ASTM F formally recognizes the use of in situ probes as a means of conducting relative humidity testing. In fact The Standard The In-Situ Method In-situ concrete moisture testing places sensors, or probes, inside the slab itself . This test method covers the quantitative determination of percent relative testing. The ASTM F standard represents a fundamental change in how. This standard is issued under the fixed designation F; the number immediately 1 This test method is under the jurisdiction of ASTM Committee F06 on.
|Published (Last):||19 September 2016|
|PDF File Size:||6.28 Mb|
|ePub File Size:||2.97 Mb|
|Price:||Free* [*Free Regsitration Required]|
Concrete slab moisture is a major cause of concrete flooring failure. When concrete is mixed and poured, water vapor migrates from the bottom of the slab to the surface to evaporate. This process requires time and quantifiable concrete moisture measurements to verify. ASTM F formally recognizes the use of in situ probes as a means of conducting relative humidity testing. In that case, builders did not allow the slab sufficient time for concrete moisture levels to equilibrate reach equilibrium moisture content according to relative humidity RH.
ASTM F Explained – ASTM F Information
Concrete slab moisture problems can cause floor covering delamination, peeling, blistering, staining and sweating. In-situ probes deepen concrete moisture measurement.
The MVER is defined as the rate of water vapor emissions from the surface of concrete and is determined with the use of a desiccant material sealed to the slab surface for a specified stndard period, then measured.
It has been believed that the change in the desiccant weight could be translated into a moisture ratio for the concrete beneath. In-situ concrete moisture testing places sensors, or probes, inside the slab itself. Stansard concrete dries, moisture migrates from the bottom of the slab to the surface where it can evaporate away.
Logically then, moisture levels at the bottom of a slab will read higher from those at the surface. In this way, in situ measurement provides a composite picture of overall slab moisture levels, and provides the data necessary to make business decisions regarding flooring installations.
Relative humidity RH in a concrete slab can fluctuate with environmental changes. Concrete absorbs water vapor from the air under high ambient humidity; concrete releases more water vapor when stsndard humidity of the surrounding air is low.
Surface-based test results will fluctuate, even more, under these changes in environmental conditions. General contractors must bear in mind two interactive processes when they are looking at construction schedules: Sub-grade water vapor can permeate even well-mixed and applied slabs. Many contractors use vapor barriers directly under the slab to slow moisture permeation.
10 Guidelines for ASTM F Compliance
And moisture can still be an issue at grade so concrete foundations must be designed to include proper moisture drainage. Without it, even a well-dried and functioning qstm can end up with concrete slab moisture problems. In situ moisture measurement systems are evolving rapidly as a result of ATSM F and reflect the industry realities of the concrete installation business.
And installers are finding results are more accurate and more dependable with RH testing. Skip to content Concrete slab moisture is a major cause of concrete flooring merhod.
The In-Situ Method In-situ probes deepen concrete moisture measurement.