Sediment-based fired brick strength optimization A discussion on different approaches

Abstract:
Sustainable sediment management is a global issue due to dredging of rivers and river
mouths for both navigability and flood protection needs. Previous studies on sediments
beneficial uses have shown that essentially the targeted materials relate to roads and
ceramics (bricks, tiles). For sustainable management, these recovery sectors impose the
minimization of transport and the restriction of the use of binders with a high carbon
footprint and addition materials in mixtures (renewable resources). Ceramics for
construction appears to constitute a direct recovery method for dredged sediments. Even
if it requires adequate water content for manufacturing, it does not require any addition
of material. However, mixtures of sediments can be operated to improve the chemical
composition before firing (optimization). Waste as aggregates (foundry and pickling
sand, silica fume, crushed brick, …) can be incorporated in such mixtures (ecofriendly
recovery). Different approaches are available to ensure the feasibility (composition and
implementation) of producing ceramic materials for construction (bricks, tiles, pottery).
In practice, they are mainly based on industrial methodological approaches (diagrams by
Winkler, Augustinik, Sembenelli). These diagrams were drawn up from well-identified
non-renewable resources (clays, sands) from mines and quarries. For dredged sediments
i.e. mixtures of clay, silty particles and fine sands, other approaches should be defined
based on these practical approaches. They can be defined considering the nature and
mineralogy of clays, or based on specific properties of the sediment or else resulting from
statistical methods. These latter are considered as coupled approaches more efficient for
a laboratory investigation. This type of coupled approach combined with an appropriate
experimental method, provides a guide for any feasibility study of raw or fired sedimentbased
bricks. A complete but simple methodology for recovering sediments as ceramic
construction material is outlined.