Behavior of Mortars with Different Porosities in Front of Attack of Aggressive Agents

Abstract

Chemical reactions that lead to decreased durability in concrete structures may result from chemical interactions between aggressive agents present in the external environment and cement paste compounds or may result from internal reactions. The chemical reactions are manifested by the physical properties of the concrete, such as porosity and permeability and the decrease of resistance and cracking. Among the several aggressive agents that attack the reinforced concrete structures it can be highlighted chloride ions, sulphate ions and carbon dioxide. In this context, the study presents the analysis of different traces of mortar executed with cement type CPII-F-32 (OPC Cement, in Brazil one of the most used cements) with w/c ratios of 0.4 and 0.7, when subjected to the attack of sulphates, chlorides and carbonation. The analyzes quantitatively evaluated the amount of ions present after exposure to the agents and demonstrate the importance of evaluating the dosage of water in the mortars to minimize future problems with durability.