B-1 AGREEMENT System Generated e-Tender No ... - e-Tendering

92 Dy. Executive Engineer
4.2.b) Measurement shall be made using commercially available coating thickness metre which
should be specifically suitable for curved surface.
4.2.c)
The minimum dry film thickness should be ensured atleast on five deformations/ribs over
each one metre length of the coated road.
4.2.d) The thickness of the coating shall also be measured on the straight length of the bar between
the ribs and that also shall not be less than, 125 microns.
4.3 Adhesion of coating.
The adhesion of the coating shall be evaluated by mandrel bent test. The coated rods shall
be bent around a mandrel through 180 as per the test procedure-A given in the Annexure.
When visually examined with unaided eye there shall not be any cracking or disbonding at the
outside radius of the bent bar.
4.4 Relative bond strength in concrete.
The relative bond strength of the coated/uncoated bars shall be evaluated by conducting pull
out test (three cured coated bars and three uncoated bars) as per the procedure given BIS-
2770 Part-1 Methods of testing bonds in Reinforced Concrete Part-1 Pull out Test (1967). The
average bond strength at 0.25 mm slip for coated bar shall not be less than that of the
uncoated bar.
4.5 Resistance to 2v impressed voltage Test.
The resistance of the coating against chloride permeation and the film integrity on the rod
shall be tested by conducting 2v. Impressed voltage test as per the test procedure- B given in
the Annexure. At the end of 1 hour, there shall not be any evolution of hydrogen gas at the
cathode or appearance of corrosion products of iron at the anode.
4.6 The abrasion resistance:
The abrasion resistance of the coating shall be tested by a Taber abraser on coated panels
as per the test procedure- C given in the Annexure. The weight loss shall not exceed 100 mg
/ 1000 cycles.
4.7 Tolerable limit for chloride :
Using anodic polarization technique the tolerable limit for chloride shall be determined as per
the test procedure-D given in the Annexure. For cement polymer rod it shall not be less than
10,000 PPM.
4.8 Chemical Resistance of the coating :
The chemical resistance of the coated bar shall be evaluated as per the test procedure-E by
partially keeping the coated rods immersed in the following four environments for 45 days.
a. 3M NaOH b. 3M CaCl2 c. Saturated CA (OH) 2 d. Distilled water.
At the end of the test period, when visually examined there shall not be any blistering,
softening or peeling on the coated rods.
4.9 Impact Resistance of the coating:
The resistance of the coated rebar to mechanical damage be assessed by standard falling
weight test as per the test procedure-F with an impact force of 9 N-m . No shattering, cracking
or bond-loss of the coating shall be observed except at the impact area.
5. ACCEPTANCE/INSPECTION
5.1 The coated rods that do not meet the requirements of the above specification shall be
rejected.
5.2 The manufacturer of the coated rebar, shall submit a certificate from an appropriate testing
agency that the coated rebars meet the requirements of the specification.
Signature of Contractor No. Of Corrections Executive Engineer