Faced with the depletion of non-renewable natural resources worldwide, and considering the greenhouse gas emissions (CO2) associated with construction, the use of alternative granular materials has become a viable option in the construction industry. In this investigation, the partial and/or total replacement of natural sands with non-hazardous waste incineration bottom ash (MSWIBA) sands was studied for the production of cement mortars using two types of cement, namely CEM I Portland cement and CEM III blast furnace slag cement. The substitution rates were 50%, 75%, and 100% by volume. Mechanical and environmental properties were evaluated for the mortars containing MSWIBA sands. The results show that the uniaxial compressive strengths for the 50% V/V substitution rate reach average values of 50 MPa after 180 days of moist curing for CEM III cement. For the 75% and 100% V/V substitution rates, the average values are around 40 MPa. In general, it is observed that CEM III cement yields better mechanical results. Leaching tests conducted on the MSWIBA sand particles and on the mortars containing 100% MSWIBA sands demonstrated that there is no health risk or hazard associated with the use of MSWIBA as a substitute for natural granular materials in the construction sector.

Itaconic acid (ITA) is a promising renewable chemical building block. Previous research on its radical homopolymerization in aqueous media has shown slow kinetics, low conversion, and low molecular weight polymers. In this paper, we demonstrate the impact of the intrinsic properties of itaconic acid on its polymerization conditions. Specifically, the role of the degree of ionization (alpha) on its structure, solubility, and reactivity towards radical polymerization in water was investigated. The results indicate that the highest solubility in water occurs when itaconic acid is half-deprotonated. At a given concentration, the reaction rate and final molecular weight decrease as the degree of ionization increases, presumably due to electrostatic effects and hydrophobic/hydrophilic variations. Despite lower reactivity, full conversion can be achieved in a relatively short time with the halfdeprotonated form of itaconic acid, because the polymerization can be achieved at higher monomer concentrations. These experimental findings are further supported by computational simulations of the monomer's structure and reactivity.

The production of pulp and paper from recycled paper generates significant quantities of deinking paper sludge (DPS). This sludge contains a significant amount of organic matter (36

The effect of two crosslink strategies on the preparation of chitosan-based covalent hydrogels was investigated employing the widely used thiol-ene reaction. This versatile "click" chemistry can be activated either photochemically or thermochemically. Initially, well-purified chitosan (CS, DA -4 %, Mw -580 kg mol-1) was separately functionalized with vinyl (CS-ene) or thiol (CS-SH) groups in aqueous media. Subsequently, two strategies were compared where thiol-ene reaction occurs respectively between: (S1) modified chitosans CS-ene and CS-SH, in a polymer - polymer strategy, and (S2) CS-ene and di(ethylene glycol) dithiol (dEG-(SH)2), in a polymer - molecule strategy. Both crosslinking strategies were evaluated through rheological measurements, starting with entangled chitosan solutions. The difference in diffusion of functional groups, whether attached to polymer chains or to free molecules, leads to faster gelation kinetics with S2. Consequently, stronger gels were obtained with S2, where the modulus was connected with the degree of functionalization, while S1 produced weaker gels closer to the percolation point, where crosslinked density was associated with the entanglement number derived from the initial concentration. Nevertheless, networks formed by both strategies were homogenous with minimal dissipative contributions to their rheological properties, indicating that structural defects are negligible.

Based on the need to reduce the carbon footprint of binders used for plant-based concretes, the development of lime-pozzolan binders is on the rise. The carbon emissions due to the binder production have to be reduced in such a way to ensure a high level of carbon storage while improving the thermal resistance of building envelopes. This paper intends to assess the technical feasibility of making plant-based concretes by mixing agricultural by-products (rapeseed straw, hemp and flax shives) with a binder composed of micronized marine sediment (non -calcined) and air lime. The hardening kinetics of the lime-sediment binder with sodium sulfate added was examined as a first step. The effect of various drying conditions on the strength development of lime-sediment mortars was then investigated to help understand the strength performances of plant-based concretes following 7 days of heat curing and 21 days at 65%RH.The results indicate that the newly formed solid products in the binder collected in plant-based concretes were mainly calcium carbonate and CO3-AFm. In spite of the low hydration degree of the binder, it was possible to reach an ultimate strength of 0.50.6 MPa at 7 % strain for a stabilized bulk density of 560 kg m- 3. The rapeseed straw concrete was characterized by a strain hardening behavior due to the presence of tangled fiber-like par-ticles and showed the lowest thermal conductivity (0.077 W m-1 K- 1 in the dry state).

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 applications could help reduce the demand for natural aggregates. We conducted experiments by replacing natural sand with varying proportions of BA-MSWI (30–100

There is a need to find alternatives to the extraction of non-renewable mineral resources for the production of new binders. Some specific building materials such as plant-aggregate-based concretes do not require high-strength binders. In this context, the lime-pozzolan technology, inherited from Roman times, can help reduce the carbon footprint of finished materials by the use of low amounts of lime. In this paper, three different marine dredged sediments were used as natural alumino-silicate resources and blended with hydrated lime. Based on previous literature dealing with the pozzolanic activity of cristallized minerals, the sediments were reduced to micronized powders. The hydration of these systems was investigated through hardening and reaction kinetics up to 365 days at 20 degrees C and 50 degrees C. The sediments used revealed two kinds of mineral assemblages and the best pozzolanic reactivity was found with quartz-rich sediments. In addition, the optimum lime content was found to be 20 wt% until 180 days.(c) 2023 The Society of Powder Technology Japan. Published by Elsevier B.V. and The Society of Powder Technology Japan. All rights reserved.

The recycling of end-of-life bio-composite materials contributes to reducing the environmental and economic costs of the building sector. The current research is about studying the feasibility of reusing wheat straw aggregates from crushed vegetal blocks after deconstruction, manufactured three years ago. These recycled materials are composed of wheat straw aggregates and interparticles of old lime. These aggregates are also partially covered by a gangue of old lime (called "surrounded lime). The objective is to investigate the possibility of incorporating recycled wheat straw a second time in a new biocomposite formulation with recycled wheat straw aggregates (RWSA). For the first time, RWSA is physically characterized (grain size distribution, densities, water absorption) to establish a comparison with the natural wheat straw. A second time, two formulation groups are defined and performed by varying the water/binder ratio (W/B = 1.1; 0.8) and considering the presence of old-lime inter-particles (equal to 55% per unit of particle mass). For each group, the quantity of RWSA in the formulations increases in mass proportion (0, 30, 50, 70, 100%). The physical bulk density, thermal (conductivity), and mechanical (compression strength) properties of the new recycled concrete are identified, with the valuation of the influence of the curing time (28 and 90 days) and formulation parameters on these properties. A third group with different straw/binder ratios (S/B ratios) is considered with formulations where the aggregates were entirely recycled without considering the presence of the old-lime inter-particles. The influences of curing time, W/B ratio, and different percentages of RWSA on the thermal and mechanical properties were highlighted. Through microstructural analysis, it can be observed that increasing the proportion of RWSA in biocomposites increases the carbonation rate and hence the strength of such compounds. The carbonation rate increased from 42.58% in biocomposites containing 100% normal straw to 81.8% in those containing 100% recycled straw due to the presence of old-lime inter-particles. This confirms the findings in terms of the increase in thermal conductivity and mechanical strengths with the substitution rate of RWSA.

The combination of lime with natural pozzolans for the production of binders in masonry construction dates back to ancient times. These were largely ignored with the industrialization of the building sector even though their use for specific applications is of interest. The use of lime-pozzolan binders with the least amount of lime is a relevant opportunity to reduce carbon emissions due to the decarbonation of limestone for the production of quicklime but also to introduce new alumino-silicate materials. In this context, the present investigation intends to relate marine dredged sediment to pyroclastic materials and to mix it with hydrated lime without any thermal treatment but after micronization. The blends were moist cured either at 20 degrees C or 50 degrees C and the paper will discuss the pozzolanic reactivity through the study of compressive strength and reaction kinetics from 3 days to 180 days. Reaction product assemblage, microstructure, and porosity refinement were also addressed after advanced curing ages. Results have well illustrated the long-term pozzolanic reactivity of the marine sediment cured at 50 degrees C through the whole combination of initially available lime after 60 days and the compressive strength development providing 12 MPa after 180 days.

Human activities require a growing need for raw materials. In order to contribute to sustainable development, many business sectors are focusing on biomass valorization. Whether from dedicated crops or first industrial processing, it generates materials with high potential that can be used in many fields. Non-food uses mainly concern the energy, chemical, and construction sectors. Whatever the intended application, a pre-treatment stage is essential to clean the material and/or to access a specific fraction. An additional modification may occur in order to endow the material with a new function thanks to a process known as functionalization. Uses of plant fractions (aggregates) in combination with cement offer advantages like low-density materials with attractive thermophysical properties for building. However, their development is limited by the compatibility of crop by-products with hydraulic binders such as Ordinary Portland Cement (OPC). This includes delays in setting time and hydrophilic character of vegetal components and their interaction with an alkaline environment. The aggregate/cement interfaces can therefore be strongly affected. In addition, the diversity of crop by-products and mineral binders increases the level of complexity. In order to overcome these drawbacks, the treatment of plant fractions before their use with mineral binders may result in significant benefits. In this way, various treatments have been tested, but the methods used at an industrial scale remain relatively under-researched. The purpose of this review is therefore to highlight the mechanisms involved in each specific process, thus justifying the operating conditions specific to each. This bibliography study aims to highlight potential treatments that could apply to biomass before their mixing with cementitious binders. According to the objective, a distinction can be made between extraction processes as hydrothermal or solvent treatments, assisted or not, and structural modification processes as surface treatments, impregnation, or grafting.

Over the last decades, microwave heating has experienced a great development and reached various domains of application, especially in material processing. In the field of polymers, this unusual source of energy showed important advantages arising from the direct microwave/matter interaction. Indeed, microwave heating allows regio-, chemio-, and stereo-selectivity, faster chemical reactions, and higher yields even in solvent-free processes. Thus, this heating mode provides a good alternative to the conventional heating by reducing time and energy consumption, hence reducing the costs and ecological impact of polymer chemistry and processing. This review states some achievements in the use of microwaves as energy source during the synthesis and transformation of polymers. Both in-solution and free-solvent processes are described at different scales, with comparison between microwave and conventional heating.

In the context of global warming, the built environment offers relevant opportunities to reduce GHG emissions that underlie climate change. In particular, this can be achieved with the development of low-embodied energy building materials such as bio-based concretes. Hemp concrete has been the subject of many investigations in the field of non-load bearing infill walls in France since the early 1990s. In addition to hygrothermal performances, the use of crop by-products definitely helps to limit the carbon footprint. Hemp concretes are often produced by mixing the plant aggregates with lime-based binders. The latter have many benefits among which the water vapor permeability. However, CO2 emissions due to the decarbonation of limestone for the production of lime largely contribute to the overall environmental balance of these materials. The use of natural pozzolans (volcanic scoria) combined with hydrated lime goes back to the Greco-Roman period and reduces carbon emissions. Nonetheless, it does not necessarily meet the issue related to the depletion of granular natural resources. Hence, this study deals with the design of a new low-carbon binder based on marine dredged sediment seen as an alternative strategic granular resource that can be considered renewable. The sediment comes from the Port of Dunkirk in the North of France and is mainly composed of silt and quartz sand. It was finely ground and compared to a lowly reactive basaltic pozzolan. Lime-pozzolan pastes were prepared and stored in a moist environment under room (20°C) and high temperature (50°C). The hardening kinetics of pastes was followed through mineralogical studies (TGA, XRD) and compressive strength development. The results showed that the hardening of pastes including the marine sediment was suitable in the case of samples stored at 50°C and make it possible to use such a binder for precast bio-based concretes.

Currently, there is a great demand for functional materials with effective pathogen-killing properties. In this research, we describe the use of green technology “reactive extrusion” for the synthesis of potent antimicrobial materials based on Ethylene-vinyl alcohol copolymer (EVOH). Herein, the antimicrobial agent, copper (II) acetate was used without pretreatment and introduced into the EVOH matrices at high temperatures. The thermal reaction of copper (II) acetate within the EVOH matrices and their effect on the thermal and thermomechanical properties of the polymer were investigated in regards to their concentration. The physicochemical, thermal, and rheological features, as well as, metal salt release kinetics were reported. The antimicrobial agent had significant effects on the properties of the matrix. Results showed a reduction in the glass transition temperatures and storage modulus of the materials in response to the incorporation of copper (II) acetate. Finally, the antimicrobial activity of the products was studied and demonstrated a possibility to create antimicrobial materials in a one-step, solvent-free extrusion process.

Sediments from dredging works are increasingly used in the building and construction industry. One of the major difficulties of sediment valorization resides notably in the very heterogeneous composition of its fine particles. This paper focused on the rheological impacts caused by the use of uncontaminated raw marine sediment (RS) in Self-Compacting Concrete (SCC). The Densified Mixture Design Algorithm (DMDA) was used to optimize RS as a raw material in the granular structure of the SCC. The AFREM grout method was used to determine the saturation dose of the superplasticizer. The rheological tests were carried out to assess the influence of fine RS particles on the workability of SCC. The stability of SCC was found to be correlated with the high percentage of fine particles less than 125 μm present in the RS. The fine nature of clays and the organic matter caused the increase in yield stress and plastic viscosity. The rheological tests were carried out to assess the influence of fine RS particles on the workability of SCC. The stability of SCC was found to be correlated with the high percentage of fine particles less than 125 μm present in the RS.

In a perspective of a sustainable development, a new generation of construction materials based on renewable plant resources has emerged to face environmental issues. However, the formulation of structural vegetal concretes (based on plant aggregates, a mineral binder and water) requires to enhance the compatibility of plant aggregates and binder. This paper presents an experimental study that evaluates the influence of vapothermal treatment, a promising method of cure under saturated water vapour pressure, on chemical composition and physical properties (loss of mass, absorption, and specific gravity) of hemp shives, entering in the composition of vegetal concrete. Indeed, developing bio-based concrete by vapothermal curing requires identifying the appropriate curing conditions both from the point of view of the hemp aggregates and the binder. In particular, these curing conditions must respect a compromise between the preservation of the physical and chemical properties of hemp shives and an efficient curing of the binder. Several levels of curing temperatures were defined between 150 and 230 degrees C (carbonization) and results of Treated Hemp Shives (THS) were compared with those of Raw Hemp Shives (RHS). The experimental results showed physical modifications explained by chemical transformations that affects the hemicellulose, cellulose and lignin composition of TSH and modifies the structure of hemp shives. The effect of vapothermal curing on hemp shives was determined through X-Ray Diffraction XRD and thermogravimetry TG. The loss of mass of THS increases as the curing temperature increases and specific gravity decreases. As for water absorption, which relates to the hydrophilic character of the treated hemp shives, it decreases slightly. This experimental study made it possible to assess the interest of a vapothermal curing in a prospect of using hemp shives in binder interaction in order to perform structural vegetal concrete.

The deinking paper sludge (DPS) generated by paper recycling incorporated in ceramic pastes has received significant attention to develop environmentally-friendly construction materials with a good thermal and sound insulation characteristic while maintaining a resistance mechanical acceptable by standards. The environmental risks associated with the incorporation of these sludge into clay bricks that rich in heavy metals such as Cr, Pb, Zn, Cu, Ni, etc. have been evaluated. The evaluation of these metals was carried out by performing the leaching test in order to be able to introduce this new material in the list of materials to be marketed in the field of civil engineering. Leaching tests were performed on clay, DPS and the finished product as fired bricks. Leaching results on clays show that they are non-hazardous products, while heavy metal leaching of DPS is above the limiting concentrations, which classifies DPS as a hazardous waste. In contrast, the leaching concentrations of the bricks incorporated by DPS, show that the heavy metals were immobilized in the ceramic structures of all the fired bricks. In this study, the per-centages of DPS added in the composition of the bricks are 8%, 10% and 12%. Results of leaching test sug-gest that replacing up to 12% of clays with DPS can provide bricks to reduce the environmental impact of abundant waste and preserve non-renewable natural resources. (c) 2021 Elsevier Ltd. All rights reserved.

The purpose of this study was to evaluate the environmental impact of the use of harbour dredging sediments (HDS) from active lagooning in the formulation of self-compacting concrete (SCC). Concerning the beneficial use of sediments as alternative granular material in construction, the developed experimental methodology allows to incorporate a more optimized content of sediments in cementitious materials than the current experimental approaches. The studied sediments do not undergo any chemical or thermal treatment. The DMDA (Densified Mixture Design Algorithm) method was used to formulate cementitious materials and optimize the sediment content. The paper focused on mortars equivalent to these “sediments” (SCMs). The experimental program considered three different HDS with three different fines rates at 125 μm. Considering the environmental regulation context, the studied HDSs are classified as non-hazardous waste with reference to the European Directive 1999/31/EC—Decision 2003/33/EC. Heavy metals contained in sediments were stabilized with the cementitious matrix, except nickel. In particular, a notable decrease in barium and chloride concentrations was observed. The different mortars are classified as inert, the clinker hydration producing hydrates that capture and stabilize heavy metals in the cementitious matrix. After a 28-day curing period in water at 20 ℃, a C25/30 mechanical class concrete was obtained. The obtained experimental results show that raw HDS from active lagooning has a real potential to be used as a secondary raw material with the incorporated notable quantity in the SCC formulation.

Telechelic poly(trimethylene carbonate) (PTMC) oligomers are synthesized and carefully characterized with molar masses between 300 and 5000 g mol(-1) in bulk by ring-opening polymerization (ROP) with 1,3-dioxan-2-one (trimethylene carbonate or TMC) as monomer and 1,4-butanediol (BDO) as co-initiator. 1,5,7-Triazabicyclo[4.4.0]dec-5-ene (TBD) organic catalyst and tin(II) bis(2-ethylhexanoate) (Sn(Oct)(2)) organometallic initiator are chosen comparatively. Due to the bi-functionality of BDO and relatively low TMC/BDO feed ratios, it is proved that PTMC chains are elaborated from one or both the BDO alcohol functions, producing two coexisting kinds of PTMC chains with BDO unit at the chain end or in the backbone. Additionally, PTMC chains bear permanent and fast exchange reactions at 100 degrees C, leading to both a dynamic redistribution of chains and their extension with BDO unit numbers mainly from 0-4 but up to 6. Longer reaction times and lower TMC/BDO molar ratios bring about more predominant exchange reactions and MALDI-TOF allows to detail the structures evolutions deeply. Better average molar masses control and narrower distributions are obtained with TBD as compared to Sn(Oct)(2). PTMC molar masses can be predicted simply by the TMC/BDO feed ratio with TBD. Kinetically, TBD is the most efficient. The glass transition temperature T-g is found to respect Flory-Fox model.

The widespread use of facemasks throughout the population is recommended by the WHO to reduce transmission of the SARS-CoV-2 virus. As some regions of the world are facing mask shortages, reuse may be necessary. However, used masks are considered as a potential hazard that may spread and transmit disease if they are not decontaminated correctly and systematically before reuse. As a result, the inappropriate decontamination practices that are commonly witnessed in the general public are challenging management of the epidemic at a large scale. To achieve public acceptance and implementation, decontamination procedures need to be low-cost and simple. We propose the use of hot hygroscopic materials to decontaminate non-medical facemasks in household settings. We report on the inactivation of a viral load on a facial mask exposed to hot hygroscopic materials for 15 minutes. As opposed to recent academic studies whereby decontamination is achieved by maintaining heat and humidity above a given value, a more flexible procedure is proposed here using a slow decaying pattern, which is both effective and easier to implement, suggesting straightforward public deployment and hence reliable implementation by the population.

In this work, thermoreversible poly(trimethylene carbonate) (PTMC) based networks with different crosslinking densities were obtained by Diels–Alder (DA) reaction between furan-functionalized PTMC precursors and a bismaleimide.