Estudo de durabilidade de concretos e argamassas através de RAA em agregados convencionais da região de Campina Grande e alternativos em concreções lateríticas Sapé-PB e Jacumã-PB.

Abstract

In concrete construction, the term durability can be understood as the capability of structures to preserve their safety, stability and ability when subjected to environmental conditions foreseen in project and during the period of expected life. Constructors and customers want to avoid spending on maintenance and repairs. This wanted durability depends basically on quality control during the stages of planning, design and execution. One of the mechanisms responsible for ageing and deterioration of concrete is a reaction between the alkali present in cement and certain reactive aggregates denominated alkali aggregate reaction - AAR. This complex phenomenon discovered early in the last century, with pathological effects on more than one hundred dams in the world, was also detected in bridges and more recently in buildings in the metropolitan area of Recife-PE. It should be noted that once AAR is triggered there is no procedures that could prevent its advance; however the best way to prevent it is a prior knowledge of the materials that will be used. This investigation studies the reaction potential among aggregates obtained from granite rocks and sand normally used in building construction in the Campina Grande-PB area and lateritic alternative aggregates found in the cities of Sape-PB and Jacuma- PB. Initially, a state of the art on ARR is presented along with characterization of used materials. To evaluate the potential of reactive aggregates, bars of mortar, chemical and petrography methods were used. To study the extension of mortar bars at 16 and 28 days of age for all aggregates the accelerated method was used. In addition, scanning electron microscopy - MEV - was performed on samples from accelerated method to analyze the obtained results. The aggregates used in this investigation revealed no reactive potential.