Polluted river sediments from the North region of France: Treatment with Novosol® process and valorization in clay bricks

Additions of dredged marine sediments and oyster shell powder (OS) as cement substitute materials in mortars are examined by several techniques. The sediments have high water and chloride contents and calcite, quartz, illite and kaolinite as principal minerals. The OS powders are entirely composed of calcium carbonate and traces of other impurities. Four mixtures of treated sediments and OS powders at 650 °C and 850 °C are added to Portland cement at 8%, 16% and 33% by weight. The hydration of composite pastes is followed by calorimetric tests, the porosity accessible to water, the bulk density, the permeability to gas, the compressive strength and the accelerated carbonation resistance are measured. In general, the increase of addition amounts reduced the performance of mortars. However, a reduction of gas permeability was observed when the addition was up to 33%. Around 16% of addition, the compressive strength and carbonation resistance were improved. RESUMEN: Morteros de cemento basado en sedimentos marinos y polvo de concha de ostra.En este trabajo se ha valorado la sustitución de cemento en morteros por sedimentos marinos dragados y polvo de concha de ostra (OS). Los sedimentos tienen altos contenidos de agua, cloruros, calcita, cuarzo, illita y caolinita como minerales principales. Los polvos OS están compuestos de carbonato cálcico y trazas de otras impurezas. Se añadieron a un cemento Portland, cuatro mezclas de los sedimentos y polvos de OS tratados a 650 °C y 850 °C en proporciones del 8%, 16% y 33% en peso. La hidratación de pastas se estudió a través de calorimetría. Se estudió además la porosidad accesible al agua, densidad aparente, permeabilidad al gas, resistencia a compresión y carbonatación acelerada. En general, un aumento en la adición produjo una reducción del rendimiento de los morteros. Se observó, sin embargo, una reducción de la permeabilidad a los gases con porcentajes de adición de hasta el 33%. Con valores del 16% de sustitución, mejoraron las resistencias mecánicas y la resistencia frente a la carbonatación.

show abstract

“…The results of the apparent porosity, bulk density and apparent gas permeability are shown in table 4.…”

Section: Porosity Density and Apparent Permeabilitymentioning

confidence: 99%

Composite cement mortars based on marine sediments and oyster shell powder

Ez-zaki¹,

Diouri²,

Kamali-Bernard³

et al. 2016

Mater. construcc.

View full text Add to dashboard Cite

show abstract

“…The approach is therefore innovative with regard to the existing studies on reuse of sediment in civil engineering which focus only on the environmental or geotechnical aspects (Marot, 1994;Boutouil, 1998;Rey, 1999;Colin, 2003;Lemée, 2006;Agostini et al, 2007;Rekik, 2007;Lafhaj et al, 2008;Nguyen, 2008;Duan, 2008;Scordia et al, 2008;Tran, 2009;Brakni et al, 2009;Zentar et al, 2009;Agostini et al, 2010).…”

Section: Introductionmentioning

confidence: 99%

Trace element mobility in a polluted marine sediment after stabilisation with hydraulic binders

Saussaye

Hamdoun

Leleyter

et al. 2016

Marine Pollution Bulletin

View full text Add to dashboard Cite

The management of dredged marine sediment is an issue for many harbours, particularly when contaminant concentrations prevent disposal at sea. The stabilisation/solidification of the sediments with hydraulic binders for a use in road subgrade layer is a potential alternative solution. However, the environmental acceptability is not yet fully established. This paper presents the results of a case study to comprehensively determine the stabilisation of As, Cd, Cr, Cu, Ni, Pb and Zn. After demonstrating that stabilisation/solidification affects the microstructure of the sediment, a mobility study is realised (single, sequential and kinetic extractions). According to the regulatory/ technical guidelines the studied elements do not pose a risk to the environment. However, results from more complex mobility studies reveal that stabilisation in the short term is only effective for Ni while other elements are mobilised after treatment by at least one type of extraction. Stabilisation in the long term is not universally effective.

show abstract

“…It can also be used to manufacture artificial aggregates [7], and in stability research as backfill material [8]. The development of DM processing technology for eliminating contaminants contained in deposits has been actively carried out as well [3,9].…”

Section: Introductionmentioning

confidence: 99%

“…In Germany, 60 million m 3 of sediments contained in DM have been generated each year. In France, 3 million m 3 of river sediments have been dredged for the past fifteen years [1][2][3]. When disposed of in a designated dumping area, DM may cause serious environmental problems in the nearby seawater.…”

Section: Introductionmentioning

confidence: 99%