The only work done on site is to make a concrete cylinder for the compression test.
Concrete air test results.
Type a meter helps in the direct measurement of the change in volume in the concrete.
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 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.
By then the truck was empty and the crew had completed the work.
Testing should always be done carefully.
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.
When the field test results arrived soon after concrete placement on a recent project we were told the mix had low air content.
Air entrained concrete is typically specified in areas of the country where frost related damage can occur.
The testing is done in a laboratory off site.
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.
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.
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 strength is measured in megapascals mpa and is commonly specified as a characteristic strength of concrete measured at 28 days after.
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 owner wanted us to remove and replace the concrete.
Large aggregate pieces should be sieved out before testing.
Wrong test results can be costly.
