Test instruments for coating concrete

Question 1

Explain the procedure for ASTM D 4263 standard test method for indicating moisture in concrete by the plastic sheet method?

Answer 1

A segment of 1.0mm thick, clear polyethylene sheet approximately 457 x 457mm (18 x 18 in.) is taped over the concrete to be tested so that the concrete is tightly sealed from the atmosphere and sunlight. The test patch is allowed to remain a minimum of 16 hours

Question 2

Which organisation produces a set of comparator plates for various prepared concrete surfaces?

Answer 2

International concrete repair institute (ICRI)

Question 3

DFT coating on concrete can be measured by?

Answer 3

Estimated from WFT
Estimated from quantity of coating used
Verified by a paint inspection gauge (tooke)
Determine by a modified gauge based on ultrasound

Question 4

List standards that may be used for dry film measurement of coatings over concrete?

Answer 4

ASTM-D6132-97 standard test method for nondestructive measurement of dry film thickness of applied organice coatings over concrete using an ultrasonic gauge.
SSPC-PA 9 measurement of dry coating thickness on cementitous substrates

Question 5

Describe the proper safe accurate operating procedure for a low voltage holiday detector?

Answer 5

Ground cable is attached directly to substrate
Sponge saturated with a solution of tap water/wetting agent
Maximum rate of 30cm/2 (1 linear ft/s) double stroke
Used on coatings up to 500 micrometers (20 mils)
May be used on concrete