KR20040009150A - Manufacturing Method of Lightweight Foam Concrete for Backfilling of Cavities in Tunnel/Underground Structure using Stone Dust in Cake State - Google Patents

Abstract

PURPOSE: A method for making a light-weight aerated concrete from a stone dust in cake state is provided to reduce the cost needed for treating the waste stone dust, prevent environment pollutions and obtain improved physical properties and quality. CONSTITUTION: The method for making a light-weight aerated concrete for filing a cavity of tunnel/underground structures comprises the steps of: mixing stone dust in cake state which is a waste material generated in a stony mountain during an aggregate/stone construction process in a light aerated concrete for filler, in the ratio of 2-4 wt% based on the total weight, and foaming the mixture through a foaming device. Particularly, the stone dust in cake state is mixed with cement in the weight ratio of 5:5 to 3:7, and then foamed.

Description

Manufacturing Method of Lightweight Foam Concrete for Backfilling of Cavities in Tunnel / Underground Structure using Stone Dust in Cake State}

The present invention relates to a method for manufacturing lightweight foamed concrete for pavement of tunnels / underground facilities using discarded cake dust in cake state,

In particular, the cavity filling material of the tunnel / underground facilities is a cake topstone clay produced in Seoksan and cement as usual, and then a small amount of foaming agent is mixed to form a dry cavity filling material, kneaded with water, and then bubbled. It relates to a light-weight foam concrete for filling the cavity to be used as a filler mortar by mixing.

The present invention effectively utilizes the cake topstone soil generated in the process of producing the stone and sand for the construction of aggregates and sand in the stone mountain as a recycled material, the cake of the former stone acid waste It not only solves the burden of treatment cost and environmental destruction of the topsoil, but also has the characteristics of lightweight foam concrete for co-filling which can guarantee safety construction and robustness as it has excellent physical properties as a filler.

In general, in underground structures including tunnels, cavities are present or generated between the concrete lining and the ground during construction or maintenance, and the rear cavity causes localized stress concentrations in the tunnel structure. Or tunnel deformation. In addition, underground artificial cavities, such as closed tunnels and natural caves, cause severe damage to ground structures such as ground subsidence.As a countermeasure against such damages, it is necessary to fill the cavities in tunnels and underground structures. In addition, the ground load on the structure is distributed evenly over the structure, and the structure and ground can be integrated and the arching effect of the tunnel can be maximized to minimize or prevent tunnel damage.

The causes of tunnel back cavity are classified by tunnel construction method as follows.

Tunnels constructed by the ASSM method before the 1980s are filled with wood or blast pavement between the ground and the lining, and the filler space should be filled with mortar, but most tunnels do not fill enough, In some cases, the wood may rot over time or be filled with blastite, causing partial flow subsidence. In case of filling with wood or blast stone, medium-to-large cavities occur between ground and tunnel lining, and in case of ASSM tunnel that directly transfers load to tunnel lining and steel beam, it can cause serious problems in tunnel structure stability. have.

In the mid 1980s, the tunnel constructed by the NATM method has a small joint size due to the close contact between the ground and the concrete lining, but there are large and small cavities at the top of the tunnel due to material separation and bleeding during lining. In addition, when the soil is discharged along with the groundwater and the natural phenomenon due to the elapsed years, the rear cavity is generated and enlarged, and the shotcrete particle leakage caused by the inflow of groundwater causes the tunnel rear cavity to be reduced.

In this case, when the cavity is generated in the tunnel and causes severe tunnel remodeling, it is generally required to block driving / passage and fill the cavity as a tunnel repair work. In this case, the cement mortar may be filled with the cavity. However, in the case of the cement mortar, there is a problem in that the quality of the material and the cavity is not completely filled due to material separation and bleeding.

This type of filling material is mainly used in mountain tunnels as air mortar / air milk, which has good air flow through mortar or cement milk, and foam urethane, which is a kind of high-molecular quantity polymer solution, for emergency recovery. It can be classified into a water glass system used when the purity of the gel type can be adjusted, and a polymer cement system limited in water as a plastic injection agent, which is a kind of polymer cement.

The mortar, which is used as the cavity filling material, is preferred as the cavity filling material to ensure separation, sedimentation prevention, non-shrinkage, and maintenance of strength of 10 kg / cm 2 during the injection operation. 900 kg of cement, 150 kg of foam, 3,45 kg of foam, 130% of water cement, 35-45% of air volume, 20-3 seconds (falling period), and air mortar filling material of 10 kg / cm 2 strength are used.

In recent years, as a filling material, roads using fly ash including 4% of fly ash, 10% of aggregate, 10% of intermediate aggregate, 62% of sand, and 24% of asphalt and 5.0% to 6.5% of asphalt, which are wastes of thermal power plants. Use of packaging ascon as a filler and its manufacturing method (Public Publication No. 1998-028032), and a mixture of cement, sand, and fly ash with water as a filler to mix air bubbles with good fluidity and filling Filler of the cavity filling method using bubble mortar to form a bubble-mixing mortar with light weight and robust compressive strength without load burden (Public Patent Publication No. 10-2000-0031838), and steel and steel dust And incineration are mixed / solidified at a ratio of 6: 4-8: 2 by weight, and the particle size is adjusted in the drying / firing step. Waste which mixes the fillers separated by size by heating with asphalt heated from 140 ?? to 160 ?? is an electric furnace which is effectively used, a filler for bitumen packing using steelmaking dust and an incinerator, and a filler of an ascon manufacturing method using the same. Publication No. 10-2000-003636), etc. are disclosed,

In addition, in order to be suitable for various works such as various civil works, construction works, underwater underground works, etc., 71 parts by weight of slag powder and 25 parts by weight of Portland cement are admixtures 2.85 parts by weight of gypsum, 0.9 parts by weight of alum stone, Low-cost composite cement composition using a slag containing carbon black (0.09 parts by weight, 0.1 parts by weight of methyl cellulose, 0.06 parts by weight of silica) (Public Publication No. 10-1997-0059135), The present invention relates to a lightweight foamed concrete composition containing fly ash as a light-weight foamed concrete and a method for manufacturing the same, wherein cement and fly ash are mixed in a weight ratio of 2 to 8 to 1, and water is added thereto. A cement paste is prepared. Next, a diluent mixture of foaming agent and water is introduced into a bubble generator to generate bubbles, and the bubble solution is mixed with the cement paste. On the contrary (lightweight foamed concrete composition containing fly ash and its manufacturing method (Patent No. 10-2000-0007185), 70 to 90% by weight of cement, 10 to 20% by weight of sand, 1 to fly ash After mixing and mixing the mixed mortar blended with water at 10% by weight in the field, and mixing the mixed mortar with 2 to 4% by weight of the foaming agent to water, 90 to 97% by weight of the bubble group generated by passing through the foamer. Filling method of the pupil part using bubble mixing mortar which bubbles-mixed mortar mixed by 3-10 wt% ratio is injected within 7m into the pupil part and cured for 12-17 hours, and then laminating the bubble-mixing mortar on it again. Korean Laid-Open Patent Publication No. 10-2000-0031838) is also disclosed.

In addition, a high-quality foam mortar with uniform foam distribution, excellent insulation and soundproofing lightness, and uniform compressive strength can be used as a thermal insulation and soundproofing material for floor slabs of various buildings, or can be used for soft ground soils. And to a method for producing the same. Mix the foaming agent of concentration 2 ~ 4 with water to make enough bubbles, and then prepare 75 ~ 80 weight of cement, 8 ~ 10 weight of sand, 15 ~ 17 weight of fly ash and 1-3 weight of Cemexpan. After mixing and stirring together to prepare a mortar, a mortar composition for foaming, characterized in that the mixture is prepared by mixing 5 to 15 weight of the bubble liquid generated bubbles with respect to 90 to 95 weight of the mixed mortar. -0028978) and a foam mortar composition and a method for manufacturing the same, which can be used as a thermal insulation and soundproofing material for floor slabs of various buildings, or for soft soils, and a method of manufacturing the same. After the mortar was prepared by mixing the mixture with 75 to 80 weights of cement, 8 to 10 weights of sand, 15 to 17 weights of fly ash, and 1 to 3 weights of Cemexpan with water, to prepare a mortar, mixed mortar 90 To ~ 95 weight There is also disclosed a foam mortar composition (Published Patent Publication No. 10-2001-0028978) characterized in that the mixture is prepared by mixing 5 to 15 weight of the bubble solution generated bubbles.

These former cavity fillers have a function of hydrate generation and a function of promoting / coagulating the pozzolanic reaction, which enables the integration of the composition, but also reduces the dispersing performance with cement particles and the water content such as high fraction of clay powder. Desirable load or strength can be expected by forming a cavity filling material without having good flowability, workability, improving resistance to freezing and thawing, and lowering the specific gravity by increasing the pore layer of the composition. It is not there.

Cake tops and soils and crushed sands used as the material for the back-filled lightweight foam concrete for tunnels / underground facility doors of the present invention are generated in the crushing process of producing rock as gravel and aggregates in the quarries. The coarse aggregate (4,7mm or more) is selected in the process, and when washing with water in the final screening process, the crushed sand (fine aggregate; 0,074mm-4,7mm) is selected and used as aggregate for mortar, and below 0,074mm. Stone dust, that is, cake topstone soil, is generated.

In addition, when cutting the rock or polish the surface water is used, and the stone powder is discharged and accumulated like water and naturally dehydrated to generate cake topstone soil.

As such, the cake topsoil produced in quarries has no value in use, and has been classified as waste (garbage) until now and landfilled. The discarded cake topsoil is transported to a landfill and is disposed of, so there is an economic problem that the landfill site and landfill costs are imposed. There is also a problem that causes river pollution by leaving the river as it is.

The present invention is based on the cake tops (waste) (waste) (waste) (20-35%) of cake topsoil (waste), which was generated and disposed of as waste in quarries, was mixed with agitated cement and water, and then foamed with a foaming agent. By constructing lightweight foamed concrete mixed with foamed foam using the machine, and placing it in the cavity of civil engineering (tunnel) / facilities (underground), it is particularly economical and its physical properties are similar to those of general cement concrete. It is to provide lightweight foamed concrete for filling the cavity by using cake topsoil which solves the problem of cake topsoil previously treated as waste and solves environmental problems.

In order to implement the present invention, the cake tops were treated as waste (20-35% by weight) and mixed with cement (35-50% by weight) and water (25-30% by weight). A cake phase with excellent workability due to the excellent physical / chemical safety, load and strength by mixing and kneading the foaming agent (diluted water and foaming agent in a weight ratio of 30 to 40: 1) using a foaming machine (weight ratio 2 to 10%). It is characterized by lightweight foamed concrete for co-filling of tunnels / facilities using stone powder.

Another object of the present invention is characterized by contributing to the economic benefits and recycling industry by eliminating the waste disposal costs by using as a lightweight foam concrete fillet flooring using the cake-like stone powder, which is an environmentally friendly material that was disposed of as waste. . In addition, the present invention is to develop and use lightweight foam concrete for backing the cavity of an environmentally friendly tunnel / facility that also prevents water pollution caused by the discharge of environmentally friendly cake topsoil.

In order to efficiently and economically utilize cake topsoil (waste) generated from quarries and landfilled as waste, cake topsoil (waste) (weight ratio 20-35%), which is an environmentally friendly substance, is added to cement (weight ratio 35). -50%) and mixed with water (25-30% by weight), and then foamed by foaming the foaming agent (water and foaming agent diluted to 30-40: 1 by weight) using a foaming machine (2-10% by weight) It is to provide lightweight foamed concrete for back filling of tunnels / facilities using cake topsoil with excellent construction properties by mixing and kneading with excellent physical / chemical safety, load and strength.

As described above, the present invention utilizes a mixture of cement and water, which is generated and discarded during the production of aggregates and masonry in quarries, by mixing and stirring cement and water therein, and mixing bubbles foamed by a foaming machine in the tunnel / Inject and construct lightweight foamed concrete for filling the cavity of underground facilities.

The specific composition ratio of the lightweight foam concrete for filling the tunnel / facility cavity using the environmentally friendly cake topsoil of the present invention is as follows.

Cake topsoil ,,,,,,,,,,,,,,, 20-35% (weight ratio),

Cement ,,,,,,,,,,,,,,,,,,,, 35-50% (weight ratio),

Water ,,,,,,,,,,,,,,,,,,,,,,,,, 25-30% (weight ratio),

Dilution bubble liquid ,,,,,,,,,,,,,,,,, 2-10% (weight ratio),

As the above, the use of the environmentally friendly cake topsoil (waste) is high in its properties, and kneading the foam foamed by a foaming machine added in addition to the ordinary cement to fill the cavity during filling and filling of lightweight foam concrete Smooth separation, no settling of solids, no shrinkage at the time of curing, guaranteed 27,220-14,895Kgf of core (condition ?? 10㎠-20㎠) and strength of 346,6-189,6Kgf / ㎠ In addition, there was no bleeding at all, and it was confirmed that the load was 300-900 Kgf and the strength was maintained at 12-70 Kgf / cm 2, especially as a result of laboratory / field experiments (condition 3-7 days curing) for each optimum mixing ratio.

In the present invention, by adding a natural friendly cake topsoil as an additive, and adding a foaming agent to form a lightweight filling material, the flowability is good, injection and filling is easy to improve workability, preventing the precipitation of solids, It is possible to maintain the rigidity by improving the strength of the filler by the function of preventing shrinkage, preventing bleeding, and reducing the load.

The physical characteristics of the present invention having the above-described load reduction and high strength retention effect are shown in the following table and examples.

(Unit: kg / m ³ )

cement Stone powder water Bubble rate (%) Compressive strength (kgf / cm ² ) 7 days 28 days One 510 220 270 44.90 35 46 2 460 200 240 50.60 28 34 3 440 290 270 43.30 32 39 4 400 260 240 49.30 22 27 5 350 230 210 55.50 17 21 6 310 200 190 60.40 15 18

Example 1

21.5% of cake topsoil (weight ratio), 50% of cement (weight), 26.5% of water (weight), 2% of diluted foam (weight ratio) Are 35 Kgf / cm 2 and 46 Kgf / cm 2, respectively.

Example 2

7-day and 28-day compressive strength of lightweight foam concrete with a specific gravity of 0.95% (weight ratio), cement 50% (weight ratio), water 26% (weight ratio), diluent foam agent 2.25% (weight ratio) Are 28 Kgf / cm 2 and 34 Kgf / cm 2, respectively.

Example 3

78.5 and 28-day compressive strength of lightweight foam concrete with specific gravity 1.0 mixed with 28.5% (weight ratio) cake, 43% (weight ratio) water, 26.5% (weight ratio) water, 26.5% (weight ratio) dilution foam, and 2% (weight ratio) Are 32 Kgf / cm 2 and 39 Kgf / cm 2, respectively.

Example 4

78.5 and 28-day compressive strength of lightweight foamed concrete with a specific gravity of 0.95 (weight ratio), cement 43.5% (weight ratio), water 26% (weight ratio), diluent foam agent 2.25% (weight ratio) Are 22 Kgf / cm 2 and 27 Kgf / cm 2, respectively.

Example 5

7% and 28-day compressive strength of lightweight foamed concrete with a specific gravity of 0.8% of cake topsoil (weight ratio), cement 43% (weight ratio), water 25.5% (weight ratio), dilution foam agent 2.5% (weight ratio) Are 17 Kgf / cm 2 and 21 Kgf / cm 2, respectively.

Example 6

7% and 28-day compressive strength of lightweight foamed concrete with a specific gravity of 0.7% (weight ratio), cement 43.25% (weight ratio), water 26% (weight ratio), diluent foam 2.75% (weight ratio) Are 15 Kgf / cm 2 and 18 Kgf / cm 2, respectively.

As described above, the present invention recycles the cake topsoil that is generated and processed in the production of aggregates and masonry in quarries to produce lightweight foamed clay bottom concrete, thereby reducing the material cost and cost burden due to landfill treatment of waste. Economical benefits obtained by omitting and preventing river pollution caused by the discharge of waste stone powder is beneficial to the environment and beneficial to the recycling industry for recycling cake topsoil.

As described above, the present invention utilizes the cake topstone soil generated and discarded in the production of masonry / aggregate in quarries as a predominant material to manufacture the light-weight foam mortar filling material in the cavity, thereby eliminating the economic burden of landfilling the cake topstone soil. In addition, the pollution of the river is prevented and it is eco-friendly, and the physical properties and quality of load, strength, etc. are also proved to be superior to the conventional ones.

Claims (3)

The cake topstone clay, which is generated from the aggregate / stone processing in Seoksan, is discarded and mixed with the total ratio of lightweight foam concrete for filling in a weight ratio of 2 to 4, and formed into bubbles that are foamed through a foaming machine. Method for manufacturing lightweight foamed concrete for filling a cavity of a tunnel / facility. The light-weight bubble for filling the cavity of a tunnel / facility using a cake topstone, wherein the cake topsoil and cement are mixed at a ratio of 5; 5 to 3; 7 (weight ratio) and foamed through a foaming machine. Method of making concrete. The tunnel according to claim 1, wherein the cake tops are composed of bubbles foamed through a foaming machine in 20 to 35% of cake topsoil (weight ratio), 35-50% of cement (weight ratios), and 25-30% of water (weight ratios). / Method for manufacturing lightweight foamed concrete for filling cavity of facility.