Tratamento de superfície com silicato de sódio para concreto: penetração de cloretos e absorção de água
Abstract
Na2SiO3 is one of several types of surface treatment for concrete. It reacts with the NaOH present in the pore solution of the concrete resulting in insoluble compounds. The aim of this paper is to describe the effect of Na2SiO3 on the transport of water and chloride ions through the concrete. To this end, results of capillary water absorption, immersion water absorption and chloride migration are presented. Results indicate that this treatment decreases the water penetration through the concrete, with a role in the corrosion kinetics of reinforced concrete. However, the results of water absorption by immersion indicated that this product should not be applied in cases where there is water pressure, that is, when the permeability is the mechanism of water penetration. Finally, it was shown that treatment with Na2SiO3 reduces the diffusion coefficient chloride resulting in increased service life of concrete structures.
Keywords: concrete; surface protection; sodium silicate; durability; service life.
Downloads
References
Andrade C. (1993), Calculation of chloride diffusion coefficients in concrete from ionic migration measurements, Cement and Concrete Research 23: pp. 724-742.
Bentur A., Diamond S., Berke N. S. (1997), Corrosion Control. In: Steel Corrosion in Concrete – Fundamentals and Civil Engineering Practice (Londres, Inglaterra: E & FN SPON): pp. 94-145.
Helene P. (2000), Durabilidad, Interpretación y evaluación de resultados. In: Manual de Diagnosis e Intervención en Estructuras de Hormigón Armado. (Barcelona, Espanha: Collegi d’Aparelladors i Arquitectes Tècnics de Barcelona): pp. 87-102.
Kagi D. A., Ren K. B. (1995), Reduction of water absorption in silicate treated concrete by posttreatment with cationic surfactants, Building and Environment 30, 2: pp. 237-243.
Medeiros M. (2008), Contribuição ao estudo da durabilidade de concretos com proteção superficial frente à ação de íons cloretos, Tese de Doutorado, Escola Politécnica, Universidade de São Paulo: p.
Medeiros M. H. F., Gomes T. S., Helene P. (2005), Hidrofugantes de superfície: Uma opção para proteção de estruturas de concreto armado, in: 47o Congresso Brasileiro do Concreto, IBRACON: Pernambuco, Brasil.
Medeiros M. H. F., Helene P. (2009), Surface treatment of reinforced concrete in marine environment: Influence on chloride diffusion coefficient and capillary water absorption, Construction and Building Materials 23: pp. 1476-1484.
Medeiros M. H. F., Helene P. (2008), Efficacy of Surface Hydrophobic Agents in Reducing Water and Chloride Ion Penetration in Concrete, Materials and Structures 41, 1: pp. 59-71.
Medeiros M. H. F., Moraes B. P., Helene P. (2006), Ensaio de migração de íons cloretos na tecnologia de concreto – limitações e cuidados na interpretação, in: Congresso Latino Americano de Corrosão, LATINCORR 2006, ABRACO: Fortaleza, Brasil.
NBR 9778 (2005), Argamassa e concreto endurecidos - Determinação da absorção de água, índice de vazios e massa específica. Associação Brasileira de normas técnicas (ABNT).
NBR 9779 (1995), Argamassa e concreto endurecido - Determinação da absorção da água por capilaridade - Método de ensaio. Associação Brasileira de normas técnicas (ABNT).
Truc O., Ollivier J. P., Carcassès M. (2000), A new way for determining the chloride diffusion coefficient in concrete from steady state migration test, Cement and Concrete Research 30: pp. 217- 226.
Thompson J. L., Silsbee M. R., Gill P. M., Scheetz B. E. (1997), Characterization of silicate sealers on concrete, Cement and Concrete Research 27, 10: pp. 1561-1567.
_______________________________
License in effect from September 2020
You are free to:
- Share — copy and redistribute the material in any medium or format for any purpose, even commercially.
- Adapt — remix, transform, and build upon the material for any purpose, even commercially.
- The licensor cannot revoke these freedoms as long as you follow the license terms.
Under the following terms:
- Attribution — You must give appropriate credit , provide a link to the license, and indicate if changes were made . You may do so in any reasonable manner, but not in any way that suggests the licensor endorses you or your use.
- No additional restrictions — You may not apply legal terms or technological measures that legally restrict others from doing anything the license permits.
Notices:
You do not have to comply with the license for elements of the material in the public domain or where your use is permitted by an applicable exception or limitation .
No warranties are given. The license may not give you all of the permissions necessary for your intended use. For example, other rights such as publicity, privacy, or moral rights may limit how you use the material.