The mixture has the following properties:
Alkaline properties (pH-12.5);
Bulk bulk density - 1,3 t / m 3;
Water requirement - 30%;
Degree of dispersion (the rest on a sieve №008) - no more than 12%;
Hydration time, min - not less than 30 min;
Developed expansion pressure, mPa - not less than 80;
Shelf life 6 months.
The non-explosive expanding mixture of HPC-1, is intended for introduction into grouting mortars, oil-well cements, dry building mixtures for the production of expanding oil-filled material RTM, expanding portland cement. The additive is characterized by an increase in the linear dimensions of the cement stone of oil wells in cementing oil and gas wells with a temperature of up to 40 ° C. HPC-1 is used when injected into grouting mortars, by premixing with cement in the cement paste composition, or by directly introducing it into the mixer used to prepare the mortar mixture in an amount of 2 to 30% of the weight of the oil-well cement. The amount of the mixture to be administered depends on the required amount of linear expansion of the cement stone, the mineralogical composition of the cement, the quality of the water used, and so on. and is determined for each specific case by laboratory.
PURPOSE AND SCOPE.1.1. НРС-1 is designed for destruction of objects in cramped conditions, i.е. in operating workshops, near buildings and structures, transport highways, industrial communications, settlements, etc.
1.2. HPC-1 is completely safe for the environment, because The process of destruction does not cause noise, is not accompanied by seismic fluctuations, emissions of solid or gaseous products. It does not require the use of any kind of energy (neither electrical nor pneumatic).
1.3. NRS-1 is advisable to use where it is impossible to use explosives.
The main area of application of HPC-1 is the loosening of foundations, the cutting of oversized blocks, the destruction of buildings and structures. HPC-1 can also be used for the liquidation of individual monolithic concrete and reinforced concrete structures in the process of ground and underground construction, as well as in other industries, for example, in metallurgical plants.
GENERAL CHARACTERISTIC OF MIXTURE AND THE PRINCIPLE OF DESTRUCTIVE ACTION.
2.1. The non-explosive expanding mixture of HPC-1 is a powder, most often white or gray, dusting, incombustible, explosion-proof, alkaline (pH = 12.5)
2.2. When the HPC-1 is mixed with water, a mixture (suspension) is formed which, when filled into a partially or completely enclosed cavity (for example, a hole) in an object, gradually hardens and increases in volume as a result of the hydration reaction of the powder. The amount of water in the HPC-1 powder should not exceed 30 ... 35%. Otherwise, the expansion pressure drops sharply. The increase in volume is accompanied by the development of pressure from 50 to 150 mPa on the walls of the hole, the value of which depends on the content of CaO powder. In this case, stresses develop in the body of the destroyed object, the values of which can exceed its ultimate tensile strength, which leads to the destruction of the object. The effect of destruction is expressed in the formation of cracks in the object body with their development in time.
2.3. Typically, the formation of cracks occurs depending on the temperature of the object and its characteristics in the range of 12 to 20 hours. The higher the ultimate strength, the longer the time for the formation of cracks. Increasing the temperature of the object helps to accelerate the formation of cracks.
2.4. The water temperature for shutting off HPC-1 in 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.
2.5. Store HPC-1 powder in a dry place on wooden pallets at a temperature of no higher than 20 degrees Celsius. The warranty period of storage is 6 months.
MAIN PARAMETERS OF THE TECHNOLOGY OF THE DESTRUCTION OF THE OBJECT OF HPC-1.
3.1. The object to be destroyed must have at least two open surfaces parallel to the axis of the holes (the optimal variant contains the requirement of freedom of all four sides of the object in the mentioned direction).
3.2. The distance between the holes should be 200 ... 250 mm. The main characteristics of the destroyed object, taken into account in the development of the drilling pattern, are: the tensile strength at break of the material of the object and the parameters of its reinforcement. Moreover, the number of holes will be the smaller, the larger the dimensions of the parts (blocks) formed when the object is destroyed, namely: for manual disassembly, the lumpiness of the destroyed object should be less than for disassembly using mechanisms. Reducing the distance between the holes accelerates the process of destruction of the object, but causes an increased consumption of the powder. In all cases, the distance from the holes to the open surface should be no more than the distance between the holes.
3.3. The holes should be placed in the same line parallel to the open surface. If the surface of the object is such that one does not achieve its complete destruction in one step, then it is necessary to perform a second destruction cycle, observing all the requirements for the drilling pattern.
3.4. The greater the depth of the hole and its diameter, the greater the expansion pressure developed. Based on practice, the rational depth of the holes should be 90 ... 95% of the projected depth of the destroyed object.
3.6. The consumption of non-explosive expanding material per 1m drill diameter 32mm is 1.5kg, and 40mm - 2.0kg. Specific consumption of non-explosive material should be taken equal to 8.0 ... 16.7 kg / m3 of the destroyed object. When destruction of reinforced concrete structures, the consumption should be increased by 30%.
3.7. If the object is characterized by increased water absorption, (Clean one or several drilled holes, depending on the size of the object, it is poured completely with water if the water level in the hole drops by more than 6 cm 30 minutes from the moment of pouring (per 1 running). the holes must be filled with water before filling with the working mixture by filling all the holes with a liquid to the mouth for 30 minutes, after which the liquid from the holes is removed by compressed air or in another way, and the holes are then filled with a working mixture.
3.8. The holes are filled with working mixture to the mouth. After filling with the working mixture, it is necessary to protect the mouth of the holes from the action of water (for example, in the rain) and to shield from direct heating by the sun's rays.
Packing: 40kg bags.
Often, during the construction or reconstruction of an object, it is necessary to pre-destroy old reinforced concrete structures. But the fact is that this material has increased strength, otherwise it would not have been able to retain the structure on itself. Dismantling in this case is a difficult task, so they can apply several options, including the destruction of concrete by ultrasound or chemical preparations.
General information
Let's consider often applied ways which will help to understand, how to destroy a concrete foundation by own hands:
Tip: when dismantling the RCS, cutting of reinforced concrete by diamond circles of the necessary density is very helpful.
To understand what method is suitable for a particular case, you need to familiarize yourself with each detail.
The simplest method
Router into small pieces of a small concrete structure you can sledge hammer. In this case, the rate of destruction in this case will depend only on your physical capabilities. Therefore, if they are small, you can spend a lot of time and effort on your work.
Alternatively, you can drill holes with a perforator in several places to reduce the strength of the material, then it will be much easier to destroy it. It is believed that even a reinforced concrete slab can be shattered with a sledge hammer, but is it worth it? Below you will learn about other easier methods.
We use powder
In this section, you will learn how to chemically destroy concrete, as often enough to remove solid building materials use chemical powders that do not burn and do not explode.
The popularity of this method is due to the fact that during the process there is no noise and there is no excess debris that can be observed during an ordinary explosion. Usually HPC-1 powder is used, since it has a high breaking strength (\u003e 30 MPa).
In the photo - diamond drilling holes
Below is an instruction for its use:
- Drill in a concrete structure holes with a diameter of 80 mm, the distance between them - from 560 mm.
- Pour in them a prepared solution - a powder with water.
- Wait about 48 hours, during this period the chemical will begin to crystallize and begin to destroy the building material.
- After the announced time, on the site of the concrete structure there will be only pieces of scrap, which you will take out to the place of utilization.
Tip: for work, you may need a service - diamond drilling holes in concrete with the appropriate crown diameters.
Use of acid mixture
Experts know what to destroy concrete without physical effort, and what substance has a harmful effect on it. Therefore, for the dismantling of sturdy ZhBK, an acidic mixture is often used, which simply dissolves the material.
To remove a small amount of a solid from the surface, simply pour on top of it with a substance, for example, hydrochloric acid.
Tip: Act very carefully, otherwise you may burn yourself or cause yourself another injury.
Usually in pure form, the acid is used extremely rarely, for this purpose, a special mixture is prepared.
With its help it is possible:
- dissolve the concrete;
- remove it from bricks;
- wash the remains off the wall.
The composition of the mixture - concentrated acids and inhibitors. The latter are necessary to protect other surfaces when processing concrete. For example, if you need to clean the frozen concrete mixer. The mixture will quickly penetrate deeply into the material and destroy it, as a result, after a while it will turn into dust, which can easily be swept off with a normal brush.
Tip: you can reuse the mixture if the building material has not been completely cleaned for the first time.
Destroy reinforced concrete
The above methods of destruction of concrete in this case are not so effective. You will have to fight with material that is much stronger. The use of a perforator for making holes is simply pointless, so it is better to immediately prepare special devices - powerful drills with diamond nozzles.
Only such an instrument can perform such work. In this case, you can drill holes at almost any angle.
Any methods of dismantling concrete structures described above are not able to supervise with diamond cutting. The high strength of the material is not a hindrance, therefore it will cut any thickness. The price of the method is high, but it allows you to quickly cope with the task.
Tip: for cutting a large block concrete block, you can use a machine with a diamond rope.
It can only be done by a professional, since it has rather complicated management. The principle of dismantling is the use of hydraulic pressure, after the unit is wrapped in a rope. The cutting speed depends directly on the strength of the concrete. For example, in especially difficult cases, about 2 m of construction can be cut in an hour.
In this case, work with ordinary concrete does not cause complications. It is 5 times faster. The machine is usually used for articles thicker than 1 m.
During operation, the following requirements must be observed:
- a constant cooling of the machine mechanism is required, as from a constant work he quickly heats up;
- next to the workplace should be a source of cold running water. In addition, water serves also as a kind of protection for the diamond coating, preventing its destruction and washing away the excess dust that forms during operation;
- it is necessary to have a permanent connection to a three-phase voltage, otherwise the equipment will not work.
Conclusion
The destruction methods described above are effective and are used widely enough, although there are many others, for example, hydrocline for the destruction of concrete. With their help, you will be able to get rid of unnecessary reinforced concrete products and start new construction in a short time. The video in this article will help you find additional information on this topic.
- Types of corrosion of concrete
- Types of concrete protection against corrosion
In the manufacture of all the rules, the corrosion of concrete products from it is not terrible, and they will serve for a very long time. Concrete should be resistant to corrosive attack on cement stone.
Corrosion of concrete is the process of destruction of the integrity of the material arising from the impact of external aggressors.
At present, concrete is one of the most demanded materials in the construction sector. The properties of this material is mostly positive and resistant to weathering.
Types of corrosion of concrete
The physical and chemical effects of the surrounding space on concrete are such that its destruction occurs, called corrosion. In the connection of cement with water, many processes occur, an aggressive environment occurs, and for the protection of concrete from corrosion, it is required to study the subtleties of this phenomenon. The types of corrosion are distinguished by specialists 3, but most often destruction occurs under the influence of several species at once:
- Biological corrosion of concrete, implying the formation of a large volume of compounds in concrete stone. This occurs under the influence of various substances in concrete penetrating. Compounds that acquire a larger volume inside cause internal stresses and, as a consequence, cracks in the concrete. Sulphate corrosion is of the greatest importance in the study of the problems of concrete destruction.
- Physico-chemical forms of corrosion of concrete, in which the components of a concrete stone dissolve in water. In this case, dissolution and washing out of calcium hydroxide, which was previously present or formed, often occurs. Blurring of reinforced concrete with water occurs at different rates. Hydroconstructions have a dense massif in which corrosion is slow, the result of it is visible only after decades. And in cooling towers that have thin shells, calcium hydroxide is washed out much faster, why repairs are required after a few years. If water is filtered through concrete, the decomposition is accelerated many times, concrete becomes highly porous, its strength decreases by more than half. This process is also called lime leaching or white death, because of the external signs of such destruction. When the material begins to be corroded by an aggressive environment, it is covered by a white coating.
- Chemical corrosion, which occurs as a result of the interaction of concrete stone and substances from the environment, easily formed soluble salts, which are then washed out. Along with water-washing substances, amorphous masses that do not have astringent properties are often deposited in concrete masses. Concrete under the influence of these forces over time turns into a loose porous mass, which breaks down very easily.
Corrosion can be called a separate branch of science, which studies all processes, called corrosion, means of preventing them and the stability of concrete structures to various natural processes. Such a phrase, like concrete corrosion, sounds unusual, but not only concrete, but also brick, asbestos cement and aerated concrete, foam concrete along with silicate blocks are corroded.
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What is the corrosion of concrete?
This process begins with the fact that the concrete hardens, turning at the same time into a cement stone, whose durability is much lower than the fillers of the stone. The composition of the cement stone includes the compounds formed during the solidification process. It has a lot of capillary moves, both open and closed, they can be filled with either water or air. The structure of solidified concrete is very heterogeneous.
With regard to hardened concrete and reinforced concrete, aggressive water - river, sea, sewage and drainage water, together with available in the air air acid gases. Within the boundaries of cities and especially in industrial areas, groundwater contains a great many different impurities that contribute to the corrosion of hardened reinforced concrete. If there are chemical plants in the vicinity, the groundwater runoff will be polluted with acids, both organic and mineral, nitrates and chlorides, ammonium, copper, zinc, iron and nickel salts, sulphates, alkalis. In the vicinity of metal processing plants, the soil will be saturated with products of pickling processes and ferrous sulphates.
More than groundwater, saturating the destruction of cement stone substances drains factories and plants. If raw water descends into rivers, then the water in the rivers becomes aggressive towards concrete structures. Corrosion of concrete very often affects hydraulic structures. Air near and at the enterprises themselves also often contains contaminants, such as nitrogen oxides, sulfur dioxide, hydrogen chloride. With people's health, the concentration of these gases does not cause harm within the limits of the approved standards, but nevertheless it is enough that the concrete structures begin to deteriorate.
Corrosion of concrete is very diverse, since there are more than a hundred substances and their compounds, which, when in contact with a concrete stone, cause its destruction. There are microorganisms, called biodestructors, which destroy all types of structures. Destructive materials microorganisms can be with them in direct contact or settle inside porous structures. The worst time for concrete structures is the processes of the metabolism of microorganisms, since all the qualities of the material and the term of its service are significantly reduced in this case. To harm concrete even at a distance are capable of bioorganisms that are producers of substances aggressive with respect to concrete.
In any liquid and gaseous environment, additional factors are not required for corrosion of concrete and reinforced concrete. If there is high humidity in the gaseous medium, this factor accelerates the corrosion processes.
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Corrosion processes in reinforced concrete
Reinforced concrete is most prone to corrosion, as it contains a metal frame.
Although the processes occurring in these materials are very similar, the destruction of reinforced concrete is a much more complicated process. The difficulty lies in the content of the metal framework, for which electrochemical corrosion is the enemy. It is believed that the reinforced concrete is very durable and durable. This is due to the formation of a passive protective layer having a protective property when the surface of the reinforcement and the alkaline nature of the concrete interact. However, if concrete is exposed to long-term exposure to atmospheric precipitation, containing salts and carbon dioxide, carbonization occurs and the medium becomes acidic as a result. As a result, the strength decreases, and the building begins to break down more quickly.
To corrosion of this species has been suspended, it is required to introduce into the concrete special inhibitors, acting specifically for the corrosion of metal. Such substances can create a film on the surface of the reinforcement inside the concrete, which increases the overall strength. This film does not allow to interact with the metal and concrete, thus, the reaction of electrochemical corrosion does not occur. These compounds are added directly to the raw solution before the production of concrete slabs or applied to finished products. The composition can penetrate into the concrete by 50 mm.
The process of corrosion destruction is complex and dangerous for buildings made of reinforced concrete. If you take it seriously and do not try to prevent and stop it, any structure will be destroyed much more quickly. Used to protect reinforced concrete and projector anodes. With their help, an electrical contact is created between the frame of the reinforcement and the metal disc, according to the properties of the more active one. During electrochemical corrosion, a metal with negative values is decomposed due to EMF. Until the metal dissolves, a more reactive, reinforced concrete frame will be out of danger.
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How can corrosion protection of concrete and reinforced concrete be made?
Widely used in construction, concrete has several developments that are used to combat and reduce destructive processes. This is like protecting the material from the effects of the external environment, and the introduction of various kinds of additives that have different functions. Some of them prevent the appearance of cracks in the concrete, its destruction and leaching. It is often used for structures of high-density concrete, a capillary structure inside which is absent.
Destruction of concrete can be stopped by the introduction of hydraulic additives. They, in order to prevent leaching, bind calcium hydroxide to a compound that is less susceptible to dissolution, calcium hydrosilicate. The protection of concrete from corrosion may consist in the use of belite cement, since this material of calcium hydroxide releases a minimum, contains less than 3calcium silicate. If the destructive liquid has small amounts and evaporates from the surface of the concrete itself, calcium hydroxide will not be washed out of the concrete. It will seal its structure and stop filtering, which is called self-healing of concrete.
If the cement stone is damaged by waters that contain salts of sulphate or chloride, this is due to the formation of products, which are then easily washed out of the concrete. It happens that the binding properties of concrete are lost. With this, it is necessary to fight in a similar way, by lowering the content of calcium hydroxide in concrete. For example, calcium chloride is 100 times less dissolving in water if compared with calcium hydroxide.
Corrosion of concrete of sulfate type is characterized by formations in the pores of concrete, which in the course of growth tear it apart. This is called "cement bacilli". Therefore, cement, the content of tricalcium aluminate in which is insufficient, must additionally have resistance to sulfates. Concrete structures should not be covered with fungi and bacteria, river and marine algae, lichens, mosses, plants, since all this has a devastating effect on them.
The protection of concrete from water with various additives can be produced in various ways. These can be improvements, technological changes, including the stages. Cement for cooking should contain active mineral additives of a certain type and the corresponding mineral composition. Such solutions can also help, where drainage, drainage and waterproofing are applied to protect concrete from corrosion.
To spend destruction of concreteimprovised means, without resorting to costly options, it is necessary to turn your eyes to the distant past, when there was also no laser cutting, no chemical powders, no jackhammers. Everything was done wisely and with a minimum of costs.
How to destroy concrete - simple ways
To begin with, the conversation will be about simple, so to speak, low-budget methods, where there is no need to use some complicated tools and devices. All these options are available, economical in terms of money costs. The only time is the time, which is sometimes required in large numbers.
Blowtorch and water is the easiest way. To do this, use a blowtorch to heat concrete and heat the heating spot with cold water. As practice shows, the material will not immediately break down. A multiple process is necessary, but this is a very effective option. Already literally after three or four approaches concrete will begin to become covered with cracks. The rest can be completed with a sledge hammer.
To use this property of concrete as a weak bending and tearing strength, you will need the following tools:
- , to use it to make holes in the concrete.
- Peak from a jackhammer;
- Boaster.
Holes are made at a distance of twenty centimeters from the edge of the structure, whether it is a wall or a foundation. In the holes is inserted a peak from the jackhammer, on which you need to beat a sledge hammer. If the peak can not be found, then you can use a piece of metal reinforcement with a diameter of at least thirty millimeters, which is sharpened on one side. A few strokes - and concrete will begin to break down. Thus, it is possible to separate a sufficiently large piece if you drill the holes along the contour of destruction.
Sometimes instead of peaks use boaster. This is a weaker tool, so you need to drill holes according to its diameter and need more of these holes. You can chop off small pieces in this way.
The Egyptian Way
This great-grandfather's method was used in Ancient Egypt. To do this, it is necessary to drill several holes with a diameter of at least thirty millimeters exactly along the cleavage line. In the holes obtained, plugs made of wood are inserted.
Please note that very dry hardwood is needed, but necessarily from the core of the tree, it is denser there. By the way, you can use birch.
Wooden plugs are inserted into the holes with interference, that is, their diameter should be slightly larger than the diameter of the hole, so they must be driven with a hammer. After that, the corks are watered. How best to organize it? To do this, you can use a plastic cup or bottle, in the bottom of which a hole is made with a needle. Such a leaky container is installed on top of the plug and poured into the water.
Dripping on a tree, water penetrates into the material, expanding it. As practice shows, wood under such influence expands to 15% of its volume. The expansion of wood creates enormous pressure, which tears not only concrete, but also any natural stones, even granite. In this way, the Egyptians in those distant times divided stone blocks into even blocks that were used in the construction of the pyramids. Be sure that in ten days your concrete will tear up exactly along the intended line.
Modern ways of destruction of concrete
These are the options today you can use to break the concrete. They are simple and also low-cost. But if you can buy a special powder HPC-1, then the process can be done in one to two days.
It is a chemical that, in contact with water, expands several times. In the beginning holes are drilled along the contour of destruction, where an aqueous mixture of powder is poured. Proportion: 1.0 kilogram of chemical per 0.27 liters of water. Mixing is done for ten minutes, then the solution is poured into the holes to the edge. Use HPC-1 can only be at a temperature of not below + 5 ° C, but not higher than + 30 ° C. If the wall temperature is high, the water added to the powder should be more cold.
It takes less than 24 hours for the chemical to break the concrete. No hammer, a jackhammer is not needed. The concrete just fell apart under the influence of an expanding chemical. A good way, effective, but will require some money costs associated with the purchase of a chemical powder HPC-1.
Sometimes you have to break a piece of concrete to get to the underground communications that require repair, or in case you decide to turn the paved road into a green zone. The following paragraphs describe how you can accomplish this task and get rid of the wastes received.
Steps
Part 1
Chop off the whole platePart 2
Separate a small partPart 3
Get rid of the fragments of concrete
- Look for special tools and equipment for breaking the concrete in the shops of the rental of tools and equipment, if you need them only once, since such devices are not cheap.
- If you need to break concrete in an area of more than 15-20 square meters, then it will be easier for you to rent a jackhammer or hire a specialist.
- Use small tools if you have to work near pipes and other fragile structures.
- For your work you, of course, will need a hammer punch. This is an expensive tool, so if you need it only once, it will be more economical to rent it.
- Try not to break the reinforcing plate fixing, as it will be more solid when you repair the break.
Edit Warnings
- Wear heavy boots, gloves and goggles when working. Be sure to wear headphones when using concrete breakers, jackhammers or punchers.
- Be careful when breaking concrete in which live electrical wires under tension or pipes with compressed gas. Calling a local utility can save your life and save money. You will find their number in the telephone directory.
- Punchers are very powerful. Be sure to hold the punch for additional handles.
- Read all instructions for using the tools and observe the safety rules. Do not use the equipment unless you have mastered all the rules for safe use.
- Use a dust mask or respirator when you cut concrete and use an underwater recess whenever possible. The concrete contains silicon dioxide, which can harm your respiratory system. Old concrete can also contain very harmful asbestos; Before starting work, make sure that it is not in the concrete.
- Pieces of concrete can have very sharp angles. Wear gloves.