Concrete Air Test Results

When the field test results arrived soon after concrete placement on a recent project we were told the mix had low air content.

Concrete air test results.

Wrong test results can be costly. The strength is measured in megapascals mpa and is commonly specified as a characteristic strength of concrete measured at 28 days after. Large aggregate pieces should be sieved out before testing. If there is more foam in the neck than the equivalent of 2 percent air content divisions after inversion and rolling discard test and use more alcohol.

Although the test results of fresh concrete are known immediately at least by the test technician results for compressive flexural strength or hardened air void parameters for example are not normally available until formal test reports come out. Type a meter helps in the direct measurement of the change in volume in the concrete. Overview of astm c231 standard test method for air content of freshly mixed concrete by the pressure method. This is carried out by means of a column of water over the known volume of concrete.

The measurement of air content in fresh concrete of normal density is typically performed using the pressure method another useful test is astm c 173 however the pressure method is frequently preferred because it is relatively fast. If when the test is complete portions of undisturbed tightly packed concrete not sand is found at the base of the bowl when the contents have been dumped out discard test and repeat. By then the truck was empty and the crew had completed the work. This is a test required to pass the american c.

The testing is done in a laboratory off site. Air entrained concrete is typically specified in areas of the country where frost related damage can occur. Testing should always be done carefully. The pressure procedure of this test method gives substantially the same air contents as the other two test methods for concretes made with dense aggregates.

3 2 this test method and test method c138 c138m and c173 c173m provide pressure gravimetric and volumetric procedures respectively for determining the air content of freshly mixed concrete. The astm test method for pressure air measurement specifies two meters to measure the air content. Also this test should not be performed on any concrete with aggregate larger than 2.