Pub Date : 2026-01-24DOI: 10.1016/j.istruc.2026.111143
Hejie Zhang , Quanbiao Xu , Jiawei Zhou , Benyue Li , Shenghang Yang , Kuanyuan Liao
To enhance the construction efficiency and seismic performance of double-sided composite shear walls, this paper proposes a novel double-sided composite shear wall (SCDSW) utilizing serrated steel-plate connections. Through quasi-static testing of six full-scale specimens (including four steel-plate connected double-sided composite shear walls and two cast-in-place shear walls) under varying axial compression ratios (0.2, 0.4, 0.6) and shear span ratios (1.69, 1.44), this study systematically investigates their failure modes, hysteretic behavior, ductility, stiffness degradation, and energy dissipation capacity. Test results indicate: steel-plate connected double-sided composite shear walls exhibit outstanding ductility at low axial compression ratios, with a maximum ductility coefficient of 5.10; at high axial compression ratios (0.6), their ultimate displacement angle increases by 28.2 % compared to cast-in-place specimens, demonstrating superior deformation capacity; as the axial compression ratio increased, the specimen's load-bearing capacity rose by 45.9 %, but the ultimate displacement angle decreased by 36.7 %. Reducing the shear span ratio increased the load-bearing capacity by 33.2 %, but ductility decreased. Furthermore, simulation results from a refined finite element model established using DIANA software showed good agreement with experimental results, validating the reliability of this connection construction and the accuracy of the numerical model.
{"title":"Experimental study on the seismic behavior of steel-plate connected double-sided composite shear wall","authors":"Hejie Zhang , Quanbiao Xu , Jiawei Zhou , Benyue Li , Shenghang Yang , Kuanyuan Liao","doi":"10.1016/j.istruc.2026.111143","DOIUrl":"10.1016/j.istruc.2026.111143","url":null,"abstract":"<div><div>To enhance the construction efficiency and seismic performance of double-sided composite shear walls, this paper proposes a novel double-sided composite shear wall (SCDSW) utilizing serrated steel-plate connections. Through quasi-static testing of six full-scale specimens (including four steel-plate connected double-sided composite shear walls and two cast-in-place shear walls) under varying axial compression ratios (0.2, 0.4, 0.6) and shear span ratios (1.69, 1.44), this study systematically investigates their failure modes, hysteretic behavior, ductility, stiffness degradation, and energy dissipation capacity. Test results indicate: steel-plate connected double-sided composite shear walls exhibit outstanding ductility at low axial compression ratios, with a maximum ductility coefficient of 5.10; at high axial compression ratios (0.6), their ultimate displacement angle increases by 28.2 % compared to cast-in-place specimens, demonstrating superior deformation capacity; as the axial compression ratio increased, the specimen's load-bearing capacity rose by 45.9 %, but the ultimate displacement angle decreased by 36.7 %. Reducing the shear span ratio increased the load-bearing capacity by 33.2 %, but ductility decreased. Furthermore, simulation results from a refined finite element model established using DIANA software showed good agreement with experimental results, validating the reliability of this connection construction and the accuracy of the numerical model.</div></div>","PeriodicalId":48642,"journal":{"name":"Structures","volume":"85 ","pages":"Article 111143"},"PeriodicalIF":4.3,"publicationDate":"2026-01-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146024499","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
To investigate the influence of pre-existing microcracks on the top surface of ultra-high-performance concrete (UHPC) on the mechanical behavior of steel–UHPC composite structures, eight pre-cracked specimens were designed and subjected to four-point negative bending tests. The key design parameters considered include the UHPC layer thickness, reinforcement ratio, and concrete cover thickness. The mechanical behavior was evaluated in terms of the load–displacement curve, cracking load, crack propagation and distribution, load–slip response, strain development, and ultimate bearing capacity. In addition, the test results from identical intact steel–UHPC composite slabs were also collected from literature to investigate the influence of pre-cracks. The results indicate that the ultimate bearing capacity of pre-microcracked specimens is comparable to that of intact specimens, with a capacity ratio ranging from 0.90 to 1.05. This indicates that pre-cracks will have small influence on the ultimate bearing capacity of steel-UHPC composite slabs. However, at 40 % and 80 % of the ultimate load, the overall stiffness of the pre-cracked specimens shows additional reductions of 5.7∼36 % and 9.4∼25.6 %, respectively. In addition, for initial crack widths of 0.05 mm, 0.1 mm, and 0.2 mm, the nominal cracking stress of pre-cracked specimens differed from that of the intact specimens by 6.6∼28.8 %, –2.0 %∼19.5 %, and –2.6 %∼7.8 %, respectively. These findings demonstrate that surface microcracks have a pronounced effect on the early-stage cracking behavior, though their influence diminishes as cracks propagate, gradually approaching the crack development pattern observed in intact specimens. This means that pre-cracks could significantly affect the long-term durability of steel-UHPC composite bridge decks due to the accelerated crack development at the initial loading stage. Moreover, upon the test results, a calculation method was proposed to compute the ultimate flexural capacity of pre-cracked steel-UHPC composite deck slabs with the consideration of contribution of tensile strength of UHPC. Good agreement is obtained between the proposed method and the experimental results, indicating it can be used for the design of pre-cracked steel-UHPC composite deck slabs.
{"title":"Investigation on the mechanical behavior of pre-cracked steel-UHPC composite bridge decks under negative bending moment","authors":"Manhua Xiong , Xudong Shao , Junhui Cao , Suiwen Wu , Minghong Qiu , Jiahui Feng","doi":"10.1016/j.istruc.2026.111168","DOIUrl":"10.1016/j.istruc.2026.111168","url":null,"abstract":"<div><div>To investigate the influence of pre-existing microcracks on the top surface of ultra-high-performance concrete (UHPC) on the mechanical behavior of steel–UHPC composite structures, eight pre-cracked specimens were designed and subjected to four-point negative bending tests. The key design parameters considered include the UHPC layer thickness, reinforcement ratio, and concrete cover thickness. The mechanical behavior was evaluated in terms of the load–displacement curve, cracking load, crack propagation and distribution, load–slip response, strain development, and ultimate bearing capacity. In addition, the test results from identical intact steel–UHPC composite slabs were also collected from literature to investigate the influence of pre-cracks. The results indicate that the ultimate bearing capacity of pre-microcracked specimens is comparable to that of intact specimens, with a capacity ratio ranging from 0.90 to 1.05. This indicates that pre-cracks will have small influence on the ultimate bearing capacity of steel-UHPC composite slabs. However, at 40 % and 80 % of the ultimate load, the overall stiffness of the pre-cracked specimens shows additional reductions of 5.7∼36 % and 9.4∼25.6 %, respectively. In addition, for initial crack widths of 0.05 mm, 0.1 mm, and 0.2 mm, the nominal cracking stress of pre-cracked specimens differed from that of the intact specimens by 6.6∼28.8 %, –2.0 %∼19.5 %, and –2.6 %∼7.8 %, respectively. These findings demonstrate that surface microcracks have a pronounced effect on the early-stage cracking behavior, though their influence diminishes as cracks propagate, gradually approaching the crack development pattern observed in intact specimens. This means that pre-cracks could significantly affect the long-term durability of steel-UHPC composite bridge decks due to the accelerated crack development at the initial loading stage. Moreover, upon the test results, a calculation method was proposed to compute the ultimate flexural capacity of pre-cracked steel-UHPC composite deck slabs with the consideration of contribution of tensile strength of UHPC. Good agreement is obtained between the proposed method and the experimental results, indicating it can be used for the design of pre-cracked steel-UHPC composite deck slabs.</div></div>","PeriodicalId":48642,"journal":{"name":"Structures","volume":"85 ","pages":"Article 111168"},"PeriodicalIF":4.3,"publicationDate":"2026-01-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146024500","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-24DOI: 10.1016/j.istruc.2026.111151
Jingxuan Zhang , Yanbing Fang , Kun Feng , Xiaoming Liang , Chuan He , Hechao Dou , Weiming Tao , Linwei Cao
Mechanical performance analyses of segmental lining structures have predominantly relied on limit state methods. However, these methods often neglect parameter uncertainty—particularly the randomness of structural parameters—which can lead to an overestimation of the safety reserve for shield tunnel segmental linings. To bridge this gap, this study establishes a novel reliability assessment framework for shield tunnel structures. Distinct from conventional approaches, this framework is built upon a refined finite element model that considers the full segmental lining structure, including segments and circumferential joints. The Akaike Information Criterion (AIC) is used to determine the statistical properties of structural internal forces under the random variability of both geotechnical and structural parameters. A key contribution of this work is the systematic decoupling and comparison of the effects of geotechnical parameter variability, structural parameter variability, and their combined uncertainties on structural reliability. The results show that while the coefficient of variation (CoV) of geotechnical parameters governs internal forces, the CoV of structural parameters has a critical impact on reliability indices. Specifically, negative bending regions at the spring line show lower reliability indices than positive bending regions. This study highlights that ensuring the quality control of structural parameters is as important as managing geotechnical risks, providing theoretical guidance for optimizing segment design in critical transition zones.
节段衬砌结构的力学性能分析主要依靠极限状态法。然而，这些方法往往忽略了参数的不确定性，特别是结构参数的随机性，从而导致盾构隧道管片衬砌的安全储备估计过高。为了弥补这一空白，本研究建立了一种新的盾构隧道结构可靠性评估框架。与传统方法不同，该框架建立在考虑全节段衬砌结构（包括节段和周向接头）的精细有限元模型之上。采用赤池信息准则（Akaike Information Criterion， AIC）来确定土工参数和结构参数随机变率下结构内力的统计特性。这项工作的一个关键贡献是系统地解耦和比较岩土参数变异性、结构参数变异性及其组合不确定性对结构可靠性的影响。结果表明：土工参数变异系数（CoV）支配内力，结构参数变异系数（CoV）对可靠度指标有重要影响；其中，弹簧线负弯曲区域的可靠度指标低于正弯曲区域。该研究强调了保证结构参数的质量控制与管理岩土工程风险同等重要，为关键过渡区管段优化设计提供了理论指导。
{"title":"Probabilistic reliability assessment of spatial mechanical performance for shield tunnel segmental lining considering uncertainty propagation","authors":"Jingxuan Zhang , Yanbing Fang , Kun Feng , Xiaoming Liang , Chuan He , Hechao Dou , Weiming Tao , Linwei Cao","doi":"10.1016/j.istruc.2026.111151","DOIUrl":"10.1016/j.istruc.2026.111151","url":null,"abstract":"<div><div>Mechanical performance analyses of segmental lining structures have predominantly relied on limit state methods. However, these methods often neglect parameter uncertainty—particularly the randomness of structural parameters—which can lead to an overestimation of the safety reserve for shield tunnel segmental linings. To bridge this gap, this study establishes a novel reliability assessment framework for shield tunnel structures. Distinct from conventional approaches, this framework is built upon a refined finite element model that considers the full segmental lining structure, including segments and circumferential joints. The Akaike Information Criterion (AIC) is used to determine the statistical properties of structural internal forces under the random variability of both geotechnical and structural parameters. A key contribution of this work is the systematic decoupling and comparison of the effects of geotechnical parameter variability, structural parameter variability, and their combined uncertainties on structural reliability. The results show that while the coefficient of variation (CoV) of geotechnical parameters governs internal forces, the CoV of structural parameters has a critical impact on reliability indices. Specifically, negative bending regions at the spring line show lower reliability indices than positive bending regions. This study highlights that ensuring the quality control of structural parameters is as important as managing geotechnical risks, providing theoretical guidance for optimizing segment design in critical transition zones.</div></div>","PeriodicalId":48642,"journal":{"name":"Structures","volume":"85 ","pages":"Article 111151"},"PeriodicalIF":4.3,"publicationDate":"2026-01-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146024513","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-24DOI: 10.1016/j.istruc.2026.111183
Yale Li , Han Wu , Binming Yang , Xuehong Li
When evaluating the seismic performance of self-centering double-limb thin-walled high piers, monotonic loading methods are commonly employed. However, this approach tends to overestimate the structure's seismic capacity, thereby adversely affecting structural performance assessments. Therefore, this study presents a Finite Element simulation of self-centering double-limb thin-walled high piers under five distinct loading paths, which has been validated by previous experimental work. The objective was to investigate how loading paths influence structural performance metrics such as damage patterns, energy dissipation capacity, and load-bearing capability. By analyzing the relationships between damage indicators (strength degradation, stiffness degradation, residual displacement ductility index) and displacement ratios, a four-level seismic fortification quantification evaluation standard for the structure was established. Research findings indicate that considering the impact of bidirectional loading on structural damage, the limit value for displacement ratio should be reduced according to the bridge category type and design Objectives. While bidirectional loading enhances the structure's energy dissipation capacity, it significantly reduces its load-bearing capacity. Furthermore, the more uneven the loading path, the greater the impact on structural performance, with bearing capacity decreasing by up to 21 % under the S5 loading path. Under unidirectional loading conditions, both the peak strength and stiffness degradation coefficients respectively increased by 5.26 % and 54.55 %, while the residual displacement ductility index decreased by 28.98 %. Across different loading paths, the performance of rocking piers with energy-dissipating tie beams consistently outperformed that of ordinary piers with concrete tie beams.
{"title":"Study on the influence of loading path on seismic performance and damage evaluation of rocking-self-centering double-limb thin-walled high pier","authors":"Yale Li , Han Wu , Binming Yang , Xuehong Li","doi":"10.1016/j.istruc.2026.111183","DOIUrl":"10.1016/j.istruc.2026.111183","url":null,"abstract":"<div><div>When evaluating the seismic performance of self-centering double-limb thin-walled high piers, monotonic loading methods are commonly employed. However, this approach tends to overestimate the structure's seismic capacity, thereby adversely affecting structural performance assessments. Therefore, this study presents a Finite Element simulation of self-centering double-limb thin-walled high piers under five distinct loading paths, which has been validated by previous experimental work. The objective was to investigate how loading paths influence structural performance metrics such as damage patterns, energy dissipation capacity, and load-bearing capability. By analyzing the relationships between damage indicators (<em>strength degradation, stiffness degradation, residual displacement ductility index</em>) and displacement ratios, a four-level seismic fortification quantification evaluation standard for the structure was established. Research findings indicate that considering the impact of bidirectional loading on structural damage, the limit value for displacement ratio should be reduced according to the bridge category type and design Objectives. While bidirectional loading enhances the structure's energy dissipation capacity, it significantly reduces its load-bearing capacity. Furthermore, the more uneven the loading path, the greater the impact on structural performance, with bearing capacity decreasing by up to 21 % under the S5 loading path. Under unidirectional loading conditions, both the peak strength and stiffness degradation coefficients respectively increased by 5.26 % and 54.55 %, while the residual displacement ductility index decreased by 28.98 %. Across different loading paths, the performance of rocking piers with energy-dissipating tie beams consistently outperformed that of ordinary piers with concrete tie beams.</div></div>","PeriodicalId":48642,"journal":{"name":"Structures","volume":"85 ","pages":"Article 111183"},"PeriodicalIF":4.3,"publicationDate":"2026-01-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146024509","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-24DOI: 10.1016/j.istruc.2026.111166
Bing Zhang , Jinsong Li , Yuexin Jiang , Sumei Zhang , Shuhong Lin
This study presents an integrated experimental and numerical investigation into the impact behavior of ultra-high-performance concrete-normal concrete-steel (UHPC-NC-steel) composite sandwich panels (UNS panels) subjected to drop-weight loading on the UHPC face. The UNS panel consists of a UHPC layer, a normal concrete layer, and a steel plate, mechanically integrated through tooth-shaped stiffeners and U-shaped stirrups. This hybrid system is designed for infrastructure in aggressive environments (such as bridge decks) where high impact resistance, structural robustness, and long-term durability are simultaneously required. Full-scale drop-weight impact tests were conducted on 1.2 m × 1.2 m UNS panels with total thicknesses of 131 mm or 156 mm. The experimental parameters included the presence or absence of the UHPC layer, NC thickness, impact velocities, and number of repeated impacts. Key response quantities (including impact force-time histories, peak and average impact forces, impact durations, deformation patterns, and failure modes) were systematically measured and interpreted. A finite element (FE) model incorporating concrete cracking/crushing, UHPC damage, steel plasticity, and contact nonlinearities was developed and validated against the experimental results. Results show that the UHPC layer markedly reduces penetration depth, confines local crushing to a small region beneath the impact point, and significantly mitigates damage to the NC layer and steel plate. Increasing NC thickness enhances global stiffness and energy absorption, thereby reducing residual deformation, whereas panels without UHPC or with thinner NC undergo deeper indentation and more severe damage. The steel plate and stiffeners effectively suppress punching shear propagation and preserve overall panel integrity. A higher impact velocity amplifies impact contact forces and local damage, while repeated impacts accelerate stiffness degradation and increase thickness loss. The FE analysis further reveals distinct energy-dissipation pathways for different configurations and clarifies the composite action among UHPC, NC, and steel during the impact process. The UNS panel demonstrates synergistic impact-resistant behavior: UHPC governs local protection, NC provides cost-effective energy dissipation, and the stiffened steel plate ensures ductile global response.
本文对超高性能混凝土-普通混凝土-钢（UHPC- nc -钢）复合夹层板（UNS板）在UHPC面板上受落重载荷的冲击行为进行了综合实验和数值研究。UNS面板由UHPC层、普通混凝土层和钢板组成，通过齿形加强筋和u型箍筋机械集成。该混合系统专为恶劣环境下的基础设施（如桥面）而设计，这些环境同时需要高抗冲击性、结构稳健性和长期耐久性。对1.2 m × 1.2 m总厚度分别为131 mm和156 mm的UNS面板进行全尺寸落锤冲击试验。实验参数包括UHPC层的存在与否、NC厚度、冲击速度和重复冲击次数。系统地测量和解释了关键响应量（包括冲击力-时间历史、峰值和平均冲击力、冲击持续时间、变形模式和失效模式）。建立了包含混凝土开裂/破碎、UHPC损伤、钢材塑性和接触非线性的有限元模型，并根据实验结果进行了验证。结果表明：UHPC层显著降低了侵彻深度，将局部破碎限制在撞击点下方的小区域内，显著减轻了对NC层和钢板的损伤；增加数控厚度可以提高整体刚度和能量吸收，从而减少残余变形，而没有UHPC或数控厚度较薄的面板会产生更深的压痕和更严重的损伤。钢板和加强筋有效地抑制了冲孔剪切传播，保持了面板的整体完整性。较高的冲击速度会放大冲击接触力和局部损伤，而重复的冲击会加速刚度退化并增加厚度损失。有限元分析进一步揭示了不同结构下不同的耗能路径，阐明了UHPC、NC和钢材在冲击过程中的复合作用。UNS面板展示了协同抗冲击性能：UHPC控制局部保护，NC提供经济有效的能量耗散，加强钢板确保延展性的全局响应。
{"title":"Dynamic response of UHPC-NC-steel composite sandwich panels under drop-weight impact on the UHPC face: Experimental study and FE analysis","authors":"Bing Zhang , Jinsong Li , Yuexin Jiang , Sumei Zhang , Shuhong Lin","doi":"10.1016/j.istruc.2026.111166","DOIUrl":"10.1016/j.istruc.2026.111166","url":null,"abstract":"<div><div>This study presents an integrated experimental and numerical investigation into the impact behavior of ultra-high-performance concrete-normal concrete-steel (UHPC-NC-steel) composite sandwich panels (UNS panels) subjected to drop-weight loading on the UHPC face. The UNS panel consists of a UHPC layer, a normal concrete layer, and a steel plate, mechanically integrated through tooth-shaped stiffeners and U-shaped stirrups. This hybrid system is designed for infrastructure in aggressive environments (such as bridge decks) where high impact resistance, structural robustness, and long-term durability are simultaneously required. Full-scale drop-weight impact tests were conducted on 1.2 m × 1.2 m UNS panels with total thicknesses of 131 mm or 156 mm. The experimental parameters included the presence or absence of the UHPC layer, NC thickness, impact velocities, and number of repeated impacts. Key response quantities (including impact force-time histories, peak and average impact forces, impact durations, deformation patterns, and failure modes) were systematically measured and interpreted. A finite element (FE) model incorporating concrete cracking/crushing, UHPC damage, steel plasticity, and contact nonlinearities was developed and validated against the experimental results. Results show that the UHPC layer markedly reduces penetration depth, confines local crushing to a small region beneath the impact point, and significantly mitigates damage to the NC layer and steel plate. Increasing NC thickness enhances global stiffness and energy absorption, thereby reducing residual deformation, whereas panels without UHPC or with thinner NC undergo deeper indentation and more severe damage. The steel plate and stiffeners effectively suppress punching shear propagation and preserve overall panel integrity. A higher impact velocity amplifies impact contact forces and local damage, while repeated impacts accelerate stiffness degradation and increase thickness loss. The FE analysis further reveals distinct energy-dissipation pathways for different configurations and clarifies the composite action among UHPC, NC, and steel during the impact process. The UNS panel demonstrates synergistic impact-resistant behavior: UHPC governs local protection, NC provides cost-effective energy dissipation, and the stiffened steel plate ensures ductile global response.</div></div>","PeriodicalId":48642,"journal":{"name":"Structures","volume":"85 ","pages":"Article 111166"},"PeriodicalIF":4.3,"publicationDate":"2026-01-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146024510","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-24DOI: 10.1016/j.istruc.2026.111157
Mohammed K. Dhahir, Steffen Marx
This experimental study investigates the potential of chemical prestressing technology to improve the structural performance of carbon textile-reinforced concrete plates reinforced with varying ratios of carbon textile reinforcement. For this aim, 30 concrete plates of dimensions 1000 mm × 160 mm × 30 mm were cast. Fifteen of the plates were made using normal concrete to serve as the control group, while the remaining fifteen were made of expansive concrete. Each group was further subdivided into five subgroups depending on the reinforcement ratio. The distributed fibre optic sensor (DFOS) technology was used to track the development of the expansion/shrinkage strains for 90 days. Moreover, the influence of expansion on the strength of the concrete was also studied during this period at key dates. In the end, all the plates were tested till failure under a four-point bending test. The findings demonstrated that the developed expansive concrete mixture achieves stable and consistent expansion with minimal damage to the concrete strength. Moreover, a full bond was established between the textile reinforcement and the expansive concrete, enabling full transfer of the expansion strain and generating significant tensile stresses within the reinforcement, exceeding 480 MPa. Lastly, the bending tests showed that chemical prestressing improves the structural performance significantly by increasing the cracking resistance and stiffness as well as enhancing the strain distribution, and thus leading to higher ultimate failure loads. Additionally, a Eurocode-based flexural behaviour model was also developed to predict the flexural behaviour of the chemically prestressed CTRC plates. The model has shown to yield good agreement with the experimental results.
本试验研究探讨了化学预应力技术在改善不同碳纤维纤维配筋比例的碳纤维纤维增强混凝土板结构性能方面的潜力。为此，浇筑了30块尺寸为1000 mm × 160 mm × 30 mm的混凝土板。其中15个板由普通混凝土制成，作为对照组，而其余15个板由膨胀混凝土制成。每组根据强化率进一步细分为5个亚组。采用分布式光纤传感器（DFOS）技术跟踪90天内膨胀/收缩应变的变化。此外，还在关键日期研究了膨胀对混凝土强度的影响。最后，对所有板进行四点弯曲试验直至失效。结果表明：所研制的膨胀混凝土混合料在对混凝土强度破坏最小的情况下实现了稳定、一致的膨胀。此外，纺织钢筋与膨胀混凝土之间建立了完整的粘结，使膨胀应变能够充分传递，并在钢筋内部产生显著的拉应力，超过480 MPa。最后，弯曲试验表明，化学预应力通过提高结构的抗裂性和刚度，改善应变分布，从而提高结构的极限破坏荷载，显著改善了结构的性能。此外，还开发了基于欧洲规范的弯曲行为模型来预测化学预应力CTRC板的弯曲行为。该模型与实验结果吻合较好。
{"title":"Flexural behaviour of chemically prestressed high-strength concrete plates reinforced with different ratios of carbon textile reinforcement","authors":"Mohammed K. Dhahir, Steffen Marx","doi":"10.1016/j.istruc.2026.111157","DOIUrl":"10.1016/j.istruc.2026.111157","url":null,"abstract":"<div><div>This experimental study investigates the potential of chemical prestressing technology to improve the structural performance of carbon textile-reinforced concrete plates reinforced with varying ratios of carbon textile reinforcement. For this aim, 30 concrete plates of dimensions 1000 mm × 160 mm × 30 mm were cast. Fifteen of the plates were made using normal concrete to serve as the control group, while the remaining fifteen were made of expansive concrete. Each group was further subdivided into five subgroups depending on the reinforcement ratio. The distributed fibre optic sensor (DFOS) technology was used to track the development of the expansion/shrinkage strains for 90 days. Moreover, the influence of expansion on the strength of the concrete was also studied during this period at key dates. In the end, all the plates were tested till failure under a four-point bending test. The findings demonstrated that the developed expansive concrete mixture achieves stable and consistent expansion with minimal damage to the concrete strength. Moreover, a full bond was established between the textile reinforcement and the expansive concrete, enabling full transfer of the expansion strain and generating significant tensile stresses within the reinforcement, exceeding 480 MPa. Lastly, the bending tests showed that chemical prestressing improves the structural performance significantly by increasing the cracking resistance and stiffness as well as enhancing the strain distribution, and thus leading to higher ultimate failure loads. Additionally, a Eurocode-based flexural behaviour model was also developed to predict the flexural behaviour of the chemically prestressed CTRC plates. The model has shown to yield good agreement with the experimental results.</div></div>","PeriodicalId":48642,"journal":{"name":"Structures","volume":"85 ","pages":"Article 111157"},"PeriodicalIF":4.3,"publicationDate":"2026-01-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146024511","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-23DOI: 10.1016/j.istruc.2026.111185
Xiaodong Liu , Zejun Zhang , Zhao Chen , Guanxu Long , Wuzhuo Peng , Gongfeng Xin , Kunhao Fu
In order to study the influence of the parameters of the textile and engineered cementitious composites (ECC) in the technique of the basalt textile grid reinforced ECC (BTGR-ECC) on the strengthening effect of the concrete beam, laboratory test was carried on nine concrete beams strengthened by the technique of BTGR-ECC. Finite element models (FEMs) were established and verified by the test results. Finally, the results were compared among theoretical analysis, numerical simulation of FEM and test. The results showed that two main failure modes occurred in the strengthened beams, including tensile failure of grids of the basalt fiber reinforced polymer (BFRP) and debonding failure of the interface. Compared with the unstrengthened beam, the yield strength of the strengthened beam could be increased about 11.1 %, while the ultimate strength could be increased about 15∼20 %. The strengthening effect of the beam was great influenced by the thickness of ECC, especially for the cracking load, which was increased more than 66.67 % compared to the unstrengthened beam, while the influence of the size of the grid was small on the strengthening effect of the beams. With the same amount of BFRP grids, the strengthening effect was the best by the single-layer layout of the BFRP grid. The maximum difference of the ultimate load between the theoretical results and the test results was about 3.5 %, while the average error of all beams was about 0.2 %. The maximum strain differences between the simulated results by FEM and the test results were not more than 15 %, while the difference in the load-deflection curve was not more than 5 %. Therefore, it can be considered that the theoretical calculation method and FEM method can efficiently simulate the behavior of the strengthened beams.
{"title":"Experimental study and theoretical analysis of the concrete beams strengthened by the basalt textile grid reinforced ECC","authors":"Xiaodong Liu , Zejun Zhang , Zhao Chen , Guanxu Long , Wuzhuo Peng , Gongfeng Xin , Kunhao Fu","doi":"10.1016/j.istruc.2026.111185","DOIUrl":"10.1016/j.istruc.2026.111185","url":null,"abstract":"<div><div>In order to study the influence of the parameters of the textile and engineered cementitious composites (ECC) in the technique of the basalt textile grid reinforced ECC (BTGR-ECC) on the strengthening effect of the concrete beam, laboratory test was carried on nine concrete beams strengthened by the technique of BTGR-ECC. Finite element models (FEMs) were established and verified by the test results. Finally, the results were compared among theoretical analysis, numerical simulation of FEM and test. The results showed that two main failure modes occurred in the strengthened beams, including tensile failure of grids of the basalt fiber reinforced polymer (BFRP) and debonding failure of the interface. Compared with the unstrengthened beam, the yield strength of the strengthened beam could be increased about 11.1 %, while the ultimate strength could be increased about 15∼20 %. The strengthening effect of the beam was great influenced by the thickness of ECC, especially for the cracking load, which was increased more than 66.67 % compared to the unstrengthened beam, while the influence of the size of the grid was small on the strengthening effect of the beams. With the same amount of BFRP grids, the strengthening effect was the best by the single-layer layout of the BFRP grid. The maximum difference of the ultimate load between the theoretical results and the test results was about 3.5 %, while the average error of all beams was about 0.2 %. The maximum strain differences between the simulated results by FEM and the test results were not more than 15 %, while the difference in the load-deflection curve was not more than 5 %. Therefore, it can be considered that the theoretical calculation method and FEM method can efficiently simulate the behavior of the strengthened beams.</div></div>","PeriodicalId":48642,"journal":{"name":"Structures","volume":"85 ","pages":"Article 111185"},"PeriodicalIF":4.3,"publicationDate":"2026-01-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146024796","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-23DOI: 10.1016/j.istruc.2026.111153
Jianhui Yang , Li Wang , Zhi Zhou , Dongbo Yang
This study proposes a novel point loading test method and conducts point loading tests on coarse aggregate ceramsite in four types of lightweight aggregate concrete (LWAC). Specifically, a point loading indenter was used to perform static point compression tests on the maximum particle size ceramsite at the center of specimens (Φ75 mm × 50 mm), measuring deformation at various positions on the compression surface and free cylindrical surface. The load-deformation relationship between the lightweight coarse aggregate ceramsite and matrix concrete was analyzed based on semi-infinite body elasticity theory. Results show that the cross-section uniformity distribution coefficient of the ceramsite correlates linearly with the concrete’s initial elastic modulus. Within an indenter diameter range of 8–12 mm, the peak load, peak stress, and energy consumption per unit area of the loaded ceramsite exhibit consistent variation with minimal fluctuations (except for individual samples), and specimens typically fail with 2–3 through cracks. The stress and strain fields near the loaded ceramsite conform to semi-infinite body elasticity theory assumptions. A tension and compression (T-C) critical deformation zone exists on both the compression and free cylindrical surfaces, serving as the critical deformation range for synergistic load-bearing between ceramsite and matrix concrete, enabling quantitative evaluation of their cooperative performance.
提出了一种新颖的点加载试验方法，对四种轻骨料混凝土（LWAC）中的粗骨料陶粒进行点加载试验。具体而言，采用点加载压头对试件中心最大粒径陶粒（Φ75 mm × 50 mm）进行静态点压缩试验，测量压缩面和自由圆柱面不同位置的变形量。基于半无限体弹性理论，分析了轻粗集料陶粒与基体混凝土之间的荷载-变形关系。结果表明：陶粒截面均匀分布系数与混凝土初始弹性模量呈线性相关；在压头直径8-12 mm范围内，加载陶粒的峰值载荷、峰值应力和单位面积能量消耗表现出最小波动的一致变化（个别样品除外），并且样品通常通过2-3个裂纹失效。加载陶粒附近的应力场和应变场符合半无限体弹性理论假设。受压面和自由柱面均存在拉压临界变形区，是陶粒与基体混凝土协同承载的临界变形范围，可定量评价陶粒与基体混凝土的协同性能。
{"title":"Interaction relationship between compressed ceramsite and matrix concrete of lightweight aggregate concrete","authors":"Jianhui Yang , Li Wang , Zhi Zhou , Dongbo Yang","doi":"10.1016/j.istruc.2026.111153","DOIUrl":"10.1016/j.istruc.2026.111153","url":null,"abstract":"<div><div>This study proposes a novel point loading test method and conducts point loading tests on coarse aggregate ceramsite in four types of lightweight aggregate concrete (LWAC). Specifically, a point loading indenter was used to perform static point compression tests on the maximum particle size ceramsite at the center of specimens (Φ75 mm × 50 mm), measuring deformation at various positions on the compression surface and free cylindrical surface. The load-deformation relationship between the lightweight coarse aggregate ceramsite and matrix concrete was analyzed based on semi-infinite body elasticity theory. Results show that the cross-section uniformity distribution coefficient of the ceramsite correlates linearly with the concrete’s initial elastic modulus. Within an indenter diameter range of 8–12 mm, the peak load, peak stress, and energy consumption per unit area of the loaded ceramsite exhibit consistent variation with minimal fluctuations (except for individual samples), and specimens typically fail with 2–3 through cracks. The stress and strain fields near the loaded ceramsite conform to semi-infinite body elasticity theory assumptions. A tension and compression (T-C) critical deformation zone exists on both the compression and free cylindrical surfaces, serving as the critical deformation range for synergistic load-bearing between ceramsite and matrix concrete, enabling quantitative evaluation of their cooperative performance.</div></div>","PeriodicalId":48642,"journal":{"name":"Structures","volume":"85 ","pages":"Article 111153"},"PeriodicalIF":4.3,"publicationDate":"2026-01-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146024777","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
<div><div>This paper presents an integrated experimental and numerical studies on compressive behavior of circular geopolymer concrete-filled stainless steel tube (GCFSST) stub columns. Geopolymer concrete (GPC)—produced from fly ash and rice husk ash— having low embodied carbon was combined with stainless steel tubes having high corrosion resistance and ductility. An experimental program was conducted on 20 stub columns, including GCFSST, GPC-filled carbon steel tube (GCFST), and hollow tube specimens. Key variables included the GPC mix design (two compressive strength grades: 20–35 MPa), steel tube material (stainless vs. carbon), and diameter-to-thickness ratio (<span><math><mrow><mi>D</mi><mo>/</mo><mi>t</mi></mrow></math></span> = 25.82–51.13). The results showed that failure modes transitioned from brittle shear-dominated (Mode 2) to ductile bulging-dominated (Mode 3) as the <span><math><mrow><mi>D</mi><mo>/</mo><mi>t</mi></mrow></math></span> ratio decreased (i.e., the tube thickens), primarily governed by the confinement factor (<span><math><mi>ξ</mi></math></span>). The post-peak behavior, ranging from strain hardening to abrupt softening, was strongly influenced by <span><math><mi>ξ</mi></math></span>, with stable or ascending branches observed for <span><math><mi>ξ</mi></math></span> > 2.0 (and <span><math><mi>ξ</mi></math></span> > 2.2–2.4 in carbon steel tubes). Stainless steel tubes enhanced axial capacity by 1–29 % compared to carbon steel due to their pronounced strain-hardening behavior, with the maximum advantage (29 %) observed in stocky sections (low <span><math><mrow><mi>D</mi><mo>/</mo><mi>t</mi></mrow></math></span>). Validated finite element models (FEMs), developed using a Ramberg-Osgood law for stainless steel, a bilinear model for carbon steel, and a modified concrete damaged plasticity model for confined GPC, accurately replicated the experimental results (mean error within ±6 %). Subsequent parametric studies quantified the significant influence of <span><math><mrow><mi>D</mi><mo>/</mo><mi>t</mi></mrow></math></span> ratio, steel yield strength, and concrete type on structural performance, revealing that axial capacity decreases sharply as <span><math><mrow><mi>D</mi><mo>/</mo><mi>t</mi></mrow></math></span> increases from 20 to 80, and that GPC type has minimal effect in stocky sections but contributes up to 35 % higher strength in slender sections (<span><math><mrow><mi>D</mi><mo>/</mo><mi>t</mi></mrow></math></span> = 80). Finally, the current design codes were assessed. Eurocode 4 provided moderately conservative capacity predictions (mean <span><math><mrow><msub><mrow><mi>N</mi></mrow><mrow><mi>u</mi></mrow></msub><mo>/</mo><msub><mrow><mi>N</mi></mrow><mrow><mi>EC</mi><mn>4</mn></mrow></msub></mrow></math></span> = 1.06, COV = 9.6 %), while AISC 360–22 was markedly conservative (mean <span><math><mrow><msub><mrow><mi>N</mi></mrow><mrow><mi>u</mi></mrow></msub><mo>/</mo><msub><mrow><mi>N</mi></mrow><mrow><m
{"title":"Compressive behavior and design of geopolymer concrete-filled stainless steel stub columns","authors":"Attasit Choosaengsri , Akhrawat Lenwari , Jaroon Rungamornrat , Pitcha Jongvivatsakul , Tinh Quoc Bui , Krissada Suwanchai , Mostafa Fathi Sepahvand","doi":"10.1016/j.istruc.2026.111161","DOIUrl":"10.1016/j.istruc.2026.111161","url":null,"abstract":"<div><div>This paper presents an integrated experimental and numerical studies on compressive behavior of circular geopolymer concrete-filled stainless steel tube (GCFSST) stub columns. Geopolymer concrete (GPC)—produced from fly ash and rice husk ash— having low embodied carbon was combined with stainless steel tubes having high corrosion resistance and ductility. An experimental program was conducted on 20 stub columns, including GCFSST, GPC-filled carbon steel tube (GCFST), and hollow tube specimens. Key variables included the GPC mix design (two compressive strength grades: 20–35 MPa), steel tube material (stainless vs. carbon), and diameter-to-thickness ratio (<span><math><mrow><mi>D</mi><mo>/</mo><mi>t</mi></mrow></math></span> = 25.82–51.13). The results showed that failure modes transitioned from brittle shear-dominated (Mode 2) to ductile bulging-dominated (Mode 3) as the <span><math><mrow><mi>D</mi><mo>/</mo><mi>t</mi></mrow></math></span> ratio decreased (i.e., the tube thickens), primarily governed by the confinement factor (<span><math><mi>ξ</mi></math></span>). The post-peak behavior, ranging from strain hardening to abrupt softening, was strongly influenced by <span><math><mi>ξ</mi></math></span>, with stable or ascending branches observed for <span><math><mi>ξ</mi></math></span> > 2.0 (and <span><math><mi>ξ</mi></math></span> > 2.2–2.4 in carbon steel tubes). Stainless steel tubes enhanced axial capacity by 1–29 % compared to carbon steel due to their pronounced strain-hardening behavior, with the maximum advantage (29 %) observed in stocky sections (low <span><math><mrow><mi>D</mi><mo>/</mo><mi>t</mi></mrow></math></span>). Validated finite element models (FEMs), developed using a Ramberg-Osgood law for stainless steel, a bilinear model for carbon steel, and a modified concrete damaged plasticity model for confined GPC, accurately replicated the experimental results (mean error within ±6 %). Subsequent parametric studies quantified the significant influence of <span><math><mrow><mi>D</mi><mo>/</mo><mi>t</mi></mrow></math></span> ratio, steel yield strength, and concrete type on structural performance, revealing that axial capacity decreases sharply as <span><math><mrow><mi>D</mi><mo>/</mo><mi>t</mi></mrow></math></span> increases from 20 to 80, and that GPC type has minimal effect in stocky sections but contributes up to 35 % higher strength in slender sections (<span><math><mrow><mi>D</mi><mo>/</mo><mi>t</mi></mrow></math></span> = 80). Finally, the current design codes were assessed. Eurocode 4 provided moderately conservative capacity predictions (mean <span><math><mrow><msub><mrow><mi>N</mi></mrow><mrow><mi>u</mi></mrow></msub><mo>/</mo><msub><mrow><mi>N</mi></mrow><mrow><mi>EC</mi><mn>4</mn></mrow></msub></mrow></math></span> = 1.06, COV = 9.6 %), while AISC 360–22 was markedly conservative (mean <span><math><mrow><msub><mrow><mi>N</mi></mrow><mrow><mi>u</mi></mrow></msub><mo>/</mo><msub><mrow><mi>N</mi></mrow><mrow><m","PeriodicalId":48642,"journal":{"name":"Structures","volume":"85 ","pages":"Article 111161"},"PeriodicalIF":4.3,"publicationDate":"2026-01-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146025354","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-23DOI: 10.1016/j.istruc.2026.111181
Christian F. Engelke, Lukas Helm, Hamid Sadegh-Azar
This paper experimentally characterizes the displacement- and frequency-dependent behavior of two ring spring types (03800, 04200) configured as push-pull units. Two test series were performed: displacement-controlled tests at multiple peak displacements (test series I) and frequency-varying tests at 1, 2, 4, and 8 Hz over a selected segment of the hysteresis (test series II). Tangent stiffness and hysteretic damping were extracted; setup compliance was quantified and removed. The force–displacement response agrees closely with the idealized manufacturer model, with only minor discrepancies near the zero crossing. Tangent stiffness shows no systematic dependence on displacement amplitude and deviates only slightly from reference values. Hysteretic damping decreases with increasing displacement and is essentially frequency-invariant over the tested band; a slight reduction of tangent stiffness with frequency is observed. Type 04200 matches theory more closely than type 03800 – plausibly because its larger number of ring elements averages manufacturing variability – while small offsets for type 03800 align with a modestly higher preload and a slightly reduced recentering force. Both ring spring types exhibit excellent cycle-to-cycle repeatability. Within the tested ranges, ring springs provide stable, largely rate-independent hysteretic damping with reliable self-centering, supporting their use as energy-dissipation devices in construction.
{"title":"Experimental study on the displacement- and frequency-dependency of ring springs under dynamic loads","authors":"Christian F. Engelke, Lukas Helm, Hamid Sadegh-Azar","doi":"10.1016/j.istruc.2026.111181","DOIUrl":"10.1016/j.istruc.2026.111181","url":null,"abstract":"<div><div>This paper experimentally characterizes the displacement- and frequency-dependent behavior of two ring spring types (03800, 04200) configured as push-pull units. Two test series were performed: displacement-controlled tests at multiple peak displacements (test series I) and frequency-varying tests at 1, 2, 4, and 8 Hz over a selected segment of the hysteresis (test series II). Tangent stiffness and hysteretic damping were extracted; setup compliance was quantified and removed. The force–displacement response agrees closely with the idealized manufacturer model, with only minor discrepancies near the zero crossing. Tangent stiffness shows no systematic dependence on displacement amplitude and deviates only slightly from reference values. Hysteretic damping decreases with increasing displacement and is essentially frequency-invariant over the tested band; a slight reduction of tangent stiffness with frequency is observed. Type 04200 matches theory more closely than type 03800 – plausibly because its larger number of ring elements averages manufacturing variability – while small offsets for type 03800 align with a modestly higher preload and a slightly reduced recentering force. Both ring spring types exhibit excellent cycle-to-cycle repeatability. Within the tested ranges, ring springs provide stable, largely rate-independent hysteretic damping with reliable self-centering, supporting their use as energy-dissipation devices in construction.</div></div>","PeriodicalId":48642,"journal":{"name":"Structures","volume":"85 ","pages":"Article 111181"},"PeriodicalIF":4.3,"publicationDate":"2026-01-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146024512","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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