Measuring Moisture In Concrete

This makes the rh test much faster than any other industry accepted method of measuring moisture in concrete slabs.

Measuring moisture in concrete.

What are the options. Inaccurate measuring of aggregate moisture increases production costs. The biggest problem in connection with the concrete production is the variation in aggregate moisture and therefore it is an important task to make sure that measuring of the aggregate moisture is easy and as accurate as possible. This requires accurate concrete moisture measurement.

Schnell munters corporation moisture control services 52 march 1998 jpcl pmc w before you coat concrete you need to know how much moisture it contains and how to. Concrete is manufactured by mixing cement aggregates such as sand and gravel and water. A second direct test astm f 1869 standard test method for measuring moisture vapor emission rate of concrete subfloor using anhydrous calcium chloride was standardized in the 1990s by the subcommittee on practices of the committee on resilient floor coverings. When measuring moisture in concrete the best and most reliable method is to use the astm f 2170 testing method.

Before the change the standard required waiting 72 hours for rh sensors to acclimate in the concrete slab before taking moisture readings. Concrete slabs appear to be solid and hard but in reality concrete is moist stuff. That if moisture is detected the concrete is probably not ready for coating. Often more than one method is used to get an accurate reading of actual moisture content.

Using a meter that conforms to astm f2170 using in situ probes that go inside the concrete make it much easier to be accurate in measuring the moisture of the concrete at its core. There are two main standards in the industry right now calcium chloride cacl testing and rh testing. Also known but less common in use are the hood method plastic sheet method and concrete moisture meters. Given the realities of moisture in concrete and the necessity of measuring the moisture condition of the concrete slab accurately only one clear conclusion exists.

Under this method you ll use a thermo hygrometer with in situ probes along with a series of prepared holes to get readings of relative humidity deep in the concrete slab. Now testers need only wait 24 hours. In this test an 18 inch x 18 inch 450 measuring and removing moisture in concrete by don j. There are three standard methods for measuring concrete moisture.

By determining the moisture conditions both within and around the slab it is easier to determine exactly when it will be safe to develop on the concrete. How concrete hardens and dries. It begins as a liquid slurry of water sand cement and aggregate and even after it hardens moisture continues to pass out of the concrete for years.