Walid MAHERZI

• Doctor of Engineering
• Assistant Professor at Institut Mines-Télécom

This study focuses on the use of dredged sediment (SD) from the dam for the synthesis of a geopolymer. The samples investigated in this work were prepared by mixing micronized and calcined sediment and ground granulated blast furnace slag (GGBFS), at different percentages (10%, 20%, 30%, 40%, and 50%). Furthermore, the influence of the molarity of...

The objective of this study is to produce porous, sustainable ceramic adsorptive aggregates for the improvement of water quality and water treatment applications. Three types of clay, Natural Zeolite (NZ), and Spent Coffee Grounds (SCG) are used in the synthesis of aggregates with high adsorptive capacities. Various characterizations are conducted,...

This study investigates the influence of basalt fiber on the rheological, mechanical, and microstructural properties of sustainable self-compacting concrete (SCC) incorporating fly ash and microsilica as supplementary cementitious materials (SCMs). Various SCC mixes were prepared, incorporating five different volume fractions of basalt fiber (0.05%...

Combined with mechanical assessments, an environmental evaluation is vital to ensuring eco-friendly binder suitability. This study evaluates the environmental impact of integrating municipal solid waste incineration bottom ash into hydraulic road binders, alongside its physico-chemical, mechanical properties, and cementitious matrix hydration kinet...

In this study, a thermodynamic model was developed to perform numerical simulations on one-part-geopolymer binders based on fly ash and micronized dredged sediments to study the effect of several parameters on the composition of geopolymer material. First, the thermodynamic model was validated by experimental results. This validation consisted in c...

This study aims to investigate the carbonation effect on microstructure and mechanical properties of One-Part-Geopolymer based on thermo-mechanical-synthesis sediments-fly ash mix. Four mixtures optimized in terms of mechanical performance and containing 0, 15, 30 and 50 % of sediments were exposed to accelerated (3 % CO2) and natural carbonation....

This study examines cement and ceramic waste (CW) for the sub-base layer of roads. This innovative method can do away with the risks associated with improper disposal of industrial waste. To achieve this objective, several proportions of cement and CW were used, ranging from 1.5 to 2% and 5% to 15%, respectively. The aim of the work was to examine...

The Grand Paris Express (GPE) is a project that aims to extend the metro network of Paris by creating four new lines, plus extending two existing lines. A total of 200 km of new tracks and 68 new stations are to be added, serving a projected 2 million passengers a day. Since it started, more than 20 Mt of earth is extracted, to which will be added...

This study underscores the potential of utilizing natural volcanic tuffs (NVTs) as supplementary cementitious materials (SCMs) in alignment with global sustainability efforts aimed at mitigating the cement industry’s negative impacts on both the economy and the environment. Experimental investigations were conducted on concrete mixtures containing...

This study aims to investigate the leaching behavior of one-part geopolymer based on micronized sediments and fly ash. Four mixtures optimized in terms of mechanical performance and contain 0, 15, 30 and 50 % of sediments were studied. Mixtures characterization indicated that adding sediments increases compressive strength from 19 MPa to 29 MPa and...

As urbanization increases, buildings require greater amounts of energy for heating and cooling, thereby necessitating the search for effective solutions. The courtyard is often considered a viable option; however, the limited availability and high cost of land resulting from rapid urbanization hinder its widespread use. Consequently, a courtyard wi...

Recent literature has exhibited a growing interest in the utilization of ground glass powder (GP) as a supplementary cementitious material (SCM). Yet, the application of SCMs in stabilizing heavy metallic and metalloid elements remains underexplored. This research zeroes in on zinc stabilization using a binder amalgam of GP and ordinary Portland ce...

This research endeavors to develop ecologically sustainable ceramic adsorptive aggregate (CAAs) for zinc removal via adsorption techniques. The study synthesized three distinct CAAs employing natural zeolite (65 wt%), nanoclay (15 wt%), spent coffee grounds (15 wt%), and FeSO4.7H2O (5 wt%). The characterization of these CAAs included assessments of...

In this scientific investigation, we explore the potential of bottom ash from municipal solid waste incineration (MSWI), hereafter referred to as BA-MSWI, as an alternative to natural aggregates in epoxy mortar production. BA-MSWI bottom ash represents a prevalent environmental issue due to its excessive production, and its use in sustainable appli...

This study has focused on the dam sediments and marble waste reuse as subgrade materials for road construction, with the overarching goals of reducing greenhouse gas emissions and conserving natural resources. Different mixtures were prepared based on sediments and marble waste, and treated with hydraulic binders. The first mixture consisted sol...

Although the lime treatment of soils has been used in many earthworks’ projects, limited studies have been devoted to the quantification of their carbonation. This is not only important regarding the impact on the final properties, it is also critical to quantify it when evaluating the carbon footprint of infrastructures. This work investigates the...

In the absence of industry data, organisms, and researchers leverage free and available data, specifically building and demolition permits. Geospatial processing is essential to integrate information from various files into a single GIS layer containing all relevant attributes for analysis. This article proposes a Geographic Information System (GIS...

The purpose of this study was to investigate the influence of fine powder (SF fines) obtained from recycled concrete aggregate on the hydration kinetics and mechanical-microstructural properties of hydrated cement through experiments and three-dimensional microstructural modelling using CEMHYD3D. Mixtures prepared with different substitution levels...

This paper aims to study the drying and autogenous shrinkage of optimized One-Part-Geopolymer binders based on micronized dredged sediments and fly ash. Four One-Part-Geopolymer with 0, 15, 30 and 50% wt of sediments and fly ash were optimized by the variation of SiO2/Al2O3 molar ratio between 3; 3.5; 4; 4.5; 5. Findings shown that the sediments in...

To meet the local demand for dredging and to adapt onshore sediment management in consequence, the EPTB wanted to explore new Rance sediment reuse possibilities, in order to overcome some of the constraints of agricultural reuse. Various possibilities are considered, in relation to territorial needs. The EPTB Rance Frémur has joined the second phas...

The EPTB Rance Frémur has been in charge of the experimental sediment management plan for the Rance estuary since 2018 for a period of 5 years. Since the installation of the tidal power dam in 1966, siltation has increased in the Rance estuary and has an impact on certain uses (e.g., sailing). The aim of the experimental plan is to test dredging an...

This study investigated the utilization of dredged sediments for the mix design of a just add water geopolymer (one-part geopolymer). For this purpose, four aluminosilicate sources were prepared, by volume substitution of fly ash by sediment, with ratios of 15, 30 and 50%. These mixtures were thermomechanically treated to increase their reactivity....

Slag is produced in enormous amounts by steelworks, which are scrap metal recycling industries that produce steel wire rods and steel reinforcing bars. In the absence of a sustainable recovery route, the latter pose a possible environmental risk. This work is concerned with the valorization of this by-product in the production of concrete pavers. T...

Today, the reuse of waste in building materials occupies an important place in the approach to the circularity of materials. National and European environmental regulations require ensuring the environmental safety of material-incorporating waste. For this, there are specific tests to verify that there is no health risk when using these materials....

This study aims to optimize the integration of dredged sediments as fillers in formulations of hydrocarbon materials such as “mastic asphalt” for sealing applications. River sediments were collected from the Hauts de France region are the following ones: Aire sur la Lys (ASL), Urban Community of Arras (ARS), European Metropolis of Lille (MEL), and...

Large quantities of dredged sediments and recycled concrete materials are generated every year all over the world. The disposal of these large quantities in landfills represents serious environmental problems. Furthermore, high-quality raw materials for construction are depleting, and their use cannot be sustained. The valorization of dredged sedim...

Sediment accumulation at the bottom of ports disrupts maritime activities and disturbs the physicochemical balance of water bodies. In France, the maintenance of the 6500-kilometer long coastline would require the extraction of about 50 million m3 of marine sediments every year. For several years, these sediments were considered waste. However, the...

Rock and eroded soil are transported by wind, tide, and human action (development works), and deposited as sediment in ports, estuaries, and rivers. The sediment accumulation at the bottom of ports disrupts maritime activities and disturbs the physicochemical balance of water bodies. As a result, dredging is necessary to reduce sediment deposits an...

Partial cement replacement by low-carbon-impact additions has the potential to reduce CO2 emissions. The aim of this study is the development of a ternary binder that includes ordinary Portland cement (OPC), ground granulated blast furnace slag (GGBS), and flash-calcined sediment (FCS). To upgrade dredged mineral material into FCS, a new heat treat...

Water scarcity is considered to be one of the most important problems faced by the world today. To alleviate this problem, it is important to study the feasibility of replacing partially or completely potable water for concrete production by treated wastewater. This paper studies the feasibility of using treated wastewater (TWW) from the Artois-Pic...

RESUME Cet article vise à la détermination de l'effet d'incorporation des sédiments de dragage dans les mortiers géopolymères "One part geopolymer" sur les résistances mécaniques et la porosité. De plus, l'effet du rapport molaire SiO2/Al2O3 sur ces deux paramètres a été mis en évidence. Pour ce faire, quatre sources d'aluminosilicates ont été util...

The valorization of dredged sediments is a promising solution to reduce the strain on natural resources, which is in line with sustainable development goals. This study aims to evaluate the potential valorization of dredged sediment in manufacturing compressed earth blocks (CEBs). The CEBs were stabilized by a combination of fly ash (FA) with sodiu...

Sediment dredging is necessary and vital to preserve maritime activities and prevent floods. The management of these sediments represent an environmental challenge for many countries all over the world. This study focuses on evaluating the feasibility of using dredged sediments for the manufacturing of compressed earth blocks (CEB). The alternative...

Developing ecofriendly bricks using natural material such as clay represents an essential step toward making building sector low cost and energy efficient. This study aims to describe the physicochemical characterization and rheological property of clay taken from Gafsa, Tunisia. The rheology of clay–water mixtures was determined to understand the...

PurposeThe development of the circular economy of mineral solid wastes implies searching for new treatment methods to guaranty their chemical quality and technical properties. The aim of this study is to use mineral solid wastes including dredged sediments (SED), construction and demolition waste (CDW), and municipal solid waste from incinerator (M...

This work concerns the reuse of treated wastewater from Er-Rachidia wastewater treatment plant (WWTP) in the mixing of ordinary C20/25 concrete, to reduce the overexploitation of non-potable groundwater, avoid its discharge into watercourses and reduce the risk of environmental pollution due to its mineral and organic matter load. In this respect,...

Due to the increase in demand for building materials and their high prices in most developing countries, many researchers are trying to recycle waste for use as secondary raw materials. The aim of this study is the optimization of a mixture of compressed earth blocks based on two sediments. These sediments were tested through the Vicat test to dete...

Dredging sediments can be implemented as primary resources in several civil engineering applications, on the condition that the release of anthropogenic compounds meets environmental requirements. The remediation of sedimentary wastes constitutes therefore, a key step before valorization consideration in circular economy schemes. This study focused...

This study investigated the potential use of Zerdezas dam Calcined Sediments (CS) and El-Hadjar Blast Furnace Slag (GGBS) from northern Algeria as a partial replacement of cement (C) in normal hardening hydraulic road binders. Two binder mix designs were optimized using a Response Surface Methodology (RSM). The first mix, 50C35GGBS15CS, consisted o...

CO2 emissions resulting from the production of cement is a major issue, but can be limited by the partial substitution of cement by low-carbon-impact additions. The aim of this study was the formulation of a ternary binder based on ordinary Portland cement (OPC), ground granulated blast-furnace slag (GGBS) and flash-calcined sediment (FCS), a dredg...

This research study evaluated the effects of adding Scottish canal sediment after calcination at 750 °C in combination with GGBS on hydration, strength and microstructural properties in ternary cement mixtures in order to reduce their carbon footprint (CO2) and cost. A series of physico-chemical, hydration heat, mechanic performance, mercury porosi...

Few studies focus on the co-valorization of river dredging sediments (DS) and residual waste glass (RWG) in alkali-activated binders. This study investigates the use of DS as an aluminosilicate source by substituting a natural resource (metakaolin (MK)), while using RWG as an activator (sodium silicate source). Suitable treatments are selected to i...

This work concerns the reuse of treated wastewater from Er-Rachidia wastewater treatment plant (WWTP) in the mixing of ordinary B25 concrete, in order to reduce the overexploitation of groundwater, avoid its discharge into watercourses and reduce the risk of environmental pollution due to its mineral and organic matter load. In this respect, Tree t...

The management of dredging sediments and plastic waste is of increasing environmental, societal, and economic importance. To address this, we produced lightweight aggregates composed of 70% sediment based mineral filler and 30% thermoplastic waste containing polypropylene, polyethylene, and polystyrene. When tested, the aggregates satisfied the req...

Waste glass based geopolymers have a high potential in the future as an eco-friendly inorganic binder. However, limited studies are available on the use of the residue of waste glass recycling in this type of binder. This work investigates the valorization of Residual Waste Glass (RWG) (the final waste of glass recycling centers) crushed at d90 < 1...

Purpose The objective of our work was to develop a software for the optimization of the processes of treatment and formulation of dredged sediments for utilization in civil engineering applications. The software proposes an optimal solution that meets the different technical and environmental requirements of sediment utilization at a lower cost. M...

The polypropylene fibers, which are currently attracting enormous attention in various geotechnical applications, carry a risk of aging under an integrated effect of heat, oxygen, light and other environmental factors, causing potentially infrastructure failure. An eco-friendly and biologically inactive material – basalt fiber, which has excellent...

Several studies have shown the potential of upgrading sediments in the civil engineering field. However, the complexity of sediments represents a scientific challenge in terms of their management. This study presents the river sediments recovery in a thermosetting matrix. The characterization results epoxy mortars show the feasibility of incorporat...

Abstract : In this paper, we are showing a laboratory test of clay soil from different locality of Tunisia and its behavior under static compaction test. The static pressing of clay soil is well used in ceramic construction especially to produce earth-compressed bricks. Laboratory test of the static compaction allows synthesizing samples of press...

Dans ce travail, les déchets de verres utilisés pour la substitution du ciment Portland CEM I 42.5R sont des verres d’emballage collectés dans la région des Hauts-de-France. Les valorisations ciblent les résidus du centre de recyclage de verre non valorisable comme les déchets de refus optiques (R-opt) et les déchets de fin de lavage (F.L). Une com...

This work involves valuing residual waste from a glass coming from a recycling station in a geopolymer matrix. This type of waste contains mineral impurities called "infusibles" characterized by a very high melting temperature compared to traditional glass which makes it difficult to use it as glass cullet. The objective of this study is to use thi...

Abstract In this work, waste glass (WG) was activated by alkaline solution to liberate some elements contained in glass and specifically silicium, which is present in more quantity in WG. The formation of geopolymere binder N-A-S-H requests combinations with aluminosilicate source, for example Metakaolin (MK) or Fly Ash (FA). The development of N-A...

The main objective of this work is to develop a new geoamterial named geopolymer binder. The development of geopolymer has of global interest in terms of economic and ecologic constructions. This innovative product is obtained by activation of a metakaolin source by sodium silicate powder (Na2SiO3) and NaOH. Several samples and formulations were pr...

The onshore management of marine and river sediments represents economic, environmental, and societal issues; these materials are considered as wastes after dredging. In the framework of the SEDIPLAST regional project, dredged sediments, which are considered as non-inert waste according to European regulation, are recovered as mineral aggregates in...

Ce travail est basé sur la formulation et l’élaboration d’un nouveau liant de type géopolymère obtenu par activation de la source aluminosilicate. L’élaboration d’un matériau modèle à base du métakaolin à un intérêt mondial en termes de construction économiquement et écologiquement rentable. Dans ce cadre de travail, plusieurs échantillons et formu...

The management of bauxite residues causes serious environmental problems worldwide due to their physico-chemical particularities. In this research, a bauxite residue collected from Gardanne Alumina Plant (France), renamed modified red mud (MRM) after dewatering treatment, was investigated for its reuse in the making of ceramic materials such as roo...

Cette étude a pour objectif de valoriser les sédiments de dragage marins en travaux publics maritimes, en les incorporant dans la formulation de bétons autoplaçants. Pour répondre à cet objectif, des études de formulation de mortiers autoplaçants à base de sédiments marins bruts et traités ont été menées. Une caractérisation complète à l’état frais...

This paper investigates the mineral, mechanical and thermal behaviour of clay sample from Djbel BouOmrane located in Gafsa area. The aim of this report is the valorisation of this collected clay and their application in ceramic construction, especially to produce eco-friendly and sustainable building materials in order to solve problems caused by m...

To successfully transition any economy towards sustainable development requires reducing the consumption of raw materials while maintaining production levels. In the French construction sector, nearly 55% of extracted materials are aggregates. A potential solution to decreasing the carbon footprint of the construction sector and reducing the consum...

ABSRACT The scarcity of natural aggregates promotes waste reuse as secondary raw material in the field of civil engineering. This article focuses on the beneficial reuse of marine dredged sediments in road building. Thus, mixtures of raw sediments and dredged sand collected from Brest Harbour (Bretagne, France) were treated with road hydraulic bind...

This article presents a qualitative and quantitative observation of composite rupture under uniaxial tension and analytical modelling of behaviour under uniaxial tension. The chapter begins with a bibliographic review of the numerical and analytical models in the literature. Then follows an analysis of rupture processes during tension testing in or...

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 establ...

In this paper the influence of the extraction operation of ferrous and non-ferrous metals on the physical-mechanical properties, geotechnical and environmental of a fine fraction (0/6.3 mm) from MSWI bottom ash is presented. These alternative aggregates are used in the formulation of cement-bound gravel with a specific road hydraulic binder. This...

In order to receive modern ships with more important size and to avoid different harbours entry siltation, significantly dredging operations are constantly required ever y year. These ports activity generate a great quantity of dredged marine sediments. In France, this quantity exceeds 45 Mm³/an. Immersion is usually adopted with respect to the nat...

Les résultats présentés dans cet article s’inscrivent dans le cadre du projet de recherche Européen SETARMS dont l’un des objec- tifs consiste à trouver des solutions innovantes et durables pour la gestion des sédiments marins dragués en Manche (France- Angleterre) pour une application en techniques routières, plus particulièrement en couche de for...

A large Research European Interreg IVA Program called “Sustainable Environmental Treatment and Reuse of Marine Sediment” is running in order to better understand the Channel sediment characteristics and to develop and promote sustainable management practices for marine sediments. A total of 13 sediments localized along the Manche channel were s...

In order to receive modern ships with more important size and to avoid different harbours entry siltation, significantly dredging operations are constantly required every year. These ports activity generate a great quantity of dredged marine sediments. In France, this quantity exceeds 45 Mm3/an. Immersion is usually adopted with respect to the...

Afin de garantir un tirant d’eau suffisant pour l’exploitation des infrastructures portuaires et des voies navigables, les gestionnaires de ces derniers sont amenés à effectuer régulièrement des opérations d’entretien qui consistent à draguer d’importantes quantités de sédiments. En France, les volumes issus des opérations de dragage représentent c...

Les résultats présentés dans cet article s'inscrivent dans le cadre du projet de recherche Européen SETARMS dont l'un des objectifs est de mettre en place des solutions innovantes et durables de gestion des sédiments marins dragués en Manche (France-Angleterre) pour une application en techniques routières. Quatre sédiments de dragage marins, notés...

Les résultats présentés dans cet article s’inscrivent dans le cadre du projet de recherche Européen SETARMS dont l’un des objectifs est de mettre en place des solutions innovantes et durables de gestion des sédiments marins dragués en Manche (FranceAngleterre) pour une application en techniques routières. Après la détermination des caractéristiq...

Les résultats présentés dans cet article s’inscrivent dans le cadre du projet de recherche européen SETARMS dont l’un des objectifs est de mettre en place des solutions innovantes et durables de gestion des sédiments marins dragués en Manche (FranceAngleterre) pour une application en techniques routières. L’utilisation de ces matériaux particuli...

In order to receive modern ships with more important size and to avoid different harbours entry siltation, significantly dredging operations are constantly required every year. These ports activity generate a significant quantity of dredged marine sediments. In France, this quantity exceeds 45 Mm 3 /an. Immersion is usually adopted with respect...