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Exploring the potential of aramid nanofibers in advancing green-engineered cementitious composites

Composites Part B: Engineering 2025年 305卷

作者： Huayang Sun Yan Wan Zhichao Xu Yanlin Huo Minjie Jia Yingzi Yang School of Civil Engineering Harbin Institute of Technology Harbin 150090 China Key Lab of Structures Dynamic Behavior and Control of the Ministry of Education Harbin Institute of Technology Harbin 150090 China Key Lab of Smart Prevention and Mitigation of Civil Engineering Disasters of the Ministry of Industry and Information Technology Harbin Institute of Technology Harbin 150090 China School of Transportation Kashi University Kashi 844000 China School of Materials Science and Engineering Jiangsu Key Laboratory of Construction Materials Southeast University Nanjing 211189 China

This study developed an environmentally friendly engineered cementitious composite (ECC) reinforced with aramid nanofibers (ANFs) derived from recycled aramid fibers. ANFs were incorporated into ECC containing high-volume fly ash to improve their strength and ductility. Results showed that adding 0.05 wt % ANFs increased the compressive strength, tensile strength, and tensile strain of ECC by 46.71 %, 46.23 %, and 51.45 %, respectively. The mechanisms through which ANFs enhance the mechanical properties of ECC were investigated through single-fiber pull-out tests, micromechanical analysis, and microstructural analysis. ANFs contributed to filling the pores within the matrix, reducing the matrix porosity and inhibiting crack propagation, which consequently enhanced the compressive properties of ECC. Furthermore, ANFs significantly narrowed the interfacial transition zone (ITZ) at the fiber/matrix interface, thereby improving the frictional bond strength and pull-out energy, ultimately enhancing the tensile ductility of ECC. This study demonstrates the potential of ANFs-reinforced ECC as a sustainable and high-performance material.

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大型液化天然气储罐在冲击荷载下的动力响应数值研究（英文）

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2019年第11期20卷 823-837页

作者： Chen YAN Xi-mei ZHAI Yong-hui WANG Key Lab of Structures Dynamic Behavior and Control of the Ministry of Education Harbin Institute of TechnologyHarbin 150090China Key Lab of Smart Prevention and Mitigation of Civil Engineering Disasters of the Ministry of Industry and Information Technology Harbin Institute of TechnologyHarbin 150090China

目的:研究冲击荷载各参数对于液化天然气(LNG)储罐的动力响应结果,定义LNG储罐受到冲击荷载时的破坏模式,并分析不同破坏模式下的破坏机理,为工程防御冲击荷载提供有效的理论研究基础。创新点:1.建立精细化的LNG储罐有限元模型;2.定义LN... 详细信息

目的:研究冲击荷载各参数对于液化天然气(LNG)储罐的动力响应结果,定义LNG储罐受到冲击荷载时的破坏模式,并分析不同破坏模式下的破坏机理,为工程防御冲击荷载提供有效的理论研究基础。创新点:1.建立精细化的LNG储罐有限元模型;2.定义LNG储罐在冲击荷载下的破坏模式并揭示其破坏机理;3.提出损伤因子Df可区分三种冲击破坏模式。方法:1.通过有限元模拟,进行冲击荷载的参数分析,得到不同冲击荷载对于LNG储罐的动力响应(图6和7);2.根据数值模拟结果,定义LNG储罐受到冲击荷载时的破坏模式(图8),并分析其破坏机理(图10和11);3.通过经验公式验算LNG储罐抵御冲击荷载的可靠性。结论:1. LNG储罐薄弱部位为外罐和环梁及底板的连接部位;2. LNG储罐受到冲击荷载的破坏模式分为局部变形、混凝土剥落和穿透三种;本研究得到了各种破坏模式下的破坏机理,并定义了损伤因子Df来区分三种破坏模式;3.通过经验公式验算,LNG储罐可以抵御英国规范建议的冲击荷载和法兰的冲击;DOE-standard公式计算结果最为保守。

关键词： LNG储罐冲击动力响应数值模拟破坏机理

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Fatigue performance of kiloton CFRP cable after hygrothermal and freeze–thaw cycles

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International Journal of Fatigue 2025年 200卷

作者： Jiajun Shi Rui Guo Guijun Xian School of Civil Engineering Harbin Institute of Technology (HIT) 73 Huanghe Road Nangang District Harbin 150090 China Key Lab of Structures Dynamic Behaviour and Control (Harbin Institute of Technology) Ministry of Education Harbin Heilongjiang 150090 China Key Lab of Smart Prevention and Mitigation of Civil Engineering Disasters of the Ministry of Industry and Information Technology Harbin Institute of Technology Harbin 150090 China

The application of carbon fiber reinforced polymer (CFRP) cable with light weight and high strength can improve the service performance of bridge structures in plateau harsh service environments. But the performance evolution behavior of CFRP cable under complicated service environments of fatigue load, hygrothermal and freeze–thaw cycles is unknown. In this paper, the tensile fatigue performance of CFRP rods used for cable before and after hygrothermal and freeze–thaw cycles is investigated experimentally. The tensile fatigue and residual tensile performances of kiloton CFRP cable are verified after hygrothermal and freeze–thaw cycles. Optical frequency domain reflectometry technology is employed to monitor the stiffness degradation of CFRP cables during fatigue loading. The results indicate that the hygrothermal and freeze–thaw cycles release the residual stress within CFRP rod, which improves the fatigue resistance. By contrast, the hygrothermal and freeze–thaw cycles have no significant effect on stiffness degradation of CFRP rod. The kiloton CFRP cable can withstand 2,000 k cycles of tensile fatigue after hygrothermal and freeze–thaw cycles, and the stiffness degradation of CFRP cable is negligible. The residual tensile bearing capacity of CFRP cable after fatigue is 10,731 kN, corresponding to a residual strength retention rate of 105 %. These findings provide essential validation data for the application of kiloton CFRP cables in bridge construction.

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Experimental study on flexural behavior of precast concrete beams in-span joined with UHPC

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Journal of Building Engineering 2025年 111卷

作者： Zijun Xu Wei Zhou Guoyang Lu School of Civil Engineering Harbin Institute of Technology Harbin 150090 China Department of Architecture and Civil Engineering City University of Hong Kong Tat Chee Avenue Kowloon Tong Hong Kong Special Administrative Region of China Key Lab of Structures Dynamic Behavior and Control Ministry of Education Harbin Institute of Technology Harbin 150090 China Key Lab of Smart Prevention and Mitigation of Civil Engineering Disaster Ministry of Industry and Information Technology Harbin Institute of Technology Harbin 150090 China

Efficient connection design is critical for the performance and applicability of precast concrete structures. This study proposes a novel in-span connection strategy using Ultra High Performance Concrete (UHPC) to assemble two standardized short precast concrete beams into a single unit, referred to as a Precast Beam Unit (PBU). This configuration relocates the joint from the beam ends to the mid-span, reducing local weakening and premature failure in high-stress regions while enhancing constructability. Static loading tests were conducted on five PBUs, with one cast-in-place beam serving as a control. The reinforcement ratio and the length of the UHPC corresponding to the diameter of the steel bar were employed as the main design parameters. The flexural behavior and failure mode of specimens were analyzed based on load displacement curves, crack propagation, and strain responses. Results showed that PBU-1 exhibited a 6.3 % higher ultimate flexural capacity than the cast-in-place beam. PBU-5, with a reinforcement ratio of 1.65 % demonstrated a 140.2 % higher ultimate bearing capacity compared to PBU-1 (0.64 % reinforcement ratio). PBUs also showed reduced deflection, narrower crack widths, and enhanced stiffness. The study proposed calculation methods for cracking analysis, short-term stiffness, and the normal section flexural capacity of PBU. Moreover, a finite element model developed in ABAQUS was employed to verify the damage situation and ultimate bearing capacity of the specimens, with good agreement with the experimental results. These findings confirm the safety and applicability of PBU and demonstrate its favorable connection performance.

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Punching shear strength of reinforced ultra-high performance concrete circular slabs with openings

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structures 2025年 79卷

作者： Lanri Lin Dayong Liu Dongliang Zhang Xiangguo Wu Yun Zhang Chengen Wu Hao Wang Ya Lu College of Civil Engineering Fuzhou University Fuzhou 350108 China CGN New Energy Holdings Co. Ltd. China PowerChina Huadong Engineering Corporation Limited Hangzhou 311122 China Key Lab of Structures Dynamic Behavior and Control of the Ministry of Education Key Lab of Smart Prevention and Mitigation of Civil Engineering Disasters of the Ministry of the Industry and Information Technology Harbin Institute of Technology Harbin 150090 China Fujian Provincial Key Laboratory on Multi-Disasters Prevention and Mitigation in Civil Engineering Fuzhou University Fuzhou 350116 China

This study investigates the punching shear behavior of reinforced ultra-high performance concrete (RUHPC) circular slabs with openings, focusing on the effects of perforation diameter, steel fiber volume fraction and shear reinforcement ratio on punching shear strength. Experimental results reveal a novel failure mechanism where energy dissipation during punching is partitioned into radial and circumferential yield line contributions, reflecting the combined ductile and brittle failure characteristics of RUHPC. A mechanical model is developed by integrating the yield line method with the rigid body displacement approach, thereby bridging plastic hinge rotations at the slab bottom and brittle fracture at the punching surface. Utilizing this model, the study further investigates the influence of the punching-to-span ratio, slab thickness, localized loading area and reinforcement ratio on the punching shear strength. The findings provide valuable insights into the design and performance optimization of RUHPC circular slabs under punching shear conditions.

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Toughened and self-healing carbon nanotube/epoxy resin composites modified with polycaprolactone filler for coatings, adhesives and FRP

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Journal of Building Engineering 2025年 111卷

作者： Guijun Xian Xiao Qi Jiajun Shi Jingwei Tian HuiGang Xiao Key Lab of Structures Dynamic Behavior and Control (Harbin Institute of Technology) Ministry of Education Heilongjiang Harbin 150090 China Key Lab of Smart Prevention and Mitigation of Civil Engineering Disasters of the Ministry of Industry and Information Technology Harbin Institute of Technology Harbin 150090 China School of Civil Engineering Harbin Institute of Technology Heilongjiang Harbin 150090 China Yangtze River Delta Carbon Fiber and Composite Material Innovation Center Jiangsu Changzhou 213126 China State Key Laboratory of Molecular Engineering of Polymers Fudan University Shanghai 200433 China

Aiming at the durability problem caused by micro-crack damage in polymer under complex load and hygrothermal conditions, an epoxy resin matrix composite with self-repair function was developed. The multi-damage self-healing function of epoxy resin can be realized by carbon nanotubes (CNTs) reinforcement and polycaprolactone (PCL) toughening. Based on 0.5 wt% CNTs addition, epoxy resin systems with different PCL fillers (1/5/10/15 wt%) were successfully prepared. Through the comparison of thermal and mechanical properties, the optimum formula was obtained as the epoxy resin with CNTs and 5 wt% PCL composite (EPCP5). Furthermore, the tensile strength and elongation at break of EPCP5 increased by 25.4 % and 42.3 %, respectively, compared to the control sample. This improvement was attributed to the formation of hydrogen bonds between PCL and the epoxy resin, enhancing intermolecular forces. The difference in glass transition temperature for samples with varying PCL content was minimal (less than 3.8 %), indicating excellent thermal compatibility between the PCL/CNTs fillers and the resin matrix. Before damage, the tensile and flexural strengths of EPCP5 were 47.28 MPa and 116.35 MPa, respectively. Compared with one cycle for 40 % prefabricated damage, the tensile and flexural strengths of EPCP5 increased by 15.8 % and 25.1 %, 17.4 % and 25.3 % after second and three repair cycles, demonstrating the significant self-healing effect. Under 40 % and 60 % prefabrication loads, the self-healing efficiency of EPCP5 for tensile and flexural strengths reached up to 116.1 % after the third repair cycle. This was because the PCL melt filled and bridged the damaged area, effectively healing and reinforcing the micro-cracks. Noticed, after damage repairing, the micro-morphology showed that the 2–4 μm through cracks in the resin matrix were well healed. Furthermore, the infrared spectrum of EPCP5 showed a combination of the individual spectra of CNTs, PCL, and the resin, which indic

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Study on Water Absorptivity and Frost Resistance Performance of Self-ignition Coal Gangue Autoclaved Aerated Concrete

Research Square

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Research Square 2021年

作者： Cong, Xinyu Tan, Yiqiu Lu, Shuang Wang, Zhaojia Huang, Tianyong School of Transportation Science and Engineering Harbin Institute of Technology Heilongjiang Harbin150090 China School of Civil Engineering Harbin Institute of Technology Harbin150090 China Key Lab of Structures Dynamic Behavior and Control of the Ministry of Education 9 Harbin Institute of Technology Harbin150090 China State Key Laboratory of Solid Waste Reuse for Building Materials Materials Academy of Science Research Beijing Building 11 Beijing100041 China

Self-ignition coal gangue (SCG) used as one of precursors to fabricate aerated autoclaved concrete (AAC). Aiming at studying water absorptivity and frost resistance performance of self-ignition coal gangue aerated autoclaved concrete (SCGAAC), three-period water absorbing tests and freezing-thawing tests were carried out and the corresponding results were recorded and analyzed. In order to modify the water absorptivity of SCGAAC, foam stabilizer was applied to adjust pore structure while calcium stearate was expected to change hydrophilic feature of CG. It was demonstrated that the compressive strength of SCGAAC containing foam stabilizer or calcium stearate declined at different levels, although the porosity became lower slightly. For water absorptivity, foam stabilizer failed to decrease the water content at any period and even increased water absorbing rates. Calcium stearate controlled water absorbing rate successfully but the ultimate water content hardly reduced. All of the SCGAAC samples exhibited intact appearance after 50 freezing-thawing cycles and showed excellent frost resistance performance. Three models were proposed to predict water absorptivity and frost resistance performance of SCGAAC and the corresponding prediction results matched test resulted ***: Self-ignition coal gangue;AAC;porosity;water absorptivity;frost resistance performance © 2021, CC BY.

关键词： Porosity

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Numerical simulation method and dent-model of circular steel tubes under low-speed impact

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Journal of Constructional Steel Research 2025年 234卷

作者： Zhang, Rong Li, Hao-wen Zhi, Xu-dong Li, Fang-hui Zhao, Ming-shuo Li, Hang Key Lab of Structures Dynamic Behaviour and Control of the Ministry of Education Harbin Institute of Technology Harbin150090 China Key Lab of Smart Prevention and Mitigation of Civil Engineering Disasters of the Ministry of Industry and Information Technology Harbin Institute of Technology Harbin150090 China College of Civil Engineering Heilongjiang University Harbin150086 China The College of Architecture and Civil Engineering Beijing University of Technology Beijing100124 China

This paper presents a study on the numerical simulation methods and dent-model of circular steel tubes under transverse low-velocity impact. The study uses drop-hammer impact tests, numerical simulations, and theoretical analysis to develop a precise simulation method. It looks at how factors like mesh size, material properties, and simplifications in the impactor model affect key mechanical behaviors, such as failure modes, impact force, and displacement. A scientific simulation method of circular steel tube under low velocity transverse impact was proposed. The numerical simulation demonstrates close agreement with experimental observations in characterizing the dynamic response and failure mechanisms of circular steel-tube specimens. Critical parameters including peak impact force and displacement exhibit deviations below 10 %, verified the accuracy of the numerical model. On this foundation, a study was conducted on the cross-sectional dent-model of a circular steel tube at the impact position. In the study, the influence of hammer shape, impact velocity, circular steel pipe span, wall thickness, and diameter on it was explored. A theoretical dent-model of the cross-section at the impact position of the circular steel tube was established. Accurate estimation of the top and bottom concave displacement of the circular steel pipe at the impact position has been achieved, providing theoretical reference for structural safety assessment and accident prevention in practical engineering. © 2025

关键词： Tubular steel structures

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Shaking table test on 1000kV frame by considering coupling effect of transmission lines under longitudinal excitations

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Tumu Gongcheng Xuebao/China Civil Engineering Journal 2020年第3期53卷 51-59页

作者： Gong, Jun Zhi, Xudong Shang, Wennian Fan, Feng Wang, Haoyang Key Lab of Structure Dynamic Behavior and Control of the Ministry of Education Harbin Institute of Technology Harbin150090 China Key Lab of Smart Prevention and Mitigation of Civil Engineering Disasters of the Ministry of Industry and Information Technology Harbin Institute of Technology Harbin150090 China Shandong Electric Power Engineering Consulting Institute Co. Ltd. Jinan250013 China

To figure out the influence mechanism of the dynamic coupling effect of transmission lines on seismic responses of the 1000 kV outgoing line frame under longitudinal excitations and discuss the influence of sag-span ratios of transmission lines, shaking table tests were performed on a single-span 1000 kV outgoing line frame by considering the dynamic coupling effect of transmission lines with a scale factor of 1:***, transmission lines were simulated by the massless springs with equivalent dynamic stiffness. Test results indicate that the seismic responses of 1000 kV frame are reduced by the strong dynamic coupling effect of transmission lines;with the decrease in sag-span ratio, the energy dissipated by the suspended system increases and the elastic constraints of transmission lines on the frame enhance, resulting in further reducing the seismic responses of 1000 kV frame. Furthermore, the results of numerical reconstruction analysis of the experiments indicate that the finite element analysis can simulate the dynamic coupling effect between transmission lines and 1000 kV frame very well. © 2020, Editorial Office of China Civil Engineering Journal. All right reserved.

关键词： Electric lines

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Effects of pure carbonation on pore structure and water permeability of white cement mortars

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CEMENT 2022年 9卷

作者： Fangzhou Ren Xingyao Chen Qiang Zeng Chunsheng Zhou Key Lab of Structures Dynamic Behavior and Control of the Ministry of Education Harbin Institute of Technology Harbin 150090 China School of Civil Engineering Harbin Institute of Technology Harbin 150090 China College of Civil Engineering and Architecture Zhejiang University Hangzhou 310058 China

The effects of carbonation on cement-based materials have drawn much attention because of its profound influences on durability performance of concrete structures. Most accelerated carbonation in lab is conducted at RH 50%–70%, which also dries out cement-based materials. The introduced drying action changes pore structure significantly, making the effects of carbonation obscure. To clarify the effects of pure carbonation, water permeability and related micro-structural characteristics are measured on mature mortars, which have been carbonated at water-saturated state. It is found that after carbonation, the porosity of mortars decreases slightly, with finer overall pore structure and lower characteristic pore size. The water permeability also decreases by roughly 40% on average. Based on the pore size distribution curves obtained through the low-field proton nuclear magnetic resonance technique, water permeability is predicted by the Katz-Thompson and Kozeny-Carman theories with satisfactory accuracy. The decrease of water permeability after carbonation agrees well with the reduced characteristic pore length, which quantitatively verifies the observed refinement of nanoscale pore structure due to pure carbonation.

关键词： Carbonation White cement mortar Pore structure Water permeability Low-field nuclear magnetic resonance (LF-NMR)

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