Article
Mechanics
Natawut Chaiwino, Nur Yazdani, Eyosias Beneberu, Kamal Sapkota
Summary: This study analyzed elevated concrete slabs using a nonlinear finite element approach, finding that typical elevated slabs may exhibit brittle behavior with low ductility and sudden explosive collapse. The application of a single layer of uniaxial CFRP at negative moment locations increased the floor load capacity by about 30%, exceeding the minimum building code specified live load.
COMPOSITE STRUCTURES
(2021)
Article
Engineering, Civil
Cheng Chen, Haiyang Cai, Lijuan Cheng
Summary: In this study, ultrahigh-performance concrete (UHPC) combined with fiber-reinforced polymer (FRP) composites was utilized for shear strengthening of corroded reinforced concrete (RC) beams, leading to significant increases in shear capacity and suppression of shear crack formation. The introduction of thin carbon FRP (CFRP) meshes in UHPC decreased crack width in concrete without observing any debonding between FRP and UHPC.
JOURNAL OF BRIDGE ENGINEERING
(2021)
Review
Construction & Building Technology
Chinyere O. Nwankwo, Jeffrey Mahachi, David O. Olukanni, Innocent Musonda
Summary: This article presents a bibliometric and systematic literature review on the use of bio-based FRP materials for retrofitting concrete structures. The study reveals that bio-based FRPs can effectively strengthen concrete beams and columns, and discusses the durability, cost, and sustainability of these materials.
CONSTRUCTION AND BUILDING MATERIALS
(2023)
Article
Engineering, Civil
Pooria Heydari, Davood Mostofinejad, Hasan Mostafaei, Hajar Ahmadi
Summary: This study aims to numerically investigate the retrofitting of reinforced concrete coupling beams using polymer composites reinforced with carbon fiber and external bonding. The results show that by using appropriate anchorage and preventing premature debonding, the load-bearing capacity of the coupling beams can be significantly improved. Additionally, compared to other reinforcement methods, the use of CFRP and steel plates can greatly increase the load-bearing capacity and ductility of the coupling beams.
Article
Mechanics
Aohan Zheng, Shan Li, Dengfeng Zhang, Yuhong Yan
Summary: The experimental investigation showed that the shear behavior of RC beams with corrosion-damaged stirrups can be significantly improved by strengthening with FRP grid-reinforced ECC matrix. The embedded FRP grid shares the shear force borne by the stirrups effectively, while the ECC enhances deformation characteristics and energy absorption. Additionally, a theoretical calculation formula based on the truss-arch model was proposed to predict the shear bearing capacity of the strengthened beams, which was confirmed to be safe and accurate.
COMPOSITE STRUCTURES
(2021)
Article
Construction & Building Technology
Mand Kamal Askar, Ali Falyeh Hassan, Yaman S. S. Al-Kamaki
Summary: The use of fiber reinforced polymer (FRP) composites to strengthen and rehabilitate reinforced concrete (RC) structures has been recognized as a promising technique. This paper provides a summary of research on the flexural and shear behavior of RC beams reinforced with FRP materials under different schemes. It also discusses the efficiency of various types of FRP materials and processes, cost comparisons of different strengthening schemes, and limitations of FRP strengthening. Additionally, knowledge gaps and possible research directions for FRP-strengthened structures are outlined, aiming for a better understanding and the establishment of design guidelines.
CASE STUDIES IN CONSTRUCTION MATERIALS
(2022)
Review
Construction & Building Technology
Baizhao Pan, Feng Liu, Yan Zhuge, Jun-Jie Zeng, Jin-Jing Liao
Summary: This paper provides a comprehensive review on the characteristics and application of high-performance cementitious composites with and without FRP grid reinforcement. It discusses the feasibility of using ECC/UHPFRCC for structural strengthening/repairing, and concludes that FRP grid-reinforced ECC/UHPFRCC exhibits better potential in improving the mechanical performance of composite structures.
CONSTRUCTION AND BUILDING MATERIALS
(2022)
Review
Chemistry, Multidisciplinary
Zhifei Deng, Zian Jia, Ling Li
Summary: Biomineralized composites have unique structural designs and mechanical properties. The structural features within the mineral building blocks significantly modify the mechanical properties of biogenic minerals. This review discusses the intracrystalline structural features and their mechanical significance in three common biomineral systems, and proposes future research directions and challenges.
Article
Engineering, Civil
M. J. Jedrzejko, J. Tian, S. S. Zhang, Y. Ke, X. F. Nie, Y. M. Yang
Summary: In recent years, researchers have proven the high efficiency of the near-surface-mounted (NSM) fiber-reinforced polymer (FRP) method for strengthening reinforced concrete (RC) beams. However, NSM FRP shear-strengthened beams often fail in debonding modes, limiting the strength utilization and strengthening efficiency of the FRP material. Anchoring measures have been proposed, but they are complicated and may still result in interfacial debonding. This study proposes a novel NSM U-shaped FRP (NUF) device that effectively increases the bond efficiency and can prevent debonding failure, thus increasing the strengthening efficiency of NSM FRP method.
ENGINEERING STRUCTURES
(2023)
Article
Mechanics
S. S. Zhang, M. J. Jedrzejko, Y. Ke, T. Yu, X. F. Nie
Summary: The high efficiency of using the near-surface mounted (NSM) fiber-reinforced polymer (FRP) technique to improve the shear capacities of reinforced concrete (RC) beams has been proven by numerous studies. However, premature debonding failures such as interfacial debonding and concrete cover separation are often observed in RC beams strengthened with NSM FRP, which significantly limits the utilization of FRP strength. This paper proposes a novel FRP anchor for NSM FRP shear-strengthened beams and carries out a test program to investigate its effectiveness. The test results show that the proposed FRP anchor can mitigate or prevent debonding failures and significantly enhance the load-carrying and deformation capacities of RC beams strengthened with NSM FRP strips.
COMPOSITE STRUCTURES
(2023)
Article
Mechanics
Justas Slaitas, Juozas Valivonis
Summary: There is a consensus on the advantages of using FRP materials for structural retrofitting, especially through prestressing. However, prestressing techniques can be complicated and may have certain drawbacks. This paper summarizes the peculiarities and issues of prestressing FRP laminates based on experimental studies and previous experiences. Additionally, a novel prestressing system for retrofitting reinforced concrete members with externally bonded FRP laminates is introduced, which utilizes efficient corrugated surfaces for compression of the FRP reinforcement.
COMPOSITE STRUCTURES
(2022)
Article
Engineering, Civil
Chris G. Karayannis, Emmanouil Golias
Summary: This study presents a new technique for strengthening deficient beam-column joints in reinforced concrete structures using C-FRP ropes and validates its effectiveness through experiments. The results indicate that this technique is a simple and efficient method for strengthening substandard RC joints.
EARTHQUAKES AND STRUCTURES
(2021)
Article
Construction & Building Technology
Minoo Panahi, Seyed Alireza Zareei, Ardavan Izadi
Summary: A hybrid strengthening method called combined externally bonded near-surface method was proposed to address the limitations of externally bonded and near-surface mounted techniques. Numerical analysis using finite element software confirmed the efficiency of reinforced concrete beams strengthened with this method, showing it as a promising alternative solution for structural engineers in design-oriented parametric studies.
CASE STUDIES IN CONSTRUCTION MATERIALS
(2021)
Article
Engineering, Civil
Naida Ademovic
Summary: Careva Cuprija (Emperor's Bridge) in Sarajevo, built in 1897 as the first single-arch reinforced concrete bridge with a span of 25.36m, is one of the largest structures of its kind in the Austro-Hungarian monarchy. After 122 years, a rehabilitation design was completed in 2015 following ICOMOS guidelines for national monuments. Assessment of the bridge's current condition and various tests were conducted to determine remaining service life, required treatments, and suitable repair methods.
ENGINEERING STRUCTURES
(2021)
Article
Chemistry, Physical
Yavuz Yardim, Salih Yilmaz, Marco Corradi, Waleed A. Thanoon
Summary: This study examines the effectiveness of using carbon-FRP anchors to improve the confinement of square reinforced concrete columns strengthened with FRP. The proposed anchors distribute stresses more uniformly, resulting in better confinement.
Article
Mechanics
Francesco Ascione, Annalisa Napoli, Roberto Realfonzo
Summary: Steel reinforced polymers (SRP) systems have shown great potential in improving the performance of existing reinforced concrete structures as a competitive alternative to carbon and glass fiber reinforced polymer composites. This paper presents an analytical investigation on the bond behavior between SRP and concrete, deriving closed form solutions to predict the entire debonding propagation process. The study also provides analytical estimates of the SRP effective bonded length and relationships for calculating the maximum axial stress at SRP laminate debonding, verifying the accuracy of the proposed modeling through comparisons with experimental results.
COMPOSITE STRUCTURES
(2021)
Article
Construction & Building Technology
M. A. Aiello, F. Bencardino, A. Cascardi, T. D'Antino, M. Fagone, I. Frana, L. La Mendola, G. P. Lignola, C. Mazzotti, F. Micelli, G. Minafo, A. Napoli, L. Ombres, M. C. Oddo, C. Poggi, A. Prota, G. Ramaglia, G. Ranocchiai, R. Realfonzo, S. Verre
Summary: The use of Fabric Reinforced Cementitious Matrix (FRCM) composites is recognized as suitable for the conservation and preservation of existing masonry buildings, improving bearing capacity and ensuring material and mechanical compatibility. Experimental results show that multi-ply strengthening schemes can significantly increase strength and ultimate axial deformation. The accuracy of design-oriented formulas for FRCM systems in different configurations has been further investigated, with varied results based on the number of layers and masonry types.
CONSTRUCTION AND BUILDING MATERIALS
(2021)
Article
Chemistry, Physical
Enzo Martinelli, Antonio Caggiano
Summary: This paper presents a numerical model to investigate the cyclic behavior of FRP strips glued to quasi-brittle materials like concrete, showing the influence of interface bond-slip law and FRP bond length on the resulting cyclic response of the joint. The results indicate general trends that can guide further experimental and numerical investigations.
Editorial Material
Green & Sustainable Science & Technology
Fausto Minelli, Enzo Martinelli, Luca Facconi
Article
Construction & Building Technology
Arnas Majumder, Flavio Stochino, Ilenia Farina, Monica Valdes, Fernando Fraternali, Enzo Martinelli
Summary: This paper investigates the potential use of raw jute fiber and jute threads as thermal insulation and structural reinforcement in composite systems with inorganic matrices. The results show that they have the potential to be used as a construction material, but the mechanical properties of the fibers worsen as sample size increases. Further studies are being conducted to assess the actual thermal and mechanical response of jute-reinforced Textile-Reinforced Mortars (TRM) for thermal and seismic upgrading of existing masonry buildings.
CONSTRUCTION AND BUILDING MATERIALS
(2022)
Article
Engineering, Civil
Annalisa Napoli, Roberto Realfonzo
Summary: This paper presents an analytical study on the confinement of masonry columns with FRCM composites, aiming to propose new models to estimate the compressive strength and assess existing formulas. A wide database of compression tests on 211 masonry members wrapped with FRCM systems is assembled, and the data is analyzed based on parameters such as fiber type, mesh geometry, number of layers, mechanical properties of the matrix, and unconfined masonry strength. Strength models for FRCM confined masonry are developed and compared with existing formulations and international guidelines.
JOURNAL OF COMPOSITES FOR CONSTRUCTION
(2022)
Article
Chemistry, Physical
Rosa Penna, Luciano Feo, Enzo Martinelli, Marco Pepe
Summary: High-performance fibre-reinforced concrete (HPFRC) combines the advantages of fibre-reinforced concrete (FRC) and high-performance concrete (HPC) to improve the overall performance of traditional concrete. This study developed a numerical simulation to evaluate the effect of freeze-thaw cycles on the flexural response of HPFRC beam specimens as the fibres' volume percentage changes. The model accurately predicted the cracking strength, postcracking strength, and toughness of the HPFRC beam element under bending load conditions.
Article
Construction & Building Technology
Elena Michelini, Beatrice Belletti, Lorenzo Franceschini, Enzo Martinelli
Summary: This study investigates the seismic response of reinforced concrete core-wall buildings with corroded bars erected in marine environments, focusing on the dependency of seismic fragility curves on aging and degradation effects. The results suggest that corrosion significantly affects time-dependent fragility curves, highlighting the importance of considering the construction date in seismic risk assessment.
STRUCTURAL CONCRETE
(2023)
Article
Green & Sustainable Science & Technology
Lucas Caon Menegatti, Leticia Ikeda Castrillon Fernandez, Lucas Rosse Caldas, Marco Pepe, Francesco Pittau, Giulio Zani, Marco Carlo Rampini, Julien Michels, Romildo Dias Toledo Filho, Enzo Martinelli
Summary: The construction industry is a major contributor to greenhouse gas emissions due to its energy-intensive and raw-material-demanding nature. Making the construction sector greener by recycling construction and demolition waste and optimizing production, assembly, and deconstruction/reuse procedures is crucial. This study evaluates the environmental performance of prefabricated deconstructable and reusable beams incorporating recycled concrete aggregates using a memory steel prestressing technique. Life cycle assessment with a cradle-to-gate approach is used to analyze the environmental impacts, and different allocation scenarios for avoided impacts due to reuse are considered. The study provides design guidelines for circular concrete structures based on the principles of design for deconstruction and prefabrication.
Article
Chemistry, Physical
Marco Lamberti, Francesco Ascione, Annalisa Napoli, Ghani Razaqpur, Roberto Realfonzo
Summary: The bonding of steel/fiber-reinforced polymer (SRP/FRP) laminate strips to concrete/masonry elements has been proven to improve the elements' strength and stiffness. However, premature debonding of the laminate-substrate is frequently observed, preventing the laminate from reaching its ultimate strength. To address this uncertainty and ensure safe and effective application of the technology, a new semi-analytic model is presented in this paper. The model accurately determines the debonding load, laminate stress and deformation, and interfacial slip for concrete substrates bonded to SRP/FRP under monotonic or cyclic loading.
Article
Chemistry, Physical
Marco Pepe, Rosario Lombardi, Giuseppe Ferrara, Stefano Agnetti, Enzo Martinelli
Summary: Existing buildings often require strengthening interventions, and textile-reinforced mortar (TRM) composites have emerged as a viable and cost-effective option. This study investigates the mechanical properties of TRM systems using sustainable phases, such as lime-based matrices and natural fabrics made from plant fibers like Jute or Flax. Tensile tests were conducted on NTRM specimens, revealing the importance of the balance between matrix and reinforcement properties for effective strengthening.
Article
Construction & Building Technology
Arnas Majumder, Flavio Stochino, Andrea Frattolillo, Monica Valdes, Geminiano Mancusi, Enzo Martinelli
Summary: Enhancing energy efficiency and structural capacity are the main objectives of masonry retrofitting. However, achieving both aspects simultaneously is challenging due to the competitive relationship with relevant geometric and physical parameters. This research focuses on improving the thermal insulation properties and structural behavior of composite building materials to achieve a dual positive effect. Jute fibers composite mortars with different fiber lengths and percentages were fabricated. The reinforced mortar samples showed higher ductility and strain energy, while the unreinforced samples exhibited fragile collapse. The composite samples also exhibited higher thermal resistance as the fiber percentage increased.
JOURNAL OF BUILDING ENGINEERING
(2023)
Article
Construction & Building Technology
Elena Michelini, Beatrice Belletti, Lorenzo Franceschini, Enzo Martinelli
Summary: This work investigates the seismic response of reinforced concrete core-wall buildings with corroded bars in marine environments, focusing on the dependency of seismic fragility curves on aging and degradation caused by environmental actions. Nonlinear finite-element analyses are used to predict the structural capacity, with chloride corrosion implemented in the PARC_CL_2.1 crack model. The methodology is applied to a pre-code six-story reinforced concrete building, and pushover analyses are performed for different ages of the building. Time-dependent fragility curves are obtained through incremental static analysis, considering different corrosion scenarios. The results highlight the significant influence of corrosion on time-dependent fragility curves, emphasizing the importance of considering the construction date in seismic risk mapping for both design standards and damage assessment due to aging and deterioration.
STRUCTURAL CONCRETE
(2022)
