Fracture process of fiber-reinforced concrete notched beams is investigated here. Polypropylene macrosynthetic fibers are utilized for reinforcing concrete specimens, and a high-strength mix design is used to produce strong bonds between the embossed polypropylene fibers and the cementitious matrix of beams. Considering different locations for the notch, this study focuses on bridging mechanism under

This research work is aimed to carryout experimental investigation on copper slag incorporated self-compacting (SCC) concrete; here, copper slag is used as a replacement to fine aggregate in the range of 0–100%. The self-compacting concrete is manufactured with powder matrix incorporating cement, flyash, metakaolin, and silicafume. The powder matrix is decided based on the objective of flow properties

It is essential to determine the thermal conductivity and earthquake performances by developing earthquake-resistant building systems that have high thermal insulation properties that will be economical for people considering the need for energy deficit and low-cost earthquake-resistant residences in the world. This study aims to evaluate the seismic performance of pre-casted reinforced concrete shear

Making optimal decisions about the reliability of existing structures requires that the information used in assessment adequately represents the properties and the condition of the structures. The knowledge gap regarding a structure to be assessed can be successively filled by individually purposeful observations on site. This paper gives an overview of an approach for utilizing nondestructively gathered

Shrinkage-reducing admixture has been proved as the best solution to reduce the shrinkage cracks on the surface of the concrete. Various shrinkage-reducing admixtures available in the local market are chemical, highly hazardous, and limited use in concrete. In the present research, rubber latex was used by replacing water up to 2% in geopolymer concrete. Volumetric shrinkage for geopolymer concrete

Even with specialized equipment, it is difficult to measure the thermal parameters of dam concrete during freeze–thaw testing. In addition, numerical calculations usually assume that freeze–thaw cycling does not change the thermal parameters of the aggregate and mortar of dam concrete, which makes it difficult to accurately determine how these parameters evolve during freeze–thaw deterioration. To

There are essential differences between recycled brick aggregate (RBA) and recycled concrete aggregate (RCA). The weak area of RCA is the old mortar attached to the aggregate surface, while the weak area of RBA is its own larger porosity. Silane has a small molecular structure, which can penetrate into the concrete with water as the medium and react with the active functional groups in the concrete

The aging engineering infrastructure is a growing problem in many countries and thus a challenge to make optimal decisions for their further safe operation. Therefore, effective diagnostic solutions are being sought to enable a reliable assessment of their technical condition. The article presents the results of static and high-frequency strain measurements of a 57-year-old posttensioned crane girder

Bond behavior is the basis of combined action of steel bar and high ductile concrete (HDC), which has an important effect on the mechanical performance of reinforced HDC structures. In this paper, nine groups of pullout specimens were tested to investigate the bond behavior and degradation mechanism of plain round bar embedded in HDC under monotonic and cyclic loading. The design parameters included

Rectangular Continuous Transverse Reinforcement (RCTR), as a replacement for conventional ties, is a relatively new form of reinforcement that can accelerate and facilitate the construction of reinforcement for RC members. In this study, the compressive behavior of concrete members with this kind of reinforcement is experimentally and theoretically investigated. Twenty-eight RC short column specimens

Frost damage is an important deterioration parameter for reinforced concrete (RC) structures in cold and humid environment, which usually acts simultaneously with sustained load caused by self-weight, immobile weight, and so forth. This article conducts a thermo-hydro-mechanical simulation on the structural behavior of RC beams under the coupled effect of frost damage and sustained load. This simulation

As a discontinuous ring structure, segmental longitudinal joints are a weakness of shield tunnels and play an important role in the determination of tunnel deformation caused by ground pressure. A longitudinal joint bending test is first carried out by employing a detailed 3D numerical model for the Shanghai Metro tunnel. This reveals that the joint stiffness varies nonlinearly with the axial force

This study experimentally examines the effect of rubber aggregate size on the static and dynamic behavior of rubberized concrete. Rubberized concrete specimens were prepared with different maximum rubber aggregate sizes ranging from 1 to 3 mm to 3 to 5 mm while the rubber content was kept constant at 15% by volume. The dynamic compressive behavior of rubberized concrete was investigated by using split

Steel fiber reinforced concrete (SFRC) is known for improving the tensile post-cracking fatigue behavior of concrete. This paper presents a method to obtain the cyclic tensile behavior of SFRC through sectional analysis, using a limited amount of input parameters. The analytical model is divided into two parts: a monotonic and cyclic model. The monotonic model calculates the uniaxial stress-crack width

The rapid reinforcement of reinforced concrete members is one of the research hotspots in the field of structural reinforcement. In this paper, the packaging technology is applied to the field of reinforced concrete structure reinforcement, and new technology of composite reinforcement of prestressed plastic steel strips and angle steel is proposed. Furthermore, in this work, axial compression tests

Transverse connection strengthening prestressed concrete T-girder bridge is an effective method to enhance the integrality of the T-girder bridge. In a previous work, a new kind of diaphragm transverse connections (DTCs) has been proposed and its validity has been proved. Aiming to study the influential parameters for the strengthening effect, finite element analysis is carried out based on a 30 m

Four circular hollow reinforced concrete columns were tested under quasi-static reversed lateral loading to investigate their seismic performance. The effects of the wall thickness ratio and confinement configuration on their seismic performance were studied, and the applicability of seismic ductility design requirements on circular hollow concrete columns was examined. The test results showed that

In order to improve the durability of concrete, hydrophobic technology is used to isolate the contact between concrete and external water. The addition of hydrophobic admixture is a popular method, but most of the hydrophobic agents mixed with cement sacrifice the partial strength of concrete to improve the hydrophobicity. In this paper, a novel and multifunctional hydrophobic admixture named YREC

The Italian “Guidelines for risk classification, safety assessment and structural health monitoring of existing bridges” were recently approved to define the technical principles for the management of the national network of existing bridges. This is a powerful tool to establish a common framework for risk mitigation and safety assessment of reinforced concrete (R.C.) bridges that represent most of

A major part of central European infrastructure buildings was designed decades ago and has different needs of strengthening. Increasing traffic volume, increasing axle loads, and a growth in transport volume as well as more restrictive design rules are the reasons why the support regions of existing bridges and flat slabs often show a lack of punching resistance today. At the University of Innsbruck

The thermal expansion deformation of concrete is significantly influenced by high temperature and moisture content. Before being heated at elevated temperatures of 100°C, 200°C, and 300°C, the initial moisture content of concrete specimens was maintained at 0%, 3.22%, and 6.55%, respectively. The temperature in the furnace was maintained at the constant temperature until the concrete center also reached

This paper mainly demonstrates some experiences in China regarding surface damage inspection and performance evaluation of reinforced concrete (RC) bridges. To begin with, the mechanisms of the major damages of RC bridges such as chloride attack, concrete carbonation, and rebar corrosion are briefly reviewed. A statistical result of concrete cracking that exists in (prestressed) concrete bridges is

In the literature, only one empirical model is available as a nondestructive method for the prediction of seismic performance levels of corroded reinforced concrete (RC) columns as a function of the initial corrosion crack width at lower corrosion levels. Because of the ruptured transverse reinforcement bars at higher corrosion levels, the structural behavior may turn brittle in terms of shear failure

Recycled powder (RP) that includes recycled paste powder (RPP), recycled mortar powder (RMP), and recycled concrete powder (RCP) is an eco-friendly alternative binder. This work investigated the influence of RP types and fineness on early-age behavior and mechanical strength of cement-based materials. The results show that substituting RP for cement causes the reduction of new hydration products in

An experimental study was carried out to evaluate the effect of several fibers on the mechanical properties, drying shrinkage, and microstructural characteristics of alkali-activated kaolin binders. Four different types of fibers were evaluated in this study: polypropylene (PP) fiber, discontinuous structural synthetic (DSS) fiber, brass-coated steel (BCS) fiber, and hooked steel (HS) fiber. The fibers

The flexural behavior of slender (1/40) long-span precast high-strength concrete girders was experimentally investigated as a competing solution to steel alternatives for highway overpasses. Half-scale specimens were produced using an economical and high-strength (120 MPa) concrete mixture, non-fiber reinforced, designed only with conventional raw materials, currently available at Portuguese precast

To solve the fabrication problems of traditional precast shear walls caused by too many connections joints, a new type of precast shear wall with unconnected vertically distributed reinforcements and concealed bracings is developed in this paper. Four full-scale shear walls, including one cast-in-place specimen and three precast specimens, were tested under low-cycle lateral loading conditions to evaluate

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

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

Although square twisted section reinforcement is no longer used in new construction, there remain many older structures still in service that were built with such bars. The increasing need for assessment of existing construction means there remains a continuing need for information on performance over older types of reinforcement. Research into plain surface bars essentially ceased when ribbed bars

The paper describes the reliability-based optimization of a TT-shaped precast roof girder produced in Austria. An extensive experimental programme was performed using laboratory specimens to gain information on the mechanical fracture parameters of the utilized concrete. Subsequently, destructive shear tests were performed on scaled-down and full-scale girders under laboratory conditions. The experiments

Reinforced concrete (RC) members may expose to impulsive dynamic loads due to the reasons such as the explosions occurring in the interior or exterior part of them, rockfall, the vehicle crash to the bridges, the collision of masses with the effects of floods and landslide. Many studies have investigated the effects of impulsive dynamic loads on the beam, column, and slab RC structural elements have

The objective of the current study is to investigate and evaluate the flexural behavior of the continuity connection of precast prestressed concrete beams in negative bending when the tendons are located at the compression side. The experimental program included four T-shaped composite cantilever beams which were loaded up to failure. The main variable of the tests was the amount of prestress force

Semi-precast reinforced concrete (RC) slab, consisting of a precast plank with steel trusses, and a cast in-situ concrete topping, has attracted more and more attention owing to its low formwork cost and low labor work. In order to investigate the influence of joint on the slab flexural performance and the force transfer mechanism at the joint, eight semi-precast RC one-way slabs were fabricated and

Prestressed structures are commonly used all over the world. They might be subjected to degradation, such as corrosion of the prestressing steel. This can influence the resistance of these structures and induce early failure. Hence, prediction of the corrosion level is important in the assessment of existing prestressed structures. For this purpose, the corrosion process and the accompanying influences

The use of lightweight concrete can provide specific advantages that are favoring for mitigating seismic risk in building design. On the other hand, a significant reduction of carbon footprint could be possible through the use of geopolymer concrete. However, geopolymer concrete is mostly assessed through small specimens without reinforcement elements. This paper aims to couple the advantage of lightweight

In this paper, novel unified equations for predicting the residual flexural tensile strength of normal-weight, lightweight, and ultra-lightweight steel fiber-reinforced concrete (SFRC) are proposed. The unified equations were obtained by conducting multiple nonlinear regression analysis on the test results from 60 notched prism tests conducted according to EN 14651. The proposed unified equations account

The concrete undergoes brittle failure, which is a disadvantage for stability and safety analysis. This drawback was compensated by addition of different types and size of fibers for improving the compressive and fracture characteristics. The incorporation of multi-scale hybrid fibers in concrete showed enhanced performance at multi-level than that of single type or size of fiber. This study examined

Bond between steel and concrete is one of the key aspects of structural design and its performance evaluation. In the past much research work has been focused on understanding bond deterioration owing to corrosion of reinforcement, however, there exists no nondestructive method to access the bond condition. In this regard, the presented experimental research work details the development of a nondestructive

The nonlinear analysis of large complex reinforced concrete (RC) frame structures with shear-critical members requires numerical approaches that combine high accuracy and computational efficiency. At the same time, existing modeling approaches either involve detailed and costly discretization of the deformations in the frame members (displacement-based approaches), or compromise on accuracy by greatly

In recent years, basalt-fiber-reinforced-polymer (BFRP) bars have become popular to replace steels. However, little is known about the performance of BFRP bars inserted in lightweight aggregate concrete (LWAC), especially the bonding performance under freeze–thaw (FT) cycles. In this study, a bond strength test was conducted for BFRP bars embedded in LWAC after FT cycles. BFRP bars, epoxy-coated bars

This paper reports an experimental study of the influence of elevated temperature on alkali activated slag (AAS) and slag-metakaolin (MK) systems. The residual compressive and flexural tensile strengths, ultrasonic pulse velocity (UPV) and porosity and water absorption ratios of AAS and AAS-MK composites after subjected to elevated temperatures of 200, 400, 600, 800, and 1000°C were investigated. Two

Bond strength of steel reinforcement embedded in ultra-high-performance fiber-reinforced concrete (UHPFRC) plays a vital role in the post-cracking behavior of reinforced UHPFRC members in flexure or tension. This paper presents an analytical study on the bond strength of steel reinforcement in UHPFRC. Three different bond-slip models, namely the modified fib model, Marchand model and the proposed model

In this investigation, a phase change material with a melting temperature of about 450°C (PCM-45) is prepared and applied to solve microstructure degradation problem of concrete matrix when exposed to temperatures more than 500°C. The morphology changes of PCM-45 and the improvement effects of PCM-45 on microstructure of cement matrix are investigated based on microstructure characteristics, ultrasonic

In this study, the bond behavior of corroded reinforced concrete was investigated by conducting pull-out tests on concrete specimens with variable induced crack widths and different splitting modes. To simulate cracks due to corrosion and focus on their effect on bond strength degradation, a novel method using expansion agent filled pipes is proposed. With the increase of the crack width over elapsed

Mechanical behavior of engineered cementitious composites (ECC) under direct shear is investigated by the double-shear tests. The main test variables are the volume ratio (0%, 1%, 1.5%, 2%) of polyvinyl alcohol fiber and strength grade of ECC. The failure mode, load-slip response and shear mechanism of ECC under direct shear are analyzed and discussed, respectively. The test results indicate that the

Corrosion reduces the area of reinforcement steel, affects its mechanical properties, the bond properties, and produces concrete cracking. Thus, reduction of the bearing capacity and stiffness, increments of deflections and redistribution of stresses and internal forces, in statically indeterminate structures, take place. In addition, the efficiency of strengthening systems of corroded structures depends

This paper investigates the influence of aggregate packing optimization based on a particle packing method (PPM) and cement paste volume (CPV) on the workability and mechanical properties of both natural aggregate concrete (NAC) and recycled aggregate concrete (RAC). The slump, compressive strength, flexural strength and Young's modulus of concrete were first examined, followed with the characterization

When traditional response surface method is used to evaluate the reliability of concrete-filled steel tubular arch bridge, due to its complex structure and highly nonlinear implicit function, the response surface fitting accuracy is not high, and the reliability accuracy is difficult to meet the requirements of design specifications. In order to solve the above problems, this paper chooses dynamic

The focus of this study is to investigate the effect of using coarse recycled concrete aggregates (RCAs) as an alternative material to natural coarse aggregate on the fresh, mechanical and durability behavior of concrete reinforced with steel fiber. Eighteen unique concrete mixes with RCA content of 0%, 50%, and 100% and steel fiber content of 0%, 1%, and 2% were prepared, and tests were performed

The Cohesive/Overlapping Crack Model is able to describe the transition between cracking and crushing failures occurring in reinforced concrete beams by increasing beam depth and/or steel percentage. Within this Nonlinear Fracture Mechanics model, the tensile and compressive ultimate behaviors of the concrete matrix are modeled through two different process zones that advance independently one of another

An experimental program consisting in producing and testing reinforced concrete pipes (RCPs) under the three‐edge bearing tests considering different types of reinforcement was carried out. Four types of RCPs were produced, these reinforced with: (1) polypropylene macrofibers; (2) basalt microfibers; (3) combination of both (hybrid reinforcement); and (4) plain concrete. The analysis of the crack patterns

Structural reinforced concrete (RC) experiences cyclic loads during their service life, and in practice, the load amplitude can always change, which will lead to a mixed high and low‐cycle fatigue failure. This paper aims to investigate the fatigue behaviors of RC beams under different load levels and more importantly, their sequential effects. Based on the path‐dependent constitutive models, the structural

Redistribution of shear forces in reinforced concrete members without shear reinforcement is a key aspect for the assessment of the shear capacity of wide beams and slabs. Such redistributions are due to the nonlinear response of reinforced concrete (both in bending and shear) and have the potential to significantly modify the internal forces during loading. This phenomenon allows in many cases, as

The 3‐D base force element method (BFEM) for damage problems is proposed, which is applied to analyze the damage mechanism of recycled aggregate concrete (RAC). A piecewise curve damage constitutive model is given to simulate the constitutive relationships of RAC phases. A spatial random aggregate model of RAC is proposed. 3‐D numerical simulations of RAC under uniaxial mechanical stress are carried

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)