Selected Answers

From Marco Antonio Alvarado Meneses of Sherwin Williams Perú on January 27, 2015:
I agree with Denis: “Salt testing on concrete subs ...read more I agree with Denis: “Salt testing on concrete substrates is not a recommended practice.” Is it possible to measure soluble salts from the surface of concrete and, if so, what method should be used?

From Vaughn O'Dea of Tnemec Company, Inc. on January 17, 2015:
SSPC’s Guide 15 excludes concrete by its very titl ...read more SSPC’s Guide 15 excludes concrete by its very title with reference to "nonporous surfaces." Are you aware of specific tests that have been used successfully on vertical concrete?

From Jim Johnson of CHLOR*RID International Inc. on January 6, 2015:
Many specifications call for testing, measuring an ...read more Many specifications call for testing, measuring and removal of excess salts from concrete. Most frequently, chloride is being tested for, but due to service and service environment, quite often sulfate and nitrate are tested for, too. Such salts on concrete cause some of the same problems they do on steel, such as blistering and poor adhesion. SSPC Guide 15 lists the various methods to test for chloride, sulfate, and nitrate and lists the specific procedures required to perform testing.

From Vaughn O'Dea of Tnemec Company, Inc. on January 6, 2015:
Can you elaborate on the method or procedure you u ...read more Can you elaborate on the method or procedure you use to quantitatively measure soluble salts from the surface concrete?

From Srinivasan K of BHEL on January 2, 2015:
We  perform swab analysis for presence of chl ...read more We  perform swab analysis for presence of chlorides, sulfates, and other contaminants, if any.

From Chuck Pease of MMI Tank on January 2, 2015:
I’m not sure I agree with your statement, Denis, t ...read more I’m not sure I agree with your statement, Denis, that “Salt testing on concrete substrates is not a recommended practice.” What is the premise or standard you base this statement on?
The test for chloride content in concrete is very significant because when chloride is present in reinforced concrete, it can cause very severe corrosion of the steel reinforcement. Chlorides can originate from two main sources:  “internal” chloride, i.e., chloride added to the concrete at the time of mixing,  including calcium chloride accelerating admixtures, contamination of aggregates and the use of sea water or other saline contaminated water; and “external” chloride, i.e., chloride ingressing into the concrete after it has hardened. In this category, we find both rock-salt (used on roads), which gets into concrete structures such as flyovers; and sea salt, either directly from sea water in structures such as bridges, or in the form of air-borne salt spray in structures adjacent to the coast.

From Denis Pazio of Euronavy, Inc. on December 30, 2014:
Salt testing on concrete substrates is not a recom ...read more Salt testing on concrete substrates is not a recommended practice.

A simple basic test that can be performed on concrete substrates for oil or dust contaminants is to drop small amounts of water on the surface. If the water beads, the concrete is contaminated. If the water is spread out evenly and is eventually absorbed into the concrete, it is typically OK to proceed.

Most of the focus should be on the flooring, and not the walls. A good evaluation and survey should be conducted beforehand to determine problem areas, and, of course, historical data from owners/agency should be consulted.