Types of test done on reinforcement steel bars

Dnyan Deshmukh

Honorary Member
Staff member
Sep 7, 2017
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Pune
#1
Types of test done on reinforcement steel bars
Following tests are done on reinforcement steel bars from third party laboratory as per the frequency set for testing.

Mechanical Test:
Area
Gauge length
Final length
0.2 % Proof load
Ultimate load
0.2% Proof Stress
U.T.S
% Elongation
Fracture
Bend 180
Rebend
Unit Weight

Chemical Test:
Carbon
Sulphur
Phosphorous

Following tests are done on reinforcement steel bars from construction site laboratory as per the frequency set for testing.
Mechanical Test:
Area
Bend 180
Rebend
Unit Weight


In general frequency for test are set as per following
For third party testing
Its done for every lot of reinforcement steel bar received or done at every 200MT of steel receiving for each diameter.

For construction site laboratory
Its done for each lot of steel received at site.

Apart from above reinforcement steel bars are also checked for
Coating of mud, oil and other foreign material - if present bars to be used after cleaning or should be rejected.
Amount of rusting and scaling on it - a small rusting on reinforcement steel bars are good for bonding between cement and concrete.
If scaling on reinforcement steel bars observed - it should be rejected.
 

Dnyan Deshmukh

Honorary Member
Staff member
Sep 7, 2017
1,850
2,669
Pune
#3
There is a methodology stated in IS 1786 for measuring effective cross sectional area of steel bars.

When bars are visually inspected and it does not show any variation in cross sectional area throughout the length.

A sample of bar of not less than 0.5 meter should be taken from lot and its weight and exact length should be measured to accuracy of +/- 0.5%.

Below formula gives the effective cross sectional area of steel bar

Cross sectional area in sqmm = w / 0.00785 × L

Where

W = weight of steel bar in Kg

L = length of bar in meter


During visual inspection of bar, if the cross sectional area is not seen uniform throught length.

A sample should be cut of not less than 0.5 meter and its weight and length should be recorded.

Then the ribs on the bar should be removed by using any mechanical means (you may remove by grinder and make surface smooth)

After removing ribs on steel bar, do record its weight.
If the difference between before and after removing rib is less than 3 %, above formula will give you effective cross sectional area.

If the difference is more than 3%, below formula should be used to calculate effective cross sectional area.

Cross sectional area in sqmm = 1.03 × w' / 0.00785 × L

Where
w' = weight of steel bar after removing ribs on it.

After calulating cross sectional area of bar, you can compare ut with the standard cross sectional area of perticular diameter steel bar.

There are no tolerance stated for cross sectional area.

IS 1786 do speak about minimum area of ribs on steel bar.

For more details, you can refer IS 1786 page 3 to 5