Examination of Cores from Four Highway Bridges in Georgia
ARMY ENGINEER WATERWAYS EXPERIMENT STATION VICKSBURG MS
Pagination or Media Count:
Six concrete cores from four structures built by the Department of Transportation, State of Georgia, were examined. Two of the structures were built in 1937, one in 1946, and one in 1947-48. Three of the structures were built using high-alkali cement and one with a cement of average alkali content slightly above 0.60 percent. The coarse aggregate in three of the structures was granitic gneiss from one source the coarse aggregate in the fourth was granitic gneiss from a second source. Evidence of alkali-silica reaction was present in all of the cores in the form of one or more of the following gel reaction product internal cracking in some coarse aggregate and localized depletion of calcium hydroxide in cement paste adjoining some pieces of coarse aggregate. No constituent usually found to be alkali-silica reactive was present. Quartz, which has been associated with alkali-silica reaction on a very few previous occasions, and plagioclase feldspar, appeared to have been the reacting constituents.
- Civil Engineering
- Construction Equipment, Materials and Supplies