ASTM’s Industrial Protective Coatings subcommittee has developed a new standard for replicating and measuring concrete surface profiles—one of the most important characteristics of a coating or overlayment bonding.
Proper bonding of overlays and coatings demands obtaining the correct profile for a concrete surface. Profiles can be imparted to concrete by blast cleaning, acid etching and other methods.
ASTM D7682-10, “Standard Test Method for Replication and Measurement of Concrete Surface Profiles Using Replica Putty,” describes how to obtain a permanent replica of the concrete surface, which can then be compared to visual profile standards or evaluated quantitatively for profile depth.
The permanent replica may also prove useful in resolving future disputes.
"This technique uses replica putty to make impressions of concrete surfaces for either visual comparison or for quantifying the surface roughness," says David Beamish, general manager of DeFelsko Corp. and a D01 member.
ASTM says the new standard will be useful to several coatings professionals:
• Coating inspectors can retain profile replicas that can be viewed or measured on-site before coating application and used as a pass/fail test of whether surface preparations meet specifications.
• Owners can retain replicas should a failure occur.
• Contractors can retain replicas for verification of adherence to the specification's required anchor profile ranges.
• Coating manufacturers can designate within the product data sheet the range requirements for the coating being used on the project.
• Engineers can write specifications utilizing the coating manufacturer's product data sheets that designate a profile range for the required coating.
Field, Lab Use
This test method is suitable for both field and laboratory use, to obtain a permanent record of concrete surface profile using replica putty and to determine the depth of that surface profile. The procedure was developed for concrete substrates but may be appropriate for other rigid substrates, according to ASTM.
The International Concrete Repair Institute (ICRI) provides a means of visually judging a concrete surface by use of nine different visual comparators called Concrete Surface Profiles (CSP). This standard complements the use of these visual comparators.
This standard does not purport to address all of the safety concerns, if any, associated with its use.
The new standard can be ordered here.