Performance evaluation of a coating protection system for concrete structures affected by internal expansive reactions

In the last decades, a significant number of large concrete structures with deterioration problems, related to internal expansive chemical reactions, have been detected in Portugal. This type degradation is associated formation products causing its disruption, leading decrease structure’s service life and, ultimately, decommissioning or demolition structure. Portugal, affected by this pathology are very important economic and strategic terms, since these reactions usually encountered dams, bridges viaducts. Two separate material-based mechanisms identified cause swelling: Alkali-Silica Reaction (ASR) Delayed Ettringite Formation (DEF). Both result common requirement for their occurrence presence sufficient moisture content inside concrete. By controlling humidity level concrete, coatings applied onto surface should contribute mitigate ASR DEF acting as barrier against ingress water allowing dry, long they adequate permeability characteristics. paper presents general criteria that may be followed select protection system, based on coating materials (hereinafter designated system), rehabilitation order them thus, improve durability structures. addition, laboratory study presented concerning performance evaluation composed two materials, terms capacity bridge cracks, liquid vapour, effectiveness