SUJANA CRS TMT (Corrosive Resistant Steel) Reinforcement Bars help in meeting the challenge of corrosion, totally. Corrosion resistant elements such as copper, phosphorous and chromium are added in appropriate measures to the hot metal for manufacturing CRS Billets.
At the Rolling Stage, the advanced Thermex Technology complements the route. The CR elements together with tempered martensite outer surface stop the corrosion of Re-Bars. Sujana CRS Bars are suitable both for atmospheric and marine applications.
Why Sujana CRS?
Corrosion is the oxidation of a metal in a normal atmospheric condition owing to the excessive presence of moisture and oxygen in the air. Corrosion of the metal is a very natural and rapid phenomenon in areas of high humidity, places close to the sea or in the presence of saline water. Gaseous emissions in industrial area also cause corrosion of the metal.
Corrosion is a silent menace that can destroy the toughest and best built structure in the world like Buildings, Bridges, Dams, Chimneys, Jetties, Industrial Plants, Port establishments etc.
When the concrete is freshly cast, it contains high ph value (ph value – 12-13). This creates a protective passive oxide layer over the steel surface, preventing it from corrosion. Gradually, with constant ingress of oxygen, water, chlorides, carbondioxide etc, the PH-value of the concrete reduces to below 8 causing the decay of the protective layer.
The Chloride ions also attack the passive layer on the metal surface exposing it to oxygen and moisture. Once the passive layer is broken the electrochemical reaction of corrosion progress is unimpeded.
Any construction of permanent nature requires concrete with steel reinforcement. The ‘durability’ of concrete depends on how far it is impermeable to water, oxygen, carbon dioxide, chlorides, sulphates etc. as these elements corrode and weaken the reinforcement bars embedded in the concrete.
Efforts to control corrosion led to Galvanized and Epoxy coated Reinforcement Bars- but failed in practical usage due to the risk of dis-bonding, causing accelerated corrosion. Added to this, Galvanization and Epoxy coatings are expensive and call for higher project lead time.
Sujana CRS offers the solution, by taking a new metallurgical route- controlled composition, alloying with anti-corrosion elements and improved production processes that would give the steel bars inherent corrosion resistant properties.
Physical Properties of Sujana CRS TMT Bars
|0.2% proof stress, min, N/mm2||500|
|Ultimate Tensile Strength, min, N/mm2||540|
|Bend||4D to 5D|
|Rebend||5D to 7D|
Chemical Properties of Sujana CRS TMT Bars