Title: Comparative studies of chloride permeability, conductivity and salt-ponding tests of concrete containing different admixtures

Authors: Silvia B. Uchoa, Indrajit Ray, Julio F. Davalos, Josealdo Tonholo

Addresses: Centro de Tecnologia, Universidade Federal de Alagoas, Alagoas 57072-900, Brazil. ' Department of Civil and Environmental Engineering, West Virginia University, Morgantown, WV 26506-6103, USA. ' Department of Civil and Environmental Engineering, West Virginia University, Morgantown, WV 26506-6103, USA. ' Instituto de Quimica e Biotecnologia, Universidade Federal de Alagoas, Alagoas 57072-900, Brazil

Abstract: Concrete modified with various chemical and mineral admixtures are gaining popularity as construction materials, but inclusion of admixtures raises questions about the validity of standard tests of transport properties and conductivity. To explore most representative tests, the present study has evaluated and compared transport properties by several methods: standard rapid chloride permeability test (RCPT), modified RCPT, electrical conductivity, electrochemical impedance spectroscopy (EIS), and salt-ponding tests. Three normal concretes and nine high-performance concretes including different combinations of mineral admixtures were investigated. Results show that the effects of heat generation in RCPT cells were dependent on the types and combinations of mineral admixtures, and that pore solutions had definite effects in RCPT results. The relatively expensive and difficult test of EIS can be replaced by one-minute RCPT and conductivity meter test. The correlations between salt-ponding tests and various RCPTs were found to be weak due to different mechanisms involved.

Keywords: admixtures; chloride permeability; conductivity; high performance concrete; HPC; salt ponding; concrete structures; chloride ingress; heat generation.

DOI: 10.1504/IJMIC.2009.027070

International Journal of Modelling, Identification and Control, 2009 Vol.7 No.2, pp.160 - 170

Published online: 14 Jul 2009 *

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