Abstract Joints are often the weakest points in a structure, making their design and performance critical. Today, a wide variety of connectors exist, differing in complexity, cost, and ease of assembly. These connectors not only influence the structural integrity of the joint but also impact the aesthetics of the final product and the efficiency of the assembly process. Given the growing interest in evaluating joint strength, assessment methods of their mechanical performance are continuously evolving. This study investigates the load-bearing capacity of joints, considering the type of joint, connectors used, and the loading method applied in experiments. Specifically, it compares the performance of selected metal mechanical connectors – screws, confirmat screws, and eccentric bolts – with wooden connectors such as wooden dowels, lamellas, and splines in permanent joints. Two evaluation methods were employed and compared: vertical compressive and tensile stress, and mixed compressive and tensile stress. Additionally, finite element analysis was conducted to support the interpretation of the experimental results. The findings of this study contribute to a deeper understanding of how different connectors affect joint stiffness. By identifying and quantifying key characteristics, these insights may help to optimize joint design for maximum structural performance.
High-fluidity concrete is widely utilized in civil engineering applications; however, it is prone to segregation, which can present challenges during construction. Incorporating rheological modifiers is a common approach to mitigate segregation in fresh cementitious systems. In this study, the effects of surface-modified hydroxypropyl methyl cellulose (HPMC) ether on the yield shear stress and apparent viscosity of cement paste were systematically investigated. Super-depth microscopy and zeta potential analyses were employed to elucidate the mechanisms underlying changes in rheological behavior, while X-ray diffraction (XRD) spectroscopy was used to examine the associated physicochemical interactions. The results demonstrated that shear stress increased with shear rate following a cubic relationship, whereas apparent viscosity decreased in a similar cubic manner. The addition of surface-modified HPMC markedly enhanced both shear stress and apparent viscosity. Curing time positively influenced the shear stress of fresh cement paste; however, the effect diminished with extended curing. Moreover, the hysteresis loop area, defined by the relationship between shear stress and shear time, increased with the incorporation of surface-modified HPMC. The modifier also promoted particle growth within the paste. Notably, cement paste containing 0.1 % HPMC with a molecular weight of 105 exhibited the highest fractal dimension of aggregates in the fresh state. The inclusion of surface-modified HPMC and its molecular weight contributed to stronger van der Waals forces and gravitational potential energy, while the electrostatic repulsive potential energy between particles decreased quadratically with interparticle distance.
This review identifies key challenges in zeolite-based concrete, including reduced early-age performance, high porosity, limited data on fracture properties, and inconsistent findings across studies. The physical characterization shows that zeolite is highly porous with a rough surface texture, and its chemical composition is rich in clinoptilolite with abundant silica and alumina, which supports pozzolanic reactivity. Zeolite increases water demand and reduces workability. Mechanical results demonstrate that compressive, tensile, and flexural strengths improve at optimal replacement but decline at higher replacement. However, the literature does not support a universal optimum replacement level. Many studies have reported improved mechanical performance at 10–15 % zeolite replacement. However, several other investigations observed different optimum levels or satisfactory performance at higher replacement percentages. The variations are due to zeolite type, fineness, chemical composition, mixture proportions, curing conditions, and testing age. Therefore, the mechanical performance of zeolite-based concrete should not be generalized through a single optimum value. Also, zeolite improves self-healing concrete by enhancing bacterial immobilization, crack closure, and strength recovery. Furthermore, zeolite significantly reduces the carbon footprint and global warming potential of concrete, offering additional benefits in lightweight applications when used as a partial sand substitute.
The growing demand for cost-effective and sustainable asphalt binder modification has increased interest in waste-derived polymers in hybrid systems. Ethylene-propylene-diene monomer (EPDM) recovered from end-of-life rubber offers a potential route to reduce reliance on commercial modifiers such as styrene-butadiene-styrene (SBS), yet EPDM–SBS interactions remain insufficiently studied. This research evaluates the viscoelastic behavior of EPDM-SBS hybrid binders and identifies performance-optimized formulations using rheological modeling and numerical optimization. Dynamic Shear Rheometer frequency sweeps (0.1–10 Hz) were performed at 40–80 °C to develop master curves, which were fitted with the Christensen-Anderson (CA) and Cross models. EPDM, despite being a waste material, markedly increased complex modulus and viscosity, particularly in the presence of SBS. Hybrid binders showed lower crossover frequency, longer relaxation times, and reduced crossover stress compared with single-modifier binders, indicating a more elastic response under long-term loading. Both models closely matched the experimental data (R2 > 0.99). Response Surface Methodology indicated temperature as the primary driver of G*/sinδ, followed by SBS and EPDM contents. Overall, within the investigated high-to-intermediate temperature rheological domain, waste EPDM showed potential to partially reduce SBS demand while maintaining favorable binder-level viscoelastic and flow characteristics.
Sandwich composites are lightweight structures comprising stiff, thin face sheets, often carbon or glass, bonded to a low-density core, delivering high strength-to-weight ratios, superior bending stiffness, and excellent energy absorption. These properties make them ideal for aerospace, automotive, and marine applications. Their performance hinges on core material selection, face sheet composition, and interfacial bonding, prompting research into optimized designs for improved mechanical behavior. This study investigates the optimization of face-sheet configurations in glass fiber-reinforced sandwich composites with PVC cores, fabricated via vacuum infusion. The research evaluates the flexural performance of composites with varying layer configurations (2/2, 2/4, and 4/2 layers at top/bottom) and fiber orientations (transverse and longitudinal) through mechanical, thermal, and chemical analyses. Flexural testing under 4-point bending revealed that asymmetric layer configurations (2/4 and 4/2) exhibited superior strength compared to symmetric (2/2) layouts, The 4/2 longitudinal configuration achieved the highest load-bearing capacity, reaching a maximum peak force of 1,103.3 N and an average breaking force of 1,098.4 N (30.4 MPa). Conversely, transverse orientations demonstrated lower capacities, with the 2/2 baseline averaging 401.2 N (11.7 MPa) and the 4/2 layout peaking near 690 N (18.9 MPa). Differential Scanning Calorimetry revealed a distinct exothermic curing reaction for the epoxy resin, identifying a glass transition temperature (T g) of 99.17 °C and a substantial total enthalpy of 439.7 J/g, indicating highly efficient cross-linking. SEM confirmed consistent individual glass fiber diameters ranging from 14.2 µm to 17.33 µm. Energy-Dispersive X-ray Spectroscopy (EDS) verified the silicate composition of the fibers, detecting 13.8–14.3 wt% silicon and 43.8–48.1 wt% oxygen in rupture regions, alongside a carbon-dominated surface layer (78.1–80.7 wt%) suggesting potential environmental or organic residues. These findings provide valuable insights for designing high-performance sandwich composites in aerospace, automotive, and civil engineering applications, balancing strength, weight, and durability.
Methanolysis of ammonia borane (AB) offers a promising approach to generating H2 on demand under mild conditions, contingent on the availability of effective and economical catalysts. This research involved the fabrication of electrospun poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) nanofibrous membranes, which were then decorated with Ni–Pd bimetallic nanoparticles (NPs) via an in situ chemical reduction approach, and the performance of these membranes in H2 production from AB methanolysis was evaluated. Structural and morphological examinations verified the successful synthesis and uniform distribution of Ni–Pd NPs within the PVDF-HFP matrix. A range of Ni1−x Pdx compositions was synthesized. The Ni–Pd–6@PVDF-HFP membrane demonstrated the greatest activity among all catalysts, achieving complete release of 3.0 mol H2 per mol AB within 8 min at 298 K and yielding a maximum H2 generation rate of 22.66 mol min−1 g−1, which was over five times greater than that of monometallic Ni. Kinetic investigations revealed an apparent activation energy of 18.5 kJ mol−1, alongside an activation enthalpy of 15.9 kJ mol−1 and a negative activation entropy (ΔS‡ = −62 J mol−1 K−1), thereby suggesting a surface-controlled associative mechanism. Studies examining catalyst loading demonstrated a first-order dependence on the Ni–Pd–6 dose. Furthermore, the catalyst maintained 89 % of its initial activity following five successive cycles.
Recycling different solid wastes to manufacture clinker-free cementitious materials has become popular due to their minimal carbon emissions. This study systematically examines the influence of Ca/Si and Al/Si ratios on multi-component alkali-activated materials (MAAM) covering fluidity, early-age strength, setting and hardening processes, gel phase compositions, and microstructure. The results indicate that the optimal initial Ca/Si and Al/Si ratios in the precursor materials are 0.71–0.36 and 0.25–0.39, respectively. The resulting gel phase demonstrate atomic ratios of 0.30–0.50 for Ca/Si and 3.26–1.62 for (Na + K + Ca)/Al, along with a high proportion of highly polymerized Si–O–Si/Al structural units. Consequently, MAAM achieves desired properties, including compressive strengths of 30–48 MPa, fluidity ranging from 24 to 30 cm, setting times of 128–174 min, and fewer volume shrinkage cracks. The decline in the Ca/Si ratio prompts a transformation of the gel phase from C-A-S-H to Ca-rich C-(N)-A-S-H. This transition lowers the Ca/Si and (Na + K + Ca)/Al atomic ratios in the gel phase, along with a diminished proportion of highly polymerized gel structural units. Ultimately, the reaction rate slows down, resulting in a looser microstructure and reduced strength. Conversely, an elevated Al/Si ratio promotes the formation of highly polymerized gel structural units, thereby achieving a denser matrix and increased mechanical properties.
High-temperature exposure deteriorates manufactured sand concrete and threatens structural safety, while water-spray cooling used in fire rescue may impose additional thermal damage. Existing studies focus mainly on natural sand concrete under natural cooling, leaving a knowledge gap for manufactured sand concrete subjected to fire-rescue cooling. This study experimentally investigated the residual mechanical properties of C40, C50, and C60 manufactured sand concrete specimens exposed to 200–800 °C followed by natural cooling or water-spray cooling, and the cross-sectional temperature field was simulated using ABAQUS. Results show that residual strength decreases markedly with temperature, and water-cooled specimens exhibit more severe surface damage. Finite element analysis indicates that both the heating rate and peak temperature in the outer region exceed those in the inner region. On this basis, a temperature-dependent strength influence parameter β(T) and a simplified method for predicting the post-fire bearing capacity of manufactured sand concrete under fire-rescue water cooling are proposed, addressing the current data gap. The findings provide a reference for fire-resistant design, fire-rescue decision-making, and post-fire structural assessment.
Bone defect repair remains a significant challenge in clinical orthopedics. Traditional bone grafting has limitations, including limited donor material, donor-site complications, and the risk of immune rejection. Moreover, achieving compatibility with a patient’s bone is difficult, which hinders clinical outcomes. To address these issues, customized implants created with computer-aided design and advanced manufacturing techniques such as 3D printing offer patient-customized solutions. In this review, we outline the principles and clinical uses of advanced manufacturing, focusing on material extrusion, direct ink writing, and 4D printing, and highlight their advantages for customized implants. Furthermore, the role of engineered porous structures – pillar-based, TPMS, and functionally graded designs – in optimizing implant performance is described. We also examine how artificial intelligence supports implant design and review the current clinical status of customized implants. Finally, we summarize the challenges of high equipment and material costs and complex regulatory procedures.
The growing demand for sustainable construction materials and the increasing industrial by-products need effective waste utilization strategies. Among various wastes, granite waste (GW) presents environmental challenges if not properly managed. Despite numerous experimental studies on GW in concrete, a comprehensive review is required to collect the relevant information and guide the user. Therefore, this review aims to critically evaluate the physical, mechanical, and environmental benefits of concrete made with the utilization of GW. The findings indicate that GW shows favorable physical properties such as fine particle size, high specific gravity, and angular texture. However, the rough surface texture of the GW particle increased the internal friction and reduced its workability. Mostly researchers suggest that up to 10 % GW can be safely utilized in concrete without compromising its performance significantly. However, the concrete performance declines at higher percentages (more than 10 %) due to the weaker bonding of the GW particle. Furthermore, GW decreased global warming potential (GWP), abiotic depletion potential (ADP), acidification potential (AP), and eutrophication potential (EP). The sustainability index (SI) and economic index (EI) analyses indicate that 20 % GW is the optimal for environmental, economic, and mechanical performance. Finally, the review recommends future studies.
In this study, untreated sewage sludge ash (SSA) was used to partially replace recycled brick fine aggregate (RBFA) or recycled concrete fine aggregate (RCFA) to prepare controlled low-strength materials (CLSM). The effects of the binder-aggregate ratio, fine aggregate type, and SSA incorporation on setting performance, compressive strength, and hydration products of CLSM were systematically evaluated, with all mixes designed for a constant slump flow. Phase composition and microstructural development of CLSM were analyzed using X-ray diffraction (XRD). Results demonstrate that in the recycled concrete fine aggregate (RCFA) – CLSM without SSA, with the increase of the binder-aggregate ratio, the setting time is shortened by approximately; However, after the addition of SSA, the opposite trend emerged, with the setting time prolonged. The recycled brick fine aggregate (RBFA) – CLSM shows a similar pattern, but the delaying effect of SSA on its setting time is weaker than that of the RCFA system. The compressive strength of all CLSM increased with the curing age and the increase of the cementitious material-aggregate ratio. When SSA is not added, the strength of RBFA-CLSM is higher than that of RCFA-CLSM, which is attributed to its lower water requirement. The incorporation of SSA significantly reduces the compressive strength of CLSM, but RBFA, due to its higher base strength, can partially offset the strength loss caused by SSA. The XRD results indicated that the main minerals of CLSM included CaCO3, SiO2, C–S–H gel and CO3-AFm phase. The gel content of C–S–H in the RCFA system is higher than that in the RBFA system. The incorporation of SSA reduced the diffraction peak intensity of CO3-AFm, and no Ca(OH)2 diffraction peak was detected, indicating that the pozzolanic reaction of the low-cementitious system and the auxiliary cementitious materials consumed all the calcium hydroxide. Finally, backfill construction was conducted with this new CLSM, and the excellent performance was confirmed.
Heat treatment procedures applied or designed to improve the machinability performance of Hadfield steels are very important. Therefore, this study consists of two main stages. In the first stage of the investigation, cast Hadfield steel was austenitised at 1,050 °C for holding times of 1 h and 5 h, followed by rapid quenching to retain the austenitic matrix. The effects of different austenitisation durations on microstructural evolution, crystallographic transformations, and the machinability characteristics of the alloy were systematically evaluated. In the second stage, the machinability characteristics of the materials were investigated using plunge electrical discharge machining (EDM), which is classified as a non-conventional machining process suitable for difficult-to-machine alloys. The experimental design incorporated three principal machining parameters: discharge current, pulse-on time, and reference voltage. For this purpose, three discharge current levels (4.5, 9, and 18 A), three pulse-on durations (50, 100, and 200 µs), and three reference voltage values (40, 45, and 50 V) were employed. According to the experimental results obtained, the most ideal processing parameter was determined by the Taguchi-based Gray Relational Analysis method, which is widely used in multiple output results. The results indicated that the optimal machining condition for the H1 sample was obtained at 4.5 A discharge current, 200 µs pulse-on time and 40 V reference voltage (A1B1C3D1). XRD analyses revealed the formation of ε and α′ martensite phases on the EDM-processed surfaces, indicating deformation-induced phase transformations during machining. Dislocation density values calculated using the Williamson–Hall method were determined as 6.76 × 1015 m−2 for the H1 sample and 10.18 × 1015 m−2 for the H5 sample. Microstructural observations also revealed the presence of recast layers, heat-affected zones and deformation twins caused by intense thermal cycles during EDM processing. The findings demonstrate that EDM-induced thermal effects significantly influence the microstructural evolution and machining performance of Hadfield steel, and that the Taguchi–GRA approach provides an effective method for multi-response optimization of EDM parameters.
Focusing on the corrosion damage and long-term performance evolution of coastal engineering structures, this paper presents a comparative review of four structural systems – steel, reinforced concrete (RC), steel-reinforced concrete (SRC), and concrete-filled steel tubular (CFST) structures – under marine environments, highlighting their distinct degradation characteristics and common challenges. Chloride-induced electrochemical corrosion is identified as the common starting point for performance degradation, while each system exhibits distinct features: steel structures by stress-corrosion-fatigue coupling; RC structures by rust expansion-cracking feedback; SRC structures by interface bond degradation; and CFST structures by tube corrosion and confinement loss. Research advances are categorized into multi-field coupled degradation models, probabilistic performance assessment, and intelligent protection technologies. Studies indicate that the coupling of chloride ingress with carbonation, freeze-thaw, wet-dry alternation, and fatigue loading drives a cross-scale degradation chain from material deterioration to system reliability decline. Recent progress in multi-field modeling, data analytics, and artificial intelligence, coupled with high-performance protective materials and intelligent maintenance, has enabled a paradigm shift from periodic inspection towards predictive maintenance. However, current research faces core limitations: insufficient understanding of time-varying degradation mechanisms under multi-factor coupling, incomplete analytical theories for complex loads and multi-hazard sequences, and a lack of unified synergy among protective materials, design methods, and maintenance standards. These constraints hinder engineering applications. Future research should prioritize time-varying constitutive models under multi-physics coupling, intelligent prediction and digital twin methods fusing monitoring data with machine learning, and unified design and assessment frameworks for whole-lifecycle performance, facilitating the transition from experience-based protection towards a predictable, designable, and manageable durability assurance system.
An analysis of copper and its alloys demonstrates their widespread application in materials engineering, particularly within the energy, chemical, marine, and transportation sectors. Copper is characterized by its high electrical and thermal conductivity, and its alloys – especially those incorporating nickel, cobalt, or zirconium – enable an optimal balance between mechanical strength and conductivity. Modern manufacturing technologies, such as additive methods (LPBF, EB-PBF) and nanotechnologies, allow for precise control over microstructure and properties, although they encounter challenges related to copper’s reflectivity, nanostructure stability, and production scalability. Advanced heat and thermomechanical treatments improve mechanical and electrical parameters, necessitating precise control of precipitation and recrystallization processes. In terms of corrosion resistance, graphene coatings and microstructural modifications reduce degradation in aggressive environments. The integration of additive technologies with traditional production methods, along with the development of nanostructured copper alloys, offers opportunities for components with optimized properties, although further research is required on the long-term stability of microstructures and coatings under operational conditions. Challenges include the trade-off between strength and conductivity, control of production defects, and the costs associated with modern methods. Proposed advancements include the integration of computer modeling with production and operational process monitoring to enhance the durability and efficiency of copper materials in demanding applications.
The utilization of seawater and sea sand (SWSS) in concrete production offers sustainable alternatives to depleting freshwater and river sand resources, yet elevated chloride content compromises durability and limits widespread adoption. This study systematically evaluates the mechanical properties, durability characteristics, and environmental impacts of SWSS concrete incorporating metakaolin, micro-silica, and nano-silica at 7.5 % cement replacement. Five concrete mixtures were fabricated and assessed through compressive strength testing at 7, 14, 28, and 91 days, alongside tensile strength, water absorption, rapid chloride permeability, and electrical resistivity measurements at 91 days. Cradle-to-gate life cycle assessment quantified environmental burdens across multiple impact categories. Results demonstrated that supplementary cementitious materials (SCMs) substantially enhanced performance of SWSS concretes, with 7.5 % nano-silica incorporated concrete achieved maximum compressive strength of 93.9 MPa, while 7.5 % micro-silica incorporated SWSS concrete exhibited lowest chloride permeability of 413 coulombs. Environmental analysis revealed 7.5 % micro-silica SWSS concrete achieved optimal sustainability with 10.1 % global warming potential reduction (346.8 kg CO2-eq/m3) relative to control concrete (385.7 kg CO2-eq/m3), while 7.5 % nano-silica incorporated SWSS concrete demonstrated superior mechanical-durability performance but elevated environmental impact. These findings indicate, strategic SCMs incorporation produces high-perormance, environmentally-efficient concrete that exceeds traditional benchmarks for marine applications.
To promote resource utilization and large-scale engineering application of municipal solid waste incineration (MSWI) bottom ash, this study systematically investigates the relationship between drying shrinkage and microstructure of concrete incorporating MSWI bottom ash as natural sand replacement, and evaluates the shrinkage-compensating efficacy of calcium sulfoaluminate-calcium oxide (CSA-CaO) expansive agent at conventional engineering dosages under varying bottom ash substitution levels. Macroscopic tests indicate incorporating MSWI bottom ash significantly prolongs the concrete’s drying shrinkage duration and amplifies ultimate shrinkage magnitude. Quantitative decoupling via Grey Relational Analysis (GRA) shows the volumetric fraction of fine mesopores (<20 nm) exhibits the highest correlation with macroscopic drying shrinkage (grey relational grade > 0.8), and pore refinement directly dictates the increased shrinkage magnitude and extended shrinkage period. Additionally, applying CSA-CaO expansive agent effectively restrains cementitious matrix drying shrinkage, with a maximum mitigation efficiency exceeding 48 %. However, at high bottom ash replacement levels, the expansive agent’s compensatory efficiency attenuates due to a weakened passive restraining effect caused by the skeleton’s reduced static elastic modulus. Microstructural analysis reveals that at a water-to-binder (w/b) ratio of 0.2 and 50 % sand replacement level, the porosity variation rate reaches 10.17 %. Later, due to MSWI bottom ash pozzolanic activity, secondary hydration reactions refine the internal pores. This refinement amplifies capillary tensile stresses during internal moisture evaporation, explaining the microscopic reasons for exacerbated late-age drying shrinkage in high-volume bottom ash concrete.
Aluminum alloys have been widely employed in armor applications owing to their low density, high specific strength, excellent ductility, superior corrosion resistance, favorable processability, and cost efficiency. This review examines the current research progress and development status of aluminum alloy armor materials. Particular emphasis is placed on summarizing research methodologies, failure mechanisms, and evaluation standards related to the ballistic and impact resistance of these materials. The influences of key factors – including alloy composition, heat treatment condition, material thickness, projectile geometry, and impact parameters – on the impact resistance of aluminum alloys are systematically analyzed and discussed. Furthermore, the review provides a comparative assessment of the failure mechanisms of aluminum alloys, other metallic systems, and non-metallic composites under dynamic loading conditions. Finally, prospective research directions are proposed, highlighting the importance of enhancing the impact resistance of composite armor systems through the optimization of constituent material properties, rational layered structure design, and improved interfacial bonding between layers.
The durability of concrete is a crucial factor in the lifespan, serviceability, and sustainability of infrastructure throughout its life cycle. This analysis analyzes the primary degradation mechanisms of concrete, including freeze-thaw damage, sulfate and acid attack, carbonation, and alkali-silica interaction, emphasizing their effects on long-term performance. The study assesses traditional and novel durability-enhancement methods, including supplemental cementitious materials (SCMs), nanomaterials, protective surface treatments, and corrosion inhibitors, based on experimental data, field investigations, and mechanistic insights. Although high-performance concretes produced using these methods exhibit exceptional resilience in controlled settings, their performance in the field shows significant heterogeneity across different environmental conditions. Emphasis is placed on aligning material selection and mix design with expected service conditions to attain both robustness and sustainability. Future directions include incorporating durability-focused predictive modeling, extensive field validation, and implementing eco-efficient alternatives, including low-carbon binders and recycled aggregates. This advanced synthesis highlights the importance of including durability factors into sustainable design frameworks for future concrete infrastructure.
Geopolymers are an emerging class of inorganic binders with considerable potential for use in protective and impact-resistant systems. Their ceramic-like microstructure, high thermal stability, compositional tunability, and relatively low density make them promising alternatives or complements to conventional armor materials such as technical ceramics, high-performance concretes, and metallic composites. Despite extensive research on geopolymers in construction and materials engineering, their application in ballistic and protective systems remains insufficiently explored and fragmented. This systematic review summarizes recent studies on geopolymer and geopolymer-based composite materials for protective applications, focusing on mechanical performance, dynamic and impact resistance, failure mechanisms, and energy absorption. Both monolithic geopolymers and hybrid multilayer systems are discussed, where geopolymers serve as load-bearing, protective, or binding layers. The influence of material composition, porosity, fiber reinforcement, and functional additives on ballistic response is addressed. The review also highlights civil and dual-use applications, including blast-resistant structures and critical infrastructure protection, and discusses sustainability aspects related to the use of industrial by-products and reduced carbon footprint. Key research gaps and future directions for advancing geopolymer-based protective systems are identified.
Marine soft clays, characterized by high compressibility, low shear strength, and water sensitivity, pose significant challenges for the construction of coastal infrastructure. This study develops and evaluates an alkali-free, Ca-based alkali-activated binder (GFPC) composed of ground granulated blast furnace slag (GGBS), fly ash (FA), phosphogypsum (PG), and calcium carbide slag (CCS), all derived from industrial by-products. A D-optimal mixture design was employed to optimize component proportions and assess synergistic effects on mechanical performance. Unconfined compressive strength tests at various curing ages and after 20 freeze–thaw cycles, combined with XRD and SEM–EDS analyses, were conducted to evaluate strength development, durability, and microstructural evolution. The optimal mix (68.4 % GGBS, 10 % FA, 11.6 % PG, 10 % CCS) achieved a 28-day UCS of 4.24 MPa, which is 36.8 % higher than that of cement-stabilized soil, and retained 2.41 MPa after 20 freeze–thaw cycles, 52.5 % higher than the corresponding value for cement stabilization. Strength loss was most pronounced during the first five cycles (38.44 %) and then stabilized. Microstructural analyses revealed abundant C-(A)-S-H gels and ettringite filling pores and densifying the soil skeleton. Environmental and economic assessments indicated 97.8 % lower carbon emissions and a 67.5 % lower unit strength cost compared with cement stabilization. These results demonstrate that the proposed alkali-free GFPC binder, derived from multiple industrial waste streams, provides a high-performance, low-carbon, and cost-effective alternative for marine soft clay stabilization, supporting more sustainable and resilient coastal infrastructure.
