Article
Construction & Building Technology
Qiang Fu, Zhenhua Wang, Mengxin Bu, Li Su, Hailei Kou, Ning Li, Ditao Niu
Summary: The uniaxial compressive stress-strain behavior of hybrid basalt-polypropylene fiber-reinforced concrete (HBPRC) with different matrix strengths was investigated in this study. The results showed that basalt fiber (BF) and polypropylene fiber (PF) reduced the damage extent of concrete and changed the failure mode from shear failure to longitudinal splitting failure. Both BF and PF improved the critical strain and peak stress of concrete, with BF having a greater improvement effect than PF. However, excessive addition of hybrid fiber decreased the peak stress of concrete. BF addition increased the concrete's elastic modulus, while PF addition decreased it. The addition of an appropriate amount of hybrid fiber had a positive effect on the concrete's elastic modulus. The toughness of concrete increased with the addition of BF and PF, as well as the increase in matrix strength. When HBPRC was destroyed, BF mainly exhibited tensile failure, while PF mainly exhibited pull-out failure and underwent extrusion and torsion deformation. BF and PF mainly improved the strength and deformation performance of concrete, respectively. A constitutive model considering the effects of both mechanical damage and fiber reinforcement was established for HBPRC.
MATERIALS AND STRUCTURES
(2022)
Article
Construction & Building Technology
Omar Gouda, Ahmed Hassanein, Tarik Youssef, Khaled Galal
Summary: The study shows that adding glass fibres to the grout can improve crack control and post-cracking performance, while increasing the compressive strength of concrete masonry prisms.
CONSTRUCTION AND BUILDING MATERIALS
(2021)
Article
Materials Science, Composites
Ahmad S. M. Al-Azzawi, Luiz F. Kawashita, Carol A. Featherston
Summary: This study involves experimental and numerical investigations of fibre-metal laminate structures with adhesive joints under static bending loads. A new cohesive zone model coupling friction and interfacial shear has been developed for delamination simulation, showing good correlation with experimental data. Delamination and shear failure were found to be the main failure modes under bending stresses, with the research providing insights into the damage evolution behavior of the structures.
JOURNAL OF REINFORCED PLASTICS AND COMPOSITES
(2022)
Article
Construction & Building Technology
Chuntao Zhang, Yu Chen, Mei Dou
Summary: In this study, axial compression tests were conducted on slender BFRP tubes to evaluate their compression characteristics as compression members. The results indicated that BFRP tubes exhibited three distinct failure modes, namely local failure, critical failure, and buckling failure. Two three-stage theoretical models for BFRP tubes were developed through experimental data analysis, which successfully predicted the stress-strain curves and the load-lateral deflection curves.
Article
Construction & Building Technology
Agostino Walter Bruno
Summary: This paper proposes a simple empirical model for predicting the effect of stabilisation on the compressive stress - axial strain behaviour of compressed earth materials. The model has been calibrated and validated against experimental data, showing good capability in reproducing various key indicators of the earth samples.
JOURNAL OF BUILDING ENGINEERING
(2021)
Article
Mechanics
Ting Ren, Hongchao Zhao, Alex Remennikov, Zhenjun Shan
Summary: Coal rejects concrete (CRC), as an alternative to natural aggregate concrete (NAC), has low strength and brittleness. To improve this issue, this study proposes a new structural form - fibre-reinforced polymer (FRP)-confined CRC (FCCR) column. Experimental results show that FCCR columns have similar mechanical performance to FCNA columns and exhibit superior axial deformation ability. The add-value use of mine wastes in the FCCR column reduces carbon emission and provides environmental benefits.
COMPOSITE STRUCTURES
(2022)
Article
Construction & Building Technology
Xinyu Shi, Cheng Zhang, Zhiyuan Liu, Philip Van den Heede, Ling Wang, Nele De Belie, Yan Yao
Summary: A numerical method is proposed to determine the semi-carbonated and fully-carbonated depth of concrete under sustained loads, and the influence of external load on carbonation depth is analyzed in detail.
CONSTRUCTION AND BUILDING MATERIALS
(2022)
Article
Mechanics
Zhe Xiong, Wei Wei, Feng Liu, Chuying Cui, Lijuan Li, Rui Zou, Yin Zeng
Summary: This study investigated the bond performance of recycled aggregate concrete structures reinforced with fibre-reinforced polymer bars, highlighting the effective corrosion prevention and the key factors influencing bond performance. The findings provide valuable insights for improving the application and design potential of such structures.
COMPOSITE STRUCTURES
(2021)
Article
Engineering, Civil
Gao Ma, Cheng Wu, Hyeon-Jong Hwang, Jiulin Bai, Zhihu Zeng
Summary: This study investigated the monotonid and repeated axial compressive behavior of damaged concrete prisms repaired by basalt fiber-reinforced polymer (BFRP). The results showed that the compressive strength and axial deformation capacities of the repaired prismatic specimens were improved after repairing. However, the initial elastic modulus and strength at the turning and ultimate states decreased with the increase of initial damage in the BFRP-repaired specimens. Based on the test results, a monotonic stress-strain relationship and a modified repeated compressive stress-strain model were proposed for BFRP-repaired concrete prisms.
ENGINEERING STRUCTURES
(2022)
Article
Mechanics
Tan Wang, Min Yu, Wentao Shan, Lihua Xu, ShanShan Cheng, Long-yuan Li
Summary: The post-fire compressive stress-strain behavior of steel fiber reinforced recycled aggregate concrete (SFR-RAC) after exposure to elevated temperatures was investigated through uniaxial compressive tests. The test considered parameters such as water-to-cement ratio, recycled concrete aggregate (RCA) substituting ratio, steel fiber content, and heated temperature. The study analyzed the failure mode, strength, elastic modulus, peak strain, and strain-stress response of the specimens. The results showed that the compressive strength and elastic modulus decreased with increased water-to-cement ratio and/or RCA substituting ratio at any exposed temperature. The steel fiber had a positive effect on the residual mechanical properties, which increased with the heated temperature.
COMPOSITE STRUCTURES
(2023)
Article
Engineering, Geological
Jin Gong, Degao Zou, Xianjing Kong, Jingmao Liu, Kai Chen
Summary: This study utilizes the scaled boundary finite element method to construct a cross-scale model of rockfill and bedrock in high concrete faced rock-fill dams, with nonconforming elements used to refine the mesh locally in the face slab. By conducting static and dynamic analyses, high compressive stress zones are identified and extrusion damage is simulated.
SOIL DYNAMICS AND EARTHQUAKE ENGINEERING
(2021)
Article
Green & Sustainable Science & Technology
Shuai Zong, Zhenzhen Liu, Shan Li, Yiyan Lu, Aohan Zheng
Summary: The study introduces steel fibres and recycled coarse aggregate to form steel-fibre-reinforced recycled aggregate concrete to enhance CDW recycling rate. Experimental results indicate that steel fibres positively influence the tensile behavior of concrete, with established predictive formulas. Recycled SFRAC is reusable and cost-effective, making the method feasible from an industrial perspective.
JOURNAL OF CLEANER PRODUCTION
(2021)
Article
Engineering, Civil
Ismail Bello, George Wardeh, Belen Gonzalez-Fonteboa, Fernando Martinez-Abella, Elhem Ghorbel
Summary: Accurately measuring the compressive strengths and stress-strain relationship of brick and mortar is crucial for studying and evaluating masonry structures. A non-contact measuring technique was used in this study to obtain full-scale strain and failure patterns, and investigate the effect of joint mortar composition on masonry behavior.
Article
Chemistry, Analytical
Ahmed Abed, Zineb Samouh, Cedric Cochrane, Francois Boussu, Omar Cherkaoui, Reddad El Moznine, Julien Vieillard
Summary: This study developed a sensor yarn based on natural sisal yarn and investigated the impact of different PEDOT:PSS coating layers on the performance of the sensor yarn. The results showed that the number of coating layers strongly influenced the electromechanical behaviors of the sensor yarns, with accurate and stable responses under cyclic conditions. Further research is ongoing to explore the mechanism behind the initial results obtained from these sisal fiber-based sensors.
Article
Mechanics
Borja Erice, Daniel Thomson
Summary: Unidirectional fibre-reinforced composites are traditionally assumed to be linear elastic before failure, but they exhibit nonlinear responses when loaded. This research explores physically-inspired finite element models to investigate the effects of fibre waviness/misalignment on the elastic modulus and combines it with localization plane plasticity for a complete understanding of the material's mechanical behavior.
COMPOSITE STRUCTURES
(2023)
Article
Thermodynamics
Jonathan Dias Nascimento, Camila Aparecida Abelha Rocha, Cristina Aiex Simao, Romildo Dias Toledo Filho
Summary: This study focused on the effect of exposing hardened cement slurries to CO2 in water saturation. Results showed that slurries with silica fume presented less calcium carbonate in the internal layers, while mixtures with styrene-butadiene rubber and crystalline silica had higher porosity and permeability, leading to higher carbonation rates.
JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
(2022)
Article
Construction & Building Technology
Rodolfo Giacomim Mendes de Andrade, Michele Schubert Pfeil, Ronaldo Carvalho Battista, Romildo Dias Toledo Filho, Olga Maria Oliveira de Araujo, Ricardo Tadeu Lopes
Summary: Steel fiber-reinforced concrete materials like HPFRC and UHPFRC offer the possibility of replacing passive reinforcement in structures like footbridges and motorway bridges. When designing for ultimate limit state, the orientation factor of fibers must be considered, which can be determined through different methods. The post-cracking behavior of specimens showed inconsistency, indicating that steel fiber-reinforced concrete materials cannot be treated as isotropic without prior investigation.
CONSTRUCTION AND BUILDING MATERIALS
(2021)
Article
Construction & Building Technology
Amanda Pereira Vieira, Romildo Dias Toledo Filho, Luis Marcelo Tavares, Guilherme Chagas Cordeiro
Summary: The effect of particle size and content on the autogenous shrinkage of high-strength concrete was investigated. The results showed that the particle size and the interaction between particle size and RHA content influenced the autogenous shrinkage at 28 and 100 days. The water absorbed internally by the preserved RHA pore structure in the high cement replacement mixes reduced the final autogenous shrinkage of concrete without decreasing compressive strength. Additionally, the RHA with a more preserved pore structure accelerated the hydration kinetics but did not affect the early autogenous shrinkage results.
ADVANCES IN CEMENT RESEARCH
(2022)
Article
Construction & Building Technology
Rayane de Lima Moura Paiva, Lucas Rosse Caldas, Adriana Paiva de Souza Martins, Romildo Dias Toledo Filho
Summary: This research focused on characterizing and evaluating the properties and greenhouse gas emissions of earth-based mortars with bamboo particles. The study found that the mortar with 9% bamboo particles showed a significant improvement in efficiency compared to the one without bamboo, highlighting its potential for the construction industry seeking circular and low-carbon solutions. Additionally, strategies related to Circular economy for reducing GHG emissions of EMB mixtures were proposed.
CONSTRUCTION AND BUILDING MATERIALS
(2022)
Article
Chemistry, Physical
Bartosz Zukowski, Yasmim Gabriela dos Santos Mendonca, Igor Jose Koury Tavares, Romildo Dias Toledo Filho
Summary: This study presents an experimental investigation of hybrid cement-based composites reinforced with polyvinyl alcohol fiber (PVA) and alkali-treated, short, natural curaua fiber. The optimal mixture consisted of 1% PVA fiber and 1.5% curaua fiber, exhibiting strain-hardening behavior and crack width control.
Review
Green & Sustainable Science & Technology
Lucas Rosse Caldas, Maykon Vieira Silva, Vitor Pereira Silva, Michele Tereza Marques Carvalho, Romildo Dias Toledo Filho
Summary: This paper conducts a systematic literature review on the application of circular economy in the construction industry, analyzing the roles and integration methods of seven tools. The results show that circular economy strategies mainly involve recycling and the use of recycled materials. Construction workers, researchers, and designers in the industry are the main users of these tools, and it is proposed to further integrate different tools to improve and update them while reducing greenhouse gas emissions.
Article
Construction & Building Technology
Tamara Nunes da C. Moreira, Visar Krelani, Saulo Rocha Ferreira, Liberato Ferrara, Romildo Dias Toledo Filho
Summary: The study shows that sisal fibers enhance the tensile stress and post cracking energy of self-healing concrete specimens, densify the interface, transmit healing agents, and facilitate crack repair.
JOURNAL OF BUILDING ENGINEERING
(2022)
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
Alfredo Quiroga Flores, Rodolfo Giacomim Mendes de Andrade, Michele Schubert Pfeil, Joaquim A. O. Barros, Ronaldo Carvalho Battista, Olga Maria Oliveira de Araujo, Ricardo Tadeu Lopes, Romildo Dias Toledo Filho
Summary: This study aimed to investigate the crack propagation behavior of steel fiber-reinforced concrete (SFRC) used in a full-scale prototype of a bridge box girder. The results showed that the peak loads were proportional to the fiber density at the shear failure section. The study also proposed crack-dilatancy and crack width-slip relations based on the shear and flexural test results.
Article
Construction & Building Technology
Mayara Amario, Marco Pepe, Caroline Santana Rangel, Romildo Dias Toledo Filho
Summary: The presence of the Attached Mortar content in recycled concrete aggregates (RCAs) gives them higher porosity and water absorption capacity compared to natural aggregates. Previous studies have focused on the impact of RCAs on the performance of concrete mixtures in fresh and hardened states, while the effects on concrete deformations, such as shrinkage, have been limited. This article presents the results of an experimental study evaluating the influence of RCAs on the autogenous and drying shrinkage of normal and high strength recycled aggregate concrete mixtures. The study found a clear correlation between the intrinsic properties of the RCAs and the resulting concrete deformation.
STRUCTURAL CONCRETE
(2023)
Article
Green & Sustainable Science & Technology
Joaquin Humberto Aquino Rocha, Andreia Arenari de Siqueira, Marco Antonio Barbosa de Oliveira, Lucas da Silva Castro, Lucas Rosse Caldas, Nathalie Barbosa Reis Monteiro, Romildo Dias Toledo Filho
Summary: This study evaluated the use of Acai seed ash (ASA) from the Brazilian Amazon as a replacement for Portland cement in self-leveling mortars. The results showed that using up to 10% ASA as cement replacement was technically and environmentally feasible, reducing greenhouse gas emissions.
Article
Materials Science, Multidisciplinary
Monique Rocha, Bruno Gomes, Amanda Aguiar, Alexandre Landesmann, Nicole Pagan Hasparyk, Romildo Toledo Filho
Summary: Bio-based aggregates are a promising alternative for reducing the environmental impacts of buildings. However, the flammability of these materials is not well understood. This study investigates the fire behavior of bio-based aggregates and finds that alkaline treatment can reduce the heat release rate and heat of combustion, but not the ignition time of these materials.
FIRE AND MATERIALS
(2023)
Article
Construction & Building Technology
Joaquin Humberto Aquino Rocha, Romildo Dias Toledo Filho
Summary: This document provides a critical analysis of the usage of Recycled Concrete Powder (RCP) in the construction industry, specifically as Supplementary Cement Material (SCM). Various treatments, such as grinding, thermal activation, and carbonation, can improve the reactivity of RCP. Additionally, the usage of other SCMs can compensate for the adverse effects of RCP. There are environmental benefits in using RCP, especially in reducing CO2 emissions, but further research is needed to establish its usage.
JOURNAL OF BUILDING ENGINEERING
(2023)
Article
Energy & Fuels
Maria D. M. Paiva, Romildo Dias Toledo Filho, Luiz Carlos da Silva Nunes
Summary: This study investigates the effect of fiber reinforcement on the tensile behavior of metakaolin-based geopolymers for well applications. The results show that polypropylene fibers can effectively arrest crack growth and improve tensile strength, while wollastonite prevents surface delamination. These reinforced systems are more suitable for downhole applications, as they can withstand greater strains before the formation of continuous cracks and loss of hydraulic isolation.
GEOENERGY SCIENCE AND ENGINEERING
(2023)
Article
Materials Science, Multidisciplinary
Manuel Alejandro Rojas Manzano, Eugenia Fonseca da Silva, Anne Neiry de Mendonca Lopes, Romildo Dias Toledo Filho
Summary: Superabsorbent polymers (SAP) are synthetic polymeric materials with the ability to absorb and retain liquid without dissolution. They are used in various applications and have the important property of water absorption in cementitious materials, influenced by polymer type, particle size, fluid ionic charge, and external factors.
MATERIA-RIO DE JANEIRO
(2021)