Journal of building engineering最新文献_第3页

Fresh properties and rheological behavior of 3D-Printed cementitious composites incorporating recycled PVC and nylon fibers: An experimental approach

IF 6.7 2区工程技术 Q1 CONSTRUCTION & BUILDING TECHNOLOGY

Journal of building engineering

Pub Date : 2025-02-27 DOI: 10.1016/j.jobe.2025.112218

Ahmed Nasr , Zhenhua Duan , Amardeep Singh , Qi Deng , Min Yang , Qiong Sun , Mohammed Abd El-Salam Arab

The increasing global use of plastic materials is leading to a corresponding rise in plastic wastes, posing significant environmental challenges. This research explores the effects of incorporating recycled plastic fibers (RPFs) derived from nylon and Polyvinyl Chloride (PVC) industry wastes into 3D-printed cementitious composites (3DPCC). The impact of using these two types of fibers on the fresh properties, rheological behavior, green strength, extrudability and buildability of 3DPCC is explored. The main variables in this study are fiber type, volume fraction (0.5 %, 1.0 %, and 2.0 %) and fiber length (6 mm and 12 mm). The results show that adding RPFs, particularly longer fibers, decreases the flowability and workability of 3DPCC, with PVC fibers having a more pronounced effect than nylon fibers. Utilizing RPFs in 3DPCC mixes increased plastic viscosity (PV) and yield stress (YS). At a volume fraction of 2 % and a length of 12 mm, PVC fibers increased the static yield stress by 214.5 %, the dynamic yield stress by 155.2 %, and the PV by 177.7 %. Furthermore, the results indicate that samples containing PVC fibers outperform those containing nylon fibers and samples without fiber content in terms of green compressive strength, crack pattern, and buildability. By using a fiber volume fraction of 2 % and 12-mm length, PVC fibers reduced structural failure by 36.8 %, allowing for the construction of 38 layers compared to 24 layers in the control sample.

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引用次数: 0

Design and performance of an adaptive-stiffness rocking structure for enhanced seismic resilience

IF 6.4 2区工程技术 Q1 CONSTRUCTION & BUILDING TECHNOLOGY

Journal of building engineering

Pub Date : 2025-02-26 DOI: 10.1016/j.jobe.2025.112226

Dayang Wu, Hao Meng, Lili Xing

The rocking structure is widely recognized for its excellent seismic resilience, including damage-free performance. However, it still faces challenges, such as low energy dissipation efficiency and significant higher-mode effects, which hinder its ability to simultaneously control displacement and force responses. To address these issues, this paper proposes the adaptive-stiffness rocking structure (ASRS) by integrating the adaptive stiffness mechanism with the rocking and energy dissipation mechanisms, thereby enhancing energy dissipation efficiency. This integration also effectively mitigates the influence of higher-mode effects, such as acceleration and shear forces. In this study, the ASRS's non-proportional damping distributed parameter model and the distributed transfer function method (DTFM) are used to solve the dynamic equations. The dynamic characteristics, including frequency and damping ratio, are derived, and parametric equations for the modal damping ratio are obtained via curve fitting. The inter-story drift ratio (IDR) design spectrum of the ASRS is calculated using the modal decomposition response spectrum method. Based on this, the preliminary design and performance assessment of the ASRS are conducted. The results show that the ASRS effectively reduces dynamic responses, such as IDR, acceleration, and shear force, by leveraging the combined action of the adaptive stiffness and energy dissipation mechanisms. Furthermore, the IDR design spectrum enables an efficient preliminary design of the ASRS.

摇晃结构因其卓越的抗震能力（包括无损坏性能）而得到广泛认可。然而，它仍然面临着一些挑战，例如低能量消耗效率和显著的高模效应，这阻碍了它同时控制位移和力响应的能力。为解决这些问题，本文提出了自适应刚度摇摆结构（ASRS），将自适应刚度机制与摇摆和能量耗散机制整合在一起，从而提高了能量耗散效率。这种整合还能有效减轻加速度和剪切力等高模效应的影响。本研究采用 ASRS 的非比例阻尼分布式参数模型和分布式传递函数法（DTFM）来求解动态方程。得出了包括频率和阻尼比在内的动态特性，并通过曲线拟合得到了模态阻尼比的参数方程。使用模态分解响应谱方法计算了 ASRS 的层间漂移率（IDR）设计谱。在此基础上，对 ASRS 进行了初步设计和性能评估。结果表明，ASRS 通过利用自适应刚度和能量耗散机制的联合作用，有效地降低了 IDR、加速度和剪切力等动态响应。此外，IDR 设计谱使 ASRS 的初步设计更加有效。

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引用次数: 0

A capacity-demand-spectrum-based method for rapidly estimating inelastic displacement of high-rise buildings under alongwind loads

IF 6.7 2区工程技术 Q1 CONSTRUCTION & BUILDING TECHNOLOGY

Journal of building engineering

Pub Date : 2025-02-26 DOI: 10.1016/j.jobe.2025.112201

Wei Li , Yu Jiang , Bo Chen

In performance-based wind design (PBWD), the nonlinear time-history analysis (NTHA) method can be used to calculate the structural wind-induced inelastic responses, but this method is complex, inefficient, and time-consuming, making it impractical for the wind design of high-rise buildings. Thus, developing a method that can rapidly estimate the structural inelastic wind effects is an urgent need for PBWD. To address this issue, a capacity-demand-spectrum-based method for rapidly estimating wind-induced inelastic displacement of high-rise buildings is proposed in this study. This method involves the following steps: First, establish the strength reduction factor-ductility factor-natural period (R-μ-T) relationship curve for a single-degree-of-freedom (SDOF) system under alongwind loads, establish the elastic demand spectrum using equivalent static wind loads, and convert the elastic demand spectrum into an inelastic demand spectrum based on the R-μ-T curve. Then, utilizing the pushover method and the characteristics of alongwind response in high-rise buildings, derive and establish the capacity spectrum of high-rise buildings under wind loads. Subsequently, plot the capacity spectrum and inelastic demand spectrum together to find the performance point, and finally restore the inelastic wind-induced displacement from this performance point using the first-mode shape vector or improved shape vectors. A case study is performed to validate the accuracy and efficiency of this proposed method. The study results demonstrate that, compared with the NTHA method, the proposed method significantly improves analysis efficiency while maintaining acceptable accuracy, making it practical for usage in PBWD.

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引用次数: 0

Behavior of through-core bolted connections between CFDST columns and steel or composite beams subjected to cyclic loading

IF 6.4 2区工程技术 Q1 CONSTRUCTION & BUILDING TECHNOLOGY

Journal of building engineering

Pub Date : 2025-02-26 DOI: 10.1016/j.jobe.2025.112219

Guo-an Yin, Bing-quan Song, Han-lin Zhang, Deng-yuan Zhu, Hai-bo Wang

The cyclic performance of through-core bolted connections between CFDST columns and steel or composite beams has been rarely studied. To address this gap, an experimental study was performed to investigate the effects of different parameters. An innovative multi-chamber system was developed by incorporating vertical clip-type transverse plates between the inner and outer steel tubes, which effectively enhances structural integrity, reduces interface slip, delays steel tube buckling and significantly improves construction efficiency. Four specimens of the interior joint at 1/2 scale of the actual specimen were designed and tested under cyclic loading conditions. The main design parameters were the column hollow ratio, the cross-section shape of inner steel tube, and the type of beam section. Lateral load vs displacement and strain vs displacement hysteresis responses were then obtained. The experimental results were analyzed, including failure mechanisms, ultimate strength, damage development, stiffness degradation, strength degradation, energy dissipation capacity, ductility and strain responses. The results of the experiment showed that the proposed composite beam-column joints had good cyclic performance. Characters of hysteresis curves of the specimens were show two forms: anti-S-type of composite beams and spindle-type of steel beams. Two typical failure modes were also observed from the conducted tests, which included buckling and tearing failure at steel beam flange and web for specimens with steel beams, as well as bolt slip and concrete cracks in concrete slab for specimens with composite beams. The cyclic performance of specimens with composite beams was better than that of specimens with steel beams. The outcomes of this study improve the practice design and implementation of semi-rigid CFDST frames in active seismic areas.

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引用次数: 0

Flowability responses of cement paste containing steel fiber to external magnetic field

IF 6.4 2区工程技术 Q1 CONSTRUCTION & BUILDING TECHNOLOGY

Journal of building engineering

Pub Date : 2025-02-26 DOI: 10.1016/j.jobe.2025.112220

Xintong Guo, Shengming Hu, Dengwu Jiao

This study explores the magneto-rheological behavior of cement paste using steel fibers as responsive elements. A custom-designed mini-slump device equipped with a camera was employed to capture the real-time flow of cement paste under magnetic fields, considering different water-to-cement (w/c) ratios (0.35, 0.4, and 0.45) and steel fiber concentrations (0%, 1%, 2%, and 3%). The findings demonstrate that the fluidity of cement pastes with steel fibers decreases by 0.7%–8.2% after exposure to a short-term vertical magnetic field, compared to those without magnetic field. After experiencing a horizontal magnetic field, the flow velocity decreases and the flow diameter is smaller in the direction parallel to the field compared to the perpendicular direction. This behavior is more noticeable with increased steel fiber content and w/c ratios, likely due to the flow-restricting effect of residual fiber aggregations formed under the magnetic field. To confirm the residual aggregation behavior of steel fibers in cement paste, the magnetically induced movement of steel fibers in transparent resin solutions was visualized, and their distribution in post-flow cement pastes was examined. It was revealed that steel fibers move under a magnetic field and retain their positions once the field is removed, leading to an uneven distribution. After exposure to a short vertical magnetic field, steel fibers are gathered in the central area, while they concentrate towards the sides following experienced a short-term horizontal magnetic field. These findings provide fundamental experimental support for actively controlling the rheological properties of steel fiber-reinforced cement-based materials.

本研究以钢纤维为响应元件，探讨了水泥浆的磁流变行为。考虑到不同的水灰比（w/c）（0.35、0.4 和 0.45）和钢纤维浓度（0%、1%、2% 和 3%），该研究采用了一个配备摄像头的定制微型坍落度装置，以捕捉水泥浆在磁场下的实时流动情况。研究结果表明，与无磁场的水泥浆相比，含有钢纤维的水泥浆在暴露于短期垂直磁场后，流动性降低了 0.7%-8.2%。在水平磁场中，与垂直方向相比，与磁场平行方向的流速降低，流动直径变小。随着钢纤维含量和容重/容积比的增加，这种现象更加明显，这可能是由于在磁场下形成的残余纤维聚集体的限流效应。为了证实钢纤维在水泥浆中的残留聚集行为，我们观察了钢纤维在透明树脂溶液中的磁诱导运动，并研究了它们在流动后水泥浆中的分布情况。结果表明，钢纤维在磁场下移动，磁场移除后仍保持其位置，导致分布不均。在短时间的垂直磁场中，钢纤维聚集在中心区域，而在短时间的水平磁场中，钢纤维则向两侧集中。这些发现为主动控制钢纤维增强水泥基材料的流变特性提供了基本的实验支持。

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引用次数: 0

Development of an earthquake-resilient column base equipped with a bidirectional hinge: Seismic performance and structural applications

IF 6.7 2区工程技术 Q1 CONSTRUCTION & BUILDING TECHNOLOGY

Journal of building engineering

Pub Date : 2025-02-25 DOI: 10.1016/j.jobe.2025.112191

Jian-Peng Wei , Hui-Yun Qiao , Han Tian

A novel earthquake-resilient column base equipped with a bidirectional hinge is proposed. The bottom contact surface of the column is optimized to reduce the stress concentration and horizontal displacement. Theoretical, experimental, and numerical investigations of the column base were conducted. First, a theoretical hysteretic model of the column base was deduced and verified through numerical investigations. The load–displacement relationships were accurately estimated. Five cyclic loading tests were conducted to investigate the seismic performance of the column base. It exhibited a preferable earthquake-resilient function and low-cycle fatigue performance. Subsequently, numerical investigations were conducted using the refined models. The true hysteretic curves and energy dissipation of the column base were analyzed. More than 90 % of the energy was dissipated by the dampers at a joint rotation of 5 % rad. Finally, time-history analyses of a six-story steel frame were performed using a simplified model. The mechanical performance of the damper is close to that in an ideal axial stress state. The column base possesses favorable energy dissipation in the overall structure. This study provides a reference for designing earthquake-resilient column bases.

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引用次数: 0

Rotating semi-active tuned liquid column damper for bi-directional eccentric structural seismic response control

IF 6.4 2区工程技术 Q1 CONSTRUCTION & BUILDING TECHNOLOGY

Journal of building engineering

Pub Date : 2025-02-25 DOI: 10.1016/j.jobe.2025.112205

Cong Fu, Liangkun Wang, Zhipeng Wang, Songtao Xue, Liyu Xie

To mitigate the translational-torsional coupling response of bi-directional eccentric buildings under seismic excitations and improve the earthquake mitigation of traditional tuned liquid column damper (TLCD), a rotating semi-active TLCD (RS-TLCD) with variable hydrostatic liquid level height and frequency, damping and rotating angle that can simultaneously control the bi-directional vibration of structures is proposed. RS-TLCD can identify the bi-directional instantaneous vibration frequency of structure through wavelet transform, and change the height of liquid column in real time to adjust its natural frequency accordingly. Meanwhile, it can change the size of adjustable flow hole to achieve real-time semi-active damping based on measured signals, while use a rotating chassis to achieve real-time adjustment of the position angle in the plane to the dominant vibration direction, to achieve bi-directional vibration control. In the case study, a 30-story bi-directional eccentric structure is presented to verify its seismic control effect, and cases with unidirectional passive TLCDs and S-TLCDs attached in X and Y directions are compared respectively. Numerical results show that generally, RS-TLCD can effectively control the displacement and torsional response of building under earthquake excitations to improve its safety and has the best earthquake mitigation performance in both X and Y directions. Meanwhile, RS-TLCD can reduce the mass of damper and the occupation of the building space because it can rotate the position angle to the dominant vibration direction, and enhance the control effect through variable liquid level height and damping.

为缓解地震激励下双向偏心建筑物的平移-扭转耦合响应，改善传统调谐液柱阻尼器（TLCD）的抗震减灾效果，提出了一种具有可变静压液面高度和频率、阻尼和旋转角度，可同时控制结构双向振动的旋转半主动 TLCD（RS-TLCD）。RS-TLCD 可通过小波变换识别结构的双向瞬时振动频率，并实时改变液柱高度以相应调整其固有频率。同时，它还可以根据测量信号改变可调流孔的大小，实现实时半主动阻尼，同时利用旋转底盘实现对主导振动方向平面内位置角的实时调整，实现双向振动控制。在案例研究中，提出了一个 30 层的双向偏心结构来验证其抗震控制效果，并分别比较了在 X 和 Y 方向连接单向被动式 TLCD 和 S-TLCD 的情况。数值结果表明，一般情况下，RS-TLCD 可以有效控制地震激励下建筑物的位移和扭转响应，从而提高其安全性，并且在 X 和 Y 两个方向上都具有最佳的减震性能。同时，RS-TLCD 由于可以将位置角旋转到主要振动方向，因此可以减少阻尼器的质量和对建筑空间的占用，并通过可变液面高度和阻尼增强控制效果。

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引用次数: 0

Effect of carbonation with different CO2 phases on early-age properties of coal char-cement mixture

IF 6.4 2区工程技术 Q1 CONSTRUCTION & BUILDING TECHNOLOGY

Journal of building engineering

Pub Date : 2025-02-25 DOI: 10.1016/j.jobe.2025.112215

Hua Yu, Sahul Kharel, Chooi Kim Lau, Kam Ng

Coal-derived char has exhibited great potential in terms of improving the engineering performance of various cement-based construction and building materials. Due to the characteristic porous structure of char materials, one of the important environmental benefits is the capability of effectively utilizing CO2, which has been confirmed by previous studies on b1iochar. However, for coal char with a similar structure and pyrolysis process, there is no relevant research on quantifying the effect of carbonation on the properties of cement-based mixtures. An experimental study on the effect of carbonation with gas, liquid, and supercritical (SC) CO2 on the early-age (i.e., 7 d) mineralogical, microstructural, and strength properties of coal char-cement mixtures was conducted. The X-ray diffraction results confirm the formation of calcium carbonate polymorphs, including calcite, aragonite, and vaterite, in char-cement mixtures carbonated by three CO2 phases. Carbonated samples show up to 102.6 % higher estimated calcium carbonate content, 17.3 % higher degree of hydration, and 13.3 % higher compressive strength, compared to sealed samples. Among all sealed and carbonated samples, the SC CO2-treated sample has the highest calcium carbonate content of 68.5 % and the highest roughness average of 28.2 μm, while the gas CO2-treated sample exhibits the highest compressive strength of 28.1 MPa at 7 d, as excessive carbonation in SC CO2 reduces compressive strength in char-cement mixtures. The experimental results of this study would be beneficial for promoting the novel coal char-cement based materials in terms of utilizing CO2 for various sustainable engineering applications.

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引用次数: 0

Seismic response and design of base-isolated hillside stilted structures

IF 6.4 2区工程技术 Q1 CONSTRUCTION & BUILDING TECHNOLOGY

Journal of building engineering

Pub Date : 2025-02-25 DOI: 10.1016/j.jobe.2025.112217

Li Ruifeng, Liu Liping, Lei Haiming, Li Yingmin

Established studies and seismic site investigations have revealed that hillside stilted structures suffer more serious damage compared with ordinary structures on flat ground due to their stiffness irregularities. However, studies on mitigating stiffness irregularities and enhancing seismic performance of stilted structures are limited. In this study, isolation bearings are introduced for the first time into the base of stilted columns, forming a base-isolated stilted structure, with the aim of controlling structural seismic response and mitigating stiffness irregularities. A series of shaking table tests were conducted on both a base-isolated stilted frame and a fixed-base stilted frame. Then, the stiffness of a stilted column-bearing tandem system was analyzed to determine the deformation of stilted columns under uniform stiffness distribution conditions. Finally, a direct displacement-based seismic design method for base-isolated stilted frames was proposed, and its validity was verified through time history analysis of 7-storey and 3-storey stilted building design cases. Test results demonstrated that installing seismic isolation bearings at the base of the stilted columns effectively reduced the seismic response of the stilted structure, verifying the effectiveness of the bearing arrangement. The results of the time-history analysis closely match the design values, and the errors in floor shear, displacement, and bearing deformation remain within 10 %, confirming the validity of the design method. Moreover, the difference in shear force among stilted columns of different lengths remains less than 10 %, indicating that using the proposed design method effectively achieves the objective of mitigating stiffness irregularities.

已有的研究和地震现场调查显示，山坡上的棚架结构由于其刚度不规则，与平地上的普通结构相比，遭受的破坏更为严重。然而，有关减轻刚度不规则性和提高棚架结构抗震性能的研究还很有限。在本研究中，首次在棚柱底部引入了隔震支座，形成了底部隔震的棚柱结构，目的是控制结构的地震响应和减轻刚度不规则性。对基座隔离式高跷框架和固定基座式高跷框架进行了一系列振动台试验。然后，分析了棚柱承重串联系统的刚度，以确定均匀刚度分布条件下的棚柱变形。最后，提出了基于直接位移的底座隔震高脚框架抗震设计方法，并通过对 7 层和 3 层高脚建筑设计案例的时间历史分析验证了该方法的有效性。试验结果表明，在棚柱底部安装隔震支座可有效降低棚架结构的地震响应，验证了支座布置的有效性。时程分析的结果与设计值非常吻合，楼板剪力、位移和支座变形的误差保持在 10%以内，证实了设计方法的有效性。此外，不同长度的棚柱之间的剪力差异仍然小于 10%，这表明使用建议的设计方法有效地实现了减轻刚度不规则性的目标。

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引用次数: 0

A novel low carbon cuing strategy for developing ultra-low water/binder cementitious materials (ULWC)

IF 6.4 2区工程技术 Q1 CONSTRUCTION & BUILDING TECHNOLOGY

Journal of building engineering

Pub Date : 2025-02-25 DOI: 10.1016/j.jobe.2025.112198

Yuan Feng, Jingjing Zhang, Siyu Wang, Rui Yu

In this study, a novel microwave-CO2 combined curing strategy is proposed and its effect on the hydration kinetics and microstructure development of ultra-low water/binder cementitious materials (ULWC) is evaluated. To be specific, microwave pre-curing is firstly applied to ULWC in its early stage to promote the formation of Ca(OH)2, thereby activating carbonation. Subsequently, rapid CO2 curing technology is used to further optimize the microstructure of ULWC. Based on this, a detailed evaluation of the macro and micro properties of the newly developed ULWC is conducted. Experimental results show that microwave pre-curing can effectively increase the rate and extent of subsequent carbonation reactions, benefiting ULWC by forming a dense outer layer that enhances durability. Additionally, compared with standard curing the proposed combined curing strategy synergistically promotes the hydration and carbonation reactions of ULWC, increasing the early compressive strength from 56.44 MPa to 79.06 MPa while reducing the CO2 emission by 5994g. The practice demonstrates that the proposed combined curing strategy contributes to the production of advanced construction products with high mechanical performance and a low carbon footprint.

本研究提出了一种新型微波-CO2 联合固化策略，并评估了其对超低水/粘结剂胶凝材料（ULWC）水化动力学和微观结构发展的影响。具体来说，首先在 ULWC 的早期阶段对其进行微波预固化，以促进 Ca(OH)2 的形成，从而激活碳化。随后，利用二氧化碳快速固化技术进一步优化超低硫水泥瓦的微观结构。在此基础上，对新开发的超细木丝水泥板的宏观和微观性能进行了详细评估。实验结果表明，微波预固化可有效提高后续碳化反应的速度和程度，通过形成致密的外层提高超低硫水泥瓦的耐久性。此外，与标准固化相比，所提出的组合固化策略能协同促进超低硫混凝土的水化和碳化反应，将早期抗压强度从 56.44 兆帕提高到 79.06 兆帕，同时减少二氧化碳排放量 5994 克。实践证明，所提出的组合固化策略有助于生产具有高机械性能和低碳足迹的先进建筑产品。

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引用次数: 0