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In this article, we will discuss how to check quality of steel on construction site.
Rebar also known as rod or steel bar is a short form of reinforcing bar, it is steel wire given as tension bar in concrete structures, utilized in reinforced concrete structures such as columns, beams, and slabs of house construction, and is also utilized in a reinforced masonry structure. It is utilized to raise the tensile strength of concrete structures.
Steel bars surface is twisted with ribs to better bond with concrete material and decrease the risk of slippage. The primarily used rebar is carbon steel hot rolled round bar, the Steel rebar is coated with epoxy resin material, made to withstand the effect of corrosion in a saltwater environment.
1. How To Check Quality of Steel on Construction Site?
Here are the following requirements that need to be qualified by good quality steel as follows:
a. TMT bars need to have an ISI certification and show the brand or manufacturer’s name together with the ISI logo on the steel bundle.
b. You need to have a chemical and physical test authenticity report from the manufacturers.
c. Watch for national certifications such as ASTM A706, ASTM A615, JIS G3109, JIS G3112, BS449, IS 1786 (HYSD) and IS 432(MS).
d. The TMT bars’ unique rib design must satisfy the ISI standards for concrete bond tests.
e. TMT Bars need to go through the microstructure rings test to confirm their hardness and strength.
f. Each TMT rod must be 12 meters in length.
g. Watch for the manufacturer’s license because a factory can only get one if they satisfy the strict safety conditions.
h. Buying only ISO and BIS-approved and certified products are recommended.
i. Watch if the TMT bars attach to IS 1786:2008. It outlines the standards for reinforced steel’s chemical composition.
j. The pitch distance between twists must be 8 to 12 times the standard bar diameter.
k. Each bar’s diameter ought to be consistent and constant.
l. After obtaining the order, the TMT must be clear of rust, grease, and paint.
m. Check the carbon level. No more than 0.25% of carbon should be present in the bar. (IS 1786-1985 C-3.2)
2. Field Tests for TMT Steel Bar
Here the field test for the TMT steel bar are as follows:
1. Mass per meter run
2. Bend Test
3. Rebend Test
1. Mass Per meter Run
Trim the samples of 1 meter in length, at least a number of 4 bars from various bundles. Calculate the length of cut bars by calculating it on a minimum of 4 sides and average out the length of the bar. Weight the bar on the weight scale and record it in the log.
Compute the actual average weight per meter of the bar for a minimum of 3 samples. Compare the result of it with the theoretical weight presented in IS 1786. Inspect the interpretation in weight is within the limit or not as per IS specification.
2. Bend Test
The bend test should be carried out as specified in IS 1599 and using mandrels of the size specified in IS 1786. The rebar sample should be bent at 180 degrees as per the procedure stated in IS 1599.
After bending the bar check the surface of the bar opposite to the bend side (which got tension, and elongated due to bending) for cracks and ruptures visible to a person with normal or corrected vision. If there is no sign of rupture and cracks, the rebar meets the requirement of the bend test.
3. Rebend Test
First, bend the bar to include an angle of 135 degrees. Keep it in boiling water at 100 degrees for 30 minutes. Then cool it down for some time.
After cooling bent it back to include the angle of 157.5 degrees The rebar should not show any rupture or cracks to a person with normal or corrected vision. Mandrel to employ for Rebend test as limited in IS 1786.
Hope you got an idea of How To Check Quality of Steel on Construction Site?
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