You shouldn't substitute the concept of REQUIRED clutch and BEST. TsNIIS did not conduct research on the adhesion of rusty reinforcement. There is GOST, when meeting the requirements of which the required adhesion is provided. There is SNiP and MGSN where tolerances for rust are presented, in the presence of which the required adhesion is provided and the use of fittings is allowed. Indeed, visually, concrete bounces off better from freshly rolled reinforcement and worse from rusty, but that doesn't mean anything.
And the TsNIIS's fables about magic rust were written at the request of the contractor in order to try to remove the meticulous technical supervision and snatch in unusable fittings.

I agree on all points.
Just to be consistent, let's add links or callouts from the standards in order to reveal the topic to the end. I am sure for many it will be relevant.

regarding the letter - the letter, to put it mildly, looks like an unsubscribe for certain people, which was already mentioned by Kostyan ": May 15, 2012, 18:31:39"
regarding the terms - I just gave an official link from the answer of the State Architectural Committee of the Republic of Kazakhstan to a similar question

by reference to standards:

MANUAL to MGSN 2.09-03 PROTECTION AGAINST CORROSION OF CONCRETE AND REINFORCED CONCRETE STRUCTURES OF TRANSPORT FACILITIES

4.4.1. In the process of delivery, transportation, storage, production of work with reinforcing steel, ready-made reinforcing elements (non-stressed and stressed), embedded products, anchor and connecting devices, it is necessary to exclude the ingress of moisture, dirt, oils, substances corrosive to steel on the surface and the presence of mechanical or corrosive damage.

Reinforcing steel before concreting must not have corrosion damage in the form of lamellar rust and pits. Non-tensioning reinforcement with a light coating of rust (no more than 100 microns) and tensioning reinforcement with a coating of rust easily removed with a soft cloth are allowed for use.

4.4.2. In case of corrosion damage and violation of the above storage conditions, reinforcing steel is checked before installation in the structure for compliance with the requirements of GOSTs according to the following indicators - tensile strength at break (sv), conventional yield strength (s0.2), elongation at break (e) , the number of bends (n), and if the requirements of the standard exist - for resistance to stress corrosion cracking and fatigue strength (when calculating structures or individual elements for endurance).

Immediately after tension and injection of high-strength reinforcement, the sections of wires and ropes protruding beyond the anchors, including their ends and anchors, are reliably isolated from the ingress and migration of moisture into the rope.

I don’t know much more clearly

how to remove rust from fittings without harming other materials

Steel rods with different section... There are smooth and periodic profile fittings. Reinforcement bars are made from high-strength types of steel. They use reinforcement 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 transverse ridges are completely free of rust.

How to remove rust from reinforcement if it has penetrated between the protrusions and cannot be mechanically removed

Is rust dangerous for fittings? If a light dusty rust has formed on the fittings, it may not even be removed. Thanks to her, the adhesion of metal to concrete occurs. But this version can lead to the destruction of the reinforced concrete structure if moisture penetrates into the concrete or chlorides appear in the solution, activating the metal corrosion process. It is better to make a decision before placing the concrete than to remove the rust from the reinforcement.

Methods for cleaning reinforcement from rust

Mechanically using a metal brush, sandpaper, a grinder, you can remove the accumulated layer of rust.

Disadvantages: slow, labor costs, rust is not completely removed.

Application of corrosion inhibitors (retarders)... Inhibitors contain phosphoric acid and react chemically with metal. Iron phosphate is formed, which protects the metal from rust.

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 one more coating of the reinforcement with an anti-acid solution.

Acid-free rust converters. Remove rust from fittings without harming other building materials: the developers of acid-free rust converters have taken care of this. The composition of such a converter includes vegetable tannins, stabilizers and corrosion inhibitors, and functional additives.

Advantages of acid-free converters:

• does not destroy concrete;
• does not require flushing;
• completely replaces mechanical cleaning from rust;
• it is applied even with a thick rust layer up to 150 microns;
• does not contain mineral acids and toxic products;
• fireproof, does not light up;
• guaranteed to protect the metal from the moment of manufacture to use in the next cycle for 18 days.

It is very easy to apply the acid-free rust converter to the reinforcement using a brush, roller, spray or dipping.

In a production environment, the latter two methods are used to process large volumes of reinforcement.

Successful completion chemical reaction visible by color - the brown color of rust changes to black.

If a very thick layer of rust is found on the reinforcement, it is necessary to treat the rods with a converter 2-3 times, without waiting for it to dry out. The effect will be sure.

The treated reinforcement can be embedded in concrete or painted with varnish after the converter has completely dried.

Buy means for cleaning reinforcement from rust

You can buy a remedy for combating corrosion on fittings in specialized stores. You can get full information about acid-free rust converters on our website. Consultants will help you determine the quantity of goods and their cost. Quality assurance provided modern technology production of acid-free rust converters.

fittings are often sold with traces of rust

Reinforcement is an important component of any modern building structure. Today it is very often purchased with traces of rust.

The reasons for its appearance can be completely different, but it can be said unequivocally that it is impossible to use such reinforcement for construction without cleaning it from rust.

Otherwise, you run the risk of significantly reducing the strength of the future structure, and over time, its complete destruction, if rust grows.

Metal corrosion rate:

1. Slight coating on the surface. The color of the material and its weight do not change.
2. A dense layer of rust that can be easily removed with a brush.
3. Localized rust due to water ingress. The section of the bar may change slightly.
4. Rust with significant corrosion of steel. There is a possibility of a decrease in the performance of the material.

If the layer of rust is insignificant, then it will be enough to simply wipe the surface of the reinforcement with a rag (although, given its ribbed texture, this will not be easy to do).

In other cases, a mechanical, thermal or chemical method of cleaning the reinforcement from rust is used.

• Mechanical method... The mechanical method consists in cleaning the surface of the reinforcement using metal brushes or special machines. This is a rather complex and, moreover, polluting process.
• Thermal method... cleaning from rust is performed by exposing the surface of the fittings to the flame of a gas burner. After cooling, rust is easily removed. However, this method is not entirely suitable for reinforcement, since there is a high probability of violation of its strength parameters.
• Chemical method... This method of removing rust from fittings is the most effective and very common both at work and at home. On the surface of the reinforcement, a layer of special chemical composition, which removes rust from the metal surface and forms a protective film on it.

Rust is easiest to remove aqueous solution sulfuric and of hydrochloric acid in the presence of an inhibitor urotropin. The function of the inhibitor is to prevent the destruction of the metal from the action of acid, but it does not interfere at all with corroding the rusty layer.

Effectively using a rust converter for these purposes. The agent reacts with the damaged metal layer and transforms it into a brown coating. The composition of such funds necessarily includes orthophosphoric acid, which forms iron orthophosphate from rust, covering the surface of the reinforcement.

Another chemical that helps to remove rust from the rebar is rust remover. It, in contrast to products containing phosphoric acid, does not create a film on the metal surface, but completely dissolves iron oxides, converting them into water-soluble salts. Cleaning is done by immersion. The advantages of the product are ease of use, effectiveness and low level pollution of the room in which the treatment is carried out.

LENIS number 2 PERFECTLY CLEANED THE VALVES!

Professional concentrated acid cleaner to transform and removing rust from reinforcement. Cleans rebar from rust, scale, plaque before your eyes!
for cleaning from oils and de-preservation click here
Contains a mixture of special acids, which instantly react with rust, transform, give the original black color of protected reinforcement. Forms an inhibitory layer that prevents rust formation. No further primer application is required. In addition to the most important, orthophosphoric acid, at your request, it can contain nitric acid, which is better suited for ferrous metal, brings it back to its original form.

WHERE CAN ONE BUY? - ONLY HERE! WE WILL DELIVER TO ANY CITY IN RUSSIA THROUGH TK! IN MOSCOW AND MO WE DELIVER BY YOURSELF
tel: 8499 7030076; 89257054713 FREE: 8 800 5553652 e-mail: [email protected]

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This is done as follows: Send your details (if an individual, then Passport data) to [email protected], we issue an invoice, pay, our car delivers the goods to the company * BUSINESS LINES * or * ENERGY * or * KIT * and sends them to your city. In a couple of days they call you and say * You have a load, come and pick it up! * You come and pick up the product. That's all there is to it.

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MODE OF APPLICATION

Attention! Shake well before use !!! It is used for local cleaning of reinforcement surfaces from rust. It is applied to the surface to be cleaned with a roller or brush for 20 minutes and washed off with a sponge or brush. In case of significant deposits, the treatment should be repeated. Application with high pressure washers is also possible. Cleaning is also possible by immersing the fittings in a container with a reagent.