Various tests conducted for Rebar

In rebar pieces, the following items are generally found :-
X stands for diameter of rebar in mm as for instance 20.
ABCD stands for brand of rebar ranging from TATA TISCON, SAIL, JSPL etc.

Y stands for yield stress of rebar as for example 500 signifies Fe500 having yield stress similar to 500 Mpa

Chemical composition test
LSA or ladle sample analysis is performed in LD and details are noted.
TPA or test piece analysis is performed at chemical lab.
The chemical composition analysis should be adhered to Amend 1 of Cl. 4.2 of IS 1786-2008

Main physical property tests for a specific rebar are provided below :

1. Tensile test : Numbers of rebar sample =4, length of rebar sample =about 600 mm
2. Bend test : Numbers of rebar sample =4, length of rebar sample =about 500 mm
3. Rebend test : Numbers of rebar sample =4, length of rebar sample =about 500 mm

Individual Sample: In order to work out the nominal mass of an individual sample, ascertain the mass of any individual sample selected arbitrarily as mentioned in 11.1 and divide the same with the actual length of the sample. The length of the sample should not be under 0. 5m

Batch: The nominal mass of a batch is computed from the mass of the test specimens selected as mentioned in 11.1 and divide it with the genuine total length of the specimens. The length of each specimen should not be under 0.5 m

Tensile test
Existing Inputs :
1. Length of sample = L
2. Weight of sample = w
A = w/0.00785L mm2
[According to Cl. 6.3.1 of IS 1786-2008 given at right]

Gauge length for a rebar of dia D mm = 5D mm
The rebar sample is marked at (5D/2) mm locations.

To get more clear information, go through the following article engineeringcivil.com

~~~~~~~~~~~~~~~~~~~~~~~~

Published By

Rajib Dey

www.constructioncost.co

~~~~~~~~~~~~~~~~~~~~~~~~

Some useful tips for making inspection of reinforcement in jobsite

Though the inspection of reinforcement involves lots of complexities and huge cost, but the problem should be properly resolved by appointing a standard consulting firm for accomplishing the inspection work.

The first step should be checking drawing. One must have adequate knowledge for analyzing a rebar drawing. The field engineers should have proper knowledge & capability to communicate with it in the jobsite.

To become an efficient rebar checker, practice for reading drawings on a regular basis. For this purpose one should gather proper knowledge with the steel rebar binding process. Given below, some useful tricks provided by some top peers who have lots of experience in this field :-

It is suggested to carry a measuring tape with yourself all the times for the purpose of examining the spacing and the splice or development length.

One should have clear conception on physical features of the construction component i.e. if some type of drainage pipe or electrical conduit should be set up or water stopper should be substituted or any other pipes / implanted item should be arranged.

Initially, the diameter of rebar should be examined properly through a vernier caliper. The other important things which should be examined thoroughly are rebar spacing, rebar development length, lap / splice length, alignment, no sag or buckling present in the bars, the couplers should be perfectly set and tightened, bars should be perfectly fixed, there should not be any rust on the bars, check for proper clear cover, no of bars should be computed properly and be similar with the drawings and should not be under or over 2 bars which are arranged there.

Always take suggestions from the contractor’s foreman or site engineer for the placement of the bars.

One should have sound knowledge with the steel quality tests like tensile strength check or torsion failure strength or coupler tension strength check etc. Make sure that the applied steel is taken from the verified lot and must not be a failed quality.

Though proper execution of design becomes very complicated because of inconsiderate field conditions and difficultly in installation / fixing of rebars, but always ensure the design of reinforcement is completely perfect as improper design can lead to failure of a building if fully neglected / violated.

Always keep in mind that the orientation of bars like main rebars should be under the distribution or temperature rebars. It can be verified from the drawings delivered to you.

Read more

~~~~~~~~~~~~~~~~~~~~~~~~
Published By
Rajib Dey
www.constructioncost.co
~~~~~~~~~~~~~~~~~~~~~~~~