Treatment of river sediments by hydraulic binders for valorization in road construction
Résumé
Reuse of dredging sediments has already generated interest and been the subject of a few comprehensive studies. The dredging of dams and rivers consists in very expensive operations that implement large volumes of materials. The valorization of sediments is an alternative for storage or sea disposal and offers a better environmental solution. Two specific cases of dredged sediment valorizations in the region of Bejaia in Algeria are studied: sediments of Kherrata dam and the Soummam River. Laboratory tests are performed to characterize the dredged sediment according to French standards of geotechnical classification. The characterization shows the need to improve their mechanical behavior, to allow use in the road field. The experimental work on solidification and stabilization sediments, in sublayers of roads is based on a treatment with hydraulic binders: cement or lime. Tests on binder-based sediment material are carried out for ratios of binders between 2 and 15 % of sediment dry weight. The addition of particle-size correctors, sand or quarry fines, is studied in order to reduce the use of lime. The results show the efficiency of treatment with hydraulic binders, in particular with cement. The quarry fines improve the mechanical behavior in the short term for sediment treated with lime.