COMPARATIVE INVESTIGATION OF CORROSION-RESISTANCE OF STEEL REINFORCEMENT IN ALINITE AND PORTLAND-CEMENT MORTARS

The corrosion resistance of steel-reinforced mortar specimens made fro m alinite cement was investigated using ordinary Portland cement (OPC) specimens as reference. The specimens were prepared and exposed in th ree different environments: continuous exposure in tap water, interrup ted exposure in tap water, and interrupted exposure in 3.5% NaCl solut ion. The steel weight loss and the half cell potential were measured u s, exposure time, up to the age of 12 months. Pore solution extraction and analysis and porosity determination were also performed. In conti nuous exposure in tap water, alinite cement provided adequate protecti on against corrosion. In interrupted exposure in tap water, a higher c orrosion was observed for alinite cement compared to OPC. In the case of interrupted exposure in 3.5% NaCl solution, the simultaneous action of free chlorides and oxygen resulted in the depassivation of steel r einforcing bars in alinite and Portland cement mortars, and led to sev ere corrosion effect. (C) 1998 Elsevier Science Ltd.