NOVATEST - Набор для химического анализа

Determination of the depth of carbonation and the penetration profile of chloride ions in concrete.‎ Carbonation reduces the alkalinity of concrete and at the same time increases the number of hydrogen ions in the concrete's pore solution, which weakens the concrete's protective effect on steel bars.‎ When carbonisation overcomes the protective layer of the concrete in the presence of water and air, the concrete will lose its protective effect on the steel bar and the steel bar will begin to rust.‎ After the steel bar has been corroded, the volume produced by the corrosion expands 2 to 4 times the original volume, thus producing an expansion stress on the surrounding concrete.‎ The generation of cracks allows water and CO2 to enter the concrete unhindered, which in turn accelerates the carbonisation and corrosion of the steel bars.‎ Due to the low alkalinity of the concrete, moisture corrodes the steel bars, and when corrosion is severe, the protective layer will burst and crack, accelerating the corrosion process, which can eventually affect the safety of the structure.‎ The use of chemical reagents such as phenolphosphateine (C20H14O4), sodium hydroxide (NaOH) and silver nitrate (AgHO3), is useful for the determination of characteristics when investigating the state of preservation of reinforcement by taking and analysing concrete samples.‎ The determinations can be carried out both to investigate the causes of a corrosion phenomenon that has already occurred and to obtain elements of judgement on the behaviour of the reinforcement over time.‎ This method can be applied to specimens produced in the laboratory or taken in situ, whereas it cannot be applied to surface-treated concrete.‎ Normative references: UNI 9944:1992 - Corrosion and protection of concrete reinforcement UNI EN 14630:2007 - Products and systems for the protection and repair of concrete structures - Test methods - Determination of the depth of carbonation of hardened concrete using appropriate methods as per UNI 11747:2019 Tests on hardened concrete.‎ The kit consists of 100 ml bottles with atomiser containing: - 1% phenolphthalein hydro-alcoholic solution (C20H14O4) - Sodium hydroxide (NaOH) - Silver nitrate (AgHO3) Further info from manufacturer on CHEMICAL ANALYSIS KIT NOVATEST