New procedure to investigate external sulphate attack on cementitious materials |
| |
Authors: | R. El-HachemE. Roziè re,F. GrondinA. Loukili |
| |
Affiliation: | LUNAM Université, Institut de Recherche en Génie Civil et Mécanique (GeM), UMR-CNRS 6183, Ecole Centrale de Nantes, France |
| |
Abstract: | In order to predict the durability of concrete structures in contact with sulphate rich environments, laboratory tests have to be sufficiently representative of the field conditions. This study is focused on the degradation of cement-based materials submitted to external sulphate attack. To be close to the natural degradation process, a new experimental procedure has been developed on the basis of two studies. The first was conducted on concrete and showed the deficiencies of common experimental programs only based on the measurement of the expansion. The second investigated the relation between the specimen size and the resistance to sulphate attack. As a result, the basic points of a representative procedure were identified. The mass and length of the specimens were monitored. The pH of the sodium sulphate solution was controlled, which allowed the assessment of leaching kinetics.This procedure was then validated by analysing, at macroscopic and microscopic scales, the influence of the water sulphate concentration on the behaviour of cementitious materials. The accelerating effect of high sulphate concentrations is due to the increase in leaching kinetics rather than the type of expansive products. Whatever the concentration, the same critical proportion of the cross section is required to generate global swelling. |
| |
Keywords: | Durability Concrete Mortar Representative test Scale effect Sulphate attack Sulphate concentration |
本文献已被 ScienceDirect 等数据库收录! |
|