Article
Construction & Building Technology
Tao Ding, Jianzhuang Xiao, Shuai Zou, Jiangtao Yu
Summary: The study found that the addition of PE fibers can compensate for the negative impact of recycled sand on the flexural properties of 3D printed concrete specimens, significantly improving the flexural strength. Scanning electron microscopy results showed that the attachment of recycled sand can increase the porosity of the specimens.
CONSTRUCTION AND BUILDING MATERIALS
(2021)
Article
Construction & Building Technology
Jacek Katzer, Aneta Skoratko
Summary: The concept of steel fibre reinforced concrete-plastic columns is proven and discussed in this paper. The 3D printed plastic stay-in-place formwork acts as a substitute for traditional formwork. The experiment demonstrates that columns with fractal-based cross-sections exhibit smooth destruction processes and significant formwork deformations, while columns with traditional circular and square cross-sections experience sudden destruction. These results prove the feasibility of using 3D printed plastic and steel fibre reinforced concrete as an alternative to traditional formwork and ordinary concrete.
CONSTRUCTION AND BUILDING MATERIALS
(2022)
Article
Construction & Building Technology
Yingli Jin, Xinquan Wang, Wen Huang, Xiao Li, Quan Ma
Summary: This study investigated the mechanical properties, durability, and microscopic characteristics of hybrid natural fibre-reinforced roadbed foamed concrete (HNFRRFC). The optimal fibre content and mix ratio were found to be 0.3% and 1:2, respectively, which enhanced the maximum strength of the concrete. All mix ratios demonstrated improved strength and durability, and a microscopic property analysis revealed the underlying mechanisms behind the augmented mechanical properties and durability of the HNFRRFC specimens. Incorporating hybrid natural fibres offers an effective means of increasing the strength, durability, and microscopic attributes of foamed concrete used in roadbed applications.
CONSTRUCTION AND BUILDING MATERIALS
(2023)
Article
Engineering, Manufacturing
Xiaoyan Sun, Jiawei Zhou, Jiangpeng Shi, Qun Wang, Hailong Wang
Summary: In this study, polyvinyl alcohol fibers were incorporated into the cementitious printing ink to alter the brittle failure mode of common printed concrete. The effects of printing and loading paths on mechanical properties and durability were investigated. The results showed that the printing and loading paths had an impact on the mechanical properties and durability of the samples.
ADDITIVE MANUFACTURING
(2022)
Article
Mechanics
Yekai Yang, Chengqing Wu, Zhongxian Liu
Summary: With the development of additive manufacturing, attention has been paid to 3D printing concrete construction technology. This study focused on the dynamic splitting tensile behavior of 3D printed ultra-high performance fibre reinforced concrete (3DP-UHPFRC). The anisotropic characteristics of 3DP-UHPFRC were evaluated and a preliminary dynamic tensile orthotropic constitutive model was proposed.
COMPOSITE STRUCTURES
(2023)
Article
Polymer Science
Ilaria Papa, Alessia Teresa Silvestri, Maria Rosaria Ricciardi, Valentina Lopresto, Antonino Squillace
Summary: This study focused on manufacturing composite material laminates using the Markforged continuous filament fabrication technique with carbon nanofiber matrix infilled Onyx. Various samples were tested to evaluate the influence of fibers on mechanical properties of composites and the effect of process parameters on 3D-printed sample quality and mechanical behavior through tests such as SEM analysis, tensile and compression tests, and thermogravimetric analysis.
Article
Construction & Building Technology
Sooraj A. O. Nair, Avinaya Tripathi, Narayanan Neithalath
Summary: This study investigates the influence of layer height on the constitutive response and failure of 3D printed concrete specimens. The results show that the uniaxial compressive strength decreases with increasing layer height, and the unstable crack propagation stress also decreases. Furthermore, digital image correlation reveals the dominant effect of inter-filament interfaces on the crack propagation response and resultant failure.
CONSTRUCTION AND BUILDING MATERIALS
(2024)
Article
Engineering, Manufacturing
Marchant van den Heever, Frederick Bester, Jacques Kruger, Gideon van Zijl
Summary: Extrusion-based 3D concrete printing (3DCP) has made significant advancements in process, control, material, and fresh-state analysis technologies, leading to a new era of reinforced concrete structures. However, there are still limitations in the numerical analysis of complex geometric forms produced by 3DCP technology. This research proposes two finite element (FE) modelling strategies to predict the structural capacity and failure mechanisms of reinforced concrete deep beams produced by 3DCP. Experimental validation shows good agreement between the proposed models and the evaluated configurations.
ADDITIVE MANUFACTURING
(2022)
Article
Materials Science, Composites
Jose Humberto S. Almeida Jr, Bruno G. Christoff, Volnei Tita, Luc St-Pierre
Summary: This work proposes a novel framework that optimizes both topology and fibre angle to minimize the compliance of a structure. The framework considers two different materials, isotropic nylon and orthotropic onyx. It optimizes topology and fibre orientation for onyx, and only topology for nylon. The objective is to minimize compliance for three volume fractions of material. Benchmark cases of bending loading are considered and 3D-printed parts show higher stiffness and improved strength.
COMPOSITES SCIENCE AND TECHNOLOGY
(2023)
Article
Construction & Building Technology
Qing Wang, Xiaodan Ren, Jie Li
Summary: A damage-rheology model is developed to predict the structural instability of 3D printed concrete caused by insufficient buildability during printing. The model accurately captures the early-age behavior of 3D printed concrete, including structural build-up, softening damage, irreversible deformation, and creep effect.
AUTOMATION IN CONSTRUCTION
(2023)
Article
Polymer Science
Tomas Kuncius, Marius Rimasauskas, Ruta Rimasauskiene
Summary: This study utilized modified FDM technology for the production of continuous carbon fiber-reinforced composites, aiming to evaluate the shear strength of 3D-printed composite structures. Results demonstrated that reducing layer height significantly enhances shear strength, while the impact of printing line width on shear strength is relatively minor. Additionally, there is a linear correlation between shear area and overlap length with shear force.
Review
Engineering, Manufacturing
Frederick Bester, Marchant van den Heever, Jacques Kruger, Gideon van Zijl
Summary: This study focuses on the criticality of reinforcement integration in concrete printing, proposing a systematic approach to evaluate twelve unique reinforcement strategies and determining their applicability in reinforcing columns, walls, and benches through a group interview of structural engineers. The results show that using fiber entrainment technology during printing is highly suitable and well-aligned with measurable advantages.
ADDITIVE MANUFACTURING
(2021)
Article
Materials Science, Ceramics
Junbo Sun, Farhad Aslani, Jenny Lu, Lining Wang, Yimiao Huang, Guowei Ma
Summary: A new fiber-reinforced high-performance lightweight engineered cementitious composite (LWECC) was proposed and thoroughly investigated for its fresh properties, compressive strength, and flexural strength, then calibrated through a printability assessment. The addition of hollow glass microspheres (HGMs) significantly improved the lightweight property of the material but inevitably negated mechanical properties. Superior toughness was observed when the printed filament was perpendicular to the loading direction, resulting in a 63% increase in compressive strength and a 40% increase in flexural strength.
CERAMICS INTERNATIONAL
(2021)
Article
Mechanics
Khalid Saeed, Alistair McIlhagger, Eileen Harkin-Jones, Cormac McGarrigle, Dorian Dixon, Muhammad Ali Shar, Alison McMillan, Edward Archer
Summary: This study investigates the mechanical properties of continuous carbon fiber reinforced polyamide polymer composite samples. The strength and stiffness of the samples increase with the increase in fiber volume content. The synergy between short and continuous carbon fiber also improves the tensile properties. The microstructure analysis shows a strong correlation between the mechanical properties and the microstructure. Acid digestion method and micro-computed tomography are used to quantify the effects of voids and confirm the impact of hot pressing on the samples.
COMPOSITE STRUCTURES
(2022)
Article
Engineering, Civil
Zhanghao Hou, Peng Liu, Xiaoyong Tian, Weijun Zhu, Chuanyang Wang, Jin He, Hongbo Lan, Dichen Li
Summary: The 3D-printed coaxial continuous hybrid fibre-reinforced composites (CHFRCs) have a positive hybrid effect on impact strength and enhanced comprehensive performances. Compared with continuous carbon-fibre-reinforced composites and continuous Kevlar-fibre-reinforced composites, 3D-printed coaxial CHFRCs have significantly higher impact and flexural strengths. Therefore, they have great potential for use in thin-walled structures, especially in aerospace.
THIN-WALLED STRUCTURES
(2023)
Article
Engineering, Manufacturing
Marchant van den Heever, Frederick Bester, Jacques Kruger, Gideon van Zijl
Summary: Extrusion-based 3D concrete printing (3DCP) has made significant advancements in process, control, material, and fresh-state analysis technologies, leading to a new era of reinforced concrete structures. However, there are still limitations in the numerical analysis of complex geometric forms produced by 3DCP technology. This research proposes two finite element (FE) modelling strategies to predict the structural capacity and failure mechanisms of reinforced concrete deep beams produced by 3DCP. Experimental validation shows good agreement between the proposed models and the evaluated configurations.
ADDITIVE MANUFACTURING
(2022)
Article
Construction & Building Technology
Marchant van den Heever, Anton du Plessis, Jacques Kruger, Gideon van Zijl
Summary: Elements fabricated by extrusion-based 3D concrete printing (3DCP) exhibit anisotropic mechanical properties, and the porosity has been found to affect the elasticity and compressive strength. This research quantitatively investigates the porosity metrics of a fibre-reinforced printable concrete (FRPC) mixture and finds that 3DCP samples have higher porosity and altered void attributes. Experimental findings show that the increase in porosity is associated with a decrease in elastic modulus and compressive capacity. The porosity is influenced by factors such as loading direction, stress concentrations, and deformability of the composite configuration.
CEMENT AND CONCRETE RESEARCH
(2022)
Article
Construction & Building Technology
Marchant van den Heever, Anton du Plessis, Frederick Bester, Jacques Kruger, Gideon van Zijl
Summary: This paper investigates the constant compression-shear performance of a fibre-reinforced printable concrete mixture and proposes a novel failure criterion. X-ray computed tomography is used to explore the microstructural morphology of 3DPC and cast specimens. The study shows that microstructural features play a crucial role in the mechanical characteristics.
CONSTRUCTION AND BUILDING MATERIALS
(2022)
Article
Construction & Building Technology
Seung Cho, Algurnon van Rooyen, Elsabe Kearsley, Gideon van Zijl
Summary: This study investigates the susceptibility of precursor foam in 3D printable foamed concrete, particularly in aspects of rheology. The research found that foam stability is not significantly affected in the static environment, however, the pumping process can cause densification for higher density concrete.
JOURNAL OF BUILDING ENGINEERING
(2022)
Article
Construction & Building Technology
Viktor Mechtcherine, Kim van Tittelboom, Ali Kazemian, Eric Kreiger, Behzad Nematollahi, Venkatesh Naidu Nerella, Manu Santhanam, Geert de Schutter, Gideon Van Zijl, Dirk Lowke, Egor Ivaniuk, Markus Taubert, Freek Bos
Summary: This article focuses on characterizing the properties of additively manufactured, cement-based materials in their hardening and hardened states. It is important for material development, structural design, and quality control of 3D-printed elements. The challenges lie in the anisotropy and inhomogeneity caused by the layered structure of the printed material. Destructive testing and non-destructive testing are discussed, along with the need for guidelines and standards.
CEMENT AND CONCRETE RESEARCH
(2022)
Article
Green & Sustainable Science & Technology
Heidi Christen, Gideon van Zijl, Wibke de Villiers
Summary: As climate change becomes more evident, it is crucial to adopt sustainable practices in all industries to reduce greenhouse gas emissions and preserve resources. In the building sector and construction industry, this includes incorporating passive design solutions and using recycled materials. This research focuses on using phase change materials (PCMs) for thermal energy storage and impregnating recycled brick aggregate in 3D printed concrete (3DPC), which effectively delays heat transfer and improves thermal comfort.
JOURNAL OF CLEANER PRODUCTION
(2023)
Article
Multidisciplinary Sciences
Heidi Christen, Seung Cho, Gideon van Zijl, Wibke de Villiers
Summary: This paper investigates the effects of adding a paraffin phase change material to 3D printed concrete on its strength and printability. The addition of phase change materials can enhance the latent and sensible heat storage capacity of concrete, which can be used in buildings to reduce unwanted heat transfer.
Article
Chemistry, Multidisciplinary
Jacques Kruger, Jean-Pierre van der Westhuizen
Summary: The Poisson's ratio of 3D printed concrete is larger compared to conventionally cast concrete, due to the presence of oblate voids in the printed specimens, resulting in orthotropic behavior.
APPLIED SCIENCES-BASEL
(2023)
Article
Engineering, Manufacturing
Frederick Bester, Jacques Kruger, Gideon van Zijl
Summary: This study presents a new reinforcement strategy for printed concrete, using modified blind rivets and stainless-steel wire ropes. The proposed strategy improves the flexural performance of the concrete by providing hardening behavior. Experimental evaluations demonstrate the effectiveness of the proposed reinforcement, with significant improvements in elastic moment capacity observed.
ADDITIVE MANUFACTURING
(2023)
Article
Construction & Building Technology
Kamoru A. Ibrahim, Gideon P. A. G. van Zijl, Adewumi J. Babafemi
Summary: This study investigates the use of limestone calcined clay cement (LC3) in 3D printed concrete (3DPC) and explores its fresh, rheological, and hardened mechanical properties. The findings suggest that LC2 can be used as a partial replacement for ordinary Portland cement (OPC), improving the buildability and mechanical performance of 3D printed concrete.
JOURNAL OF BUILDING ENGINEERING
(2023)
Review
Construction & Building Technology
Bjorn Ter Haar, Jacques Kruger, Gideon van Zijl
Summary: In order to determine targeted actions for stakeholders in the construction industry, this paper conducts a systematic literature review and bibliometric analysis to identify driver-barriers of off-site construction (OSC) and 3D concrete printing (3DCP). The findings suggest that the success of off-site 3DCP building systems requires actions from multiple stakeholders at different levels.
AUTOMATION IN CONSTRUCTION
(2023)
Article
Construction & Building Technology
Kamoru A. Ibrahim, Gideon P. A. G. van Zijl, Adewumi J. Babafemi
Summary: Supplementary cementitious materials (SCMs) are popular and promising materials as partial replacements for cement in construction engineering. This study compares the rheology and hardened mechanical properties of fibre-reinforced printed concrete (FRPC) containing limestone calcined clay cement (LC3-FRPC) and fly ash (FA-FRPC). The results show that LC3-FRPC has better workability, open time, and buildability, but slightly lower mechanical properties compared to FA-FRPC. Overall, this study provides important insights for further research and application of SCMs in construction engineering.
JOURNAL OF BUILDING ENGINEERING
(2023)
Article
Construction & Building Technology
Jean De'M Malan, Algurnon Steve van Rooyen, Gideon P. A. G. van Zijl
Summary: The interlayer bond strength and durability properties of 3D printed concrete are found to be inferior to those of cast concrete, with a greater impact from the pass time. Cast samples have randomly distributed compact voids, while printed samples have interconnected pores in the interlayer regions. The results emphasize the importance of improving the interlayer bond in 3DCP.
Article
Engineering, Multidisciplinary
Keyu Zhu, Xitao Zheng, Jing Peng, Jiaming Sun, Ruilin Huang, Leilei Yan
Summary: This paper discusses the influence of multiple impacts on the compression strength of honeycomb sandwich structures with composite face sheets. It is found that the size of the impactor affects the turning point of the compression strength. Additionally, high impact energy leads to damage in the bottom face sheet and reduces the overall compression strength.
COMPOSITES PART B-ENGINEERING
(2024)
Article
Engineering, Multidisciplinary
Danqian Wang, Yanfei Yue, Jueshi Qian
Summary: Magnesium Potassium Phosphate Cement (MKPC) as a binder for steel rebars shows improved corrosion resistance when subjected to carbonation, due to the increase in pH and the formation of a more protective oxide film.
COMPOSITES PART B-ENGINEERING
(2024)
Article
Engineering, Multidisciplinary
Zhibin Li, Wenyu Wang, Pengcheng Xue, Xingyu Wei, Jian Xiong
Summary: This work proposes a design approach and manufacturing method for carbon fiber reinforced plastic (CFRP) corrugated sandwich truncated cones (CSTC) to improve their anti-debonding ability and ensure reliability. The study establishes theoretical models for CSTCs' stiffness and failure modes, which are verified through experiments and finite element analysis (FEA). The research reveals the effect of geometric parameters on failure modes and performs an optimal design for CSTC structures. The findings have significant implications for the design and application of lightweight CSTCs in constructions, such as launch vehicle adapters.
COMPOSITES PART B-ENGINEERING
(2024)
Article
Engineering, Multidisciplinary
Mingyu Zhang, Lei Chu, Jiahua Chen, Fuxun Qi, Xiaoyan Li, Xinliang Chen, Deng-Guang Yu
Summary: This review summarizes the different structures and construction methods of fibrous membranes with asymmetric wettability. It also reviews the biological applications of these membranes and suggests future challenges.
COMPOSITES PART B-ENGINEERING
(2024)
Article
Engineering, Multidisciplinary
E. Mofakhami, L. Gervat, B. Fayolle, G. Miquelard-Garnier, C. Ovalle, L. Laiarinandrasana
Summary: This study investigates the effects of fibre concentration on the mechanical response of welded glass-fibre-reinforced polypropylene (GF-PP). Experimental observations reveal a significant reduction in weld ratio, up to 60%, indicating a decreased strength compared to the bulk material. Increasing fibre content in the welded material results in a decrease in stress at break and strain at the maximum stress. The use of DIC technique and X-ray microtomography further confirms the localized strain amplification in the welded zone due to the significant increase in fibre density.
COMPOSITES PART B-ENGINEERING
(2024)
Article
Engineering, Multidisciplinary
Emad Pourahmadi, Farjad Shadmehri, Rajamohan Ganesan
Summary: This research compares the mechanical properties of laminates manufactured using automated fiber placement and conventional autoclave curing methods. The results show that laminates manufactured using automated fiber placement have a lower interlaminar shear strength compared to laminates reconsolidated using autoclave curing. A finite element simulation method is proposed to quantitatively analyze these differences.
COMPOSITES PART B-ENGINEERING
(2024)
Article
Engineering, Multidisciplinary
Johnny Jakobsen, Benny Endelt, Fahimeh Shakibapour
Summary: This study proposes a new bolted/pinned joining method for composite applications, which improves load transfer by introducing a patch-type reinforcement. Experimental results demonstrate significant improvements in both static and fatigue load conditions compared to existing methods. Finite element simulations highlight the advantage of this method, as it creates a more efficient load-transferring mechanism through different stress distributions.
COMPOSITES PART B-ENGINEERING
(2024)
Article
Engineering, Multidisciplinary
Gisele G. Cintra, Janine D. Vieira, Daniel C. T. Cardoso, Thomas Keller
Summary: This paper proposes a novel approach to assess multi-crack behavior in layered fiber-polymer composites. The generated Compliance and R-curves provide useful insights into understanding the multiple delamination process and allow for separate evaluation of strain energy release rate (SERR) for each crack. The developed cohesive zone model successfully simulates the failure process zone of three parallel cracks, showing good agreement between the numerical model and experimental results.
COMPOSITES PART B-ENGINEERING
(2024)
Article
Engineering, Multidisciplinary
Renil Thomas Kidangan, Sreedhar Unnikrishnakurup, C. Krishnamurthy, Krishnan Balasubramaniam
Summary: The induction heating process can accurately identify fiber orientation and stacking order, making it a valuable tool for large-area inspection and quality control in manufacturing fiber-reinforced composites.
COMPOSITES PART B-ENGINEERING
(2024)
Article
Engineering, Multidisciplinary
Sungjun Hwang, Yousoo Han, Douglas J. Gardner
Summary: Bleached Kraft pulp, unbleached Kraft pulp, and old corrugated cardboard pulp are suitable for producing cellulose nanofibril suspensions. Spray drying is a fast, simple, cost-effective, and scalable drying method. Spray-dried cellulose nanofibrils can be used as reinforcing materials in polypropylene matrices. The particle size of cellulose nanofibrils affects the material properties.
COMPOSITES PART B-ENGINEERING
(2024)
Article
Engineering, Multidisciplinary
Mehdi Mahdavi, Abbas Zolfaghari
Summary: This study aims to improve the recovery forces of shape memory polymers (SMPs) through material extrusion additive manufacturing. By using glass fiber (GF) as reinforcement and manufacturing multi-layer composite specimens, it was found that PLA with 6.62% GF exhibited the best recovery force, which was further optimized through annealing heat treatment.
COMPOSITES PART B-ENGINEERING
(2024)
Review
Engineering, Multidisciplinary
Xiang Ao, Antonio Vazquez-Lopez, Davide Mocerino, Carlos Gonzalez, De-Yi Wang
Summary: The vulnerability of natural fibers to heat and fire poses a significant challenge for their substitution of traditional fiber reinforcements in composite materials. Natural fiber/polymer composites (NFCs) are regarded as potential candidates for engineering applications due to their environmental friendliness and low-impact sourcing. Thus, appropriate approaches need to be implemented to enhance the fire safety of NFCs. This review summarizes and discusses the latest understanding of flammability and thermal properties of natural fibers, with a special focus on their interaction with polymer matrix in fire behavior. Additionally, the latest developments in flame-retardant approaches for NFCs are reviewed, covering both flame retardancy and fire structural integrity. Finally, future prospects and perspectives on fire safety of NFCs are proposed, providing insights into further advancements of NFCs.
COMPOSITES PART B-ENGINEERING
(2024)
Article
Engineering, Multidisciplinary
Cheng Wang, Siqi Huo, Guofeng Ye, Bingtao Wang, Zhenghong Guo, Qi Zhang, Pingan Song, Hao Wang, Zhitian Liu
Summary: The demand for multifunctional, transparent epoxy resin with superior dielectric, mechanical, and fire-safety performances is increasing in modern industries. Researchers have developed an epoxidized, phosphaphenanthrene-containing poly(styrene butadiene styrene) (ESD) for advanced fire-safe epoxy resin, which maintains high transparency and improves UV-blocking property. The addition of 10 wt% ESD results in improved mechanical properties, decreased dielectric constant and loss, and outperformance compared to other fire-safe epoxy resins. This research provides an effective method for developing multifunctional flame-retardant epoxy resin.
COMPOSITES PART B-ENGINEERING
(2024)
Article
Engineering, Multidisciplinary
Bo Pang, Heping Zheng, Zuquan Jin, Dongshuai Hou, Yunsheng Zhang, Xiaoyun Song, Yanan Sun, Zhiyong Liu, Wei She, Lin Yang, Mengyuan Li
Summary: This study develops an internal superhydrophobic material (ISM) using waste denitrification fly ash, which maintains stable hydrophobicity under harsh conditions of use and does not rely on expensive fluor-based surface modifications. The synthesized ISM has excellent matrix strength, strong waterproof properties, and retains superhydrophobicity even at damaged or friction interfaces.
COMPOSITES PART B-ENGINEERING
(2024)
Article
Engineering, Multidisciplinary
Meirbek Mussatayev, Qiuji Yi, Mark Fitzgerald, Vincent K. Maes, Paul Wilcox, Robert Hughes
Summary: Real-time monitoring of carbon fibre composites during Automated Fibre Placement (AFP) manufacturing remains a challenge for non-destructive evaluation (NDE) techniques. This study designed a directional eddy-current (EC) probe to evaluate the detectability of out-of-plane wrinkles. Experimental evaluations and finite element modeling were conducted to better understand the relationship between eddy-current density and defect detection. The findings suggest that the probe configuration with an asymmetric driver coil and differential pickup coils shows the best capability for wrinkle detection.
COMPOSITES PART B-ENGINEERING
(2024)