Title: Characterization of dredged sediments of Bouhanifia dam, Algeria, for the potential use in road construction

Abstract

Dam silting has become a common problem due to the deleterious aspects that it generates, such as reducing both water quality (during turbid hydrodynamic events) and storage capacity of the reservoir. Various approaches of dam desilting have been undertaken to deal with this issue; however, the problem is far from being solved due to millions of cubic metres of sediments that are being trapped and not bypassing towards downstream, which results in coastal erosion increment. This is particularly the case of the Bouhanifa dam in Algeria. So far, several geotechnical studies have been carried out aiming at evaluating this problem. The main objective of the current research study is the characterization of the dredged sediments of this dam for potential use as raw material to be harnessed for the construction industry. The valorisation of the dam dredged sediments might include the mechanical stabilization in road construction, which reduces the excavation of natural qualified materials. The feasibility of using different fractions (5%, 10%, and 20%) of Bouhanifa dam dredged sediments as an admixture to the calcareous tuff which is a natural material usually applied in roads construction in Algeria is studied herein. A rough prediction of the long-term mechanical behaviour of the sediments and tuf is reported based on their physical, chemical, and mineralogical characteristics and short-term mechanical performance tests. The current study suggests the feasible use of tuff admixed sediments as embankment or subgrade materials; however, the long-term mechanical behaviour investigation of these materials is essential, and their mechanical stabilization is recommended to enhance their geomechanical behaviour as it is expected from the sediments to present lower strength when compared with the tuff.