Concrete Air Test Results

Air entrained concrete is typically specified in areas of the country where frost related damage can occur.

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. 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. 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.

The owner wanted us to remove and replace the concrete. 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 strength is measured in megapascals mpa and is commonly specified as a characteristic strength of concrete measured at 28 days after. Overview of astm c231 standard test method for air content of freshly mixed concrete by the pressure method.

This is a test required to pass the american c. Type a meter helps in the direct measurement of the change in volume in the concrete. The astm test method for pressure air measurement specifies two meters to measure the air content. The only work done on site is to make a concrete cylinder for the compression test.

Large aggregate pieces should be sieved out before testing. Lightweight concrete is typically done with the volumetric method the infamous rollermeter because the aggregate is too porous and the test results will be thrown off with so much entrapped air. 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. 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.

By then the truck was empty and the crew had completed the work. The testing is done in a laboratory off site. Also this test should not be performed on any concrete with aggregate larger than 2.