Acelerated Test Methods: Determining the Diffusion Coefficient of Concretes in the Saturated Condition

Abstract:

The chloride diffusion coefficient indicates the capacity of a particular type of concrete to resist chloride penetration and is therefore used to predict the service life of a particular reinforced concrete structure exposed to environments containing this type of aggressive agent. Its experimental determination is time-dependent and time-consuming. For that reason, our study analyzes the characteristic behavior of the diffusion coefficient (D) of concretes in the saturated condition by testing higher NaCl concentrations and lower contamination ages than those used in standardized tests, in addition, the objective is to analyze the behavior of surface chloride concentration (Cs) over time. Therefore, it was concluded that for concrete dosed with pozzolanic cement, the Cs value varied with increasing tendency at higher ages. In addition, the D value obtained by the proposed method presented values ​​close to those obtained by standardized tests at contamination ages of 21 and 35 days.

• Periodical: Defect and Diffusion Forum (Volume 372)
• Pages: 91-100
• DOI: https://doi.org/10.4028/www.scientific.net/DDF.372.91
• Online since: March 2017
• Authors: Tassia Fanton*, João A.M. Bender, Leandro G. Blois, Franciele Müller, André T.C. Guimarães
• Keywords: Accelerated Testing, Chloride, Concrete, Diffusion, Maritime Environment

References

[1] Andrade, T. Tópicos sobre Durabilidade do Concreto. In: ___. Concreto: Ensino, Pesquisa e Realizações. 1. ed. São Paulo: IBRACON, 2005. cap 25, pp.753-792.

[2] Nepomuceno, A. A. Mecanismos de transporte de fluídos no concreto. In: ___. Concreto: Ensino, Pesquisa e Realizações. 1. ed. São Paulo: IBRACON, 2005. cap 26, pp.793-827.

[3] Ribeiro, D. V. Corrosão em Estruturas de Concreto Armado: Teoria, Controle e Métodos de Análise. 1ed. Rio de Janeiro: Elsevier, (2014).

[4] Helene, P.R.L. Contribuição ao Estudo da Corrosão em Armaduras de Concreto Armado. São Paulo, 1993. 231p. Tese (Livre Docência). Escola Politécnica da Universidade de São Paulo.

DOI: 10.21041/conpat2019/v1cc271

[5] Guimarães, A.T.C. Vida útil de estruturas de concreto armado em ambientes marítimos. São Paulo, 2000. Tese (Doutorado). Universidade de São Paulo.

DOI: 10.21041/conpat2019/v2pat21

[6] Rincón, O. T. ; Carruyo, A. R.; Andrade, C.; Helene, P.; Díaz, I. Manual de inspeccion, evaluacion y diagnostico de corrosion em estructuras de hormigon armado. DURAR – Red Tematica XV. B – Durabilidad de la armadura, (1998).

[7] Neville, A. M. Propriedades do Concreto. 2 ed. São Paulo: PINI, 1997. 828 p.

[8] GIL, C. A. Influencia del contenido de humedad del hormigón sobre la difusividade del íon cloruro. Madrid, 2009. Tese (Doutorado). Universidad Autónoma de Madrid.

[9] Crank, J. The Mathematic of Diffusion, second Ed., Oxford Univ. Press, Oxford, UK (1975).

[10] ASSOCIAÇÃO BRASILEIRA DE NORMAS TÉCNICAS. NBR 5738. Procedimento para moldagem e cura de corpos de prova cilíndricos. Rio de Janeiro, (2015).

[11] NT BUILD 443, Concrete, Hardened: Accelerated Chloride Penetration, NORDTEST, Espoo, Finland, November (1995).

[12] Guimarães, A. T .C. Gil, C. A. Llorca, M. A. C. Almenar, G. V. Behaviour of Chloride Content at the Surface of Concrete in Submerged Test Conditions. In: XII DBMC, International Conference on Durability of Building Materials and Components. Porto, Portugal. Abril (2011).