Standard Test Method for Measuring Vapor Emission Rate (MVER) of Concrete Subfloor Using Anhydrous Calcium Chloride. Apparatus – the kit plus a gram. The applicable industry standard for this test, ASTM F, defined the scope of CaCl testing: “This test method covers the quantitative determination of the rate. Measuring Moisture Vapor Emission Rate of Concrete Subfloor Using Anhydrous Calcium Carbide.
|Published (Last):||25 November 2016|
|PDF File Size:||13.68 Mb|
|ePub File Size:||19.7 Mb|
|Price:||Free* [*Free Regsitration Required]|
Your email address will not be published. This measurement is the equivalent weight asgm water evaporating from ft 2 of concrete surface in a 24—h period.
Concrete moisture emission is a natural process driven by environmental conditions. Historical Version s – view previous versions of standard. CaCl measured only the top one-half to three-quarters inch of the slab. All concrete subfloors emit some amount of moisture in vapor form. Over decades, CaCl gained industry acceptance as a practical standard.
The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard. The asfm chloride moisture test has been the industry standard for making this determination and is a practical, well-established and accepted test of dynamic moisture.
Concrete floor installers began using the calcium chloride CaCl moisture test back in the early s to conclude when a new concrete slab was fit for floor coverings. Concrete moisture vapor migrates from the xstm of concrete slabs to their surfaces in order to evaporate.
The CaCl moisture test is a building practice with lineage. Submit a Comment Cancel reply Your email address will not be published. The results obtained reflect the condition of the concrete floor surface at the time of testing and may not indicate future conditions. Where the challenge became clear was in determining whether the surface emission rate determined by desiccant weight gain truly reflected the moisture conditions deeper in the slab.
It is the responsibility of the user of this standard to establish appropriate safety and health practices, and determine the applicability of regulatory limitations prior to use. Builders, then, made threshold floor covering decisions based on errant readings. This is how concrete dries. In light of such research, the American Society for Testing and Materials made two changes to moisture measurement industry standards.
Referenced Documents purchase separately The documents listed below are referenced within astmm subject standard but are not provided as part of the standard.
Public Knowledge Base
Axtm builders continue to use the CaCl moisture test, post-installation moisture problems eventually redefined it as a test method worthy of scrutiny. The moisture vapor emitted from a concrete slab is measured in adtm.
In fact, moisture-plagued concrete slabs certified by ASTM F protocol proved to be a patterned and persistent challenge to the concrete flooring industry — so much so that industry professionals began to investigate the scientific integrity of the CaCl moisture test.
The moisture vapor emission rate only reflects the condition of the concrete floor at the time of the test.
But their truth has entered a new era and the challenges of moisture emissions-based testing are becoming increasingly clear. Therefore, the natural migration process of concrete moisture drying is influenced by environment.
This site uses Akismet to reduce spam. At that point, it was safe to install floor covering over a concrete substrate. Link to Active This link will always route to the current Active version of the standard. The CaCl moisture test produced data based on moisture vapor emission rate MVERthe quantitative indication of how many pounds of slab moisture evaporated from square feet of concrete over a hour period.
This led to continued moisture problems when that moisture eventually reached a covered concrete surface where they could no longer evaporate. Generally, high ambient RH slows concrete drying as the slab absorbs moisture vapor; low ambient RH causes concrete to emit moisture vapor.
All floor coverings are susceptible to failure from excessive moisture vapor emissions. CaCl tended to underestimate the true moisture conditions at the high end of the moisture spectrum, while it tended to overestimate the moisture conditions of older slabs.
It will produce quantified results directly applicable to flooring manufacturer’s specifications.
Learn how your comment data is processed. Work Item s – proposed revisions of this standard.