KR20190049123A - method for shotcrete mixing design and construction using recycled aggregate and photocatalyst - Google Patents

Abstract

The present invention relates to a shotcrete mixing design capable of reducing the material cost while maintaining strength and a construction method. The shotcrete mixing design, as a mixing material mixed with shotcrete, comprises: cement; fine powder sludge; recycled aggregate; sand; and coarse aggregate and the shotcrete mixing design and the construction method of the present invention use the recycled aggregate and a photocatalyst, wherein the recycled aggregate, as the mixing material for surface-treating the shotcrete, comprises: the cement; the fine powder sludge; fine aggregate; the photocatalyst (TiO_2).

Description

Technical Field [0001] The present invention relates to a shotcrete composition and recycling aggregate and photocatalyst,

The present invention relates to a method of mixing and designing shotcrete using recycled aggregate and a photocatalyst, and a construction method using the same.

As the population growth and industry developments require efficient development of the country, cutting slopes are continuously expanding due to the development of roads and housing complexes, and the general method used for the protection and reinforcement of slopes Depending on the function, it can be classified into the prevention method of the reduction of the safety factor (slope protection method) and the method of increasing the safety factor (slope reinforcement method).

The method of preventing the reduction of the safety factor is a method of preventing the decrease of the slope safety factor by the erosion of the slope surface by weathering and the weathering by the exposure of the slope surface by the air. It is generally regarded as the slope surface protection method. Attachment, cutting of the cutout, block laying, shotcrete. In order to increase the safety factor of the slope in the section where the required safety factor of the slope is not secured due to slope cut-off, it is necessary to adjust the slope slope gently or to use the technique of retaining wall, pile, anchor, nail, . Among them, suitable methods are selected and applied according to ground conditions, aesthetics, maintenance and site conditions considering slope use, soil and rock characteristics.

The shotcrete method, which is one of the slope protection methods, is a method of spraying material that has been pumped up to a predetermined position through a high pressure hose or pipe by using compressed air in a field bimbe or factory concrete, This is a method to improve the stability of the slope surface because it can be applied easily to the slope where the slope is difficult and the vegetation is difficult, Has been applied to many sites since long ago. The shotcrete method can be divided into a high-strength shotcrete casting (24MPa) method which functions as a structure by mixing with a temporary shotcrete casting (18MPa) method and a reinforcement method (nailing, permanent anchor, etc.) according to the purpose of use.

However, the material used for the shotcrete method is likely to be re-inflated due to surface contamination and peeling due to bleaching when cement, aggregate, and additives (rapid curing agent) are exposed to the outside for a long time.

In order to solve this problem, the increase of the shotcrete quality standard requires the increase of cement usage and the use of supplementary materials such as steel fiber, and the increase of the usage material is a factor of increase of the construction cost per shot area of the shotcrete method. do.

In order to solve this problem, the present invention provides a technique for using recycled aggregate and sludge (fine powder) that is required to replace the waste cement and aggregate by recycling waste concrete, in order to prevent the cost rise of cement and aggregate The purpose.

Another object of the present invention is to provide a method of designing an optimum mixing ratio at which the compressive strength necessary for applying the recycled aggregate and sludge to the shotcrete composition can be exhibited.

Further, the present invention aims at developing a shotcrete technology using a photocatalyst (TiO2) capable of removing a certain amount of NOx and SOx generated by vehicle soot in order to solve pollution of the atmospheric environment, which has recently become a social problem .

Recycled aggregate and photocatalyst including cement, fine powder sludge, fine aggregate, photocatalyst (TiO2) are used as a blending material of shotcrete, including cement, fine powder sludge, recycled aggregate, sand and coarse aggregate. It provides a shotcrete formulation design and construction method.

According to the present invention, the present invention provides an optimal shotcrete mixing method capable of maintaining the strength and reducing the material cost.

 In addition, by applying the reduced cost to the application of the photocatalyst material, the functional shotcrete method having the atmospheric purification function can be provided by complementing the disadvantages of the conventional shotcrete method such as whitening, and exhibiting the fine dust removing effect by the photocatalyst.

1 is a view of a shotcrete installation according to the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS The objects, particular advantages and novel features of the present invention will become more apparent from the following detailed description taken in conjunction with the accompanying drawings, in which: FIG. Also, terms used are terms defined in consideration of the functions of the present invention, which may vary depending on the intention or custom of the user operator. Therefore, definitions of these terms should be based on the entire contents of the present specification.

The shotcrete mixing material used in the present invention may be cement, sludge (fine powder), fine aggregate (recycled aggregate and sand), coarse aggregate (13 mm recycled aggregate), and the shotcrete surface treatment materials include cement, sludge Sand), photocatalyst (TiO2) or the like is used.

The shotcrete mixing material according to the present invention can be applied to prevent the loss of the incision and prevent collapse by spraying the shotcrete to a thickness of 10-20 cm when excavating at the incision temporary reinforcement site. In the permanent reinforcement of the incision site, (Nail, permanent anchor, rock bolt, etc.), it can be used to install the permanent structure of the cutout, and it can prevent the initial deformation by inserting shotcrete after tunnel excavation for reinforcement inside the tunnel. After applying shotcrete, the shotcrete surface treatment method may be applied to the tunnel wall through concrete pouring to reduce the pollutants (NOx, SOx) in the tunnel.

In addition, the shotcrete formulation material of the present invention can be used for repairing other road facilities, and the shotcrete surface treatment method can be applied to repair old road facilities such as a median, (NOx, SOx), which is a photocatalytic function, and the removal of contaminants from the exterior of buildings by the effect of self-clinics, as well as prevention of deterioration of beauty caused by discoloration and whitening by applying shotcrete surface treatment technology to the exterior of buildings with exposed concrete You can aim for the effect.

 The materials used for the shotcrete formulation are cement, sand, gravel, and admixtures.

The economics of each 10cm thick material required in the National Road Construction Design Practice are compared as follows.

Basis for calculating the material cost of used materials division standard unit Price Remarks cement Usually cement 40kg / bag 4,180 Price data 11 P106 National standard sand Athletic sand m3 13,667 Price data 11 P101 Gangwon average Pebble 13mm m3 15,417 Price data 11 P101 Gangwon average sand recycle m3 2,000 The best of Gangwon Pebble 13mm m3 3,500 The best of Gangwon

Material cost when using ordinary aggregate division Quantity unit unit price Price cement 57.1 kg 105 5,967 sand 0.11 m3 13,667 1,503 Pebble 0.75 m3 15,417 11,563 Sum T = 10cm m2 19,033

Recycled aggregate 100% Replaceable Material cost division Quantity unit unit price Price cement 57.1 kg 105 5,967 sand 0.11 m3 2,000  220 Pebble 0.75 m3 3,500 2,625 Sum T = 10cm m2 8,812

Recycled aggregate 50% Replaceable Material cost division Quantity unit unit price Price cement 57.1 kg 105 5,967 sand 0.11 m3 7,833 862 Pebble 0.75 m3 9,458 7,094 Sum T = 10cm m2 13,922

Cost reduction rate by each condition division Price General standard difference Reduction rate Normal 19,033    - 0 50% substitution 13,922 5,110 26.9% 100% substitution 8,812 10,221 53.7%

It is possible to maintain the target strengths as described above, and to derive the optimum mixing design method that can reduce the material cost.

 In addition, by applying the cost thus reduced to the application of photocatalyst material, the functional shotcrete method with atmospheric purification function as well as the slope reinforcement which exhibits the fine dust removal effect by the photocatalyst while compensating the disadvantage of the conventional shotcrete method, The same or lower price can be applied.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, Of the right.

Claims (1)

As a blending material blended with shotcrete,
Cement, fine powder sludge, recycled aggregate, sand, coarse aggregate,
As a shotcrete surface treatment compounding material
Mixture design and construction method of shotcrete using recycled aggregate and photocatalyst including cement, fine powder sludge, fine aggregate, photocatalyst (TiO2).

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