Microstructure and permeability of concrete with glass powder addition conserved in the sulphatic environment

Abstract

Most mechanical properties and durability of cementitious materials are related to the performance of the hydrated cement that coats the granular skeleton. In this paper, concrete is formulated by substituting 30% of cement by finely ground glass powder. The experimental study consists of investigating the effect of conservation in tap water or sulphate water on the performance of concrete. The mechanisms of concrete damage have been related to the development of the microstructure of the material. The degradations were observed using scanning electron microscope (SEM) and quantified by X-ray diffraction (XRD). In addition, chloride ions permeability and gas permeability tests were performed. The results showed that glass powder presents a pozzolanic activity and hence it affects favourably the microstructure of the paste which becomes denser and less permeable.

Une grande partie des caractéristiques mécaniques et de durabilité des matériaux à matrice cimentaire provient des performances du ciment hydraté, matrice cohésive qui enrobe le squelette granulaire. Cette étude consiste à formuler un béton, en substituant 30% de ciment par de la poudre de verre finement broyée et observer expérimentalement sa dégradation dans un environnement agressif (eau séléniteuse) ou l’eau du robinet sur les performances du béton. Les mécanismes de dégradations ont été reliés au développement de la microstructure du matériau. Ils sont observés au microscope électronique à balayage (MEB) et quantifiés par diffraction des rayons X (DRX). Ces examens ont été complétés par des mesures de perméabilité aux ions chlorures et au gaz oxygène.

Keywords:

• concrete
• glass
• permeability
• microstructure
• sulphate

Mots-clés:

• Béton
• verre
• perméabilité
• microstructure
• sulphate

Acknowledgements

The study was performed with the financial support of the French–Algerian research collaboration (CMEP-Tassili) between the laboratory of materials, procedures and environments of the University of Boumerdes and the civil and mechanical engineering laboratory of INSA-Rennes in France. The authors would like to thank EGIDE and the laboratory of chemical science and inorganic materials for their support.