Ability of Two Dam Fine-Grained Sediments to be Used in Cement Industry as Raw Material for Clinker Production and as Pozzolanic Additional Constituent of Portland-Composite Cement

Antoine Faure,Agnès Smith,Isabelle Moulin,François Thery,Coryse Coudray,Baptiste Anger,Horacio Colina

doi:10.1007/s12649-017-9870-8

Abstract

Fine-grained sediment deposition is a phenomenon that occurs at different extents in all the reservoirs. This particle accumulation has to be properly managed, in accordance with the operational needs and the environment. As an extracted and on-land managed sediment has to be considered as a waste material according to both European and French regulations, sustainable reuse options need to be investigated. One of them could be a beneficial reuse as a raw material in cement industry either as partial substitution in Portland clinker raw mix or as a supplementary cementitious material (SCM) after thermal treatment in order to activate its possible pozzolanic activity. Two dredged materials, labelled SEP and STA, both from French hydroelectric reservoirs, are characterized on physical, chemical and mineralogical aspects. SEP is used as raw material partial replacement for clinker synthesis and the other one is calcined in the range 550–1000 °C aiming to obtain a pozzolanic reactive material that could be used as supplementary cementitious material in blended Portland cement. After thermal treatments, the products are characterized and compared to ordinary Portland cement (OPC) and to pozzolanic active materials (fly ash from pulverized-coal power plant). Results showed that each sediment is suitable for the only tested reuse option. For the clinker prepared with SEP sediment, the morphology and the mineralogical composition correspond to those of a typical Portland clinker. Concerning calcined STA pozzolanic activity, the optimum thermal treatment was found to be 900 °C using the chemical Frattini test. Similar compressive strength results were obtained with calcined STA and silico-aluminous fly ash.Graphical

Highlights

Water reservoirs are built and used for various purposes such as power source, irrigation and drinking water storage
It can be seen that, thanks to close chemical compositions between the industrial argillaceous matter and SEP sediment, 100% of the quarried clay rock was substituted by the incorporation of alternative dredged raw material
According to NF EN 196-5 [66], a Portland cement replacement should be considered as a pozzolanic material if the representative dot is located below the Ca(OH)2 solubility curve

Summary

Introduction

Water reservoirs are built and used for various purposes such as power source, irrigation and drinking water storage. Whatever their use, they are subject to sedimentation phenomena. Several factors affect spatial and temporal variations such as geological, topographical and hydro-meteorological features as well as human interventions [2]. Temporal variations are both annual and interannual [3]. Sedimentation phenomena of the finer fractions mainly occur close to the dam structure where the reservoir usually is deeper [6]

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