1. Influence of relative humidity on delayed ettringite formation
- Author
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Mohamad Al Shamaa, Loic Divet, Georges Nahas, Stéphane Lavaud, Jean-Michel Torrenti, Institut de Radioprotection et de Sûreté Nucléaire (IRSN), Comportement Physico-chimique et Durabilité des Matériaux (IFSTTAR/MAST/CPDM), Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-Communauté Université Paris-Est, Département Matériaux et Structures (IFSTTAR/MAST), Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-PRES Université Paris-Est, Laboratoire de Mécanique et Technologie (LMT), École normale supérieure - Cachan (ENS Cachan)-Centre National de la Recherche Scientifique (CNRS), Matériaux pour Infrastructure de Transport (IFSTTAR/MAST/MIT), PRES Université Nantes Angers Le Mans (UNAM)-Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR), Division Physico-chimie des Matériaux (LCPC/PCM), Laboratoire Central des Ponts et Chaussées (LCPC)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12), and Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-PRES Université Nantes Angers Le Mans (UNAM)-PRES Université Paris-Est
- Subjects
Ettringite ,Materials science ,TENEUR EN EAU ,PROPRIETE MECANIQUE ,PERMEABILITE ,[SPI.MAT]Engineering Sciences [physics]/Materials ,[SPI]Engineering Sciences [physics] ,chemistry.chemical_compound ,[SPI.MECA.MEMA]Engineering Sciences [physics]/Mechanics [physics.med-ph]/Mechanics of materials [physics.class-ph] ,Dynamic modulus ,BETON ,medicine ,FORMATION DIFFEREE D'ETTRINGITE ,General Materials Science ,Relative humidity ,Composite material ,Porosity ,ComputingMilieux_MISCELLANEOUS ,ALCALI REACTION ,BETON JEUNE ,HUMIDITE ,Building and Construction ,Permeability (earth sciences) ,chemistry ,Swelling ,medicine.symptom - Abstract
This experimental study aims to determine the effect of relative humidity on concrete expansion due to delayed ettringite formation (DEF), which still remains imperfectly known. Test methods were designed to trigger reaction in concrete specimens and determine how ambient RH affects expansion of the specimens. Saturated salts solutions were used to achieve distinct ambient RH conditions within containers. Also, chemical analysis was performed to determine and quantify the fractions of alkalis leaching out of the pore solutions of concretes. Results showed that the critical ambient RH value that corresponds to significant suppression of DEF could be greatly dependent on the alkalis fractions leached out. Finally, the consequences of swelling due to DEF on the concrete properties are assessed. After swelling, both of gas permeability and porosity was increased significantly and dynamic modulus was reduced by about 45%.
- Published
- 2015
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