Outlook for the use in concrete of aggregates with high sulfate content

European standard limits the sulfate content in aggregates in order to avoid any concrete degradation due to internal sulfate attack. As a result, some materials (natural aggregates, concrete demolition waste, excavation materials) cannot be used in concrete production. Indeed, when sulfate content is beyond the threshold set by the European standard, reaction can occur with some components of cements and cause disorders for the concrete structure after the formation of swelling and/or un-cohesive minerals as ettringite or thaumasite. The present study was conducted to valorize excavated material with high sulfate content from digging of the tunnel of the future rail link between Lyon and Turin. This objective was set up in the framework of a sustainable development approach. It would lead to limit the excavation of new careers and the storage of excavated materials and to promote an efficient and sustainable management of natural resources. Moreover, it would limit the transport of excavated material by road thus reducing the emission of greenhouse gases. The first part of this work was devoted to the study of leaching sulfates from the excavation materials. Then the behavior of mortars formulated with high sulfate sand and cements known to be resistant to sulfate attack. An innovative solution has yielded promising results in valuing these excavated materials using either a supersulfated cement or a Portland cement with very low C3A and alkali contents.

Language

  • French

Media Info

Subject/Index Terms

Filing Info

  • Accession Number: 01688874
  • Record Type: Publication
  • Source Agency: Institut Francais des Sciences et Technologies des Transports, de l'Amenagement et des Reseaux (IFSTTAR)
  • Contract Numbers: 13L06201, LTF - valorisation matériaux d'excavati
  • Files: ITRD
  • Created Date: Dec 18 2018 10:17AM