Evaluation of Use of Lithium Nitrate in Controlling Alkali-Silica Reactivity in Existing Concrete Pavement (05-0579) - MP-24
Christopher Y. Tuan, University of Nebraska, Lincoln
Michael T. Kelly, U.S. Army Corps of Engineers
Haosu Sun, University of Nebraska, Lincoln
Mark E. Buss, U.S. Army Corps of Engineers

Presented herein are findings from a two-year field trial in which lithium nitrate was applied at a rate of 0.006 gal per square foot, twice a year, on an existing concrete pavement in Norfolk, Nebraska, in the attempt to arrest on-going alkali-silica reaction (ASR) distress. Various destructive and non-destructive means were utilized to measure the effectiveness of the treatments. Concrete cylinders were cored for petrographic examination and split-tension testing. Powder samples were taken to determine lithium content. Nondestructive evaluations included using crack mapping, a Schmidt hammer, a velocity (“V”) meter, and an impact echo apparatus. The amount of lithium penetrated into the pavement by gravity soaking has been very limited. The results to date have not shown definitive benefit of the lithium material in controlling or mitigating the ASR process, presumably the pavement has not reached the deterioration state for optimal lithium penetration. The feasibility and effectiveness of other application techniques on hardened concrete such as by electrolysis, surface pressurization, and vacuum impregnation should be investigated for comparison against gravity soaking.