Performance of Chlorides Penetration and Corrosion Resistance of Mortars with Replacements of Rice Husk Ash and Nano-SiO2

• Published in: International journal of electrochemical science Vol. 10; no. 1; pp. 332 - 346
• Main Authors: Pellegrini-Cervantes, M.J., Barrios-Durstewitz, C.P., Nuñez-Jaquez, R.E., Arredondo-Rea, S.P., Baldenebro-Lopez, F.J., Rodríguez-Rodríguez, M., Ceballos-Mendivil, L.G., Castro-Beltrán, A., Fajardo-San-Miguel, G., Almeraya-Calderon, F., Martinez-Villafañe, A.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01-01-2015
• Subjects: accelerated-corrosion; chloride; mortar-nanometric; Plastic-mortar; chloride; accelerated-corrosion; Plastic-mortar; mortar-nanometric
• ISSN: 1452-3981; 1452-3981
• DOI: 10.1016/S1452-3981(23)04996-9

The use of nano-silica oxide (nSO) and ash as cement replacement in mortars has allowed improve the performance of their physical, chemical and electrochemical properties. Researchers have used as a replacement or addition of cement in mortars various types of nSO and ash, including rice husk ash (RHA). In the study of the synergy of simultaneous use of nSO and ash, research has focused on improving the physical and mechanical properties of mortar, with few reports directed to the study of the resistance to corrosion in corrosive environments with the presence of chlorides. It was evaluated in the present work the performance of the simultaneous use of RHA and nSO as replacement of ordinary Portland cement (OPC) in mortars with plastic consistency according to ASTM C1437-99 with use of superplasticizer and relation water/ cementitious of 0.50 at 30 and 90 days of age, conducting studies on compressive strength, total porosity, accelerated corrosion test with impressed voltage at 12.0 V and Rapid Chloride Penetration Test according to ASTM C1202-97. OPC was replaced by 15% RHA and 0.50% nSO individually and simultaneously, resulting the most effective simultaneous use with decrements in porosity of 5.7% and charge passed of 77.7% and increases in compressive strength and to corrosion of 6.1 and 34.0%, respectively. The use of superplasticizer facilitated the manufacturing of mixtures with RHA and nSO, but decreased the speed of the hydration process of the mixture, demeriting the performance of the properties of the hardened mortar. The replacement of OPC by 15% RHA and 0.5% nSO in simultaneous use in mortars of plastic consistency has advantages in the performance of the physical, mechanical and electrochemical properties, due to the synergistic effect of ash-nSO and porosity-compressive strength, presenting very low chloride permeability.