Fresh properties - Air content

The measured air content (EN 12350-7) of the fresh concrete is shown below. As expected the non air entrained concretes (Mix G, L and O) had low air contents.

The target range for air content in fresh concrete of 3.5 - 5.5 % was met for all the "Cylinders + cubes" batches, and 10 out of 12 "Small block" batches, where the upper limit was exceeded by 0.1 % for Mix B and subceeded by 0.3 % for mix D.

For the large blocks the homogenization of the slump concretes provided a challenge as it increased the air content of the concrete. Consequently, it was necessary to aim for a rather low air content of the two batches to be homogenized in order to stay within the target air content range. However, for three concretes the air content of the fresh concrete was measured above the target range, i.e. Mix A "Large block 1+2" at 5.8 %, Mix I at 5.7 % and Mix N at 6.1 %. The latter case was extreme as the two individual batches had an air content of 2.9 %, i.e. well below the target range.