ICRI CSMT flashcards
ICRI CSMT · Build recall with a focused review session.
32 cards. Read the term and the definition here. The deck at the top of this page is optional.
- Residual mixing water
- Water remaining in concrete after cement hydration, available to evaporate or migrate; higher water-cement ratio leaves more free water and raises equilibrium relative humidity.
- Capillary transport
- Movement of liquid water through the fine pore network of concrete driven by surface tension and suction; dominant at high relative humidity and a major path for moisture rise.
- Vapor diffusion
- Transport of water vapor through concrete pores down a vapor pressure gradient, from warm or wetter zones toward cooler or drier zones, independent of liquid flow.
- Equilibrium relative humidity
- The stable RH the concrete pore air reaches for a given moisture content and temperature; it is the quantity ASTM F2170 approximates after probe equilibration.
- Moisture-related coating failure
- Blistering, bubbling, or debonding of coatings caused by vapor pressure buildup or water at the bond line; prevented by verifying substrate moisture before application.
- F2170 probe depth
- The probe tip is placed at a specified depth, commonly 40 percent of slab thickness for slabs on grade, to sample representative pore humidity rather than the dried surface.
- Probe equilibration
- The period after inserting the F2170 probe during which the sensor must stabilize with the concrete pore air before a valid reading is recorded.
- Sleeve sealing
- Sealing the top of the F2170 hole and the sleeve against the concrete so ambient air cannot enter and dilute the pore humidity being measured.
- In-situ RH acceptance
- Comparison of the F2170 relative humidity result to the flooring or coating manufacturer's published limit to determine whether the slab is acceptable for installation.
- F2170 test location count
- The standard sets a minimum number of test locations based on slab area and requires additional locations when results vary widely across the slab.
- F1869 test setup
- A pre-weighed calcium chloride dish is sealed under an airtight dome on a cleaned slab surface for a fixed exposure period to absorb vapor.
- MVER units
- Moisture vapor emission rate reported in pounds of water per 1000 square feet per 24 hours, or the metric equivalent, calculated from dish mass gain.
- Surface preparation for F1869
- The slab surface must be free of curing compounds, sealers, adhesives, and dust before placing the dish; contamination invalidates the emission result.
- F1869 exposure period
- The fixed time the sealed dish remains on the slab, typically about 60 to 72 hours, after which the dish is removed and weighed.
- F1869 limitation
- The test measures short-term vapor emission from the surface and does not directly measure in-situ relative humidity at depth in the slab.
- F2420 surface RH
- A sealed hood or chamber placed on the slab surface encloses an RH sensor, measuring surface relative humidity rather than humidity at depth.
- F2659 moisture meter
- A handheld electrical impedance or capacitance instrument giving relative readings used to screen and map moisture variation across a slab surface.
- Relative meter readings
- F2659 readings are instrument-specific and relative; they cannot be converted to RH or MVER without calibration to a quantitative method.
- Screening versus acceptance
- Surface methods map moisture and guide test placement; quantitative F2170 or F1869 results are used for specification acceptance.
- Embedded metal interference
- Rebar, conduits, and other embedded metal distort F2659 electrical readings, so measurements near them are unreliable and should be avoided.
- Method selection rule
- Choose F2170 when the product limit is in-situ RH, F1869 when the limit is MVER, and surface methods for screening and mapping.
- Test timing
- Testing is performed after curing and before flooring installation, when the slab moisture condition is representative and not affected by recent wetting.
- Vapor retarder effect
- A properly installed vapor retarder under a slab reduces vapor drive from the soil but does not eliminate moisture already in the concrete.
- Environmental stability
- Stable temperature and relative humidity in the test area during equilibration and exposure periods are required to obtain representative and repeatable results.
- Test location distribution
- Tests are spread across the slab and include areas of concern such as exterior walls, penetrations, and patched areas, following the standard's minimum count.
- Reporting test method
- The report identifies the standard used, test date, locations, slab thickness and depth, and ambient and slab conditions for each measurement.
- F2170 reporting
- Report equilibration time and the stability criterion met, along with the recorded relative humidity and slab temperature at each location.
- F1869 reporting
- Report exposure time, dish area, mass gain, and the calculated MVER with units for each test location.
- Pass-fail interpretation
- Results are compared to the manufacturer's published limit and stated as pass or fail, with any areas requiring mitigation identified.
- Product-specific limits
- Adhesives and coatings publish their own allowable in-situ RH or MVER values; the product's published limit governs, not a generic rule of thumb.
- Vapor-reducing primer
- A coating or primer system applied to a slab to reduce vapor transmission; it can raise the allowable limit only when specified as a complete system.
- Silica dust control
- Drilling and grinding concrete generate respirable silica; use wet methods or HEPA vacuum, plus eye and respiratory protection.