Mitigation of Alkali-Silica Reactivity in New Mexico

008064491998PDFResearch PaperConcrete testsAlkali silica reactionsAdmixturesResearchMix designFly ashLithium compoundsConcrete bridgesAlkali-silica reactivityConcrete additivesConcrete deteriorationConcrete durabilityConcrete mixesLithium nitrateNew MexicoPortland cement concreteUnited StatesUniversity of New MexicoMcKeen, R. GordonLenke, Lary R.Pallachulla, Kiran KumarUniversity of New Mexico. ATR InstituteNew Mexico. State Highway and Transportation Dept.United States. Federal Highway AdministrationUS Transportation CollectionThe research experiments reported were conducted at the Materials Research Center, ATR Institute, University of New Mexico, at the request of the Research Bureau, New Mexico State Highway and Transportation Department (NMSHTD). The purpose was to determine the amount of additives required for mitigation of alkali-silica reactivity (ASR) based on screening tests. Fly ash additives routinely used in New Mexico and a new material - lithium nitrate - proposed by the Strategic Highway Research Program were evaluated. The work was motivated by continuous problems with early deterioration of concrete bridges due to alkali-silica reactivity. The work was based on the use of acceptance criteria established by NMSHTD for expansion due to ASR, as measured in screening tests. Recommendations resulting from this research do not consider all aspects of the behavior of concrete mixtures and structures. The additive recommendations are based on reduction in mortar-bar expansion during accelerated tests. Figures, tables, references.75