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8 Pages

Analysis of AAR preventive methods: Petrographic analysis and accelerated bar method

C.F.C. Silva, E.C.B. Monteiro & A.D. Gusmão

ABSTRACT: Numerous concrete works are affected by the alkali-aggregate reaction (AAR) in various countries. Prevention is still the only efficient way to prevent the occurrence of AAR, but the damages caused are irreversible. One quite effective way is to use test methods that help in the investigation of this debilitating reaction. The purpose of this study is to carry out a comparative analysis of the result of the petrographic method and the expansion limits of three standards of the accelerated mortar bar method performed on aggregates in the state of Pernambuco, Brazil, in an attempt to identify the reactive characteristics that influences the results of the expansions. The accelerated method did not prove secure since it presented different reactivity results, depending on the expansion limits of each standard used. However, according to the results, it is advisable to develop new studies, and propose new testing methods that are more reliable when using aggregate in concrete structures.