To study the effect of pore structure changes on the fatigue life of concrete in areas with large temperature differences, a concrete fatigue test program was designed after a temperature cycle of −50 to 70°C. Results show that temperature differences considerably influence pores with a size ranging from 0.1 to 27.98 nm. Furthermore, the fatigue life of concrete gradually decreases with the increase

A 3‐stage model is used to evaluate the results of an experimental campaign, previously carried out with the aim of studying the deflection of reinforced concrete structures made with reinforced concrete (RC) and fiber‐reinforced concrete (R/FRC). In particular, 12 four‐point bending tests were performed on beams, whose cross‐sections were obtained by combining four effective ratios of the tensile

The influence of the specimen size of ultra‐high‐performance fibre‐reinforced concrete samples on the spatial distribution and orientation of the steel fibres is investigated. Specimens of varying size are produced by using the same protocol. They are imaged by micro‐computed tomography to perform a statistical analysis of the spatial arrangement of the fibres. The tensile strength of the specimens

The developments of compressive arch action (CAA) and tensile catenary action (TCA) in beams can provide secondary loads for resisting progressive collapse. However, to date, the contributions of CAA and TCA in regards to progressive collapse have not been considered in design codes, owing to inadequate studies. In this study, a division of resistant mechanisms was initially proposed. Then, based on

The effect of the boundary conditions, defined as the thermal expansion restraint imposed by the external uniaxial compressive load in plain concrete subjected to high temperatures, is discussed. A numerical mesoscopic investigation uncoupled the load induced thermal strain (LITS) into three main components (aggregates and matrix strain contributions and the effect of the thermal expansion restraint)

Industrial waste has rapidly increased day by day due to the fast‐growing population and usage of products, which dumps unscrupulously, resulting in environmental pollutions. Waste foundry sand (WFS) is one of the industrial solid wastes. River sand is generally used in concrete as a fine aggregate, which is limited (scant), and river excavation for sand leads to environmental deterioration. To resolve

Lately, there has been increasing demand for structural solutions and building technologies with minimalized CO2 footprint. One way to approach the carbon neutrality is through reuse of structural components. In order to enable economic reuse of precast concrete elements, their connections must be designed to allow an effortless dismount. While dismount ability provides additional value to the structure

The work presented herein sets out to investigate experimentally, via drop‐weight testing, the behavior of slender reinforced concrete (RC) beam specimens under impact loading. During testing, the behavior of each specimen is established through the combined use of conventional instrumentation and a high‐speed video camera. The primary objective of this work is to investigate the reasons that trigger

The measurement of strain in structural elements is a necessary means of investigating the condition of a structure, both in research and in practice. The measurement methods for recording strain considered in this work represent both well‐established techniques (strain gauges), as well as techniques that are part of rather current research streams (fiber optic sensors, digital image correlation).

Prior to cracking, reinforced concrete (RC) has full‐interaction (FI) behavior, that is there is negligible slip between adjacent elements. After cracking, the regions in the vicinity of a crack exhibit partial‐interaction (PI), that is relative slip between elements occurs. RC development has in the past relied heavily on FI strain based approaches and, consequently, they are in general not able to

This research, which is based on the digital technologies building information modeling (BIM) and artificial intelligence, describes achievements in the field of detecting, assessing, and digitalising damage in existing buildings. The purpose of the study is to highlight the potential and current benefits of combining structural‐assessment methods with the automatic digitisation of hazard‐induced damage

This study investigates the in‐plane lateral stiffness and ductility of composite PVC encased concrete walls subject to the lateral loads using pushover tests to determine lateral strength and ductility characteristics of composite PVC encased walls filled with plain concrete, macro‐synthetic fiber reinforced concrete (RC), and steel RC. Eighteen concrete wall specimens were cast and subjected to pushover

This paper proposes an innovative precast through‐girder system that can be used in shallow bridge structures. It discusses various components of the through‐girder system, including the edge (through) girders, transverse beams, and longitudinal and transverse connections. The through girders are made of precast concrete box beam segments that are spliced longitudinally through posttensioning. The

Resilience of concrete structures was the main theme of the fib symposium 2020 in Shanghai, and in this editorial, I present some reflections from my online key‐note lecture given at that occasion. I hope that these reflections can offer some food for thought on the future of the construction industry in general and of structural concrete in particular. Resilience stems from the Latin word resilio

Durability design and service life modeling of concrete structures rely on environmental exposure classes based on the prevailing deterioration mechanisms. International standard environmental exposure classes, for example, those found in the fib Model Code 2010 and ISO 22965‐1:2007 are predominantly based on European environmental conditions. Although these exposure classes are more suited to the

This study investigates the effect of support types on plastic hinges in reinforced concrete (RC) beam under the influence of impact loading. In previous studies, the assumption of the linear distribution of inertia force under impact loading was examined and verified according to experimental, analytical, and numerical results. Furthermore, it was emphasized that the most important parameters affecting

In this editorial article by Kasuga (2021),1 the image of the author, Akio Kasuga should have been included in the first published version. Here is the image of Akio Kasuga that was previously added in the original article: The original article in the online version has been updated. REFERENCE 1. Kasuga A. What is fib's Great Reset?. Struct Concr. 2021;22:4–5. https://doi.org/10.1002/suco.202170001

Cracking of concrete induced by rebar corrosion is a main cause for deterioration of reinforced concrete structures especially for those exposed to chloride environment. In all of the parameters influencing the service life of concrete structures, water‐to‐cement ratio is a very important one for it determines the resistance of concrete against chloride aggression and corrosion‐induced damage. In this

Engineered cementitious composite (ECC) is a type of cementitious product with high tensile strength and ductility. It exhibits high strain and multiple cracking behavior instead of deep and wide cracks due to tensile and bending loads. In this study, the efficiency, mechanical properties of different ECC mixtures containing different contents of zeolite were investigated. The zeolite to cement ratios

One of the well‐known methods for rehabilitation of insufficient or damaged reinforced concrete (RC) beams is to add a new RC layer. Although RC beams strengthened or repaired in this way have proved themselves under monotonic and repeated loads, the behavior under cyclic loads has not been adequately investigated yet. In this experimental research, beams were strengthened, repaired, or revived (repaired

Concrete‐encased concrete‐filled steel tubes (CFST) has extensive applications in the world. According to previous researches, if the CFST is placed in the compression zone, the confinement increases, and the compressive capacity of the concrete is completely used. The prestressed strands also increase the core concrete confinement and eliminate tension cracks. Therefore, in this paper, to achieve

Grouted tendons are commonly used in construction of bridges and other post‐tensioned structures. The quality of grouting is essential to provide the durability and robustness of the structure. In this paper, the bond and re‐anchoring of post‐tensioned tendons in grout in case of tendon failure is assessed. A set of tests were conducted to simulate the failure of a post‐tensioned tendon in the beam

The use of bundled bars in highly loaded concrete members instead of individual bars can reduce or even avoid reinforcement congestion, allowing easier placing and compaction of concrete, since bundles (with two or more side‐by‐side bars) are less obstructive to fresh‐concrete flow. However, there is still a lack in knowledge of the fundamental phenomena related to the bond behavior of bars in bundles

In a recent experimental research, the authors measured the circumferential strains on the cylindrical envelope of concrete specimens during pull‐out tests. This paper presents a theoretical approach, complementing the previous experimental study, aiming at predicting these measured circumferential strains and developing the understanding of the three‐dimensional behavior of the concrete cylinder.

A new type of connection between shear walls is proposed for the shear wall with precast concrete hollow molds (PCHM). The overlapping reinforcements are inserted into the PCHM before pouring concrete into the hollow in this method. Full‐scale test specimens are tested under low cyclic loading test to analyze their seismic performance, such as failure modes, hysteretic characters, stiffness degradation

This paper presents the bond‐slip tests of six self‐stressing steel slag concrete filled steel tubular (SSSCFST) columns. The effects of the self‐stressing (expansion ratio) of steel slag concrete (SSC), diameter‐thickness ratio and confinement factor on bond‐slip behaviors are analyzed, and the bond‐slip mechanism of the SSSCFST columns is revealed. According to the static equilibrium condition, an

Steam‐cured concrete products have been widely employed in building slab ballastless track for China High‐Speed Railway lines, such as track sleeper and track slab. These components are usually subjected to long‐term fatigue load due to the wheel‐rail interactions by high‐speed trains. Especially in Northeast China where the winter temperature keeps subzero for months, the concrete elements are exposed

Corrosion of I‐shaped steel in the primary support of the subsea tunnel is inevitable due to high chloride ion content, which will weaken the bond performance between concrete and I‐shaped steel, resulting in a reduction in the service time of the subsea tunnel. Based on Xiang'an subsea tunnel, the bond–slip behavior between concrete and corroded I‐shaped steel was studied by the accelerated corrosion

Electrochemical chloride extraction (ECE) is an effective method to remove chloride ions in reinforced concrete. In addition, cracks in concrete have self‐healing properties. The self‐healing properties of concrete may affect the ECE process. Based on moving mesh technology, this paper simulates the ion migration process of ECE in crack‐self‐healing concrete. According to the simulation results, the

This paper discusses the synergetic effect of ground granulated blast‐furnace slag and hooked‐end steel fibers on the fresh, mechanical, and microstructural properties of steel fiber‐reinforced self‐compacting concrete containing fly ash. A total of 12 mixtures were prepared. Hooked‐end steel fibers at four different volume fractions (0%, 0.3%, 0.6%, and 0.9%) were applied as reinforcement, while the

This study focuses on the relationship between the internal viscous damping and the stiffness of concrete material and structure having small deformation amplitude. New damping parameters were proposed to describe the energy dissipation capacity and the vibration–amplitude attenuation rate. An improved damping suspension test method for predicting the essential material parameters, elasticity modulus

The construction of underground structures is playing a relevant role in modern society. As a result of noticeable tunnel boring machine (TBM) evolution, mechanized excavation methods are gaining increased market shares. TBM driven tunnels are generally used in combination with precast concrete segments as the main support system for reducing or minimizing surface disturbances during construction and

The objective of this paper was to evaluate the strength and ductility of laterally confined concrete. To reach the purpose, the effects of the investigated parameters including concrete strength, the volumetric ratio, tensile strength, configurations of transverse reinforcements, as well as the longitudinal reinforcements ratio on the strength and the ductility of laterally confined concrete were

To investigate the influence of hybrid effect of different sizes of polypropylene fibers (PPFs) on the compressive constitutive mechanical parameters of roller compacted concrete, nine groups of fiber reinforced concrete specimens containing different sizes of PPFs were designed and the uniaxial compressive testing was conducted. Based on the existing compressive constitutive model and the test stress–strain

This study assessed the performance of self‐compacting rubberized concrete against carbonation and chloride penetration. In addition to fresh‐state and compressive strength tests, durability of the studied mixes was evaluated by measuring carbonation and chloride penetration depths, total porosity, and pores'size distribution. It was found that an increase in rubber content leads to a decrease in compressive

Generation of waste has been a significant problem in recent decades in many engineering fields. Self‐compacting rubberized concrete (SCRC) is a new type of SCC, which replaces part of natural aggregates by rubber aggregates in SCC to increase the application range of waste tyre rubber. This study investigates the effect of age and crumb rubber aggregate ratio on fresh and mechanical performance. Eight

One of the main areas where it is generally accepted that fibers play a significant contribution in construction practice is in the control of cracking. The primary objective of the fibers is to traverse cracks after they nucleate. The fibers provide some post‐cracking resistance to the otherwise brittle concrete. Much of the research contained in the literature on the cracking behavior of fiber reinforced

An experimental study on the nonlinear damping behavior of recycled aggregate concrete (RAC) beams is conducted through subjecting dynamic loadings at the different damage stages. The effects of the loading frequency, loading amplitude, damage, recycled aggregate, and replacement percentage on the energy dissipation by damping and the equivalent viscous damping ratio (EVDR) of the RAC beams are analyzed

The tumultuous year of 2020 finished in chaos, and 2021 started with nobody able to predict what would happen. This is the beginning of a new period, with humanity facing challenges that it has never seen before. Like it or not, we have been plunged into a virtual world. Groping our way forward, we have discovered that committee sessions, meetings and symposiums can be made to work online. At the same

In this study, the self‐healing behavior of engineered cemetitious composites (ECC) containing different types and quantities of fly ash (FA) under colloidal nano silica (CNS) curing conditions was investigated through the examination of their different permeability properties. FA in two different characters, Class F and Class C, were used in the preparation of the mixtures in high volumes (FA/portland

The porous lightweight aggregates adversely affect fresh properties of concrete, including slump and disruption of pumping concrete. Besides, this type of concrete is very susceptible to shrinkage cracking. In this study, two types of lightweight aggregates were used with a combination of two types of coating, including hydrophobic polymers ‐polyvinyl acetate and styrene‐butadiene rubber coatings.

When the structural capacity of precast concrete structures is to be determined, reliable and practical models for estimation of the ultimate load carrying capacity of the structural connections are essential. In this paper, rigid‐plastic upper bound solutions for the load carrying capacity of keyed shear connections subjected to shear and normal forces are derived and compared to experimental results

Shear connections in prefabricated concrete buildings are important for the structural performance in both the serviceability and the ultimate limit state. A normal force has a large impact on the shear strength and deformation capacity, however, no experimental record includes compression–shear and tension–shear interaction. This article presents an experimental investigation of keyed shear connections

With an increase in CO2 emission, corrosion of reinforcement as a result of carbonation has become more significant to researchers besides corrosion due to chloride ion ingress. Many structures are exposed to coupled effects of carbonation and chloride attack; therefore, investigating the effect of this combined attack on the durability of concrete is a vital subject. Also, the use of supplementary

The influence of microstructural changes on concrete properties at elevated temperatures is presented and discussed in this paper, as the exposure to elevated temperatures brings in marked changes in concrete thermal, mechanical and kinematic properties owing to the heat‐induced evolution of material's microstructure. The major microstructural changes consist in increasing pore size, occurrence of

Use of hollow cold‐formed steel (CFS) sections has gained popularity in the construction of light industrial and commercial structures. However, their overall load carrying capacity under flexure can be severely affected due to the possible buckling failure modes. Addition of concrete as an infill material for hollow CFS sections can significantly improve their overall performance by resisting their

The behavior of fiber reinforced concrete (FRC) depends on the characteristics of both the concrete matrix and fibers. Previous studies have concluded that the number of hooked ends increases the contribution of steel fibers to the tensile performance of concrete. ACI 318 code, MC10 fib code and RILEM TC 162‐TDF standard permit the use of steel fiber reinforced concrete (SFRC) for example, the minimum

In this study, the efficiency of using high strain hardening ultra high performance concrete (HSH‐UHPC) on strengthening existing reinforced concrete beams was investigated by experimental and analytical means. First, the HSH‐UHPC constitutive relation was obtained using “Dog‐bone” specimen under uniaxial tensile test. Then three reinforced concrete beams strengthened with HSH‐UHPC layers and one control

In order to understand the overall picture, the different technologies for the use of thin‐walled prefabricated elements in bridge construction as well as the first‐time application of them in a bridge project in Austria are described in this paper. Thereafter a newly developed construction method for the on‐site fabrication of lightweight box‐shaped segments from thin‐walled concrete elements, strengthened

To research the flexural performance of ultra‐high performance concrete (UHPC) filled high‐strength steel tube (UHPCFST) and UHPC filled double skin high‐strength steel tube (UHPCFDST) under bending load, an experimental investigation was presented. In this paper, four UHPCFST specimens, one UHPCFDST with square tube inner specimen and three UHPCFDST with circular tube inner specimens were designed

In order to further study the seismic behavior and working performance improvement path of reinforced concrete columns under oblique earthquake action, seven concrete columns with HTRB630 steel bars were designed. The loading direction axial compression ratio and column end restrained pattern were chosen as the main design parameters. The low cyclic reversed load test has been carried out on understanding

Cores were drilled from the panels made of different concrete mixtures. The compressive strength and splitting strength of core and cube specimens were tested at the ages of 7, 28, 60, 90, and 180 days. The effect of the diameter on concrete core splitting strength was examined. The strength correction factors were determined to convert the splitting strength of the core with diameter of 75 mm to that

Despite the Covid‐19 pandemic, 2020 was a successful year for Structural Concrete. The Impact Factor increased up to 2.174 and the number of paper submissions amounted to 835, compared to 587 in 2019. I could manage this impressive number of paper submissions thanks to the support of Akio Kasuga, Deputy Editor‐in‐Chief, and Frank Dehn, David Fernandez‐Ordoñez and Tamon Ueda, the three Associate Editors‐in‐Chief

Three‐Mile‐River Bridge is located in Lu‐shan County, Henan, China. The bridge length is 80 m and width is 17.25 m with the deck thickness being 0.3 m. The deck construction is finished in June 2018, which consumed 200 cubic meter of crumb rubber concrete (CRC) with added super‐absorbent polymer (SAP), and opens for traffic in July 2018. This is the first case of SAP‐CRC bridge deck reported to the

In this work, fracture monitoring of steel and GFRP bars reinforced concrete beams in flexure is investigated by using non‐destructive acoustic emission (AE) and digital image correlation (DIC) techniques. The combined methodology provides complementary information from 'the ear' aided by the AE and from 'the eye' aided by the DIC. AE waveform parameters of the number of AE hits and their amplitudes

This paper aimed to develop a method to analyze and rank self‐consolidating concrete (SCC) according to its robustness, considering isolated and simultaneous variations in its main components, like water (±6%) and cement content (ΔC±), in three matrices with binder to aggregate ratio (rich, intermediate and poor). In the experimental campaign, only water variations (±6%) were considered, and the cement

Continuous tunneling using a tunnel‐boring machine is a very popular method when it comes to the construction of large tunnel projects. The use of precast reinforced concrete elements, called tubbings, is a highly economical way to secure the tunnel post excavation. Unfortunately, a loss of the load‐bearing capacity has been observed in the past in the joints between the tubbings. Reasons for that

Geopolymer concrete (GPC) is an innovative and eco‐friendly construction material. In the experimental investigation, examine the effect of ground granulated blast furnace slag (GGBFS) in the GPC by replacing the fly ash in the various ratios in the different mix design. Fly ash/GGBFS as 100/0, 75/25, 50/50, and 25/75 respectively rate by weight percentage taken in the mix design. All the mix designs

Most old‐type reinforced concrete (RC) buildings reinforced with smooth bars are often subjected to dynamic loads and the structural joints are usually in a complex tensile‐compressive stress state. To evaluate the safety and durability of RC structures with the finite element method, the dynamic bond performance of smooth bars in concrete under transverse tensile‐compressive stresses needs to be well

The increase of coarse aggregate content decreases the shrinkage of concrete, decreases the cost of concrete production as well as reduces the carbon dioxide emission to the environment. In this study, the mixture proportions of PFCC (post‐filling coarse aggregate concrete) for C40, C50, and C60 were designed and the comprehensive performances of workability, compressive strength and elastic modulus