Measuring Moisture In Concrete

What are the options.

Measuring moisture in concrete.

Before the change the standard required waiting 72 hours for rh sensors to acclimate in the concrete slab before taking moisture readings. 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. Now testers need only wait 24 hours. 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.

Inaccurate measuring of aggregate moisture increases production costs. 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. This requires accurate concrete moisture measurement. There are two main standards in the industry right now calcium chloride cacl testing and rh testing.

Concrete slabs appear to be solid and hard but in reality concrete is moist stuff. Testing rh deep in the slab is crucial for determining. 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. The water creates a chemical reaction in the cement causing it.

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. That if moisture is detected the concrete is probably not ready for coating. Concrete is manufactured by mixing cement aggregates such as sand and gravel and water. 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.

When measuring moisture in concrete the best and most reliable method is to use the astm f 2170 testing method. This makes the rh test much faster than any other industry accepted method of measuring moisture in concrete slabs. Also known but less common in use are the hood method plastic sheet method and concrete moisture meters. In this test an 18 inch x 18 inch 450 measuring and removing moisture in concrete by don j.

How concrete hardens and dries. Astm f2170 in situ rh testing will give you the most reliable information to help you manage your flooring project successfully. 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.