Title: Abnormal Cracking in Highway Structures in Georgia and Alabama
Author(s): Calvin C. Oleson
Publication: Journal Proceedings
Appears on pages(s): 329-354
In 1947-1948, an investigation was made of abnormal cracking in concrete highway structures in Georgia and Alabama. Highway department records were searched for reliable data on cements and aggregates used in the con-struction. A preliminary analysis of the data indicated the possibility of alkali-aggregate reaction. Subsequent studies were made to determine probable average alkali contents of all cements included in the survey. It was found that three cements, all having average alkali contents of more than 0.6 percent, when used with-natural siliceous aggregates from Montgomery, Ala., and allied sources, were involved in the cracking. A restriction of alkali in cements was imposed in 1947. A continuing observation of the performance of approved cements in concrete in the two states has been in progress since the initial investigation. Visual observations, comprehensive soniscope tests, and precise measurement of length changes have been included in the studies. Extensive laboratory tests of aggregates have been undertaken.