Article
Construction & Building Technology
Jose Roberto Hino Junior, Carlos E. T. Balestra, Ronaldo A. Medeiros-Junior
Summary: This study compared four test methods to determine concrete resistance to chloride penetration and investigated the sensitivity of these methods to the effect of fly ash. The sensitivity of the fly ash effect varied in each test. As the fly ash content increased, the chloride depths measured in different tests became closer.
CONSTRUCTION AND BUILDING MATERIALS
(2021)
Article
Construction & Building Technology
Qing-feng Liu, Zhe Hu, Xing-er Wang, Haitao Zhao, Kai Qian, Lin-jie Li, Zhaozheng Meng
Summary: This study presents a multi-species and multi-phase model considering the time-dependent cracking in concrete. The crack propagation and chloride diffusion are coupled by statistical learning approach, and the effect of the electrostatic potential on multi-species transport is considered. The validity of the model is verified against third-party experiments, and the impacts of different crack characteristics and environmental factors on chloride transport are discussed.
CONSTRUCTION AND BUILDING MATERIALS
(2022)
Article
Construction & Building Technology
Goran Adil, Ceki Halmen, George Seegebrecht, John T. Kevern
Summary: The corrosion performance of reinforced pervious concrete was evaluated through field and laboratory assessments, showing that the pervious concrete around reinforcement delays cracking and spalling compared to conventional concrete. Despite similar corrosion rates, the two-layered samples provided a longer time to cracking, consistent with prior studies on pervious concrete corrosion.
ACI MATERIALS JOURNAL
(2021)
Article
Construction & Building Technology
Mahmoud Shakouri, Christopher L. Exstrom, Guilherme D. Piccini
Summary: The study found that pretreated corn stover ash can enhance the long-term chloride resistance of concrete by promoting pozzolanic reactions. Additionally, while CSA concrete has lower chloride binding capacity compared to OPC concrete, the desorption testing results in a low-pH environment indicate that CSA concrete is more durable than OPC concrete.
JOURNAL OF SUSTAINABLE CEMENT-BASED MATERIALS
(2022)
Article
Environmental Sciences
Qazi Amjad Ali Pathan, Abdul Sami Qureshi, Sajjad Ali Mangi
Summary: The study examines the effect of ageing factors on service life modelling of fly ash cement concrete (FACC) and finds significant variations in the predicted results. More reliable modelling results are needed for reinforced concrete structures in chloride environments, such as the recent failure of the Miami Building in the USA.
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
(2022)
Article
Acoustics
Jiaqi Guo, Weiling Yang, Chong Xu, Bo Peng, Jinhai Lin, Yuan Qian
Summary: Through experimental and numerical investigation, it is found that chloride penetration decreases the peak strength and elastic modulus of the segment concrete by 42% and 46.1% respectively, reducing the energy storage capacity of concrete and weakening its ability to resist damage. Corrosion of steel bars leads to outer cracks extending continuously and inner cracks initiating around the inner steel bars.
SHOCK AND VIBRATION
(2021)
Article
Construction & Building Technology
Andres Antonio Torres-Acosta, Alberto Patron-Solares, Pablo Alcantara-Lagunes
Summary: A new methodology for durability health monitoring during bridge construction using concrete indicators was developed and compared with data from in-service bridges. Results showed excellent correlations and empirical models confirmed the feasibility of using saturated electrical resistivity test for structural health monitoring, instead of more complicated and expensive methods.
STRUCTURAL CONTROL & HEALTH MONITORING
(2021)
Article
Construction & Building Technology
Qing-feng Liu, Muhammad Farjad Iqbal, Jian Yang, Xian-yang Lu, Peng Zhang, Momina Rauf
Summary: This study developed a predictive model for chloride diffusion coefficient of concrete using artificial neural network (ANN) technique, which showed strong prediction potential. The performance of the model was assessed through normalization of variables and in-depth statistical error analysis, indicating its robustness and reliability.
CONSTRUCTION AND BUILDING MATERIALS
(2021)
Article
Construction & Building Technology
Van Quan Tran
Summary: This study uses machine learning algorithms to predict the chloride diffusion coefficient of concrete containing SCMs. The performance of eight machine learning models is evaluated, and the Gradient Boosting model is found to have the highest accuracy. SHAP, ICE, and PDP 2D techniques are used to identify the most influential input variables and quantify their impact on chloride diffusion in concrete.
CONSTRUCTION AND BUILDING MATERIALS
(2022)
Article
Chemistry, Physical
Abdulrahman Fahad Al Fuhaid, Hani Alanazi
Summary: This study aimed to develop a prediction model for the chloride diffusion coefficient (Dcl) of concrete incorporating supplemental cementitious material. Five machine learning algorithms were used to develop the model and the SVM models demonstrated the highest prediction accuracy. The SVM algorithm was proven to be the best for estimating Dcl and helpful in concrete durability design.
Article
Chemistry, Physical
Zhihong Fan, Dagen Su, Zhijie Zhang, Mingfeng Zhong, Xinxing Zhang, Jianbo Xiong, Pengping Li
Summary: Chloride penetration resistance is an important performance measure for evaluating the durability of concrete. Laboratory accelerated migration tests cannot reflect the real process of chloride ingress into concrete in the natural environment. The transfer parameter kt should be introduced when using the test results of accelerated methods. This study analyzed the attenuation rule of the chloride diffusion coefficient of different cement-based materials over time and deduced the theoretical natural diffusion coefficients. The transfer parameter kt can be calculated to evaluate the long-term performance of concrete in the marine environment.
Article
Construction & Building Technology
Quang Dieu Nguyen, Arnaud Castel
Summary: This study investigated concrete cores extracted from different underground reinforced concrete pipelines exposed to chloride and carbonation environments, with pipeline ages ranging from 43 to 70 years. The main objective was to determine the minimum concrete cover to reinforcement for 100 years of service life, considering the exposure conditions of the pipelines. The study assessed chloride content at the steel-concrete interface, carbonation depth, reinforcement corrosion, and other concrete durability-related properties. The service life of the pipelines was discussed based on measured corrosion rates and observed corrosion-induced concrete cracking. The high humidity in concrete pipes is suspected to significantly delay oxygen renewal at the steel-concrete interface. A concrete cover of 25 mm and 20 mm appears to be adequate for 100 years of service life in chloride and carbonation environments, respectively.
CONSTRUCTION AND BUILDING MATERIALS
(2023)
Article
Construction & Building Technology
Andre Valente Monteiro, Arlindo Goncalves
Summary: This article presents a probabilistic methodology based on a frequentist approach for assessing the limit state of depassivation of concrete structures. It introduces the concept of passivation curve, providing a valuable tool for decision-making in the life-cycle management of concrete structures. The article also discusses the experimental and code requirements for condition assessment and the physical interpretation of passivation probability.
JOURNAL OF BUILDING ENGINEERING
(2022)
Article
Construction & Building Technology
Dawang Li, Ping Li, Long-yuan Li
Summary: In this paper, a new chloride binding isotherm is proposed to describe the chloride binding in concrete. The trilinear function is used to reflect the nonlinear binding feature of chlorides in concrete when exposed to a chloride environment. The analytical solution of the chloride diffusion equation with the trilinear binding isotherm is more accurate in predicting the penetration speed of chlorides and the service life of concrete structures.
JOURNAL OF BUILDING ENGINEERING
(2023)
Article
Green & Sustainable Science & Technology
Amit Kenny, Ela Ofer Rozovsky
Summary: This study examined the properties of ecological concrete taken from a submerged breakwater in the East Mediterranean Sea. It was found that the biogenic carbonate cover on the concrete surface reduced the diffusion of chloride ions and carbonation rate, without negatively affecting the compressive strength.
Article
Chemistry, Physical
Marcos Garcia Alberti, Jaime Carlos Galvez, Alejandro Enfedaque, Ramiro Castellanos
Summary: The combination of polypropylene fibers with steel rebars or fibers has been found effective for the structural design of elements exposed to high temperatures. The new polyolefin fibers show potential as an alternative to steel fibers in structural design.
Article
Construction & Building Technology
A. Picazo, M. G. Alberti, J. C. Galvez, A. Enfedaque
Summary: This study analyzes the shear contributions of fibers in fiber reinforced concrete (FRC) through shear push-off tests, examining the influence of different types of structural fibers and comparing experimental results with a crack opening behavior model. The significance of the research lies in exploring the shear residual capacity of concrete reinforced with different structural fibers and the applicability of shear-friction theory.
CONSTRUCTION AND BUILDING MATERIALS
(2021)
Article
Chemistry, Multidisciplinary
Michiel Fenaux, Encarnacion Reyes, Jaime C. Galvez, Amparo Moragues, Jesus Bernal
Summary: This work studied the transport equations of ionic species in concrete at both the pore-scale and macroscopic scale, comparing the tortuosity-connectivity parameters in different concretes. The proposed model provided good results compared with experimentally obtained chloride profiles for additional concretes.
APPLIED SCIENCES-BASEL
(2021)
Article
Engineering, Civil
M. Rivera, A. Enfedaque, M. G. Alberti, J. C. Galvez, J. M. Simon-Talero
Summary: The use of fibers in reinforced concrete offers the opportunity to optimize the structural design and increase durability, while reducing the need for flexural and shear reinforcement. By analyzing the stress-crack-width relationship and considering crack appearance and evolution, the contribution of fibers to the structure can be calculated. The results show that fibers can reduce flexural reinforcement by up to 40% and significantly decrease the demand for shear stirrups, especially in polyolefin fiber-reinforced concrete.
JOURNAL OF BRIDGE ENGINEERING
(2022)
Article
Chemistry, Physical
Julio A. Paredes, Jaime C. Galvez, Alejandro Enfedaque, Marcos G. Alberti
Summary: The paper aims to optimize the mechanical and durability properties of ultra-high performance concrete (UHPC) through the combination of nano silica and metakaolin, as well as nano silica, metakaolin, and silica fume. This combination led to the best performances in both mechanical and durable properties of the UHPC.
Article
Chemistry, Physical
Alejandro Enfedaque, Marcos G. Alberti, Jaime C. Galvez, Jhonatan Santiago Proano
Summary: This study conducted flexural fatigue tests on fiber-reinforced concrete specimens and found that the fatigue life of PFRC at SLS or ULS was significantly higher than that of SFRC. Furthermore, the fracture surface analysis revealed a linear relationship between the fibers present in the fracture surface and the number of cycles that both SFRC and PFRC could bear.
Article
Mechanics
M. A. Olivares, J. C. Galvez, F. Suarez
Summary: This study investigates the feasibility of using damage tolerance to design posttensioning anchor heads in civil engineering, aiming to build safer structures. The simulation of damage using finite element models reveals that this approach can be effective in improving structural safety.
ENGINEERING FRACTURE MECHANICS
(2022)
Article
Chemistry, Physical
Alejandro Enfedaque, Fernando Suarez, Marcos G. Alberti, Jaime C. Galvez
Summary: This study examines the behavior of polyolefin fibers as concrete reinforcement and compares the accuracy of different constitutive models, showing that the softening function proposed by the authors is more suitable for this type of fiber. Using this constitutive model can more accurately reproduce the behavior of concrete.
Article
Chemistry, Physical
Andres Bonilla, Cristina Argiz, Amparo Moragues, Jaime C. Galvez
Summary: Zinc provides protection to galvanized steel by forming a passive layer in alkaline solutions, preventing corrosion. This study investigates the behavior of galvanized steel exposed to strong alkaline solutions and the synergistic effects of sulfate ions with other ions.
Article
Construction & Building Technology
Eduardo Galeote, Alvaro Picazo, Marcos G. Alberti, Albert de la Fuente, Alejandro Enfedaque, Jaime C. Galvez, Antonio Aguado
Summary: This paper analyzes experimental results and previous studies to gather data on the flexural residual strength of fiber reinforced concrete (FRC), and identifies general correlations and trends regarding the influence of fibers on FRC behavior, providing valuable information for design decisions.
STRUCTURAL CONCRETE
(2022)
Article
Engineering, Mechanical
M. G. Alberti, J. C. Galvez, A. Enfedaque, A. Picazo, W. J. Ramirez
Summary: Fibre reinforced concrete (FRC) has been widely used in civil and building construction as a way to reduce or replace traditional steel-bar reinforcement. Steel fibres are the most commonly used, but there have been advancements in plastic fibres as well. However, there is still a lack of understanding about the behavior of polyolefin fibre reinforced concrete (PFRC) under different fracture modes and size effects.
THEORETICAL AND APPLIED FRACTURE MECHANICS
(2022)
Article
Chemistry, Multidisciplinary
Tomas Luis Ripa Alonso, Noemi Corral Moraleda, Marcos Garcia Alberti, Ruben Munoz Pavon, Jaime C. Galvez
Summary: This article discusses the issue of using de-icing salts in the corrosion of steel rebars in bridge decks and their impact on post-tensioning elements. It focuses on structures affected by an aggregate-alkali reaction and without any waterproof treatment, using a structure repaired in 2020 as an example. The internal stresses resulting from the aggregate-alkali reaction caused longitudinal cracks in the upper face of the deck, allowing concentrated penetration of chloride ions, ultimately leading to the brittle fracture of the steel bars and corrosion of the prestressing elements. The article also provides insights into the most probable mechanisms behind the unexpected brittle fracture of the steel bars, highlighting the importance of these conclusions.
APPLIED SCIENCES-BASEL
(2023)
Article
Chemistry, Physical
Fernando Suarez, Alejandro Enfedaque, Marcos G. Alberti, Jaime C. Galvez
Summary: Fibre-reinforced concrete (FRC) has made significant progress in recent times due to the inclusion of guidelines in national and international standards. New materials, such as polyolefin macro-fibres, have been proposed as alternative reinforcements to traditional steel fibres, overcoming their limitations. The behaviour of polyolefin fibre-reinforced concrete (PFRC) under high temperatures needs to be analyzed to assure its extended use.
Article
Chemistry, Physical
Alejandro Enfedaque, Marcos G. Alberti, Jaime C. Galvez, Pedro Cabanas
Summary: Fiber-reinforced concrete (FRC) is an alternative for structural applications due to its outstanding mechanical properties. This study simulated the fracture behavior of five types of FRC using an inverse analysis approach and highlighted the synergies created through fiber cocktails. The findings provide important insights for engineers in designing high-performance FRC structures.
Article
Education & Educational Research
Encarnacion Reyes, Jaime C. Galvez, Alejandro Enfedaque
Summary: Introducing a contest-based gamification activity has positively impacted students' motivation, learning outcomes, and passing rates in the course, as well as receiving positive feedback from students.
EDUCATION SCIENCES
(2021)
