News — in situ

The Study In July 1996, Dr. Göran Hedenblad,  Lund Institute of Technology, Stockholm, Sweden performed experiments measuring the relative humidity within concrete by performing in-situ testing at different depths within a concrete slab. His work identified a Relative Humidity (RH) gradient within a slab that had its surface exposed, where the RH increased as depth into the slab increased. Hedenblad went on to show that after the concrete slab was covered by a flooring material with minimal permeability,  moisture was prevented from migrating out of the concrete surface. During the process, the RH gradient equalized to an average RH throughout...

ASTM F2170 EXPLAINED 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 F2170 formally recognizes the use of in situ probes as a means of conducting relative humidity testing. In fact, ASTM F2170 represents a fundamental change in moisture measurement. The Standard The Problem (as defined in ASTM F2170): “Excessive moisture permeating from floor slabs after installation can cause floor covering system failures such as debonding and deterioration of...

Relative humidity (RH) is often mistaken for moisture; however, these are two completely separate terms. Moisture content represents the amount of water in liquid form, while humidity levels represent the amount of water in vapor form. In ASTM F2170, relative humidity is defined as "the ratio of the amount of water vapor actually in the air compared to the amount of water vapor required for saturation at that particular temperature and pressure, expressed as a percentage." Simply put, relative humidity represents the amount of water vapor that is present in the air in comparison to the amount that the air can hold. The Difference...

Hi everyone! As you all know flooring failures cost companies millions of dollars annually. Most failures are due to moisture-related issues. Moisture in the pores of concrete can migrate toward the warm dry air above the surface, causing loss of adhesion and blistering. This can be minimized if not prevented with proper moisture testing prior to applying. It is now easier than ever to perform ASTM F2170 since it has gone from being a 72-hour test to only a 24-hour test. Check out our full line of moisture detection equipment at www.CatalystSalesLLC.com