Beneficial reuse of Brest-Harbor (France)-dredged sediment as alternative material in road building: laboratory investigations

ABSTRACT

The scarcity of natural aggregates promotes waste reuse as secondary raw material in the field of civil engineering. This article focuses on the beneficial reuse of marine-dredged sediments in road building. Thus, mixtures of raw sediments and dredged sand collected from Brest Harbur (Bretagne, France) were treated with road hydraulic binders. Formulation were prepared and characterized as recommended by the French Technical Guidelines for soil treatment with lime and/or hydraulic binders. Mechanical resistance results are quite similar for both the hydraulic binders, suggesting a similar reactivity with the studied sediment sample. However, some discrepancies can be noted on sustainability parameters. Indeed, water resistance after immersion at 40°C is significantly better for the mixtures treated with cement containing more glass-forming oxides (SiO₂ + Al₂O₃) and fluxing (Fe₂O₃+CaO + MgO + K₂O + Na₂O). Moreover, the both hydraulic binders can lead to swelling in the road materials as observed in scanning electron microscopy analyses. Indeed, microscopic observations indicated volumetric swelling of treated samples, which is greatly influenced on the one side by ettringite quantity and on the other hand by the presence of water in pores material.

KEYWORDS:

• Marine sediment
• beneficial reuse
• waste management
• road materials
• sustainability

Disclosure statement

No potential conflict of interest was reported by the authors.

ORCID

Eleanor van Veen http://orcid.org/0000-0002-5432-3521

Mohamed Boutouil http://orcid.org/0000-0002-2752-8265