Brief Analysis of Moisture Measurement in Concrete
Builders and flooring contractors sometimes rely on calcium chloride testing to monitor the moisture content of concrete slabs to determine if they are ready to receive floor coverings. The calcium chloride test can measure the moisture (steam emissions) in the upper half to 1/4 inch of the slab, however, professionals debate whether it provides the contractor with a complete picture. Although contractors are aware of the importance of surface moisture in slabs, understanding the moisture content of slabs is crucial.
In order to assist in optimizing the precise measurement of moisture in concrete, ASTM has developed the F-2170 standard. The F2170 standard is a testing method that has some significant advantages compared to calcium chloride. The main advantage is that this testing method places the probe inside the concrete slab itself. This process is called the in-situ method, which provides contractors with accurate relative humidity (RH) readings from within the concrete slab itself. RH testing is an excellent tool for predicting the performance of slab after reaching equilibrium. In this way, it predicts potential floor failures related to moisture.
A Brief Analysis of Moisture Measurement in Concrete Water Absorption: 4-5 "thick slabs may take 30-60 days to cure properly. Once the concrete has cured for at least 30 days, moisture testing can begin. Because even under ideal conditions, concrete takes a long time to dry, attempting moisture testing before 30 days is often a waste. If you work in particularly humid environments, concrete may take longer to be tested.
Before applying adhesives, floor coverings, or other structural components, it is necessary to measure the moisture content in the concrete. If excess moisture remains in your concrete slab, any adhesives, wood, oilcloth, tiles, or sprayed elastic flooring you install will eventually fail, potentially leading to litigation and requiring significant dismantling and replacement.
Imagine completing a large building project, such as a new school, by simply tearing off the floor after installation, as water trapped in the concrete can cause floor defects. This issue poses safety risks to students, faculty, and staff, and therefore needs to be corrected. Appropriate moisture testing can pre determine issues, but now the construction deadline will be missed, penalties will be imposed on the construction contract, and material costs will increase.
Due to this potential disaster, it is better to correct any moisture issues as soon as possible. Whether concrete slabs are used in healthcare facilities, schools, warehouses, or office buildings, ASTM F2170 testing should be used to prevent structural and visual damage to the completed building.
You need to have a humidity/relative humidity meter and sensor in order to achieve high accuracy in measurements.
Your device should be able to measure the relative humidity (RH) of concrete and the ambient temperature. By determining the humidity conditions inside and around the slab, it is easier to determine when it is safe to develop on concrete.
