The alkali-aggregate reaction affects the durability and the mechanical resistance of the concrete structures, provoking cracks in the structural elements. Despite of these
pathological manifestations, it cannot affirm that, even so the reaction is slow, the ultimate limit state cannot be reached. The occurrence of this phenomenon on blocks foundation is rarely described in literature. Recently was identified in foundations of buildings in the Metropolitan of Recife Region, constituting a problem that comes calling the attention of the community technique and the productive sector of civil construction. The pile caps affected by the AAR must suffer interventions with adequate techniques of recovery to each situation. Inside of that focus, this work presents the results of the attendance of the services of microcement injection in cracks in the blocks of a building in recovery process. It still presents the reinforcement proposal for the pieces of infrastructure affected by expansible reaction. To go accomplished extractions of specimens, cleaning and superficial closing of the cracks with an epoxy mixture and kaolin, application of the microcement inside the cracks and extraction of specimens after the injection for verification of the effectiveness of the fulfillment of the cracks with the injected material. The results can supply important subsidies for repair pile caps damaged for the action of AAR
