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

94 Dy. Executive Engineer
ANNEXURE
TEST PROCEDURE-A
Determination of adhesion of the coating:
Adhesion of the coating is to be tested as per ASTM-A-775/775 M 94 d. 10 mm Dia coated rods of
length 1 m. shall be used in this test. The coated rods shall be padded with sponge and bend to 180
degree around a 75 mm diametre mandrel. The bending shall be done at an uniform rate and not
suddenly. No cracking of the coating shall be visible to the unaided eye on the outside radius of the
bar. If the test is to be conducted on other than 10 mm diametre rod, then the diametre of the mandrel
has to be changed accordingly as tabulated below:
Diametre of the Rod (MM)
8 mm and 10 mm
12
16
25
32
Diametre of the mandrel (MM)
75
100
125
200
250
TEST PROCEDURE-B
Applied Voltage Test:
Two identical coated bars of same size and length shall be used in the test. 14 mm gauge copper wire
shall be soldered to the one end of the each bar. The other end of the bars shall be sealed with an
insulating material to a length of 2.5 cm. The exposed area on which test is to be conducted shall not
be less than 240 sqcms, if 10 mm. diametre rods are used, then the length exposed shall not be less
than 80 n cm. A non-conductive plastic container of size not less than 150 x 150 mm x 850 mm is
filled with 7 % NaCl solution (70 gms./litre) up to the height of 800 mm. The coated rebars shall be
suspended vertically so as to have a clearance of 25 mm from the bottom, 40 mm from the sides and
40 mm in between the rods. A potential of 2 V in between the coated rods shall be impressed for a
period of 60 minutes using suitable DC power source. The voltage and current shall be measured by
using a high resistance voltmetre having an internal resistance of not less than 10 Mega Ohms and
having a range upto 5 V (minimum) Storage batteries may also be used for impressing the voltage.
During this 60 minutes of testing, there shall not be any coating failure as evidenced by evolution of
hydrogen gas at the cathode or by appearance of corrosion products of iron at the anode.
TEST PROCEDURE-C
Determination of abrasion resistance of the coating:
Test shall be conducted as per ASTM D 4060 using Taber Abraser using CS-19 wheel under 1 kg.
load per wheel. Abrasion resistance of the coating shall be conducted on panel of size 100 mm x 100
mm in which 8 mm Dia hole shall be drilled. The panel shall be coated as per specified procedure.
After curing, thickness of the coating shall be measured to the nearest 0.1 mg. Then the coated panel
shall be mounted on the turntable. The abrading heads shall placed on the panel and the vacuum
pickup nozzle kept in position. The counter shall be set in position. The vacuum pickup and turntable
of the abrader shall be fixed for 1000 cycles. After 1000 cycles loose abrading remaining on the test
specimen shall be removed by light brushing. The final weight of the specimen shall be measured for
finding the loss in weight. The weight loss shall not exceed 100 mg. The test shall be conducted on
duplicate specimens.
TEST PROCEDURE-D
Chloride tolerable limit :
10 mm Dia cement polymer coated rod of length 10 cm. shall be used. Bottom edge of the coated rod
shall be sealed using lacquer. Then test specimen is kept immersed in 0.04N NaOH + 10,000 PPM
Chloride and potential is monitored using high impedance Multimetre against suitable reference
electrode such as saturated calomel electrode. After getting stabilized potential, using appropriate
current regulator (0-100 mA), the test specimen is anodically polarized at a constant current density of
290 uA/sqcm. using a Platinum/Stainless Steel/TSIA/Polished mild steel as cathode. Potential with
time is followed for 5 minutes. At the end of 5 minutes, no rust spots shall be observed on the coated
rod.
Signature of Contractor No. Of Corrections Executive Engineer