Ensuring the quality of steel is crucial for the longevity and strength of buildings or homes. Subpar steel can lead to increased costs and compromise the safety of the structure. This article provides a comprehensive guide on how to assess the quality of steel on a construction site, focusing on TMT bars, which are fundamental to construction.
The use of low-quality steel can impact the service life of buildings, increase construction costs, and pose safety risks for homeowners. It is essential to evaluate the quality of steel before commencing construction to avoid last-minute compromises and financial setbacks.
ISI Certification : TMT bars should have ISI certification, displaying the manufacturer’s name and ISI logo.
Test Authenticity Report : Obtain a chemical and physical test authenticity report from the producers.
National Certifications : Look for national certifications such as ASTM A706, ASTM A615, JIS G3109, JIS G3112, BS449, IS 1786 (HYSD), and IS 432(MS).
Rib Design : Ensure the distinctive rib design meets ISI criteria for concrete bond tests.
Microstructure Rings Test : TMT bars must pass the microstructure rings test to verify hardness and strength.
Length : Each TMT rod should be 12 meters in length.
Manufacturer’s License : Check for the manufacturer’s license to ensure strict safety requirements are met.
ISO and BIS Approval : Purchase only ISO and BIS-approved and certified products.
IS 1786:2008 Compliance : Check if TMT bars adhere to IS 1786:2008 for reinforced steel’s chemical composition.
Twist Pitch Distance : The pitch distance between twists should be 8 to 12 times the standard bar diameter.
Diameter Uniformity : Ensure each bar’s diameter is uniform and constant.
Condition on Delivery : TMT bars should be free of rust, grease, and paint upon delivery.
Carbon Level : The carbon level in the bar should not exceed 0.25% (IS 1786-1985 C-3.2).
Bend Test : Perform the bend test following IS 1599’s instructions. The bar should be bent 180 degrees, and no cracks or ruptures should be visible.
Re-bend Test : Bend the bar to form a 135° angle, immerse it in boiling water, and then bend it back to a 157.5° angle. No ruptures or cracks should be visible.
– Mass Per Meter Run
Sample Cutting : Cut samples from several bundles into 1-meter lengths.
Average Height : Average the height of cut bars across at least four sides.
Weighing : Weigh the bar on a scale and enter the weight in the register.
Average Bar Weight : Count three samples to get the average bar weight per meter.
Comparison : Compare the result to the theoretical weight defined in IS 1786 and check for acceptable weight fluctuation.
Ensuring the quality of steel through these checks and tests can contribute to the overall safety and durability of construction projects, preventing future issues and ensuring a cost-effective construction process.
