Abstract
From 1990 to 2008 an integral component of the portland cement concrete module of the annual National Highway Institute Highway Materials Short Course was a series of independent and parallel evaluations of fresh and hardened properties for a single load of concrete. Up to six testing teams independently sampled concrete from the truck and tested the fresh concrete for temperature, slump, and air content by pressure and by volume meter. The experiment was repeated annually to demonstrate test procedures and the variability in test results for concrete from a single load. Results indicate the time dependency in both slump and apparent air content, the relationship between slump and apparent air content, and the difference between air content as indicated by the AASHTO T 152/ASTM C231 pressure air meter and the AASHTO T 196/ASTM C173 volumetric air meter.
Get full access to this article
View all access options for this article.