Abstract This study evaluates the static and fatigue bond behavior in basalt fiber-reinforced polymer (BFRP) bars embedded in concrete. For bond behavior under a mono-tensile load, BFRP bars with four types of surface patterns (round, rectangular, cross-winding, and spiral-winding) were adopted, and 20 groups of rib parameters were introduced for round-type BFRP bars. The bond–slip relationships and

Abstract High temperatures impose a negative effect on the mechanical properties of concrete. An experimental setup designed by the theory of nonlinear resonance vibration, the method of mercury intrusion porosimetry (MIP) and split Hopkinson pressure bar (SHPB) were used to test damage, porosity and mechanical properties of the pre-heated Brazilian discs of 10-year-old concrete respectively. According

Abstract There are two specific aims in this study; first is to develop and validate an automated crack detection technique for the fire damaged beam. Second is to investigate whether the detected crack information and thermal-structural behaviors can be numerically related. To fulfill the aims, fire tests and residual strength tests are conducted on RC beams having different fire exposure time periods

Abstract A nonlinear finite element model (FEM) is developed to assess the behaviour of a cracked concrete interface, reinforced with embedded steel bars and subjected to monotonic loading. A dowel action finite element modelling approach is conceived for that purpose. The bond between the steel bars and the surrounding concrete is also considered in the model and an interface finite element is included

Abstract Geopolymer concrete (GPC) with Glass fibre-reinforced polymer (GFRP) bars can provide a better construction system with high sustainability, high durability, and adequate strength. Few studies deal with the combination of these materials. The present investigation obtains the flexural capacity and behaviour of GPC and ordinary Portland concrete beams reinforced with GFRP bars (GFRP-RGPC and

Abstract This study deals with (a) the development of a prototype 3D printer for concrete structures having a bed size of 1 × 1 × 1 m for a laboratory testing and (b) laboratory testing of cementitious materials with different design mixes to find their suitability and efficacy for the developed 3D printer. In this printer, a program with the concept of computer numerical controlled milling was adopted

Abstract In regions where the concrete structures are exposed to a salty environment, the concrete requires high resistance to chloride-ion penetration. To achieve higher resistance against chloride ingress, a pozzolanic admixture incorporating a high volume of SiO2 and Al2O3 has been developed. The admixture is a fine mineral powder with a specific surface area of 13,000 m2/kg or higher. It is typically

Abstract The strength of reinforced concrete members can be enhanced using externally bonded reinforcement (EBR) and near surface mounted (NSM) methods. However, small number of studies has adopted the NSM method for torsional strengthening. To date, no study has examined the use of spiral NSM steel wire rope and epoxy adhesives for torsional strengthening. Therefore, this study examines the behaviour

Abstract Experimental and theoretical investigations on the flexural performance of steel reinforced ECC-concrete composite beams subjected to freeze–thaw cycles are presented in this paper. Four groups of reinforced composite beams with different ECC height replacement ratios subject to 0, 50, 100 and 150 cycles of freeze–thaw were physically tested to failure. Experimental results show that the bending

Abstract Axial compression test was conducted to investigate the effect of confinement on plain concrete cylinders by wrapping polyethylene naphthalate fiber reinforced polymer (PEN FRP) with large rupture strain (LRS) capacity. To draw comparison on the confinement effect by PEN FRP wrapping, the confining effect by basalt FRP (BFRP) wrapping was also investigated. A total of 25 tests was completed

Abstract Reversed cyclic loading tests of two circular hollow RC piers were conducted in this study to investigate the effect of different amounts of inner and outer circular hoops on their flexural behavior. The test results showed that the column with a smaller amount of inner circular hoops presented better flexural response than the as-built column with an equal amount of inner and outer circular

Abstract To study the influence of different water–binder ratios on the corrosion, permeability, and freezing properties of concrete, we produced different strengths of concrete with respective water–binder ratios of 0.32, 0.38, 0.50, and 0.66. The corrosion resistance of the concrete was studied via three corrosion methods: full immersion, half immersion, and dry and wet cycles. The impermeability

Abstract This paper presents a mechanical model for the simulation of reinforced concrete (RC) wall boundary elements with lap splices, which builds on the tension chord model. The model is composed of an assembly of components, each one accounting for a different source of deformation. Namely: (i) an anchorage-slip element accounting for the strain penetration of the longitudinal reinforcement into

Abstract The flexural behavioral properties of ultra high performance concrete (UHPC) low-profile T-beams reinforced with a combination of steel fibers and steel reinforcing bars were investigated in this paper. Five large scale T-beams were tested and analyzed regarding their deflection, ductility, strain, curvature, load capacity and crack development. The experimental variables include the reinforcement

One type of failure of reinforced concrete seismic walls is out-of-plane buckling. This type of failure appears at the compressive cycle of loading during the cyclic seismic loading. This work is mainly experimental and tries to investigate the influence of the mechanical factor of tensile deformation on the behavior of seismic walls and particularly on the phenomenon of lateral buckling. Five test

Abstract This paper reports the results of a seismic performance study of a precast shear wall with a new horizontal connection. The new connection is the rabbet-unbonded horizontal connection, which is composed of rabbets and unbonded rebar segments. The rabbets are used to improve the shear capacity and prevent slippage of the connection, and the unbonded rebar segments are used to improve the ductility

Experimental investigation on seismic performance of RC shear walls reinforced with CFRP bars in boundary elements to enhance the resilience was presented which is expected for stable resistance capacity and small residual deformation. Six RC shear walls reinforced with CFRP bars as longitudinal tensile materials in boundary elements were tested under reversed cyclic lateral loading while subjected

This work quantified the hierarchy of the influence of three common mixture design parameters on the compressive strength and the rate of strength increase over the long term of low-calcium fly ash geopolymer concrete (FAGC) through designing 16 mixtures by the orthogonal experimental design (OED) method. The parameters used in the study were liquid to fly ash (L/FA) ratio, sodium hydroxide concentration

Performance-based approach, introducing a new two-phase computational model for determining the response of prestressed hollow-core concrete slab exposed to natural fire including heating and cooling phase, is presented. Firstly, the two-dimensional coupled hygro-thermo-chemical model is used to determine time dependent temperature and moisture field in the characteristic cross-section of the concrete

The exposure of concrete to gamma radiation gives rise to a set of physical and chemical processes over multiple length scales, from molecular to bulk. The literature includes a number of bulk-scale studies which report the radiogenic heating of concrete and the loss of water (unbound, physically-bound, and/or chemically-bound) due to irradiation. This paper mechanistically quantifies observations

This study investigated the mechanical behavior of normal strength (NS) and high strength (HS) concrete containing recycled fine aggregates (RFAs). A high slump mixing design was employed, which may be potentially used as filled structural concrete. The compressive strength, tensile strength, and elastic modulus were measured according to the RFA replacement ratio and curing time. In addition, the

This paper presents a general procedure based on fracture mechanics models in order to analyze the level of cracking and structural safety in reinforced concrete elements at early ages, depending on the stripping time. Our procedure involves the development of a thermo-mechanical numerical model based on the finite element method that accounts for the change in the mechanical properties of concrete

This study aimed to investigate the effects of small openings on the structural performance of reinforced-concrete (RC) structural walls. Cyclic lateral loading tests were conducted on five RC walls with an aspect ratio of 2.6 and small openings. The main test parameter was the size of the small openings. The specimens were designed to fail after flexural yielding, considering the typical failure mode

As part of the research on cement composites using cellulose nanocrystal (CNC) aqueous solution instead of general water, this study produced high-toughness cement composites reinforced with flax and steel fibers to improve the tensile deformation capacity, assessing the isothermal conduction calorimetry analysis, drying shrinkage, and strength characteristics. The mixing amount of CNCs was 0.4, 0

In this article, incorporation of nano-SiO2 (NS), nano-TiO2 (NT) and nano-Al2O3 (NA) particles and their binary and ternary blends on water filtration in oil-well cement slurry was examined. The nanoparticle contents were chosen at proportions corresponding to 1, 2, 3 and 4% based on the weight of cement. The experimental specimens were tested at three various temperatures of 70, 80 and 90 °C using

This paper investigates numerically and experimentally the performance of reinforced concrete (RC) beam with unequal depths subjected to combined bending and shear. Such beams can geometrically be considered for unleveled reinforced concrete (RC) floor slab-beam system. However, it may generate critical disturbances in stress flow at the re-entrant corner (i.e. location of drop in beam depth). This

This paper proposes a new kind of U-type reinforcement ferrule (URF) connection for the assembly of precast concrete (PC) components, which has a good fault-tolerance ability and low cost of construction with a simple post-grouting process. The modified connection features welded U ferrules, which can increase the bonding mechanism and internal stress transmission in the spliced region. A series of

Basalt fiber reinforced polymer (BFRP) rebars reinforced coral aggregate concrete is a new type of concrete used in ocean engineering. In order to investigate the bond performance between BFRP rebars and coral concrete, 30 pull-out tests were carried out in 10 groups with different diameters of BFRP rebars, bonding lengths and strength of the coral concrete. The results show that good bonding between

The study reported herein aims at investigating the behavior of medium-scale circular reinforced concrete columns wrapped with fiber reinforced polymer (FRP) sheets under concentric and eccentric axial loads. The experimental program was devised to assess the effects of loading conditions, absence/presence of an FRP jacket as well as the FRP wrapping system. To achieve the study objectives, four column

A simple yet effective constitutive model-referred to as the “Fixed Strut Angle Model” (FSAM)-is presented in this paper for simulating the nonlinear axial/shear behavior of reinforced concrete membrane (panel) elements subjected to generalized and reversed cyclic loading conditions. In the formulation of the FSAM, normal stresses in cracked concrete are calculated along fixed crack (strut) directions

The objective of this study is to assess the shear friction characteristics of lightweight aggregate concrete (LWAC) prepared using artificially expanded bottom ash and dredged soil granules. A total of 37 concrete mixtures were prepared under the classification of three series. In the first and second series, the natural sand content for replacing lightweight fine aggregates and the water-to-cement

To quantify the post-earthquake residual seismic capacity of reinforced concrete (RC) column members, experimental data for 6 column specimens with flexural, flexural–shear and shear failure modes are used to derive residual seismic capacity of damaged RC column members for specified damage states in this work. Besides of the experiment data, some related researches are also investigated to suggest

A new plastic–damage constitutive model based on the combination of damage mechanics and classical plastic theory was developed to simulate the failure of concrete. In order to explain different material behaviors of concrete under tensile and compressive loadings, the plastic yield criterion, the different kinematic hardening rule for tension and compressive and the isotropic flow rule were established

Among fiber-reinforced composites, steel fiber has been widely-used for concrete infrastructure such as silos, tunnels, specifically aiming at reducing the weight of concrete and enhancing its strength by overcoming the brittleness. However, there is still little known about appropriate quality management and applicability assessment for steel fiber composites. This study fills this knowledge gap by

High-volume slag (HVS) can reduce the CO2 emissions of concrete, but increase the carbonation depth of concrete. In particular, because of the effects of climate change, carbonation will accelerate. However, the uptake of CO2 as a result of carbonation can mitigate the harm of CO2 emissions. This study proposes an optimal mixture design method of low-CO2 HVS concrete considering climate change, carbonation

In this paper, a prediction method based on artificial neural network was developed to rapidly determine the residual shear resistance of reinforced concrete (RC) beams after fire. Firstly, the temperature distribution along the beam section was determined through finite element analysis using software ABAQUS. A residual shear strength calculation model was developed and validated using the test data

Twenty-seven large-scale beams with dapped-end have been prepared, cast and tested to failure in the three points loading arrangement. One control beam has been designed in accordance with requirement of standard code while the dapped-end reinforcement scheme of other beams has been derived from the control beam. In selected beams, engineered cementitious composites (ECC) has been utilized in the dapped-end

Huge amounts of by-products are generated from industrial processes which affect the environment adversely. Production process of conventional cement is energy demanding and it also emits enormous amounts of greenhouse gases. Geopolymers are the new generation green material that has a great potential of replacing the conventional cementitious materials. The fresh and hardened properties of sodium

Reactive powder concrete (RPC) is an advanced cementitious material with ultra-high strength, remarkable durability and excellent toughness. However, temperature dependent creep is a major concern as very little work has been reported in the literature. Therefore, systematic investigations are still missing in state of the art. This paper focuses on the impact of Polypropylene (PP) and hybrid (steel

Although pretensioned concrete structures have increasingly been used worldwide, a number of design issues need to be addressed to further improve the structural performance. Transfer length of pretensioned members was investigated with several test variables in this study by adopting various sensing technologies including the Smart Strands with embedded fiber optic sensors. The effect of increased

This research describes the results of an experimental work that aimed to investigate the flexural capacity of RC columns with low longitudinal reinforcement ratio that was strengthened with near surface mounted GFRP bars. The experimental program consisted of four square reinforced concrete columns, including one control specimen that were designed with a longitudinal reinforcement ratio below the

In this research, a cable-type wall system that could replace the conventional aluminum curtain wall system for reinforced concrete high-rise buildings is proposed. The cable-type wall system is a newly developed system, which could be used as an existing exterior skin system, and can effectively support the wind load acting on the exterior of the high-rise buildings by the pre-induced initial tension

The aim of this work is to propose a technique to calculate the strength of short concrete-filled steel tube columns under the short-term action of a compressive load, based on the phenomenological approach and the theoretical positions of reinforced concrete mechanics. The main dependencies that allow the realization of the deformation calculation model in practice are considered. A distinctive feature

Aging and structural deterioration under severe environments are major causes of damage in reinforced concrete (RC) structures, such as buildings and bridges. Degradations such as concrete cracks, corrosion of steel, and deformation of structural members can significantly degrade the structural performance and safety. Therefore, effective and easy-to-use methods are desired for repairing and strengthening

Workability of concrete varies during pumping. Even though concrete satisfies the required workability before pumping, it often does not satisfy the required standard after pumping. Moreover, serious problem could happen such as segregation and blockage. In this study, the rheological properties of concrete change during pumping from the pressure distribution over the pipe length was investigated.

If reinforced concrete columns and walls in high-rise buildings are subjected to axial load for a sustained duration, long-term lateral deformation (or curvature) as well as axial shortening increase over time due to the creep and shrinkage of concrete. In the present study, sustained load tests were performed to evaluate the time-dependent axial shortening and lateral displacement occurring in eccentrically

With the increase in high-rise building construction, failure to consider constructability in the design phase can result in huge wastes in the construction phase, as well as losing opportunities for design improvement. However, existing approaches for reflecting constructability rely heavily on reviews, resulting in an inefficient decision-making process. Thus, by considering appropriate timing and

Differential axial shortening (DAS) in a tall building can produce adverse effects on its structural and nonstructural elements. Therefore, DAS should be considered in the design phase and appropriate measures should be taken to reduce its unfavorable effects. In this study, the utilization of outriggers, which has been originally designed to reduce lateral displacements, is proposed to reduce DAS

In Korea, radiant floor heating systems are commonly used in residential buildings, even high-rise houses. If these existing radiant floor heating panels could be used for cooling as well, additional benefits beyond the basic advantages of radiant heating and cooling systems in terms of energy efficiency and comfort level could be conferred upon the homeowner, such as avoiding redundant investments

In this study, an output-based neuro controller was built based on the idea of the adaptive neuro-fuzzy inference system (ANFIS) and its capabilities in response simulation, data cleansing and restoration capability were verified using measurement data from actual structural testing. The ANFIS is a family of the deep learning algorithm, which incorporates the benefits of adaptive control technique

The corrosion of steel reinforcement is commonly believed to be the primary cause of structural deterioration of reinforced concrete (RC) structures; as a result of this deterioration, a RC structure can incur a considerable reduction in structural serviceability and safety. Because of their inherent redundancy, statically indeterminate structures develop resistant mechanisms that can potentially assist

A renewable energy storage system is being proposed through a multi-disciplinary research project. This system utilizes reinforced concrete pile foundations to store renewable energy generated from solar panels attached to building structures. The renewable energy can be stored in the form of compressed air inside the pile foundation with a hollowed section. The pile foundation should resist complex

In the present study, tensile tests were carried out to investigate the tensile behaviors of textile reinforced mortar (TRM) composite specimens. The TRM specimens were composed of one layer of carbon fibers, as the reinforcement, and aluminum cement-based mortar, as the matrix. The primary parameter of the test specimens was the anchorage method, which was newly developed to improve the tensile behavior

The rapid-hardening method employing the injection of calcium sulfoaluminate (CSA) cement mortar into voids between preplaced ballast aggregates has recently emerged as a promising approach for the renovation of existing ballasted railway tracks to concrete tracks. This method typically involves the use of a redispersible polymer powder to enhance the durability of the resulting recycled aggregate

Within the EC funded project smart elements for sustainable building envelopes, carbon textile reinforcement was incorporated into reactive powder concrete, namely textile reinforced reactive powder concrete (TRRPC), to additionally improve the post-cracking behaviour of the cementitious matrix. This high-performance composite material was included as outer and inner façade panels in prefabricated

This paper presents an experimental investigation on the stress–strain behavior and the damage mechanism of polypropylene fiber reinforced concrete (PFRC) under monotonic and cyclic compression. Fifty-four specimens for different fiber volume fractions and aspect ratios were tested. Acoustic emission (AE) technique was used to monitor the damage progression. The damage mechanism of concrete was analyzed

The effects of different contents and particle sizes of waste glass powder on alkali–silica reaction (ASR) expansion of cementitious composite bar were investigated in this study. Waste glass powder with particle size less than 300 μm exhibits an excellent mitigation effect on ASR expansion. With larger content and smaller particle size, the mitigation effect of waste glass powder on ASR expansion

To avoid excessive slip of beam longitudinal bars at the joints of an earthquake-resisting moment frame, ACI 318 Building Code set a minimum joint depth of 20 times the diameter of the largest longitudinal beam bars passing through the joint, which is based on prior experimental verification of beam-column joints with Grade 420 MPa reinforcement. In view of that the 20-bar-diameter criterion cannot

In 2013, our research group published a contribution in which a new version of genetic programming, called Geometric Semantic Genetic Programming (GSGP), was fostered as an appropriate computational intelligence method for predicting the strength of high-performance concrete. That successful work, in which GSGP was shown to outperform the existing systems, allowed us to promote GSGP as the new state-of-the-art

Concrete structures expand and contract in response to temperature changes which can result in structural strain and cracking. However, there is a limited amount of robust field data on hybrid concrete floor structures. Shortage of such data impacts on our understanding of how concrete structures respond to thermal effects and ultimately the overall design of concrete structures. Thus, a comprehensive