Designing Efficient Flash-Calcined Sediment-Based Ecobinders

Abstract

To ensure the optimum navigation of boats and protection against flooding, waterways and ports are regularly dredged. The volume of dredged materials represents 56 million m3 in France and 300 million m3 in Europe. These materials show a high potential for a use as supplementary cementitious material (SCM). In this paper, sediments treated by the flash calcination method (STFC), which is based on a low-energy consumption process, are utilized as a mineral admixture in a cementitious matrix. The results of the physical, chemical, and mineralogical characterization prove that this heat treatment has an interesting impact on the final properties of the sediments. Mortars based on the flash-calcined product have comparable mechanical properties to control mortar. For a substitution rate below 10%, the performances are even equivalent to a metakaolin (MK80)-based mortar. Calorimetry testing demonstrated that calcined materials also improve hydration processes in the cement matrixes by generating additional heat release due to sediment pozzolanic activity. Across this study, it is shown that waste material including sediment can be transformed after optimized heat treatment into a valuable resource for the building and infrastructure sector.

Development of Flash-Calcined Sediment and Blast Furnace Slag Ternary Binders

“…On the other hand, 8 GJ of energy is needed for a ton of pure clinker [5,26], with an energy requirement of about 1.3 GJ per ton for GGBS [28]. Besides improving the mechanical properties of cementitious materials, flash-calcined sediments reduce the carbon footprint by limiting the quantity of clinker used [29,30]. The development of ternary binders containing flash-calcined sediment with GGBS and OPC has not been addressed in the literature.…”

The Influence of External Sulfate Attack on the Durability of Reinforced Mortars in the Presence of Calcined River Sediments

“…The use of calcined clays as pozzolanic materials in concrete has received considerable interest in recent years as part of a broader focus on the use of waste materials, locally available minerals, and industrial by-products as alternative cement additives [10,11]. Calcined dredged sediments, which initially contain substantial amounts of clay minerals, are promising new SCMs for use in concrete [12][13][14][15][16][17][18][19][20][21]. A large amount of dredged sediment is accumulated.…”