Vol.5,No.2,2025-Table of Contents
- OPEN ACCESS ARTICLE
- Experimental study of load transfer mechanisms of onshore wind turbine foundations
- Sustainable Structures Vol.5,No.2,2025 DOI:10.54113/j.sust.2025.000078 Online published:2025-5-3
- Abstract In Europe, the development of the wind energy market will evolve between 2020 and 2030 towards a renewal of existing wind farms to reach the objectives set by the law on energy transition for green growth. This renewal process involves the replacement of wind turbines after their service lives by more powerful machines, which would necessitate reconstruction of new foundations to accept the loads of the larger turbine. To reduce environmental impacts and limit greenhouse gas emissions, this practice appears to be far from optimal. This paper therefore focuses on assessing the suitability of a 1g small-scale model as a tool to support an evolutionary design enabling reuse of existing foundations during repowering. As part of the FEDRE research project, the study evaluates the model’s ability to simulate foundation behavior under quasi-static loading. The broader methodology integrates field monitoring, small-scale testing, and COMSOL Multiphysics® simulations to assess the feasibility of reuse before proposing practical solutions.… More
-
Views:20
Downloads:38
Download
- OPEN ACCESS ARTICLE
- Temperature effects on the compressive properties of wood-plastic composites
- Sustainable Structures Vol.5,No.2,2025 DOI:10.54113/j.sust.2025.000077 Online published:2025-5-3
- Abstract Wood-plastic composite (WPC) is made of plastic matrix, wood fiber or particles, compatibilizers and other modifiers. WPC has the appearance and strength of wood but offers toughness similar to plastics making it a suitable material for practical applications. In this paper, the influence of temperature on the compressive properties of two kinds of WPC specimens with equal size was studied, and the relationship between load displacement and stress strain of WPC composites at four kinds of temperatures was analyzed. It was found that with the increase of temperature, the mechanical properties of WPC decreased and the ultimate displacement increased. The relationship between the ultimate stress, the ultimate strain, the ultimate displacement and the temperature is analyzed, and the performance of the specimens with two sizes is compared. The reduction factor for strength in the Eurocode 5 and other references are compared with this paper, so as to provide a reference for the research in related fields.… More
-
Views:29
Downloads:31
Download
- OPEN ACCESS ARTICLE
- Experimental research and damage analysis on the seismic behavior of ESJ-strengthened seismic-damaged RACFRST columns
- Sustainable Structures Vol.5,No.2,2025 DOI:10.54113/j.sust.2025.000076 Online published:2025-5-3
- Abstract This study examines the seismic response characteristics of pre-damaged recycled-aggregate concrete-encased rectangular steel tube (RACFRST) columns. Four column prototypes underwent cyclic loading experiments to assess the rehabilitation effectiveness of enveloped steel jackets (ESJ) on seismically compromised members. Comprehensive analysis of hysteresis characteristics, rigidity deterioration patterns, strength degradation trends, energy dissipation mechanisms, deformation ductility, and strain distribution was performed using experimental data. A dual-parameter seismic damage evaluation framework was subsequently developed and validated through experimental measurements. Findings revealed that ESJ-retrofitted specimens demonstrated 23-37% enhancement in load-bearing capacity, 18-29% improvement in initial stiffness, and 32-45% increase in cumulative energy dissipation compared to reference specimens. The efficiency of rehabilitation demonstrated a negative correlation with prior damage severity, resulting in a 19% decline in efficacy as the initial damage index rose from 0.3 to 0.6. The proposed damage assessment model yielded indices ranging between 0.92-1.08 for retrofitted components, demonstrating strong correlation with experimental observations. This validated methodology enables quantitative seismic performance evaluation for ESJ-strengthened RACFRST structural elements in post-earthquake rehabilitation scenarios.… More
-
Views:17
Downloads:24
Download
- OPEN ACCESS ARTICLE
- Carbonation and chloride penetration resistance of sustainable structural concrete with alkali-activated and ordinary Portland cement binders: a critical review
- Sustainable Structures Vol.5,No.2,2025 DOI:10.54113/j.sust.2025.000075 Online published:2025-5-3
- Abstract The use of concrete with alkali-activated binders in structural engineering applications is restricted by the uncertainty surrounding its long-term performance. Durability of concrete with alkali-activated binders is particularly governed by the resistance to carbonation and chloride penetration. Carbonation lowers the pH of concrete, compromising its alkalinity, while chloride ions can induce localized corrosion of embedded steel reinforcement. This paper examines the performance of concrete where Ordinary Portland Cement (OPC) is partially or entirely substituted with supplementary cementitious materials like fly ash and ground granulated blast furnace slag (GGBS). For concrete incorporating alkali-activated binders, this review emphasizes the impact of binder composition, activator type and concentration, and curing conditions on its resistance to carbonation and chloride ingress. Methods for assessing these parameters were explored to understand the viability of alkali-activated binders in structural applications. Concrete with alkali-activated binders that contain higher calcium exhibit better resistance to chloride penetration and carbonation. Combining GGBS with fly ash enhances the carbonation resistance more effectively compared to using each binder separately to produce structural concrete.… More
-
Views:53
Downloads:29
Download
- OPEN ACCESS ARTICLE
- Performance of geopolymer paste as adhesive and resin material for bonding fiber externally and hardening reinforcing rebars
- Sustainable Structures Vol.5,No.2,2025 DOI:10.54113/j.sust.2025.000074 Online published:2025-5-3
- Abstract Nowadays the construction of buildings confronts numerous challenges, environmentally, economically, and structurally efficiently. In addition, the saving of raw sources become essentially required especially for the building and construction sector. One of these solutions is based on utilizing sustainable material for construction technology. The goal of this research is to develop a more environmentally friendly material with the same performance qualities as adhesive epoxy and steel reinforcing bars. The goals of this research may be accomplished in two stages. The first step in reinforcing reinforced concrete (RC) beams is making geopolymer paste (GPP), a new kind of externally adhesive substance that may replace epoxy polymer (EP) with textiles made of synthetic glass fibers and natural jute fibers. The second advantage of GPP over PET resin for making rebars is using synthetic and natural threads, such as jute and glass fibers. In this investigation, nine reinforced concrete beams were prepared. Four of these beams were reinforced at the flexural zone with a combination of glass fiber textile (GFT) and jute fiber textile (JFT) externally bonded with epoxy or geopolymer paste. The other four specimens were reinforced with 50% GFR or JFR and 50% steel bars. In addition, one control beam is reinforced with 100% steel bars. A three-point load test is experimented on, and all RC beams are monitored up to failure. The study and analysis focused on load deflection, toughness, ductility index, and failure mechanism of beams. The theoretical ultimate load was calculated to predict and compare it to the experimental ultimate capacity of beam. According to the findings of the tests, sustainable GPP was able to harden the fiber rebars manufacturing process and serve as an externally excellent adhesive substance, on par with or even better than EP resin. The beam strengthened with jute fiber sheet that installed using GPP exhibited more cracking compared to the installation using EP resin.… More
-
Views:32
Downloads:39
Download
- OPEN ACCESS ARTICLE
- Analysis of mechanical properties of fly ash and boiler slag integrated geopolymer composites
- Sustainable Structures Vol.5,No.2,2025 DOI:10.54113/j.sust.2025.000073 Online published:2025-5-3
- Abstract This study explores sustainable alternatives to conventional raw materials in composite manufacturing by integrating fly ash (FA) and boiler slag (BS) into geopolymer composites. FA and BS were combined with alkali activators (AA) to evaluate their mechanical and physical properties under varying compositions and curing conditions. From bottom ash, only the boiler slag portion was selected for use in this study, which was ground to 300µm particle size. The research examined the effects of BS content (25%, 50%, and 75%), solid-to-liquid ratios (0.5, 1.0, 1.5, and 2.0), AA ratios (Na₂SiO₃/NaOH: 1.0 to 2.5), and curing temperatures (60°C to 90°C) on the compression strength of the composites. Results showed that composites with 25% BS and an AA ratio of 1.5 achieved the highest compressive strength (30.38 MPa) after 7 days of curing. Apparent porosity and water absorption decreased with increasing BS content, while optimal curing temperatures ranged from 70°C to 80°C. At elevated temperatures, compressive strength declined due to thermal degradation, but composites maintained the performance comparable to conventional materials. SEM analysis revealed a geopolymer matrix with dense microstructures. These findings demonstrate that incorporating BS and FA into composite manufacturing provides a viable eco-friendly alternative to traditional materials, reducing reliance on geo-sand and cement while enhancing sustainability.… More
-
Views:96
Downloads:40
Download
- OPEN ACCESS ARTICLE
- Chloride transport modeling for normal and fly-ash concrete using naturally logarithmic apparent diffusion coefficient with considering eutrophication potential effect
- Sustainable Structures Vol.5,No.2,2025 DOI:10.54113/j.sust.2025.000072 Online published:2025-5-3
- Abstract This study indicates two issues of available time-dependent diffusion coefficient function; non-smoothness of diffusion coefficient decay, and inconsistency of stable time of diffusion coefficient. A naturally logarithmic apparent diffusion coefficient function is thus developed for closed-form solutions of chloride transport model. The developed model is validated with experimental data, and its generality is ensured by comparing with the finite difference approach. From the study, the stable time of the developed diffusion coefficient appears 2.87-3.21 years after exposure, and the stable time of surface chloride appears 5 years after exposure. Such early appearance of these stable times behaves different from other studies, causing different long-term chloride prediction and concrete service life. Using the developed model, the influence of cover depth and percent fly-ash is determined in service life prediction. Additionally, this study develops a model to predict environmental impact in terms of eutrophication potential, currently considered as an emerging global issue. The developed eutrophication potential model shows that the increase of fly-ash replacement of 0% to 50% reduces such eutrophication potential due to concrete production by as much as 38%. Moreover, the relationships between the service life and the eutrophication potential for normal and fly-ash concrete tend to be linear.… More
-
Views:12
Downloads:25
Download
- OPEN ACCESS ARTICLE
- Calculation of the load-bearing capacity of a wood-wood joining system adapted to digital and democratized manufacturing
- Sustainable Structures Vol.5,No.2,2025 DOI:10.54113/j.sust.2025.000071 Online published:2025-5-3
- Abstract CAD/CAM technology applied to wooden structures means that traditional joining techniques, rather than metal-fastener-based systems, can now be industrialized. The development of the "Spatial Masterkey" system manufactured with a 3-axis CNC milling machine is presented. The system democratizes traditional joining techniques. It is designed for the construction of lightweight roofs, based on articulated joints with 50x50 mm section bars, working under traction and compression. A test campaign involving 6 different trials was proposed for the evaluation of the behavior of the different nodes. Satisfactory practical results were obtained in relation to the estimated theoretical values. Tensile and compressive tests on the horizontal/vertical bar nodes yielded higher results than the calculated values (8.50 kN before failure). With regard to the tests on the diagonal bars, cylindrical doweling reinforcements were required, which increased the resistance capacity by almost 130%. Future lines of research that can be pursued within this field are also proposed.… More
-
Views:15
Downloads:27
Download