Binder Composition Research Articles

Study of the impact in bituminous mix using crushed waste glass

Glass may be utilized in a wide variety of contexts; nevertheless, as its use expands, so does the amount of trash that is generated annually from broken glass. Reusing or recycling these products is the most productive course of action that may be taken. This study's objective is to determine how well a flexible bituminous pavement functions after having broken glass shards added to it as aggregate material. Crushed glass was added to the mixture at percentages of 5%, 10%, and 15% by weight. An equivalent amount of glass particles replaced fine aggregate in order to meet the target. As the proportion of glass in the mixture increased, the optimal binder composition of the mixture dropped. Both the flow values and the stability values rose rapidly as the fraction of shattered glass increased; however, the stability values decreased as the glass content reached 15%. According to the findings of the research that was conducted, substituting crushed glass for fine aggregates might potentially increase the stability and flow value of the design mix by up to 10%. The structural qualities of the mix would improve, and the amount of crushed waste glass produced would decrease. This partial replacement for fine total would without a doubt improve the longevity of the adaptable bituminous asphalt, and as an added perk, the amount of time spent unloading crushed waste glass would be decreased by half.

Triethanolamine-modified binder with synergistic effects on Zn anode in improving the cycling stability of aqueous rechargeable Zn[sbnd]Ni batteries

Aqueous rechargeable ZnNi batteries (ARZNBs) have been broadly considered as beyond-lithium energy-storage devices owing to their safety and potentially high energy density. However, the current practical ARZNBs suffer from short-circuit attack led by inherent problem of zinc anodes. Among the optimization methods of Zn anodes, proper binder engineering of anode is a facile and competitive solution, which is potentially needed to confront the problem of Zn dendrite, poor zinc reversibility, and the difficulties in enlargement for practical production. Herein, Zn anode is fabricated by simply mixing the triethanolamine (TEA) with traditional binder glue via aqueous processing. Specifically, it is composed of the commercial available chemical additive, triethanolamine (TEA), exploiting polyvinyl alcohol (PVA) substrate and potassium polyacrylate (PAAK) additive to retain water and help dissolve PVA. While the TEA helps to achieve the better dispersing and wetting properties of slurry, together with the stable interface structure and better electrolyte tolerance of anode. Notably, the leveling effect of TEA on anode is proved in this strategy, which is beyond the traditional approaches of adding additives to electrolyte. As a result, the scale-up large-area ZnNi pouch battery (∼3 Ah) prepared using this composite binder delivers ultra-long and stable galvanostatic cycling performance (∼1.3 V, >450 cycles and 1200 h) and superior energy efficiency compared to the benchmark of traditional anode, with considerable cyclic discharge loading (∼753 mA g−1Zn and ∼75 mA cm−2). The TEA-modified binder with synergistic effects on Zn anode offers a promising avenue to build low-cost and high-performance ARZNBs.

Calcium silicate/polyvinyl/chitosan/alginate-based bioceramic slurry for 3D printing of scaffolds: Interfacial interactions – Mechanical properties relationship

At present, there are few studies investigating the influence of mechanical properties of binders on bioceramic slurry at the micro- and macroscopic levels. In this work, we used molecular dynamics (MD) simulations and experiments to investigate the influence of mechanical properties of polyvinyl alcohol (PVA), chitosan (CS), and sodium alginate (SA) polymers on calcium silicate (CSi, CaSiO3)/binder bioceramic slurry and to choose the most suitable binders to prepare CSi/binder slurry. It was found that PVA demonstrated excellent stiffness, ductility, toughness, solubility, and low shear thinning. The formation of large number of hydrogen bonds (HBs) at the CSi/PVA interface results in strong interfacial bonding and higher compressive strength of CSi/PVA slurry while other binders suffer low solubility, higher shear thinning, poor stiffness, and ductility problems. From the calculated mechanical parameters, interfacial binding energy, and compressive tests, it was found that the slurry prepared by CSi and 10 PVA (mixing ratio: 1:0.9) demonstrate the best mechanical properties, a compressive strength of 7.3 MPa, thus, meeting the requirements of compressive properties of cancellous bone defects. The simulation results were supported by experiments. This study provides a theoretical and experimental guide for binder selection in bioceramic slurry and the design of future binder composites.

CO2 curing of mortar with natural and recycled concrete aggregate: An environmental and economic assessment

Previous studies have primarily focused on quantifying the impact of CO2 curing in terms of net CO2 emissions, overlooking its broader effect on the overall environmental performance of cementitious materials. This study aims to comprehensively assess the effect of CO2 curing on the performance and sustainability of mortars incorporating conventional and/or recycled materials (Recycled Concrete Aggregate (RCA) and Slag Cement (SC)). Four types of mixtures were analyzed, with two binder compositions (100% Ordinary Portland Cement (OPC) and 70% OPC + 30% SC) and two types of aggregates (Natural Aggregate (NA) and RCA). Each mixture had two groups of samples: one cured under normal conditions (reference group) and the other cured for 12 h in a CO2 curing chamber before starting normal curing. Strength, environmental impact, and cost were studied for all mixtures. Results showed that CO2 curing improved all single impact categories in environmental performance to varying extents. CO2 curing also enhanced the overall life cycle assessment results and reduced cost for all studied mortars. CO2 curing of cement mortars may, therefore, create a cheaper and more sustainable material. Using a Multi-Criteria Evaluation, it was demonstrated that CO2 curing increased the overall performance of all mixtures compared to conventional curing. Mortars containing recycled materials (e.g., RCA and/or SC) experienced significant improvements in terms of environmental performance despite their lower compressive strength. This suggests that CO2 curing may become a potential technology to enhance the sustainability of cement-based composites with recycled materials, contributing to a more environmentally friendly construction industry.

The Effect of the Addition of Coal Fly Ash (CFA) on the Control of Water Movement within the Structure of the Concrete.

Studies were carried out to find a relation between the important physical property, i.e., water absorption and the main mechanical parameter, i.e., compressive strength (fcm), of concretes containing coal fly ash (CFA) in the amounts of 0% (CFA-00), 20% (CFA-20%), and 30% (CFA-30). The methodology of the water absorption tests reflected the conditions prevailing in the case of reinforced concrete structures operating below the water table. The microstructure of all materials was also assessed. Based on the conducted studies, it was found that both the fcm of concretes with the addition of CFA and its water absorption depended on the percentage of waste used, whereas both analyzed parameters were closely related to the structure of the cement matrix and interfacial transition zone area between the coarse aggregates and the paste. It should be stated that at the content of 20% CFA in the binder composition, an increase in the fcm of the material is observed, with a simultaneous increase in its water absorption. On the other hand, the addition of 30% CFA results in a significant decrease in both the strength of the composite and its water absorption. Thus, it was found that in the case of concretes with the addition of CFA, the strength of the material is directly proportional to the level of its water absorption. Moreover, the concrete including 30% CFA may increase the durability of reinforced concrete structures subjected to immersion conditions. From an application point of view, the obtained research results may be helpful in understanding the impact of the CFA additive on the level of water absorption in cement concretes with this waste.

Low-temperature calcination composite binder from dolomite and its application to facing board materials

The article presents the research to obtain low-temperature calcination binder from dolomitic limestone with a MgO content of less than 20%. The initial dolomite material was calcinated at the following temperature range from 700 to 800 ℃ and firing time 25–45 min. The result of the selection of the optimal firing conditions is semi-calcination product caustic dolomite with a minimum content of residual Mg(CO3)2 and free CaO with bending strength 10–11 MPa. Physical-mechanical characteristics and mineral composition of samples were determined by the use of differential thermal analysis and infrared spectroscopy studies. Preliminary experimental samples of facing composite board materials were prepared and the main physico-chemical parameters were determined: bending strength 4–7.6 MPa, density 800–1400 kg/m3 and water absorption 10–25%. A three-dimensional model for the production of glass dolomite slabs has been developed.

Analysis of the cohesion/adhesion proportion around bitumen-mineral failure interface under tensile loading

The occurrence of cohesive/adhesive hybrid failure at the bitumen-aggregate interface is widely acknowledged, however, the quantitative evaluation of the cohesion/adhesion proportion is relatively weak. This study explored cohesive/adhesive hybrid failure and provided a quantitative analysis of the proportion between cohesion and adhesion. For this reason, this study considered a variety of experimental factors that included temperature (5 °C, 15 °C, and 25 °C), mineral morphology (three mineral types and three surface textures), and measured film thickness (varying from 10 μm to 900 μm). By performing the bonding strength test, the strength was recorded and interface failure was accordingly captured. The results indicated that the cohesion/adhesion proportion varied significantly with the temperature, mineral morphology, and measured film thickness. In addition, it was found that bonding strength decreased with the increase in the film thickness and temperature, which can be well explained by variation in adhesion/cohesion proportion. Complete cohesive failure was observed when the film thickness increased beyond a critical value at a relatively high temperature. An additional noteworthy finding was the resemblance of a lunar crater for the failure interface at high temperatures, signifying the heterogeneous composition of the bituminous binder around the interface.

Composition, nanostructure and stability of Cu-modified C-A-S-H in antibacterial alkali-activated slag

Antimicrobial alkali-activated slag (AAS) has been envisioned as a biologically resistant binder for potential application in sewer structures against biogenic sulfuric acid attacks. This work investigates the composition, phase assemblage, micro- and nano-structural alterations of AAS binders incorporating Cu-based antimicrobial agents (i.e., copper oxide and copper nitrate), as well as their antimicrobial properties and degradation mechanism under biological corrosion caused by sulphur-oxidising bacteria Acidithiobacillus thiooxidans. The results show that the incorporation of copper oxide or copper nitrate increases the degree of hydration of slag but reduces the mean chain length (MCL) of C-A-S-H as Cu preferably affects the bridging AlO4-tetrahedra over SiO4-tetrahedra. The substitution of Cu for the CaO polyhedral at the edges and corners of the C-A-S-H main chain makes the Al linkage blocked. Cu also possesses a charge-balancing role, resulting in a lower protonation of C-A-S-H in the Cu-doped AAS than that in the neat AAS, where C-A-S-H is a Tobermorite structure with MCL between 5 and 11. The Cu-doped AAS pastes show excellent antimicrobial efficiency, in particular, the CuO-doped AAS demonstrates 100 % effectiveness in inhibiting biofilm formation, with the corrosion depth significantly reduced by a factor of 10. The Cu ion is released initially from the outer surface of C-A-S-H due to its low bond dissociation energy, followed by the weak position, namely the AlO4-tetrahedra at the bridging position, rendering the rupturing of the C-A-S-H structure.

Multifunctional composite binder with synergistic transport mechanism to achieve high performance all-solid-state batteries

All-solid-state batteries (ASSBs) using solid polymer electrolytes (SPEs) show a wide range of prospects in many aspects, but they do not perform well at high current densities. In order to solve the above problems, much effort has been spent on the improvement of electrolyte materials, but there is a lack of research on binders. This paper emphasizes the critical role played by the binder in the positive plates without any liquid infiltration,and an aqueous composite binder (CB) is designed by utilizing the characteristics of polyethylene oxide (PEO) and carboxymethyl cellulose lithium (CMC-Li) in lithium-ions transport. Electrochemical and Fourier transform infrared spectrometer (FTIR) tests demonstrate that the two polymers in the CB build a high-speed channel for migrating lithium-ions through synergistic action. The binder containing multiple reactive groups is tested to be highly competitive in both mechanical and electrochemical properties, which creates sufficient conditions for achieving high-performance ASSBs. The cells with CB as the binder are assembled which show a capacity of 65.5 mAh·g−1 at a current density of 3C while PVDF-based ASSBs exhibit only 3.3 mAh·g−1, and exhibit a capacity retention of 86.7% after 700 charge/discharge cycles at 0.5C (for comparison, PVDF-based ASSBs exhibit only 42.5%). This novel composite binder provides guidance for the further development of solid polymer batteries.

Service life prediction and environmental impact evaluation of recycled aggregate concrete with supplementary cementitious materials

The application of recycled aggregate concrete (RAC) can promote the harmonious development of resources and environment. However, the mechanical properties and chloride permeability resistance of RAC are worse than those of natural aggregate concrete (NAC), which limits RAC application in chloride-attack environment. In order to solve this problem, supplementary cementitious material (SCM) is added into RAC to improve its performance. In this research, the changes in durability-based service life of RAC due to the addition of unconventional SCMs composed of red mud (RM), ground granulated blast furnace slag (GGBFS) and/or glass power (GP) have been studied. Based on prepared reinforced concrete specimens with 4 kinds of recycled coarse aggregate (RA) substitution level and 5 kinds of binder composition, the accelerated corrosion tests were conducted for determining corrosion rate. Using the corrosion rate data detected in this paper, combined with the chloride rapid migration coefficient and chloride threshold etc. data, the service lives of reinforced concrete structures with SCMs concrete were found to be much longer than those with Ordinary Portland cement (OPC) concrete. Furthermore, life cycle assessment integrated with strength and service life was performed for concrete with specific mix design to study the effect of unconventional SCMs addition on the environmental behaviors of RAC with different RA content. The results showed that RA substitution level had little effect on material environmental benefits, but the improvement effect of SCMs was obvious. Finally, the multi-criteria analysis method was used to evaluate the overall performance of concrete with different binder composition and RA content in terms of strength, service life and environmental impact. For any substitution level of RA, the SCMs composition with optimal effect in improving overall performance of concrete was 10% RM and 15% GGBFS (percentage by weight of binder).

Востановление городских памятников: ресурсный потенциал Северного Кавказа

Introduction. Repair and restoration binders and compositions based on them are necessary, first of all, for the repair, restoration and restoration of cultural heritage sites, both in the Russian Federation and abroad. They are subject to special requirements, so the conduct of related engineering and survey, research and development work is an important condition for the development of modern scientifically verified, practically tested and in demand in practice repair and restoration materials. One of the main conditions for the practical implementation of the proposed investment project is the presence of a mineral resource base in the region and the country. The resource potential of carbonate, halogen and clayey rocks is fully represented in the mountainous part of the Chechen Republic (CR). Based on the results of research and prospecting work on the territory of the Czech Republic, 6 forecast areas were identified, promising for the identification of deposits of carbonate Purpose of research. Development of compositions of binders for repair and restoration work based on the resource potential of the rocks of the mountainous part of the Czech Republic. Materials and methods. The work uses methods of analytical research and scientific generalizations, expert assessments, process modeling and system analysis. Results and discussion. The classification of inorganic binders was performed, which for the first time included organic-inorganic binders and additives in repair and restoration binders and compositions. Because of exploratory research, it was proposed to repair, restore and restore historical and cultural monuments using the ones developed at the Kh.I. Ibragimov RAS of modern technologies and materials for repair and restoration work. A concept for the development of a new scientific direction "High-strength composite materials based on lime (hydraulic and hydrate), gypsum (gypsum and anhydrite) and magnesia binders for the repair and restoration of cultural heritage sites" has been developed. Conclusions. The article presents the results of studies of repair and restoration binders and compositions based on them. It is shown that they are subject to special requirements, therefore, carrying out related engineering and survey, research and development work is an important condition for the development of modern scientifically verified, practically tested and in demand in practice repair and restoration materials. The paper shows that the new developed classification is more complete and allows more accurate determination of the compositions necessary for restoration work. According to the results of the work, it is clear that it is possible to carry out the repair, restoration and restoration of historical and cultural monuments using the proposed technology. When carrying out such work on the territory of the Chechen Republic, it is possible to do these using local raw materials. Resume. It is planned to continue work in this direction and analyze the sources of raw materials for restoration work in more regions of the North Caucasus.

Mechanical Compression Behaviour of "Green" Rocket Propellants

The issues related to mechanical resistance of solid rocket propellants, which can appear during storage or handling of the launching system, are considered to directly influence the burning performance. Thus, in this study, four new types of composite rocket propellants, based on an environmentally friendly oxidizer (phase-stabilized ammonium nitrate), a metallic fuel (aluminium), and a "green" polyurethane-based binder (synthesized from an oligomeric isocyanate and a blend of polyester-polyols obtained through the catalytic degradation of polyethylene terephthalate), were subjected to compression mechanical analysis in order to highlight the importance of the binder on the response given by the tested materials subjected to compressive loads. The samples showed remarkable mechanical performances, the experiments allowing us also to determine the influence of the binder composition and fuel granulation on mechanical properties of the composite propellant.

MODIFIED COMPOSITE CEMENTS IN THE SYSTEM СаО–Al2O3–SO3–H2O

Problem statement. One of the most important issues today is the reconstruction, reinforcement of buildings and structures, as well as the creation of new construction materials with the required physical and mechanical properties. The solution to this problem is possible through controlling and regulating the properties of the initial components of the concrete mixture, increasing the amount of surface components at the interface. To control the properties of construction materials, and thus to obtain the cement stone with the specified physical and mechanical properties is possible by means of using various mineral and surface-active additives in the composition of hardened cement stone. Development of sulfoaluminate compositions based on calcium sulfates, alumina cement and surface-active substances (surfactants) makes it possible to significantly expand the raw material base and the scope of application. The purpose of article – obtaining a composite binder with increased density, water resistance and improved technological factors. Conclusions. Alumina cement G-40, 50 and gypsum G-5-II in the ratio of 30−70 % (with hemihydrate gypsum being its main material) have been used in the research to achieve the set purpose. Their properties have been determined as well as the optimal ratio of components for obtaining a specific mineralogical composition with the maximum content of chemically bound water is carried out. Studies have shown that increased content of calcium sulfate has a positive effect on the amount of ettringite and that the optimal value is in the range of 30−40 % by weight of the composition. The exact ratio of components can be determined based on their mineralogical compositions and hydration process conditions. At the ratio of AC-40/G % – 70/30 % a considerable amount of calcium hydroaluminates remain; compressive and flexural strength is 14 and 10 MPa, respectively. When conducting research, the effect of plasticizers on the main technological and physical and mechanical properties of composite binders has been established: the Sika Viscocrete G additive has the greatest plasticizing effect. The composite binders presented above can be used for the manufacture of dangerous structures.

Feasibility and Sustainable Performance of RAP Mixtures with Low-Viscosity Binder and Castor Wax–Corn Oil Rejuvenators

The utilization of Recycled Asphalt Pavement (RAP) mixtures in pavement construction is an environmentally friendly approach that promotes sustainable development by reducing energy consumption and material waste. However, the high cost of conventional rejuvenators limits the widespread use of RAP mixtures. In this study, a novel approach is proposed to enhance the performance of RAP mixtures by incorporating a combination of high-penetration asphalt binder and rejuvenators, namely Castor wax and Corn oil. The newly developed rejuvenator consists of 8.5% Castor wax oil, 3% Corn oil, 3% fatty acid amine surfactant, 0.2% additive, and 79.8% water. The test results demonstrate that the modified mixture exhibits superior properties compared with conventional RAP mixtures. The Multiple Stress Creep Recovery test results showed a 20% reduction in cumulative strain rate for the RAP mixture with the new rejuvenators compared with that for the conventional ones. Furthermore, the Tensile Strength Ratio test indicated a notable 9.47% improvement in the rejuvenated RAP mixture’s resistance to moisture-induced damage compared with the conventional mixture. Evaluation of viscoelastic behaviors revealed a slight reduction in dynamic modulus for the rejuvenated binder, but a significant improvement in elastic behavior. In terms of rutting resistance, the Hamburg wheel tracking rut depths of the rejuvenated binder were significantly lower, representing reductions of 21.83% for specific binder compositions. Additionally, the absence of the stripping phenomenon further confirmed the superior moisture resistance of the modified mixture. The rejuvenated binder exhibited a remarkable 28.55% increase in fatigue load cycles to failure compared with the reference RAP binder, demonstrating substantial resistance to fatigue cracking. These quantitative comparisons not only confirm the superior performance of the modified mixture over conventional RAP mixtures, but also highlight the potential cost savings achieved through the utilization of Castor wax and Corn oil rejuvenators.

Concrete Composites Based on Quaternary Blended Cements with a Reduced Width of Initial Microcracks

This article is devoted to the study of the combined effect of siliceous fly ash (FA), silica fume (SF), and nanosilica (nS) on the cement matrix morphology and size of microcracks occurring in the Interfacial Transition Zone (ITZ) between the coarse aggregate and the cement paste of concrete composites based on ordinary Portland cement (OPC). The manuscript contains analyses of width of microcracks (Wc) occurring in the ITZ area of concretes based on quaternary blended cements and changes in ITZ morphology in the concretes in question. Experiments were planned for four types of concrete. Three of them were composites based on quaternary blended cements (QBC), while the fourth was reference concrete (REF). Based on the observations of the matrices of individual composites, it was found that the REF concrete was characterized by the most heterogeneous structure. However, substitution of part of the cement binder with active pozzolanic additives resulted in a more compact and homogenous structure of the cement matrix in each of the QBC series concretes. Moreover, when analyzing the average Wc values, it should be stated that the modification of the basic structure of the cement matrix present in the REF concrete resulted in a significant reduction of the analyzed parameter in all concretes of the QBC series. For QBC-1, QBC-2, and QBC-3, the Wc values were 0.70 μm, 0.59 μm, and 0.79 μm, respectively, indicating a decrease of 38%, almost 48%, and 30%, respectively, compared with the working condition of concrete without additives. On the basis of the above results, it can therefore be concluded that the proposed modification of the binder composition in the analyzed materials clearly leads to homogenization of the composite structure and limitation of initial internal damages in concrete.

In situ interlocked gradient adaptive network binder with robust adhesion and cycle performance for silicon anodes

The potential for silicon anodes as an alternative to graphite anodes for lithium-ion batteries (LIBs) has been extensively studied. Unfortunately, structural and interfacial instability limits their commercial application. Polymer binder design preserves the electrode's structure against large Si volume changes in LIBs, thereby improving battery cycle life. Developing robust conductive binder networks is essential for optimizing anode capacity potential. Herein, a biopolymer composite binder (IFH) composed of flexible hyaluronic acid and fluorinated copolymer inspired by constructional engineering is constructed. In situ interlocked is achieved by establishing multi-hydrogen bonding networks and chemical bonding between polar groups in the copolymer chain. IFH exhibits excellent mechanical characteristics as well as flexibility and elasticity. In addition, the covalent bonds between ester and amide bonds effectively enhance the mechanical properties of the electrode, inhibit the sliding of silicon particles, maintain the integrity of LIBs, and improve the conductivity of lithium-ion. Specifically, excellent electrochemical performance (1049 mAh g−1 at 1 A g−1 after 500 cycles) of silicon/carbon anodes fabricated with gradient adaptive network IFH binder was achieved. Moreover, SiO–C composite electrodes as well as Si–C electrodes show excellent electrochemical performances. This work provides new insights into the design of multifunctional polymer binders for next generation LIBs.

Reinforced Epoxy Binder Modified with Borpolymer.

Polymer binders based on epoxy resins have unique properties that contribute to their use in many composite industries. The potential of using epoxy binders is due to their high elasticity and strength characteristics, thermal and chemical resistance, and resistance to climatic aging. This is the reason for the existing practical interest in modifying the composition of epoxy binders and understanding the strengthening mechanisms in order to form reinforced composite materials with a required set of properties based on them. This article presents the results of a study of the process of dissolving the modifying additive of polymethylene-p-triphenyl ether of boric acid in the components of an epoxyanhydride binder applicable to the production of fibrous composite materials. The temperature and time conditions for the dissolution of polymethylene-p-triphenyl ether of boric acid in anhydride-type isomethyltetrahydrophthalic anhydride hardeners are presented. It has been established that the complete dissolution of the borpolymer-modifying additive in iso-MTHPA occurs at a temperature of 55 ± 2 °C for 20 h. The effect of the modifying additive of polymethylene-p-triphenyl ether of boric acid on the strength properties and structure of the epoxyanhydride binder has been studied. Increases in transverse bending strength up to 190 MPa, elastic modulus up to 3200 MPa, tensile strength up to 0.8 MPa, and impact strength (Charpy) up to 5.1 kJ/m2 are observed when the content of the borpolymer-modifying additive in the composition of the epoxy binder is 0.50 mass. %.

Carbonation resistance of calcined clay-ground granulated blast furnace slag alkali-activated mortar

Alkali-activated materials are obtained from the alkaline activation of a precursor rich in SiO2 and Al2O3, which can be derived from by-products or industrial residues. Calcined clay is a potential candidate as a precursor for this type of material. Large amounts of suitable clays for alkali-activated materials are available around the world. This paper evaluated the performance of different alkaline-activated mortars using calcined clays (low grade) and ground-granulated blast-furnace slag (GGBFS), including physical and mechanical performance, reaction products phases, microstructure, and resistance to accelerated carbonation. The results indicate that the increase in GGBFS content up to 60% has a significant effect on the properties of the mortars, due to the effect of Ca-rich phases such as C-(A)-S-H/C-(N)-A-S-H, promoting the densification of the microstructure, and an increase in pH from 11.91 to 12.78 for specimens with 100% calcined clay and 60% GGBFS respectively, leading to a better carbonation resistance. On the other hand, adding GGBFS leads to a reduction in concrete initial and final setting time and lowers thermal stability compared to the reference calcined clay material. The increase in the modulus ratio of the activator from 1 to 1.5 also improves the mechanical properties and resistance to carbonation of geopolymer mortars with various binder compositions.

Robust 3D Network binder for Stable and High‐Performance Si‐Based Lithium‐Ion Battery Anodes

AbstractSilicon (Si) is becoming one of the most promising candidates for lithium‐ion batteries (LIBs) owing to its high theoretical capacity, ultralow lithiation/delithiation voltage, non‐flammability, abundant natural reserves, etc. However, Si particles undergo violent volume expansion/contraction during the charge/discharge cycles, resulting in a series of serious problems such as Si particle pulverization, solid electrolyte interphase film overgrowth, and electrode structure collapse, which severely hinders the application of silicon‐based LIBs. Herein, a composite binder crosslinked by polyacrylic acid and p‐toluene sulfonic acid protonated polyaniline is proposed to improve the electrochemical performance of Si‐based anodes. The cross‐linked composite binder processes 3D networks, fast self‐healing features, and excellent mechanical strength, which can alleviate the damage caused by the expansion of Si particles to the electrodes and protect the structural integrity of the Si‐based electrodes. As a result, the Si‐based anodes with the composite binder present excellent cycle stability (2092.9 mAh g−1 after 300 cycles at 400 mA g−1). In addition, the novel binder reveals well compatibility with commercial Si microparticles. More importantly, the self‐healing Si anode is firstly equipped in an all‐solid‐LIB with solvate ionic liquid‐based quasi‐solid electrolyte and shows excellent cycling stability as well as rate capability.

Impact of Nanoclays on Chemical Fractions and Mechanical Performance of Asphalt Binders

Asphalt binder often is modified to obtain better performance of the pavement. Some recent studies have considered nanoclay as an alternative to currently practiced styrene-butadiene-styrene (SBS) modification to reduce the asphalt binder’s overall cost. This study evaluated any notable changes in the chemical composition of the binder due to the nanoclay modification and investigated any correlation between the chemical composition and mechanistic properties of the asphalt binder. It was found that changes in the chemical composition of nanoclay-modified binders are crude source–dependent. After nanoclay modification, the binders that originated from the Arabian crude were found to be more acidic than the binders from the Canadian crude source. However, nanoclays did not have any notable impact on the polarity of the tested asphalt binders regardless of their crude sources. The saturates, aromatics, resins, and asphaltenes (SARA) analysis results of asphalt binders revealed that the n-heptane insoluble contents increased notably after modification with nanoclays, whereas the saturates content decreased due to aging. Some mechanical properties (e.g., viscosity and rutting factor) were found to be correlated with n-heptane insoluble contents. Moreover, the sessile drop analysis test result showed that the nanoclay-modified binders offered superior bonding with gravel than with sandstone. Multiple linear regression analyses suggest that there is a fair (R2=0.55) correlation between the binders’ SARA components and compatibility for gravel.