Optimisation de la valorisation des déchets de verre et de sédiments dans des liants recomposés : Activation - Formulation de mortiers - Stabilisation physico-chimique

Civil engineering consumes a sizeable amount of natural and non-renewable resources, and also generates a lot of waste, such as those linked to the deconstruction of buildings. One of the avenues to reduce the environmental impact of this field is to recycle industrial by-products and waste in matrix of construction. This work of thesis concerns the co-valorization of two types of waste. The first one is dredged sediments of fluvial nature, characterized by a very high content of organic elements and the existence of primary mineral phases (clay, quartz, kaolin, etc.). The second one is residual waste from a valorization centre of waste glass. They contain mineral materials (pieces of porcelain, sand, etc.). First, the sediments were characterized and, in some cases, treated by calcination. They were then incorporated as additive in a cementitious matrix. Results highlighted a pozzolanic activity similar to that of other mineral additions, such as metakaolin or silica fume. As for the waste glass, they have undergone an alkaline activation before to be introduced into a geopolymer matrix. This work allowed to prove that waste glass could play the role of a source of sodium silicates, essential elements for the geopolymer reaction.Finally, the two types of waste were used together for applications in road technique and in matrix of construction. Results were encouraging in comparison to specifications and standards in effect for these applications.Le génie civil consomme une quantité non négligeable de ressources naturelles non renouvelables et génère aussi beaucoup de déchets, comme ceux liés à la déconstruction des bâtiments. Une des pistes pour réduire l’impact environnemental du secteur consiste à valoriser des sous-produits industriels et déchets dans des matrices de construction. Ce travail de thèse s’intéresse à la co-valorisation de deux types de déchets. Les premiers sont des sédiments de dragage de nature fluviale caractérisés par une teneur en éléments organiques très élevée et par l’existence de phases minérales primaires (argiles, quartz, kaolin, etc.). Les deuxièmes déchets sont des déchets résiduels issus d’un centre de valorisation de déchets de verre. Ils contiennent des matériaux minéraux (fragments de porcelaine, sable, etc.). Dans un premier temps, les sédiments ont été caractérisés et, dans certains cas, traités par calcination. Ils ont ensuite été incorporés comme additif dans une matrice cimentaire. Les résultats ont montré une activité pouzzolanique comparable à d’autres additions minérales comme le métakaolin ou les fumés de silice. Les déchets de verre ont quant à eux subi une activation alcaline avant d’être introduits dans une matrice géopolymère. Ce travail a permis de prouver que les déchets de verre pouvaient jouer le rôle d’une source de silicates de soude, éléments essentiels pour la réaction géopolymère. Enfin, les deux types de déchets ont été utilisés ensemble pour des applications en technique routière et dans des matrices de construction. Les résultats se sont montrés encourageants par rapport au cahier des charges techniques et aux normes en vigueur pour ces applications

Optimization of the valorization of waste glass and dreged sediments in recomposed binder : Activation - Formulation of mortars - Physico-chemical stabilization

Le génie civil consomme une quantité non négligeable de ressources naturelles non renouvelables et génère aussi beaucoup de déchets, comme ceux liés à la déconstruction des bâtiments. Une des pistes pour réduire l’impact environnemental du secteur consiste à valoriser des sous-produits industriels et déchets dans des matrices de construction. Ce travail de thèse s’intéresse à la co-valorisation de deux types de déchets. Les premiers sont des sédiments de dragage de nature fluviale caractérisés par une teneur en éléments organiques très élevée et par l’existence de phases minérales primaires (argiles, quartz, kaolin, etc.). Les deuxièmes déchets sont des déchets résiduels issus d’un centre de valorisation de déchets de verre. Ils contiennent des matériaux minéraux (fragments de porcelaine, sable, etc.). Dans un premier temps, les sédiments ont été caractérisés et, dans certains cas, traités par calcination. Ils ont ensuite été incorporés comme additif dans une matrice cimentaire. Les résultats ont montré une activité pouzzolanique comparable à d’autres additions minérales comme le métakaolin ou les fumés de silice. Les déchets de verre ont quant à eux subi une activation alcaline avant d’être introduits dans une matrice géopolymère. Ce travail a permis de prouver que les déchets de verre pouvaient jouer le rôle d’une source de silicates de soude, éléments essentiels pour la réaction géopolymère. Enfin, les deux types de déchets ont été utilisés ensemble pour des applications en technique routière et dans des matrices de construction. Les résultats se sont montrés encourageants par rapport au cahier des charges techniques et aux normes en vigueur pour ces applications.Civil engineering consumes a sizeable amount of natural and non-renewable resources, and also generates a lot of waste, such as those linked to the deconstruction of buildings. One of the avenues to reduce the environmental impact of this field is to recycle industrial by-products and waste in matrix of construction. This work of thesis concerns the co-valorization of two types of waste. The first one is dredged sediments of fluvial nature, characterized by a very high content of organic elements and the existence of primary mineral phases (clay, quartz, kaolin, etc.). The second one is residual waste from a valorization centre of waste glass. They contain mineral materials (pieces of porcelain, sand, etc.). First, the sediments were characterized and, in some cases, treated by calcination. They were then incorporated as additive in a cementitious matrix. Results highlighted a pozzolanic activity similar to that of other mineral additions, such as metakaolin or silica fume. As for the waste glass, they have undergone an alkaline activation before to be introduced into a geopolymer matrix. This work allowed to prove that waste glass could play the role of a source of sodium silicates, essential elements for the geopolymer reaction.Finally, the two types of waste were used together for applications in road technique and in matrix of construction. Results were encouraging in comparison to specifications and standards in effect for these applications

Manufacturing of Low-Carbon Binders Using Waste Glass and Dredged Sediments: Formulation and Performance Assessment at Laboratory Scale

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 increase the potential reactivity of each residue. The DS is thermally treated at 750 °C to promote limestone and aluminosilicate clays’ activation. The RWG (amorphous, rich in silicon, and containing sodium) is used as an alkaline activator after treatment in 10 M NaOH. Structural monitoring using nuclear magnetic resonance (29NMR and 27NMR), X-ray diffraction, and leaching is conducted to achieve processing optimization. In the second stage, mortars were prepared and characterized by determining compressive strength, water absorption, mercury porosimetry and Scanning Electron Microscopy with Energy Dispersive Spectroscopy (SEM-EDS). Results obtained show the great advantage of combining RWG and DS in an alkali-activation binder. The treated RWG offers advantages when used as sodium silicate activating solution, while the substitution of MK by calcined sediments (DS-750 °C) at 10%, 20%, and 30% leads to improvements in the properties of the matrix such as an increase in compressive strength and a refinement and reduction of the pore size within the matrix

Study of the impact of waste glasses types on pozzolanic activity of cementitious matrix

AC

Manufacturing of Low-Carbon Binders Using Waste Glass and Dredged Sediments: Formulation and Performance Assessment at Laboratory Scale

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 increase the potential reactivity of each residue. The DS is thermally treated at 750 °C to promote limestone and aluminosilicate clays’ activation. The RWG (amorphous, rich in silicon, and containing sodium) is used as an alkaline activator after treatment in 10 M NaOH. Structural monitoring using nuclear magnetic resonance (29NMR and 27NMR), X-ray diffraction, and leaching is conducted to achieve processing optimization. In the second stage, mortars were prepared and characterized by determining compressive strength, water absorption, mercury porosimetry and Scanning Electron Microscopy with Energy Dispersive Spectroscopy (SEM-EDS). Results obtained show the great advantage of combining RWG and DS in an alkali-activation binder. The treated RWG offers advantages when used as sodium silicate activating solution, while the substitution of MK by calcined sediments (DS-750 °C) at 10%, 20%, and 30% leads to improvements in the properties of the matrix such as an increase in compressive strength and a refinement and reduction of the pore size within the matrix

Use of residual waste glass in an alkali-activated binder – Structural characterization, environmental leaching behavior and comparison of reactivity

International audienceWaste 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 < 13 μm in a geopolymer activating solution. RWG is thus used as source of free silicon with metakaolin (MK) as source of aluminosilicates. The activating solution from RWG was prepared in four ratios with a sodium hydroxide solution of 10 M: R1 (10M-NaOH + 10 g RWG), R2 (10M-NaOH + 20 g RWG), R3 (10M-NaOH + 30 g RWG) and R4 (10M-NaOH + 40 g of RWG). The effect of these treatments on the mobility of metallic and metalloid trace elements (MMTE) and major elements (Si4+ and Al3+) was measured. The structure of the solid phases produced after drying at 120 °C/24 h was studied using Fourier Transformed Infrared (FTIR) spectroscopy, Nuclear Magnetic Resonance (NMR) and XRD analyses. From these analyses, activating solution R3 was deemed optimal. The formulation of geopolymer mortars using MK and three activator sources: The optimized activating solution from RWG (R3), Commercial Sodium Silicate solution (CSS) and a reference activator formed by NaOH with RWG blended with the MK to obtain the same molar ratios in the geopolymer mixture. The mechanical and environmental performance results both highlight the interest of dissolving the RWG in NaOH first before insertion into the matrix. This study shows that treated glass R3 becomes an activating solution with good reactivity for obtaining a geopolymer binder and enhanced properties compared to the CSS sourc