Recommendations

Recommendations for expanding the use of non-explosive materials for destruction of solid concrete and reinforced concrete structures

Introduction

These Guidelines define the scope, parameters and conditions for the effective application of the method nonexplosive destruction of oversized blocks, mass foundation, brick treasure, concrete and reinforced concrete structures. They contain regulatory requirements and recommendations for nonexplosive destruction of buildings in various conditions.

Recommendations developed by summarizing the experience of testing and use in the mining and construction business of physical explosions.

1. Purpose and scope.

1.1. nonexplosive method is intended for destruction of objects in crowded conditions, ie in existing shops, near buildings, highways, industrial communications, settlements, etc.

1.2. process has full security to the environment, as destruction process does not cause noise, is not accompanied by seismic vibrations, emissions of solid or gaseous products. The method does not require any type of energy (either electrical or pneumatic).

1.3. non-explosive compounds are useful where it is impossible to use explosives.

The main application of the method is the loosening of the bases and cutting oversized blocks, demolition of buildings and structures in the physical liquidation of mines associated with the restructuring of the coal industry of Ukraine.

The method can also be used to eliminate some of the monolithic concrete and reinforced concrete structures in mining and civil engineering, as well as other industries, such as steel mills.

2. General characteristics of the material and the principle of destructive action.

2.1. Modern technology nonexplosive damage foundations, masonry and other concrete and reinforced concrete structures based on the use of modified quicklime. By co-grinding calcine calcium carbonate and modifiers are non-explosive destructive materials containing calcium oxide in the range of 65 to 90 .. 95% by weight.

2.2. destructive non-explosive substance HPB-80 (TU 2.7.00030937 BV) is a powder usually white or gray, dusting, non-flammable, explosion-proof, which has alkaline properties ( pH = 12,5)

2.3. non-explosive when mixed with water, destroying the material, a mixture (suspension), which, when filled in partially or completely closed cavity (eg, hole) in any object, gradually, as a result of hydration powder hardens and increases in the volume. The amount of water in the powder NRW -80 should not exceed 30 ... 35%. Otherwise, the expansion pressure drops. The increase is accompanied by development pressure from 50 to 150 MPa on the walls of the hole, the value of which depends on the content in the powder CaO. In the body of the destroyed object develop stress values ??may exceed its maximum tensile strength, which leads to the destruction of the object. The effect of destruction is expressed in the formation of cracks in the body of the object with their development over time.

2.4. Usually cracking occurs depending on the temperature of the object and its characteristics in the range of 12 to 20 hours. The higher tensile strength, the longer the cracking. Raising the temperature of the object speeds up the formation of cracks.

2.5. temperature gauging water HPB-80 in the summer should be (depending on the temperature of the destroyed object) from 10 to 20 degrees Celsius in the winter - from 20 to 50 degrees Celsius.

2.6. powder NRW Store in a dry place on wooden pallets at temperatures above 20 degrees Celsius. Shelf life - 6 months.

3. The main parameters of the technology by expanding non-explosive destruction of the object materials.

3.1. destroys the object must have a parallel to the holes at least two open surface (the best option contains a demand for freedom of all four sides of the object in that direction).

3.2. blasthole spacing should be 200 ... 500 mm. The main characteristics of the destroyed object to be considered when designing schemes hole drilling are: tensile strength of the material parameters of the object and its reinforcement. And the number of holes will be smaller, the larger the size of parts (units) formed in the destruction of the object, namely, manual disassembly lumpiness destroyed object should be less than for a showdown with the use of machinery. Reducing the distance between blast holes accelerates destruction of the object, but it causes an increased flow of powder. In all cases, the distance of the holes to the exposed surface should be less than the distance between the bore-hole.

3.3. blast holes should be placed in a line parallel to the exposed surface. If the surface of the object is such that at a time is not reached its full destruction, it is necessary to make the second cycle of destruction in compliance with all requirements under the scheme arrangement of holes.

3.4. larger hole depth and diameter, the greater the pressure developed extensions. Based on the practice rational hole depth should be 90 ... 95% of the planned depth of the destroyed object.

3.5. blasthole drill recommended diameter 25 ... 40 mm (when using a 40 mm diameter holes increases the probability of spontaneous emission of the material from the hole).

3.6. expanding non-explosive material consumption per 1 m of the hole diameter of 32 mm is 1.5 kg and 40 mm - 2.0 kg. Specific consumption of non-explosive material should be assumed to be 8.0 ... 16.7 kg / m 3 of the destroyed object. With the destruction of concrete structures flow must be increased by 30%.

3.7. If the object is characterized by high water absorption, the boreholes before filling in the mixture to saturate with water or an aqueous solution of surface - active agents (surfactants), ie 0.1% - aqueous wetting dB, which is widely used in coal mines. For this all boreholes filled with liquid to the mouth for 30 minutes, after which the liquid is removed from the hole with compressed air or other means, and themselves filled boreholes after working mixture. Aqueous solutions of surface - active substances (surfactants) should be preferred to the water for the following reasons: under the influence of the surfactant changes the mechanical properties of materials, which is due to reduced surface free energy and, therefore, reducing the work required to increase the cracking (surface) SAW getting into the area of ??micro-cracks due to the reduction of surface energy facilitates the development of micro-cracks in the crack fracture.

3.8. blast holes are filled with a mixture of working to the mouth. After pouring the mixture of working to protect the mouth of the holes from the action of water (eg, rain) and shielded from direct sunlight, heating.

3.9. recommended even after the appearance of hairline cracks, water the object water or aqueous surfactant. Spraying water, especially an aqueous solution of surfactant to the surface of the object being destroyed in the area of ??cracking (humidification zone) helps to increase the width.

4. Conditions and parameters of the effective application of quick-stemming from plaster.

4.1. Prevent the release of material from the hole to apply quick-tamping of plaster. It should be used if:

- object temperature above 30 0 C;

- the diameter of the hole more than 40 mm (normal temperature of the object);

- the water content of the mixture will be working less 0,25;

4.2. Reactive tamping made of gypsum (TU-21-39-10-82). Gypsum binder or simply cast a white powder in bulk density of 1.18 ... 1.20 t / m 3 , and Cured 1.62 ... 1.66 t/m3. Optimum water content in the solution is 30 ... 31% of the dry weight. In this case, the setting starts at 6 ... 7 min., And ends at 27 ... 30 minutes. At the specified water content in plaster solution compressive strength is: 30 minutes. - 6.0 ... 7.0 MPa after 60 min. - Up to 11.0 MPa. Gypsum has the ability to slightly - to expand 1% hydration.

4.3. Equipment gypsum tamping should be made of polyethylene thickness of about 0.1 mm or paper GOST (66-62-53) with the number of turns equal to two just before the destruction of the object or centralized. Filled envelope must be delivered to the place of use in corrugated cardboard or wooden boxes, paper or plastic bags. While tamping in paper envelopes should be further put in plastic bags.

4.4. Reactive stemming from plaster should be stored in dry, specially designated place. To do this, the car is allowed to use, safe, container. Allowable storage time tamping one month.

4.5. before using fosfogipsovaya tamping should be saturated with water. For this purpose, the cover is punctured it, that is, on the surface of the hole formation. The distance between the holes for tamping, made in a paper envelope, should be less than 20 mm and the number of holes at least 0.2 units / cm 2 . Perforated shell immersed in water and allowed to stand 1.0 ... 2.0 min. End of water saturation is determined to stop the release of air bubbles from the water. After that, the shell is removed from the container and placed at the face on a piece of board or cut where they are for 30-40 seconds. During this time, excess water remaining on the surface and inside the shell, time to flow. Perforation shells filled with plaster can be made in the manufacturing process, in storage or prior to use.

4.6. Each shell with plaster, placed in the hole must be thoroughly crushed and drowned in it.

4.7. Number of shells with gypsum placed in one hole should be determined empirically, depending on the intensity and the probability of spontaneous emission of the alleged non-explosive material from the hole. Ease of crushing shells in the hole, and even saturation of gypsum water is ensured by the perforation on its surface. In all cases, the length of the self-hardening tamping should be 5 ... 10% of the length of the hole.

4.8. When applying inclined (60 0 to the horizon) or vertical boreholes allowed gypsum powder to put in the hole (on the surface of the non-explosive material in bulk form, and then adding to it (by gravity) of the appropriate amount of water.

4.9. allowed to use alabaster tamping, tamping or cement with liquid glass, made at the site of works in accordance with building nomes.

5. organization works.

4.1. Procedure for destruction of the object.

4.1.1. process of destruction of the object consists of the following operations:

- preparation to the destruction of the object (the object is freed from the equipment, cleaning it from the ground and debris obkopka and marking plots destruction, etc.);

- drilling holes as marked (the scheme);

- working suspension preparation and filling of holes;

- quick-cooking tamping (if necessary), and filling her holes;

- spraying liquid on the surface of the destroyed object to increase the intensity of cracking;

- disassembly of the object (and the subsequent exposure of rebar cutting, removal of the destruction of the object of the fracture zone);

The most labor-intensive work in the complex, is mainly determined by the duration, cost and unit labor costs destruction 1m 3 of the object is to drill holes.

4.1.2. During the preparation to the destruction of the object (for example, building structures) must be followed:

- survey of the facility;

- development cards (work rules);

- Preparation and checking of the necessary equipment;

- instructing personnel involved;

5.2. equipment for drilling.

5.2.1. Drilling holes in the object by means of drills. Working tool punch are different types of crowns.

5.2.2. Drilling holes optimal diameter (32 ... 40 mm) should be applied crowns special purpose for the holes diameter 42 ... 43 mm - crowns used during the horizontal and sloping mountain workings in the coal mines, 52 ... 53 mm - Crown, used in vertical shafts.

5.3. Preparing the mix and filling her holes.

5.3.1. To prepare the working fluid is required:

- scales for weighing the powder;

- container for mixing the powder with water and measuring vessel for dispensing water;

- mixer (with a large amount of work);

5.3.2. Preparing the mix is ??as follows. In a bucket poured, for example, 2 liters of water and 150 ... 200 ml of plasticizer. Then slowly pour the bucket 6 kg powder working intensively stirring the mixture with a stick or hand mixer. Mixing leads to mass produce a good yield, with no visible lumps. Mixing time weight is less than 5 ... 8 min.

Keep in mind that the higher the temperature of the object, the cooler should be water for mixing the powder. At low (below 0 0 C) temperatures of the object should use the hot (up to +50 0 C) water.

increasing water content in the working mixture to slow the process of the formation of cracks in the destruction of the object and reduces the probability of spontaneous emission of the material from the hole.

6. Safety.

When working with non-explosive powder expanding to observe safety, namely:

- wear safety glasses, dust mask and gloves, as non-explosive substance HPB-80 alkaline and causes burns to the skin;

- not to look in the hole, filled with a mixture of working, as the spontaneous emission of a mixture, especially in the hot season;

- in contact with skin or eyes, rinse with abundant water is the place.

Beware of imitations! Beware of imitations! Beware of imitations! Beware of imitations!