Cleaning of reinforcing bars is done manually with metal brushes or mechanized way using a sandblasting machine. In order to reduce the effect of vibration on the adhesion of reinforcement to concrete, when removing damaged concrete around reinforcing bars, mechanical impact on the reinforcement with jackhammers or hammer drills is not allowed.
Figure 3 – Cleaning fittings
Damage to reinforcing bars is not allowed diamond blades. Minimum depth concrete cutting along the perimeter of the repaired area with reinforcing bars should be 15 mm, and the maximum should not exceed the thickness of the protective layer.
The exposed reinforcing bars must be completely exposed, and the gap between the prepared concrete surface and the bar must be at least 10 mm when the aggregate size in the repair material is up to 5 mm and at least 20 mm when the aggregate size is more than 5 mm.
Opened reinforcing bars are cleaned of rust using the methods indicated in Table 3.
If necessary, if the old reinforcement is unreliable or the coating thickness should be more than 20 mm, welded reinforcement is installed in accordance with the design. It must be fixed to the concrete being repaired, leaving space between the mesh and the surface: the EMACO layer above the reinforcement must be at least 10 mm.
Old fittings, as well as newly installed ones, must be cleaned to a cleanliness level of Sa 2 1/2 in accordance with the requirements given in Table 3, and treated with the anti-corrosion composition MASTERSIL 300. Instructions for the preparation and application of MASTERSIL 300 are given on pages 15 and 20.
Table 3
| Rust removal method | Determination of purity degree | Note | |
| Blasting and abrasive cleaning | Sal | Only scale, rust and surface layers that are not associated with the base material have been removed. | |
| Sa 2 | Scale, rust and surface layers have been almost completely removed | ||
| Sa 2 1/2 | Scale, rust and paint removed; Only residues remain on the surface of the steel, visible as “shading”. | ||
| Sa 3 | Completely removed inspection without magnification: scale, rust and paint coatings | ||
| P Sa 2 1/2 | Scale, rust and paint have been removed in accordance with the requirements of the degree of cleanliness Sa 2 1/2 - visible “shading” of the pores. Surface layers with high adhesion to the base remain. Between these zones there is an intermediate zone. The adhesion of layers located in the intermediate zone must be checked after applying the first layer of protective material. | Mandatory only for blast cleaning coated steel surfaces with partial coating remaining. |
Continuation of table 3
| Rust removal method | Determination of purity degree | Technical properties prepared metal surfaces. Pre-cleaning - if necessary. Secondary cleaning is always performed | Note |
| Cleaning manual or mechanical | St 2 | Deleted upper layer with insufficient adhesion and scale. The rust has been removed so much that the surface of the steel after secondary cleaning has a slight metallic sheen. | |
| Fire cleaning | F 1 | Surface layers, scale and rust have been removed. The residues remaining on the surface became visible as “shading” of different colors. | Careful secondary mechanical brushing required |
| Etching | Be | The remains of surface layers, scale and rust have been completely removed. | Covers (surface layers) must be removed before etching. |
3.2.4 Dust removal and surface moistening
Immediately before application repair staff the surface must be cleaned and moistened manually or, to quickly saturate the surface with water, mechanically.
The surface is cleaned manually with metal brushes, then from dust by blowing air from a compressor equipped with a water and oil separator. After this, moisten the surface manually with a brush for 6 hours.
Mechanized surface cleaning is performed using a machine high pressure(at least 160-180 atm). No later than 30 minutes before the start of laying the repair composition, the same apparatus moistens the surface to be repaired until the concrete is completely saturated with water.
Excess water is removed from the surface with compressed air from a compressor equipped with an oil separator or with a foam sponge.
3.2.5 Requirements for trained concrete surfaces
Physical and mechanical requirements for concrete surfaces prepared for repair are established depending on the type of material and method of preparing the concrete surface.
When used for repair work concrete based on mineral binders, the physical and mechanical properties of the concrete being repaired must meet the requirements:
Strength of concrete at separation, not less than 1.5 MPa;
The use of various concrete structures continues to occupy a leading place in construction, and sometimes even irreplaceable. Reinforced concrete is a combination of steel reinforcement, which acts as the frame of the structure, and, in fact, concrete. Concreting such structures requires precise implementation of the technology, because their future strength and service life of the material depend on this.
Since the reinforcement is in in this case acts as a frame, therefore, to acquire the strength of reinforced concrete, it is important, first of all, its condition. Rust of reinforcement during concreting is unacceptable. Metal corrosion, destroying the surface and penetrating inside, reduces cross section and leads to a decrease in performance bearing capacity the entire structure. When concreting, only new reinforcement should be used, in mandatory complying with building standards. However, even new fittings may be subject to rust formation during transportation and storage. Therefore, all reinforcing elements are subjected to special treatment. Considering that treating reinforcement from rust is a fairly important process, it is given appropriate attention and time.
There are several types of cleaning. This includes manual anti-corrosion treatment of reinforcement, mechanical treatment of reinforcement using special chemicals. Since mechanical cleaning, not to mention manual, takes more time and is a rather complex process from a physical point of view, rust converting chemicals are usually used in practice for corrosion treatment before concreting.
On the chemical products market, such products are represented by a whole variety of drugs from various manufacturers and having different compositions. Note that the treatment of reinforcement from rust before concreting is carried out only by those converters that do not contain various acids.
In most cases, the process of cleaning small amounts of material using chemicals takes 15 to 30 minutes. Cleaning the reinforcement from rust before concreting can be done by applying the converter to the surface with a roller, a regular brush or using a high-pressure apparatus.
The leaders in their field are the IFKHAN 58 PR converters and the corrosion inhibitor Foral PI (forming a film for long-term protection).
IFKHAN 58 PR is a rust converter for fittings, which is a liquid but slightly thick texture of a dark brown color. It consists of retarders, which stop the corrosion process due to a special film, and plant-based tannins, which convert iron oxides into compounds that have high adhesion to metal. Having decided ifkhan 58pr to buy and use this anti-corrosion agent, you will do right choice, because it was developed specifically for cleaning fittings and, in addition, can be used for other household and even industrial purposes.
In order to treat rusted metal with it, it is enough to first remove the loose red coating from the structure using a metal brush. Then you need to apply the converter to the surface using a regular roller or spray. Its thickness can be adjusted with any solvent. At correct use means color metal structure should change from red to black. Depending on the thickness of the layer of surface damaged by rust, red spots may not disappear the first time. In this case, ifkhan 58 pr is applied up to 4 times with a time interval of 15-20 minutes. Before the last application, the previous layer must completely dry. This anti-corrosion agent is quite economical and non-toxic. However, it has its own peculiarity, which is compliance temperature regime when using it. To provide maximum result the use of Ifkhan 58 pr is possible only during warm periods, when the mark on the thermometer does not fall below 4 degrees Celsius.
If you need the fittings to be cleaned of rust at sub-zero temperatures, or, suppose, the structures are processed for the purpose of their further storage in winter period, you need the corrosion inhibitor Foral PI. This product is also a liquid texture product with a dark brown color, but unlike the previous version it contains high-quality inhibitors to combat corrosion and petroleum polymer resins. It is water-repellent and non-toxic. The method of using Foral PI is no different from others. For small rust formations, it is recommended to pre-treat the surface with Antex 1. The advantage of this anti-corrosion drug is precisely the feasibility of its use at temperatures reaching -40 degrees Celsius. Having decided to buy the corrosion inhibitor Foral PI and use it for metal processing in living conditions, do not forget what to store this remedy must be in an airtight container, avoiding contact with fire. When working with it, it is recommended to use eye protection and a respirator.
In conclusion, we emphasize once again that the treatment of reinforcement before concreting, installation of the foundation and other processes is one of the key conditions for the strength of these structures in the future. Do not neglect what you have read above - use proven means!
Reinforcement is a type of metal product and, like all iron, it is susceptible to oxidation.
Often corrosion on metal products appears due to improper storage and handling of them.
Humid air and water are the main enemies of all iron products and fittings are no exception.
Unfortunately, rust carries with it the destruction of the structure of the metal itself, up to its complete destruction, so you need to fight it and be sure to get rid of it, and the sooner this is done, the better.
Rebar is the most common material in construction and is often used to fence large areas.
Not everyone knows how to clean rust from fittings, so we are happy to share this important and useful information.
To the question of how to clean rust from fittings, there are two answers, or rather ways to remove it from metal surfaces.
There are two main methods for cleaning metal from rust.
First method It is called mechanical and only at first glance it seems simple and accessible, but in reality it is quite labor-intensive and tedious, and the result is not satisfactory enough. To manually get rid of rust, you will have to try very hard and put in a lot of effort, and a metal brush and sandpaper will help you with this, and you will also need a lot of patience and strength.
Second and easier method is called chemical and involves cleaning the fittings using industrial cleaners. This method is very fast, easy and effective, thanks to it the metal acquires its former, shiny and beautiful appearance.
Among the agents that can be used in this method are such acids as lactic, hydrochloric and boric. They are just capable of coping with harmful rust.
Chemicals are not dangerous in themselves if you handle them carefully and follow the instructions. But remember that this is still acid and safety precautions have not yet been canceled, so we strongly advise you to purchase latex gloves and a mask.
This information may be especially useful for large enterprises, which use reinforcement for different directions, for fencing, construction, design of metal structures.
How to clean rust from fittings is up to you, but we tried to tell you how to make this unpleasant and long process much simpler, easier and faster. And if we succeed, we will be very happy.
And if you have questions about this, we will definitely answer them for you.
NITTRON is a neutral rust converter with enhanced inhibitors.
Designed to modify corrosion on the surfaces of ferrous metals, building metal structures, pipes, and reinforcing steels. The composition can be used in various industrial fields, for car repair work, and in everyday life.
Preparation and processing of reinforcement for concreting
We recommend treating reinforcement before concreting with an anti-corrosion agent. . A liquid neutral rust converter was specially developed for this purpose, plus a related function - processing metal structures before painting. In the process of preparing reinforcement for foundations and reinforced concrete, for concreting under the foundation, when preparing reinforcement for installation and similar work, it modifies corrosion on the surfaces of ferrous metals into a protective anti-corrosion layer. In this way, the reinforcement is cleaned of rust before concreting. The product can be used in everyday life and various industries.
Price of preparation and processing of reinforcement for concreting KF-58PR
The price of the preparation and processing of reinforcement for concreting KF-58PR is 165 rubles per kilogram at retail. Wholesale price depends on the volume of purchase: up to 500 kg - 158 rubles, up to 1000 kg. – 150 rubles, up to 1500 kg – 143 rubles, price of a large wholesale batch (from 1501 kg) – 135 rubles per kilogram. We offer you to buy wholesale or retail anti-corrosion preparation and treatment of reinforcement before concreting at the manufacturer’s price in Moscow, Nizhny Novgorod, Krasnoyarsk, St. Petersburg, Kemerovo, Yekaterinburg, Rostov-on-Don, Kazan, Irkutsk, Barnaul, Chelyabinsk, Kaluga, Kurgan, Sayanogorsk, Abakan, Ufa, Yoshkar-Ola, Novocheboksarsk, Tyumen, Cheboksary, in the cities of the single customs zone - Alma-Ata, Chisinau, Minsk, in which companies are opened. In other cities of Russia you can contact our business partners.
Preparation of reinforcement for installation for foundations, for reinforced concrete
The procedure for preparing reinforcement for concreting, installation for foundations, for reinforced concrete using a rust converter is determined by technical recommendations TR001–99 developed by the Research Institute of Reinforced Concrete. These recommendations are universal, therefore they can be used when processing other iron products for concreting, and not just reinforcement. The main provisions of anti-corrosion treatment of reinforcement against rust before concreting are the need to remove loose rusty deposits with a wire brush. The converter can then be applied by spraying or brushing. If you did everything correctly, thoroughly cleaned the reinforcement from rust before concreting, then the color of its surface should change from red to black. If this does not happen, 15–25 minutes after the first treatment, red spots remain on the surface, we advise you to repeat the operation. Depending on the thickness of the rust, the surface, especially when preparing reinforcement for the foundation, is treated with a converter up to four times. Subsequent processing of reinforcement for concreting can be carried out on a wet surface. And only before the final application should the surface dry thoroughly. The approximate consumption of KF58PR when preparing reinforcement for installation and concreting is 100–150 ml/m2. The processing temperature must exceed +4°C.
how to remove rust from fittings without harming other materials
Reinforcement refers to steel rods with different cross-sections. There are smooth and periodic profile reinforcement. The fittings are made from high-strength types of steel. Reinforcement is used for the manufacture of reinforced concrete, as well as for strengthening metal structures.
Therefore, it is very important that the iron rods covered with ribs and cross projections are completely free of rust.
Preparation of sandblasting to Ca-2 of almost white metal. Zinc-rich epoxy primer thickness 22 microns. Epoxy intermediate rough layer 75 microns dry film thickness. Epoxy enamel 35 microns thick. Moderately aggressive environment. . Intermediate thick layer of chlorokuho with a thickness of 40 microns of dry film.
Antioxidant primer of iron or lead oxide electrolytic lead up to 35 μ oil. Two finishing hands with synthetic or aluminum enamel. Cracks or cracks in cast iron are often easily repaired. The crack was completely healed with a stone rounding the beginning. Crack filling should be done with nickel electrodes, by preheating the surface and in accordance with the electrode manufacturer's instructions.
How to remove rust from fittings if it has penetrated between the protrusions and cannot be removed mechanically
Is rust dangerous for fittings? If light dusty rust has formed on the fittings, you don’t even have to remove it. Thanks to it, adhesion of metal to concrete occurs. But this version can lead to destruction reinforced concrete structure, if moisture penetrates into the concrete or there are chlorides in the solution, which activate the process of metal corrosion. It’s still better to make a decision before laying concrete than to remove rust from the reinforcement.
It consists of passing an oxyacetylene torch on the surface of the steel at high speed and at high temperatures. Due to the difference in expansion coefficients compared to a steel support, most of the rust and scale is released while the rest is dehydrated. As long as the surface is still hot and dry when you work on it.
Abrasive blast cleaning. . Accelerating fine abrasive particles at high speed using compressed air, steam, water or centrifugal discs. These particles may be fine sand, granules or scrap steel, or they may be synthetic abrasives such as carborundum or aluminum oxide, but they should always be uniform in size and as small as possible. There are three possible cleaning grades: blasting abrasive, off-white metallic abrasive, and white metallic abrasive.
Methods for cleaning fittings from rust
Mechanically using a wire brush, sandpaper, grinder You can remove the accumulated layer of rust.
Disadvantages: slow, costly work force, the rust is not completely removed.
Application of corrosion inhibitors (moderators). Inhibitors contain phosphoric acid and react chemically with the metal. Iron phosphate is formed, protecting the metal from rust.
Sandblasting is generally regarded as a cleaning method suitable for the pre-painting phase, primarily because it removes rust, scale and old paint until the metal remains white. Emulsion purification: consisting of using organic solvent together with an emulsifier, so that the combination can be diluted in water and form a stable cleaning medium.
Alkaline solvents: from alkalis such as caustic and potassium to detergents. Solvents Acids: inorganic such as phosphoric, in combination with grease-resistant solvents and wetting agents, which reduce surface tension, but their anti-corrosion effects are not entirely satisfactory.
Disadvantages: inhibitors cannot be used for reinforcement that is poured with concrete: acid will destroy concrete like an alkaline medium. Additional costs will be required for another coating of the reinforcement with an anti-acid solution.
Acid-free rust converters. Remove rust from fittings without harming others building materials: The developers of acid-free rust converters took care of this. The composition of such a converter includes vegetable tannins, stabilizers and corrosion inhibitors, and functional additives.
Organic solvents: Some are toxic or flammable, but the most commonly used solvents are naphthas, mineral alcohol, benzene, toluene, xylenes, turpentine, asphalt hydrocarbons and halogenated derivatives. Chemical pickling: in pieces of steel not too large, by which they are introduced into tanks where the surface layer of the metal is dissolved, removing the oxide and husk and obtaining a uniform surface.
Processing consisting of converting active metal surface, conducting electricity, into an insulating surface and therefore passive. Its main advantages are: it provides greater paint coating adhesion, it is more resistant to blistering in humid environments, and it resists corrosion.
Advantages of acid-free converters:
- does not destroy concrete;
- does not require washing;
- completely replaces mechanical cleaning from rust;
- used even with a thick layer of rust up to 150 microns;
- does not contain mineral acids and toxic products;
- fireproof, does not catch fire;
- guarantees protection of the metal from the moment of production until use in the next cycle for 18 days.
It is very easy to apply acid-free rust converter to reinforcement using a brush, roller, spray or dip method.
Pre-treatment products of intermediate quality between phosphate solutions and standard primer paints. They are usually a combination of products that form a continuous coating on the surface that is corrosion resistant and highly adhesive.
This is a type of protection that consists of using electric current to prevent or reduce the rate of corrosion of metal in the electrolyte, causing the steel to act as a cathode and not corrode. It is important that the appropriate parameters for cathodic protection of a particular structure or installation are correctly specified and calculated; Also important is constant monitoring of meters and good operation in general. Maximum efficiency can be achieved through the use protective coatings with extreme care of their choice to prevent them from attacking under alkaline conditions or forming bubbles.
In production conditions, the last two methods are used to process large volumes of reinforcement.
The successful completion of a chemical reaction is indicated by the color - Brown color rust changes to black.
If a very thick layer of rust is found on the reinforcement, you need to treat the rods with a converter 2-3 times without waiting for it to dry. There will definitely be an effect.
This process consists of coating steel with a zinc film, which is achieved by immersing the parts in a bath of molten zinc, which has excellent resistance to atmospheric corrosion and natural water. This material provides cathodic protection at a relatively low cost and is the most commonly used protection for steel components in construction as it is very effective on external parts. One of these procedures is hot-dip galvanizing of steel, which provides very durable coating and very effective for parts in contact with sea water, especially corrosive.
The treated reinforcement can be placed in concrete or painted with paint after the converter has completely dried.
Buy a product for cleaning fittings from rust
You can buy a product to combat corrosion on fittings in specialized stores. Full information You can find out more about acid-free rust converters on our website. Consultants will help you determine the quantity of goods and its cost. Quality guarantee provided modern technology production of acid-free rust converters.
This fastener coating provides an even, glossy finish but is not suitable for long-term outdoor exposure unless supplemented with paints. High resistance screws and nuts should also be coated with lubricant in order to tighten them.
Enamel is made on steel or cast iron parts using a mixture of silicates, fluxes and paint pigments that provide a hard coating and are resistant to corrosion. Edges and corners should be rounded to avoid cracks on the enamel surface, which is very easy to clean.