming a shotcrete laying surface to be integrated with the concrete so that the wire mesh filling form is embedded by attaching and attaching a high-performance wet shotcrete composition on the front of the wire-filling formwork;
Finishing the shotcrete laying surface and carved so that the outline of the natural rock shape appeared shotcrete surface construction step of constructing the shotcrete engraving surface,
Wet curing step of the wet curing to prevent shrinkage cracking of the shotcrete slice,
Method of constructing a landscape structure containing a high-performance wet shotcrete composition using a wire mesh formwork, characterized in that it comprises a colorant and coating agent coating step for applying a colorant and a coating agent to show the surface texture of the natural rock after the wet curing step .
The method of claim 1, wherein the wire mesh formwork is installed in the wire mesh formwork,
A formwork plate installed to face the slope,
Lath and spaced apart from the formwork to face,
A spacer member connected to each other such that the formwork plate and the lath have a gap;
Construction method of a landscape structure containing a high-performance wet shotcrete composition using a wire mesh formwork, characterized in that the formwork and the support frame for fixing the lath is included.
The method according to claim 1, In the shotcrete laying surface construction step,
The high-performance wet shotcrete composition is made of 80 ~ 85% by volume of shotcrete and 15 to 20% by volume of air before mixing,
The shotcrete before blending is based on 100% by weight of shotcrete before mixing 18 to 28% by weight of coarse aggregate, 40 to 50% by weight of fine aggregate, 12 to 22% by weight of cement, 3 to 13% by weight of water, silica fume 1.4 to 2.4 weight %, 1.6 to 2.6% by weight of the expansion material, 0.01 to 0.1% by weight of the high-performance fluidizing agent made of 0.0001 to 0.01% by weight of AE,
The AE agent is a construction method of the landscape structure containing a high-performance wet shotcrete composition using a wire mesh formwork, characterized in that 0.0027 ~ 0.005 parts by weight based on 100 parts by weight of the cement.
The method of claim 3,
The unit binder comprising the cement, the silica fume and the expandable material in the shotcrete before mixing is a high-performance wet shotcrete composition using a wire mesh formwork, characterized in that 440 ~ 480kg / ㎥.
The method according to claim 1,
Shotcrete installation surface integrated with the concrete and the backfill layer construction step of constructing a backfill layer filled with any one or more types of sand, gravel and crushed stone is further included so that the wire mesh formwork is embedded. Construction method of a landscape structure containing a high performance wet shotcrete composition using a wire mesh formwork.
The method according to claim 1,
Method of constructing a landscape structure containing a high performance wet shotcrete composition using a wire mesh formwork to form the landscape structure in a plurality of layers so as to correspond to the stair shape by repeating the slope stabilization step to the application of the coloring agent and coating agent.

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