| 1944 | F. H. Jackson, Principal Engineer of Tests for PRA's Division of Physical Research, heads a team in California studying the causes of the disintegration of concrete structures in California, Oregon, and Washington. Defects, some of which appeared after only 3 or 4 years of service, require intensive review to ensure freedom from these troubles on future projects. The problem in California appears to be exposure to the alkali-aggregate reaction, a problem that Jackson believes can be solved by application of the principle of air entrainment. |
