Generally speaking, the main function is to remove the rust on the surface of the steel bar, protect the steel bar matrix, and present the primary color after use.
Why use rust remover?
Because Article 5.2.4 of the Code for Acceptance of Construction Quality of Concrete Structure Engineering (GB 50204-2002) stipulates: "Steel bars shall be straight and undamaged, and there shall be no cracks, oil stains, granular or flaky old rust on the surface." Therefore, in order to meet the qualified requirements, many derusting products have appeared in the market.
What if those rust removers are unqualified products?
At present, many products of rust remover have been searched online, some of which contain rust remover made of sulfuric acid, hydrochloric acid, nitric acid, phosphoric acid, complexing agent, water and other raw materials. These products are unqualified. The use of rust removers of these products will cause environmental pollution, do great harm to human health and even corrode steel bars. It is also forbidden to clean steel bars with strong acid during construction.
Which rust removers are qualified products?
Qualified rust remover is an efficient rust remover prepared from various organic acids (vegetable acid, citric acid and edible phosphoric acid), complexing agent, penetration enhancer, corrosion inhibitor, surfactant, water and thickener.
The main features include high safety performance, no phosphorus, no volatilization, no odor, no toxicity, no flammability and explosion, high performance, thorough rust removal, no harm to mother, no washing after rust removal, no influence on subsequent post-treatment process, environmental protection and high efficiency, neutral PH, weak acidity of waste liquid, no acidification reaction, no heavy metal ions, simple treatment after dilution, and direct discharge, which can avoid the expenses and labor costs generated by customer wastewater treatment.
Most products of steel bar rust remover sold online are added with hydrochloric acid in pursuit of rust removal effect, but hydrochloric acid is strictly prohibited in building codes. How to identify whether the rust remover for steel bars contains hydrochloric acid? First, take samples to the local quality supervision station or chemical research institute to detect the hydrochloric acid content (or consult Dida Steel Derusting Company to provide technical support). Secondly, through sensory recognition. The high content of hydrochloric acid has a pungent smell and the medicine is yellow. Low-content or high-purity hydrochloric acid will soon turn yellow after being exposed to the sun for a few minutes. At present, some bad manufacturers sell rebar rust remover containing hydrochloric acid, which seriously damages the interests of rebar rust remover industry. Users are advised to consider carefully.