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Shrinkage of concrete refers to the volumetric change of concrete due to cement hydration (i.e., self‐desiccation) and environmental drying (i.e., water evaporation). It creates dimensional instability and induces tensile stress when the concrete is restrained that may be large enough to cause cracking. The most fundamental way to mitigate concrete shrinkage is to decrease the shrinkage of cementitious paste in the mix design. Some major factors of concrete mix design affecting the shrinkage include water‐to‐cementitious material (W/CM) ratio, dosage of superplasticizer (SP), concrete strength, and cementitious paste volume (CPV). While the effects of concrete strength and CPV on shrinkage are straightforward, those of W/CM and SP are more complicated because they also affect the pore size and distribution that influence the moisture movement. In this paper, it is advocated to study the concrete shrinkage by its wet packing density (WPD). Considering that the shrinkage of concrete is associated with the moisture movement in capillary pores and that the WPD accounts for the void ratio in fresh concrete, it will be shown in this paper that the shrinkage can be correlated negatively to the WPD with the consideration of CPV. The paper thus provides a new insight to the interdependence amongst shrinkage, CPV, and WPD of concrete. [ABSTRACT FROM AUTHOR]

This paper presents an experimental and analytical study on the age‐dependent mechanical properties of geopolymer concrete. The effect of total aggregate content and the ratio of sand‐to‐total aggregate content on the engineering properties of geopolymer concrete has been investigated. Geopolymer concrete cubes, prisms, and cylinders were prepared and tested for evaluation of the engineering properties of geopolymer concrete at the times of 3, 7, 28, 56, 90, and 180 days. The experimentally obtained results showed that the combination of 70% of the total aggregate by volume and 0.35 by weight the ratio of sand‐to‐total aggregate had been given the maximum strength of fly ash‐based geopolymer concrete. The assessment of available models for the calculation of age‐dependent modulus of elasticity and compressive strength with experimental results has been studied as well. An analytical model has been suggested for predicting the modulus of elasticity and compressive strength of geopolymer concrete at any age. The proposed models showed a good match with the experimental results. The present experimental and analytical study will be helpful in the production and design of geopolymer concrete structures. [ABSTRACT FROM AUTHOR]

Due to the outstanding mechanical properties of the reactive powder concrete (RPC), it has attracted a great deal of attention. In which, incorporating fibers can improve its behavior and properties. The main objectives of this study were to consider different mixing methods and the effect of fiber content and type on the mechanical properties of RPC. The best mix proportion was selected for the final tests among 13 initial mix designs based on the 7‐day compressive strength and flow value of the fresh concrete. Different macro and microfibers (including steel, polyvinyl alcohol, glass, carbon, and basalt fibers) with volume fractions of 0.5% and 1.5% were added to the final RPC mix by two different mixing methods, and mechanical properties such as compressive, tensile, and flexural strengths and energy absorption capability were investigated. Based on the results of experiments, the addition of 1.5% hybrid (macro and micro) steel fibers had the most positive effect on increasing the mechanical properties of RPC compared to other fibers. The hybrid fibers increased the compressive, tensile, and flexural strengths and flexural toughness of the specimens by 42.5%, 26.9%, 87.6%, and 396%, respectively. According to the results, the addition of 0.5% fibers to RPC did not significantly enhance the mechanical properties of the concrete. [ABSTRACT FROM AUTHOR]

The local bearing strength and deformation capacity of the reactive powder concrete (RPC) specimens can be dramatically improved by arranging steel spirals. In effect, the actual stress level of spirals is closely correlated with the compression behavior of concrete loaded over limited area. However, limited work has been focused on the actual stress of steel spirals in RPC. To obtain the actual confinement provided by the high‐strength spirals in anchorage zones, 10 RPC specimens loaded over limited area were conducted. The load–spiral strain relationships and the deformation–spiral strain responses were discussed to investigate the lateral response of RPC. The high‐strength spirals failed to reach the yield strength at the peak load, and the actual strain of the spirals ranged from 1800 to 2500 με, while the residual strength of the high‐strength spirals could be fully utilized after the peak load. The actual stress of the spirals at the peak load decreased with the concrete compression strength, which increased the volumetric ratio of spirals. Furthermore, the actual stress predicting equation of spirals in RPC at the peak load was developed based on the results. Meanwhile the formula for calculating the bound value of the volumetric ratio of spirals was derived to determine whether the spirals yielded at the peak load. In view of the above analyses, a method for calculating the local bearing capacity considering the actual stress of the spirals was further developed. [ABSTRACT FROM AUTHOR]

Ultra‐high performance concrete (UHPC) is increasingly used for various engineering applications, owing to its superior strength properties. Such properties, however, can be accompanied by workability issues, especially if the dosage of steel fibers is significantly increased. As a potential solution, this study explored the use of a combination of steel microfibers and macrofibers through a holistic experimental testing program. This was to understand the effects of steel fiber combinations on the workability and flexural strength of various UHPC mixtures. The microfibers were investigated for five different dosages from 1.0% to 3.0% (with an increment of 0.5%). In parallel, two mixtures were prepared with a 2.0% dosage of macrofibers in the form of twisted wire and hooked fibers. At the next stage, six additional mixtures were prepared with a combination of microfibers and macrofibers of various dosages. Further to the measurements extracted from the workability and flexural strength tests, digital image correlation (DIC) analyses were employed to obtain firsthand information about the widths and depths of cracks observed in the flexural specimens tested under an increasing load. The outcome of this study showed how a combination of microfibers and macrofibers can contribute to improving the flexural response characteristics of UHPC, especially without having to increase the dosage of steel fibers to the ranges that can adversely affect the mixture's workability. [ABSTRACT FROM AUTHOR]

Numerical simulation of the bond is a powerful and versatile tool to analyze different aspects of reinforcement and concrete interaction, such as the formation of internal cracks, damage of concrete around the bar or bond degradation near the cracks. In the present study, a three‐dimensional rib‐scale finite element modeling technique was employed to study the latter phenomena. Numerical models were calibrated using the experimentally measured reinforcement strain profiles in the short tensile reinforced concrete elements reported herein and elsewhere. The selected experimental programs cover a wide range of bar diameters (10–29 mm) that are commonly used in the engineering practice. A parametric analysis was performed to identify the key parameters affecting the bond stress distribution in the vicinity of cracks. Based on the results of the parametric analysis, a simple bond damage model was proposed. Unlike the existing models, which take into account a single parameter, namely, bar diameter, the proposed bond damage model also considers the effect of concrete grade and reinforcement strain in the cracked section. [ABSTRACT FROM AUTHOR]

Artificial lightweight aggregates (LWA) generally can be more deformable in lateral expansion than that of natural crushed stone. Therefore, concrete made of LWA can exhibit a higher Poisson effect, and this characteristic could be advantageously used in the confined elements. In the present study, experimental research on behaviors of semi‐lightweight aggregate concrete filled steel tube (LWACFT) under axial compression is performed, in which the key parameters such as the volume content of LWA and the thickness of steel tube are involved. The results showed that the bearing capacity of LWACFT columns is influenced by the compressive strength and Poisson effect of LWAC in dual‐facets. With a rational LWA volume fraction, the bearing capacity of LWACFT columns is not less than that of traditional CFT. Furthermore, the experimental results of bearing capacity are compared with the results by current design codes. With the volume content of LWA and the steel thickness as the variable, the modified and simplified models have been proposed to predict the axial load versus strain curves and the bearing capacity of LWACFT columns. The research results have demonstrated that the predicted results by the model proposed in this study agree well with the experimental ones. [ABSTRACT FROM AUTHOR]

Differential axial shortening (DAS) between columns and core, due to time‐dependent phenomena and elastic deformation, is a very important aspect to be considered in the design of concrete high‐rise buildings. This research compares the DAS of 250‐ and 500‐m‐tall buildings considering different materials for the columns and core. In fact, a parametric study is performed to evaluate the effects on DAS when using composite, reinforced concrete (RC), or high‐performance concrete (HPC) columns, such as an RC or lightweight aggregate RC (LWARC) core. A finite element commercial software has been validated and then employed to estimate the DAS. All studied cases are defined on the basis of the Cristal Tower, located in Madrid, to provide reliable estimates of DAS. Results illustrate that columns made of HPC present lower DAS at infinite time and required diameters similar to the composite solution. Furthermore, an LWARC core shows higher axial shortenings compared to the RC alternative. For these reasons, the combination of HPC columns with the LWARC core is presented as a promising solution to reduce the effects of DAS in tall buildings. [ABSTRACT FROM AUTHOR]

This paper describes tests performed with large, post‐installed bonded fasteners installed in concrete of very low compressive strength. Concrete with several strengths were studied, including strength classes under C20/25. The goal was to determine whether such connections could be designed according to EN 1992‐4, as they deviate from the scope of this standard by the fact that the concrete is outside the permissible compressive strength range. Additionally, these tests aimed to cover the knowledge gap regarding bonded fasteners installed with large‐diameter threaded rods, deep embedment depths, and reduced edge distances, since little research has been done in this area. Tests on single fasteners and on a group of four anchors were performed, and the results were compared with the design values calculated according to EN 1992‐4. Conclusions have been drawn, and possible underestimation of the load‐bearing capacity of such anchorages has been quantified. [ABSTRACT FROM AUTHOR]

The paper reviews the development of limit analysis, from Galileo through Coulomb to the Mathematical Theory of Plasticity formulated by Hill and Hodge, Prager and Drucker, and independently by Gvozdev. The application to structural concrete slabs was pioneered by Johansen and Gvozdev and extended to walls (membranes), beam shear, and punching shear by Nielsen and the Copenhagen Shear Group. Simultaneous and subsequent advances were—and are—made by research groups in a.o. Zurich, Cambridge, Toronto, Houston, and Lausanne. The concept of yield lines, essential for the development of solutions, is introduced, and the distinction from the conventional notion of cracks is discussed. An overview of applications is given, focusing on slab flexure, in‐plane and beam shear, and punching shear. [ABSTRACT FROM AUTHOR]

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 to study slump, density, compressive and splitting tensile strengths, flexural behavior, surface hardness, surface abrasion resistance, water absorption, and sorptivity of each mix. It is shown that concrete containing RCA has a lower unit weight, compressive, splitting tensile and flexural strength, flexural toughness, surface hardness, and abrasion resistance, and a higher water absorption and sorptivity in comparison with conventional concrete. An increased compressive, splitting tensile and flexural strength, flexural toughness, surface hardness, and abrasion resistance, and a decreased water absorption and sorptivity of concrete with an increased steel fiber content from 1% to 2% is less significant compared to those from 0% to 1%. The results also show that, at RCA content of 50%, incorporating 1% steel fiber develops a concrete mix with similar or even better properties compared to unreinforced conventional concrete. At 100% RCA content, incorporating 2% steel fiber develops a concrete mix with similar properties to unreinforced conventional concrete having water to cement ratio of 0.3, but inferior properties to unreinforced conventional concrete having water to cement ratio of 0.5. These findings indicate that recycled aggregate concrete with similar or even better properties compared to concrete with natural aggregate can be developed through properly designing mixes, providing a great avenue toward the production of green construction material for structural applications. [ABSTRACT FROM AUTHOR]

This paper first presents a comprehensive database of 58 (specifically, 38 roadway and 20 railway) concrete arch bridges built in Spain during the last century. The collected information includes geometrical and mechanical data to define the main relations among different parameters and to identify specific trends. In addition, this information has been combined with data collected by other authors to compare results with other worldwide bridges with similar features. In summary, 112 concrete arch bridges covering a span range from 12 to 384 meters have been used to investigate relations of a variety of parameters such as flatness, arch and girder depths, bending stiffness, slenderness, effective slab thickness and dimensionless axial forces. Finally, based on this study, a data‐drive simplified procedure for the preliminary design of such bridges is proposed. [ABSTRACT FROM AUTHOR]

The interface transition zone (ITZ) is a critical component of concrete, as it has a significant effect on the material's mechanical properties. This paper using specimens of bonded new and old concrete analyzes the effect of the interface in recycled concrete on damping performance using semi precast concrete specimens with old and new concrete. To determine the effect of the bonding zone between new and old concrete on the damping ratio of recycled concrete, the free vibration attenuation test method was used. When the acceleration signal from the specimen's transverse vibration is transformed to the frequency domain, the study observes two prominent peaks. The damping ratio is between 0.005 and 0.007 at the high‐frequency position and 0.06–0.08 at the low‐frequency position. When the excitation position is not in the bonding zone, the damping ratio measured in the bonding zone has a smaller average value. Under different recycled aggregate replacement rates, there is a significant difference in the damping ratio and frequency of old and new concrete bonded specimens, as well as complete recycled concrete specimens. The bonding zone's damping ratio data is more discrete than that of other locations. The damping ratio and the acceleration amplitude exhibit an excellent linear relationship, with the damping ratio increasing as the amplitude increases. The damping ratio varies significantly more in the longitudinal direction, with no apparent relationship to the acceleration amplitude. [ABSTRACT FROM AUTHOR]

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 these problems, a study was performed on WFS as a partial substitution instead of natural sand in concrete. The effects of WFS on concrete performance were assessed through durability and mechanical performance. The results from experimental tests show that, compared to concrete blends with WFS up to 30% substitution, the control mix strength was only 7.6% (28 days) higher, and this improvement is not too high. In the same manner, concrete mixtures that contain WFS up to 30%, and their durability properties were somewhat same to blank max (control). Test results showed that WFS with a substitutions ratio up to 30% can be successfully used in concrete without disturbing its durability and strength properties. [ABSTRACT FROM AUTHOR]

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 to the coupling effects of fatigue load and minus temperature environment. Therefore, this paper investigated the mechanical damage evolutionary behavior of steam‐cured concrete under coupling effects of flexural fatigue loading and minus temperature. Additionally, the mechanism behind it was discussed. The results showed that the mechanical damage of steam‐cured concrete subjected to fatigue loading under minus temperature was more significant than that under room temperature. The influences of ice content on the degradation in mechanical properties of steam‐cured concrete are illustrated by the phenomenological model. A two‐stage statistical damage variable can well reveal the impact of fatigue cycles and temperature on fatigue damage and total damage concrete. Steam‐cured concrete based on PC‐FA‐GGBS binder system exhibits better resistance to the flexural fatigue loading and minus temperature coupling effects due to its better pore structure and less ice content. [ABSTRACT FROM AUTHOR]

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). This work's contribution lies in providing an overarching comparison of these approaches, thereby informing practitioners and researchers as to parameters concerning their assembly, application, and their accuracy. To such ends, two test series were carried out, one on RC tension rods and another on a RC beam in a four‐point bending test. From the latter scenario, for example, certain generalizations were to be deduced for varying load levels: low strains are measured well using the fiber optic technique. Conversely, digital image correlation was discovered to be an adequate choice when assessing higher strain levels and concomitant concrete cracking, as this non‐contact technique avoids imprecisions caused by adhesives. Findings are to assist the future user by contrasting the three techniques in terms of assembly, handling, application and resilience of sensors, external influences as well as measurement resolution and accuracy. Such practice‐oriented remarks should simplify a selection of the suitable measurement techniques catering to the respective, context‐dependent testing scenario. [ABSTRACT FROM AUTHOR]

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. The proposed approach accounts for the specimen materials and geometrical parameters including the ribs and strain gauges locations and proposes an expression for the normalized and absolute circumferential strains along the specimen circumference due to ribs actions. This paper presents a new three‐dimensional model of the specimen behvior during a pull‐out test, which provides new insight on bond mechanics and illuminates the role of the radial pressures developed as part of the bond action. Several simulations were performed on specimens with three different diameters, two concrete strengths, and a different number of bonded ribs. All the simulations show very good agreement with the measured strain data. This study enhances the understanding of bond resistance during a pull‐out process and contributes to the understanding of the ring action that is developed in a concrete cylinder during a pull‐out test. [ABSTRACT FROM AUTHOR]

A large experimental campaign and its analysis are presented with the main goal to experimentally investigate possibly significant influence factors on concrete edge breakout, tested on bonded anchors that are loaded in shear towards a free edge. The main investigated influence factors are (i) the used coarse aggregate type, and (ii) the concrete age. Three normal strength concretes with different coarse aggregate type (quartz, limestone, and basalt) were cast and tested at two different ages—28 and 70 days. The experimental investigation comprised material characterization tests performed on aggregates and concretes, and structural tests, that is, quasi‐static shear tests on installed anchors for three edge distances. The concrete failure surfaces were measured by means of photogrammetry in order to detect variations in cone size and shape dependent on coarse aggregate type and concrete age. The analysis based on the available data, normalizing with compressive strength obtained at the age of the anchor tests, reveals only a minor aggregate effect for the two larger investigated edge distances. Additionally, present differences between concretes are found to be smaller than those between different ages of the same concrete. [ABSTRACT FROM AUTHOR]

The use of recycled aggregate (RA) to produce recycled aggregate concrete (RAC) is a proven way of decreasing the consumption of natural aggregate (NA) and the landfilling of construction and demolition waste. However, adoption of codes for the design of RAC and RAC structures has been lacking. Within the framework of the new fib Model Code 2020 and Eurocode 2, provisions for RAC can be adopted. Therefore, in this study, a comprehensive and critical review of literature on RAC is performed as well as own meta‐analyses of results. Material properties of RAC and structural behavior of reinforced and prestressed RAC members are analyzed, and based on the findings, code adjustments for RAC are proposed. The results show that, in order to incorporate RAC into design codes, changes are necessary in expressions for physical–mechanical properties (volumetric mass, modulus of elasticity, tensile strength, fracture energy, peak and ultimate strains, shrinkage strain and creep coefficient), durability‐related properties (minimum concrete cover for durability) and structural behavior (shear strength of members not requiring shear reinforcement and deflections). The recommendations are formulated in terms of the total mass substitution ratio of RA that can be classified as Type A according to standard EN 206 for concrete. The results and findings presented herein can provide an important contribution toward the codification of RAC use and the wider utilization of RA in construction. [ABSTRACT FROM AUTHOR]

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 analyzed. A three‐dimension effective confinement coefficient of confined circular and rectangular columns was proposed to evaluate the effective confinement area of core concrete in both plane and elevation, and the strength and ductility enhancement factor prediction models of confined concrete were developed to evaluate the strength and ductility of confined concrete. The results showed that concrete strength, the volumetric ratio and configurations of transverse reinforcements, and the distribution of longitudinal reinforcements had obvious influence on the strength and ductility of confined concrete and only when lateral stress exceeded the yield strength of transverse reinforcements, transverse reinforcements had significant effects on the strength and ductility of confined concrete. Furthermore, the proposed strength enhancement factor and ductility enhancement factor models of confined concrete can be utilized to evaluate the strength and ductility of laterally confined concrete. [ABSTRACT FROM AUTHOR]

There is an increasing trend towards using recycled aggregate (RA) in concrete due to the shortage of high quality natural aggregates. The use of RA in concrete results in the conservation of natural resources, protects the environment and encourages sustainable construction. Though some studies have been conducted on the use of recycled aggregate concrete (RAC), the effect of mixture composition on its properties has not been well addressed. In the reported study, the effect of mixture composition, namely cement content and water/cement ratio and the proportion of RA on the mechanical properties of RAC was evaluated, with the intention of developing varying grades of RAC. As reported in earlier studies, the properties of RAC were generally inferior to that of normal aggregate concrete (NAC). Notwithstanding this, RAC with acceptable mechanical properties can be produced utilizing RA, for example RAC with low strength can be used in non‐structural applications. The construction industry should be encouraged to use RAC in building construction; as its use will lead to technical, economic and environmental benefits. Further, the use of RAC will lead to a sustainable development of the construction industry, particularly in regions that lack good quality natural aggregates. Based on the data developed in the reported study, the following quantities of RA are recommended to produce RAC: (i) 20% to produce low strength (20–30 MPa) concrete, (ii) 40% to produce medium (30–50 MPa) concrete and high strength (more than 50 MPa) concrete. Mathematical correlations between the mechanical properties of RAC with varying mix design parameters, such as cement content and water cement ratio and the quantity of RA, are also reported. These correlations can be used to predict the properties of RAC prepared with other proportions of RA and mix design parameters. [ABSTRACT FROM AUTHOR]

The paper describes the main mechanisms of carbonation and chloride penetration into concrete and how the rate of penetration can be measured with laboratory tests. It is also discussed why nondestructive test (NDT) methods for measuring directly the resistance of aged field concrete to carbonation or chloride penetration are not available. Only destructive tests are applicable which, given the very high‐spatial variability encountered, become prohibitive in terms of costs and damage. The only way to assess the resistance of aged field concrete to carbonation or chloride penetration is through surrogate tests measuring variables that are linked to it. There are two standardized test methods with potential as surrogate tests, as they are fast and entirely nondestructive: the coefficient of air permeability kT ("Torrent" method) and the electrical resistivity ρ ("Wenner" method). Data obtained on‐site with both methods are presented, confirming their potential to assess the resistance of aged field concrete to carbonation or chloride penetration. [ABSTRACT FROM AUTHOR]

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, a system for subsequent strengthening by the use of concrete screws was developed. Various laboratory tests showed that the system leads to a significant increase of punching resistance with minimal efforts for its installation. This article deals with the development of a numerical model that can predict the punching loads of unstrengthened and screw‐strengthened punching plates. Further the punching loads from the laboratory tests and the simulations are compared to the predictions of a design approach. The presented novel design approach is an advancement of the existing Eurocode 2 provisions and allows the influence of the screws on the punching resistance to be taken into account. The comparison shows that the numerical model predicts the punching resistances in an appropriate way and the design approach predicts them on the safe side. The presented design approach was included into the technical assessment for the concrete screws of the system reLAST as post‐installed punching reinforcement system [Z‐15.1‐340 (2019)] in order to be applicable in practice. [ABSTRACT FROM AUTHOR]

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, cumulative signal strength (CSS), average frequency, and rise‐time successfully pick‐up the divergent cracking initiation and fracture progression in steel‐reinforced concrete (RC) and GFRP‐RC beams. AE‐XY plots and longitudinal strain profiles obtained from DIC give an early, online, and real‐time representation of progressive AE activity and strains inside concrete much before it is visible to the naked eye. AE in conjunction with DIC was able to efficaciously depict the micro‐and‐macro cracks evolution and their advancement in steel‐RC and GFRP‐RC at various stages of loading Moreover, DIC identified critical damage areas as a function of loading periods, while AE was capable of monitoring the damage process and revealed changes in the overall behavior. It is successfully demonstrated that combined AE and DIC monitoring can enhance non‐destructive monitoring skills in RC structures involving widely different steel and GFRP bars as reinforcements and depict efficaciously their fracture/cracking behavior. [ABSTRACT FROM AUTHOR]

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 tests and push‐out tests, the experimental results indicated that: (1) The cracks of experimental specimens could be divided into two main forms: splitting failure (corrosion rate less than 5.79%); spalling failure (corrosion rate more than 5.79%). (2) A three‐stage bond‐slip law for concrete and corroded I‐shaped steel was proposed, and the formulae for calculating the bond strength were established. Furthermore, the degradation process of bond‐slip caused by corrosion was analyzed by energy principle and damage mechanics. Based on energy principle, it found that the elastic energy stored in the interface increased before the peak point of bond‐slip curve and decreased after the peak point, while the dissipated energy in the interface always increased with slip value. Finally, the interface relative damage variable was defined based on secant line anti‐sliding modulus and slip equivalent principle. The interface damage development process can be divided into three stages: initial damage, rapid damage development, and slow damage accumulation. [ABSTRACT FROM AUTHOR]

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 public with "pump concrete" technical being employed. The scanning of SAP‐CRC samples taken from the job site shows that rubber crumbs are largely uniformly distributed. The free restrained test on SAP‐CRC concrete and the test of restrained externally squared eccentric ring experiment on the mortar specimens made by filtering 10 mm coarse crumbs out of paving concrete show that SAP‐CRC exhibits an improved property in shrinkage behavior and cracking resistance. The original deck design is a three‐layer configuration: 0.3 m concrete + water approval sealing + 0.03 m hot mix asphalt. Consider CRC's excellence in preventing cracking, the sealing, and hot mix asphalt is removed, which results in a 10% reduction in construction cost and time. It is a technical success to add SAP into fresh CRC to suppress so called "rubber particle up‐floating phenomenon," as well as an engineering/commercial success in the sense that this deck project is implemented following common practices of commercial construction operation and cost‐saving, which sets an case study to future similar applications that potentially will consume large quantity, if not all, of recycled rubbers from scrap tires worldwide. [ABSTRACT FROM AUTHOR]

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 and loss modulus, was developed and validated. The results show that the viscous damping energy dissipation capacity of concrete material and structure having small deformation amplitude is proportional to the product of the loss factor and the stiffness, and the vibration‐amplitude attenuation rate is proportional to the product of the damping ratio and the natural frequency. The variation in dimensionless damping mainly results from the change in the stiffness of concrete material and structure. The porosity shows the smallest elasticity modulus and the largest energy dissipation capacity of nano‐phase in cement paste under constant loading conditions. The improved damping suspension test method is proposed based on theoretical analysis and is validated using an experiment and finite element analysis. [ABSTRACT FROM AUTHOR]

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 understood. Therefore, an experimental study including 248 pull‐out specimens is performed to characterize the dynamic bond properties of smooth bars in concrete under transverse tensile‐compressive stresses. Based on the experimental results and other data, the effects of various factors on the peak bond stress, the slip at the peak bond stress, and the shape of the softening branch are analyzed in detail. With two bond parameters and one shape parameter, a simple bond stress‐slip model is proposed. Through comparison with experimental results, the validity of the model is verified. [ABSTRACT FROM AUTHOR]

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 precast prestressed transverse beams span between the through‐girders involving the use of transverse posttensioning. An important feature of this system is to implement ultra‐high performance concrete (UHPC) at the all joints. The use of UHPC allows to minimizing the joint width and achieving superior durability. A numerical example is presented to demonstrate the analysis and design of the through‐girder bridge superstructure accounting for both high‐performance concrete (HPC) and UHPC options. The UHPC superstructure option can reduce the sizes of the structural members and allow to enhancing the structural performance. [ABSTRACT FROM AUTHOR]

Innovative drilling methods gain importance in the field of post‐installed fasteners. For this reason, users, customers and manufacturers demand methods other than the standard drilling procedure of hammer drilling, as they are hollow drilling with included cleaning and diamond drilling without emitting drill dust. One open question regarding these drilling methods is the equivalence of the behavior under the conditions of cracked concrete over the entire lifetime. These conditions are typically tested in the crack movement test, which simulates the real behavior of a fastener in cracked concrete over a designed lifetime of 50 years. In this contribution, the example of a post‐installed mechanical bolt anchor is used to explain how a difference in the behavior is a consequence of different drilling methods in noncracked concrete, in cracked concrete and in cracked concrete in which the crack is cycled. Additionally, it is observed that the behavior in the crack cycling test is significantly influenced by the drilling method. [ABSTRACT FROM AUTHOR]

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 with steel girders, is explained with the focus lying on the construction of a prototype in a 1:1 scaling. The conceptional design, the manufacturing in a prefabrication plant in Austria and the transport to a construction site are illustrated. Finally, an application example of the new technology is shown based on a design using the incremental launching method. The research confirms the feasibility of the on‐site assembly of segments from thin‐walled prefabricated elements and that this construction method, once minor constructive details will be solved in the ongoing research project, has great potential for a broad application in bridge construction. [ABSTRACT FROM AUTHOR]

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 to evaluate the influence of steel ratio, steel yield strength, and cross‐section combination form on the flexural performance of the specimens. Experimental results indicated that the composite action between UHPC and high‐strength steel tube was efficient, all specimens showed ductile failure under pure bending load. As the steel ratio and steel yield strength increased, the ultimate flexural capacity of specimens significantly increased, but the changes of flexural stiffness were not obvious. The results also demonstrated that when the hollow section ratio was 0.535 to 0.567, the UHPCFDST with circular tube inner specimens had higher ultimate flexural capacity and ductility than the UHPCFST specimens. Compared with square inner tube, when the steel ratio was the same, circular inner tube was recommended for UHPCFDST specimens. An analytical model of ultimate flexural capacity for UHPCFST and UHPCFDST specimens was proposed. Compared with the three current codes, the accuracy of the model was proved. [ABSTRACT FROM AUTHOR]

This article investigated four concrete beam‐column connections experimentally, including an interior precast specimen, an exterior precast specimen and two corresponding cast‐in‐place (CIP) specimens. Longitudinal rebars of precast columns were connected by embedded bolt connectors, while longitudinal rebars of precast beams were welded in CIP core areas. These full‐scale beam‐column connections with axial compression ratio 0.5 were tested under reversed cyclic loading to estimate seismic behavior. The results revealed that failure pattern of all specimens was flexural failure which occurred at beam ends near column face. No obvious damage took place in core areas and columns. The hysteresis curves of all specimens were relatively plump, showing relatively good energy dissipation capacity. The difference of bearing capacity between precast specimens and corresponding CIP specimens was not greater than 5%. Displacement ductility of the interior and exterior precast specimens was 3.17 and 2.70, which was about 5.4% lower and 3.4% higher than that of corresponding CIP specimens, respectively. A degenerated four‐linear restoring force model was proposed for the precast beam‐column connections with bolt connectors in columns. [ABSTRACT FROM AUTHOR]

An experimental and analytical study on 15 specimens of lap splices embedded in nonconventional concrete without confining reinforcement was performed under direct tension. The experimental program involved two groups of straight‐ended and anchored‐ended bars; three different techniques were employed with different splice lengths. For straight‐ended bars, conventional lap splice was studied as a benchmark. The anchored‐ended steel bars were hooks, hooks intersecting with cross bars, and plate‐end bars. It was found that, the used techniques not only achieved higher tensile stress at failure, but also different modes of failure were observed. Besides, a splice length of five times bar diameter was found to be sufficient to achieve the nominal yield stress of the reinforcing steel bar in the case of anchored‐ended bars. Finally, an analytical model was proposed in order to predict the ultimate tensile stress of the straight‐ended spliced bars. The accuracy of the proposed model was verified against the test results of 137 existing specimens from previous research. The comparison showed good agreement between the results of the proposed model and the test results. [ABSTRACT FROM AUTHOR]

The strengthening of concrete structures is becoming more and more important. To achieve this need for strengthening measures, technically innovative, simple and economical systems for subsequent strengthening are required. At the University of Innsbruck, a system for subsequent strengthening of the punching shear zone through the installation of concrete screws has been developed. These screws are installed from the soffit side of the slab in vertically predrilled holes and are arranged concentrically around the support. This paper discusses the results of four test series, with a total of 21 specimens used to develop the system. The system, which can be very easily installed, demonstrates a significant increase of the shear punching capacity and a reduction in brittle failure modes. In addition, cyclic loading with typical levels of service load has no negative effect on the effectiveness of the system. Finally, the influence of the flexural reinforcement ratio on the effectiveness of the strengthening system was investigated. [ABSTRACT FROM AUTHOR]

In this study, steel reinforced grout (SRG) is proposed for shear strengthening of reinforced concrete (RC) beams using the near‐surface embedded (NSE) technique. It is believed based on several research contributions in the literature that the NSE technique precludes or delays the onset of premature debonding and achieves higher strength increase in strengthened beams compared to the externally bonded (EB) counterpart. The tests conducted in this study used 13 RC beams to determine the shear behavior of RC beams strengthened in shear using SRG. The effect of the strengthening technique (NSE versus EB), SRG fabric density, strengthening scheme (side‐bonded vs. U‐wrapped), and the strengthening configuration (continuous vs. discontinuous) on RC shear enhancement was studied. The strengthening effectiveness of the SRG system was assessed in terms of the shear capacity, failure mechanism, load‐deflection response, and strain results. The NSE‐SRG increased the beam shear strength by an average of 100%, alleviated SRG debonding, and enhanced the deformation characteristics. The average increase in the shear strength of the EB‐SRG strengthened beam was 54% and 105% for the continuous and discontinuous SRG strips, respectively. An analytical model is proposed to predict the shear capacity of both the NSE‐SRG and EB‐SRG strengthened beams and give accurate and safe predictions. [ABSTRACT FROM AUTHOR]

Utilizing steel slag and recycled concrete as fine aggregate could save the consumption of natural resource and reduce the environmental pollution. In this work, the effect of steel slag aggregate and recycled aggregate on the compressive strength and chloride migration coefficient of three types of concretes were investigated and compared with natural aggregate. The interfacial transition zone (ITZ) microstructure and the connection between aggregate and bulk cement matrix was determined by using a quantitative backscattered electron (BSE) image analysis, N2 adsorption–desorption and X‐ray diffraction analysis. Results showed that the compressive strength and chloride resistance ability of natural aggregate concrete (NAC) and steel slag aggregate concrete (SAC) was highly dependent on aggregate volume content. The performance of recycled aggregate concrete (RAC) were much poorer than that of SAC and NAC. Pore structure and phase analysis confirmed that the improved properties of SAC can be partially attributed to the densified ITZ. Regarding RAC, a porous ITZ was observed in BSE image and pore structure analysis, which caused a poor compressive strength and a large chloride migration coefficient. It was found that the improvement of chloride resistance ability by using supplementary cementitious materials in NAC was more remarkable than that in SAC. [ABSTRACT FROM AUTHOR]

In this paper, four‐point bending tests of six prestressed reactive powder concrete (RPC) sound barrier unit panels were performed, the flexural behavior, deflection, and failure modes of both in situ and prefabricated panels were studied. The results show that the major failure modes for in situ panels were bending failure. Prestressing the panels can effectively increase the cracking loads and improve the stiffness of the in situ panels, but it cannot improve the ultimate flexural capacities. The ductility of the in situ panels decreased with the increase of prestressing degree. The stiffness of the prefabricated panels was improved by prestressing. Increasing the thickness of back and front plates, the ductility of the panels decreased accordingly, and the ductility of the prefabricated panels decreased more obviously than that of in situ panels. Based on the test results, considering tensile strength of RPC and prestressing stress, a modified formula for flexural capacity of in situ panels was established. In the meantime, considering the "bridge" effect of steel fiber, the formulae to calculate the crack width and deflection at service limit state were also developed for future design. [ABSTRACT FROM AUTHOR]

The paper presents an innovative method to determine anchor forces in anchor channels exposed to longitudinal shear loads. The channel's load‐bearing behavior is experimentally investigated by fiber‐optic techniques recording the longitudinal strains. For the first time these recordings uncover the inner flux of forces and enable to deduce the load distribution on the anchors. Before applying on anchor channels, the devices and components as well as its application are tested on a tension rod. Altogether 200 tests on anchor channels are performed varying the types of channel and anchor, the number of anchors, the closest distance of an anchor to the loaded edge and the position of load application. The tests confirmed that all available anchors (up to five were tested) transfer forces into the concrete member. Load distribution on the anchors is not uniform but depends on the type of anchor, the position of load application, the distance between the anchors and load application and the number of anchors available. By contrast, channel type and edge distance of the front anchor have little impact. [ABSTRACT FROM AUTHOR]

The aim of this paper is to present through a practical example, some recommendations to properly model confined concrete in three‐dimensional nonlinear finite element analysis. The example chosen is of particular interest for tunneling and structural engineers as it compromises the joints between segments of the concrete lining used with the tunnel boring machine technique. These sections are designed to transmit high pressures, sometimes exceeding the Standards' recommendations. To carry out the nonlinear finite element analyses (NLFEAs) a dedicated software, was employed. A discussion about which parameters play a fundamental role to efficiently model the problem is carried out. Finally, a comparison between NLFEA results and an experimental campaign is presented highlighting the differences in terms of stress values within the steel bars, the failure mechanism and evaluation of the contribution of steel to the resistance of confined concrete. [ABSTRACT FROM AUTHOR]

This paper investigated the shear transfer behavior between substrate recycled aggregate concrete and new natural aggregate concrete. A total of 72 push‐off tests with substrate‐to‐new concrete specimens were performed considering the effects of concrete strength grade, replacement ratios of recycled coarse aggregate, and lateral constraints ratios. Existing design codes and empirical models for calculating shear strength were reviewed and verified. Results show that concrete cracks occurred and developed along the shear transfer plane. Increasing the concrete grade and lateral constraints can both improve the crack stress and shear strength, while the incorporation of recycled coarse aggregate has a slight adverse effect on them. The model in fib Model Code 2010 based on shear‐friction theory gave the most accurate but still conservative values compared with experimental results and can be used to predict the shear transfer behavior between substrate recycled aggregate concrete and new natural aggregate concrete. [ABSTRACT FROM AUTHOR]

In this paper, analytical models for concrete cover separation (CCS) of FRP strengthened reinforced concrete (RC) beams with multiple steel bolts were developed based on concrete tooth model for strengthened RC beams without anchors. The derivation of the models involved three major steps: (a) determination of the crack spacing (width of the concrete teeth); (b) determination of the pull‐out strength of steel bolt considering the effect of shear crack; and (c) determination of the peak load of FRP strengthened beams when CCS occurs based on the concrete tooth model. Validation test on five RC beams was conducted to investigate the effect of anchorage systems on the premature debonding of FRP strengthened RC beams. Results showed that steel bolts with enough embedding length can effectively suppress the initiation and propagation of CCS, thus improve the performance of FRP strengthened RC beams. Moreover, a database of FRP strengthened RC beams with mechanical fasteners (MFs) and failed in CCS or FRP fracture (FR) was assembled from the literature. The analytical predictions agreed well with the experimental results. [ABSTRACT FROM AUTHOR]

The natural fibers are evolving in the construction industry in many forms due to its dominant characteristics since decades. This paper delivers a review of the behavior of basalt fiber reinforced concrete under static and dynamic loading conditions. The main aim of the paper is to signify the influence of basalt fibers in concrete as chopped fibers, minibars, rebars, and meshes by showcasing the physical and mechanical properties of the concrete. The proposed review paper furnishes a summary of obtainable evidence about the incorporation of basalt fibers in concrete under various loading conditions. The effect of size and volume fraction of the fibers in concrete subjected to static loading and dynamic loading is discussed and reviewed. Additionally, the optimum length, diameter, and aspect ratio of the fibers with its volume fraction depending on the constituents in concrete is exhibited. Basalt fibers, can operate as an exceptional reinforcing material which can replace the conventional reinforcement with appropriate implementation. Highlights: Application of basalt fibers in concrete based on different loading conditions has been reviewed.Properties and applications of basalt fibers in various forms were assessed.Static and dynamic behavior of basalt fiber reinforced concrete has been summarized based on the studied literature.Addition of suitable forms and size of basalt fibers in concrete were examined.Parameters such as volume fraction, aspect ratio of basalt fibers has been highlighted. [ABSTRACT FROM AUTHOR]

The addition of carbon fiber can change plain concrete (PC) to a quasi‐ductile material and improve its flexural properties through sharing the tensile stress transduced from concrete matrix. However, the influence rule and its mechanism of air entrained by carbon fiber on properties of concrete with different water to cement ratios (W/C) is not clear at present. Therefore, this research aims to explore this influence rule and mechanism. Eighteen kinds of concrete samples with W/C of 0.25, 0.3, and 0.45 including 216 specimens in total were studied. Their mechanical and permeability‐related properties were tested, and carbon fiber's air‐entraining models were established. The results show that carbon fiber has effect of improving the flexural strength, compressive strength, and impermeability of concrete with W/C of 0.25, but when W/C increases, the effect of carbon fiber on improving the flexural strength, reducing the compressive strength and impermeability of concrete increases. The calculation results of the air‐entraining models suggest that one possible air‐entraining mechanism of carbon fiber can be summarized as that carbon fiber entrains more air into concrete as W/C increases, and another one can be summarized as that the air entrained by carbon fiber increases the connectivity of the pore structure of concrete. [ABSTRACT FROM AUTHOR]

In order to solve the impact of road ice and snow on traffic, carbon fiber modified‐electrically conductive concrete (ECON) was prepared in the laboratory and applied in road engineering. The workability, mechanical properties, electrical conductivity and electro‐thermal effect of ECON were investigated. The microstructure was analyzed by scanning electron microscope. The results show that ECON with compressive strength grade of 30 MPa and resistivity of 0.1 Ω∙cm can be prepared by using carbon fibers with volume content of 0.75% and length of 9 mm. Semi‐dry mixing method and the use of cellulose ether have good dispersion effect on the carbon fibers. The performance of ECON in laboratory and field was compared and the ECON had a good workability, higher strength and lower resistivity in site construction for the high‐power force mixer was used. [ABSTRACT FROM AUTHOR]

Fiber Reinforced Shotcrete (FRS) is an essential element of ground control in many types of underground structure. It has been found to be an important aid to the improvement of safety in underground spaces and is a highly effective method of ground control across a wide range of ground conditions. However, the design of FRS linings remains problematic and uncertainty exists regarding the true load capacity of linings, especially with regard to out‐of‐plane load resistance. Most existing methods utilize either an elastic method of analysis or Yield Line theory to estimate load resistance, but these methods fail to account for the beneficial effect that in‐plane restraint has on load resistance. To address this short‐coming, the present research describes an experimental programme to examine the effect of Compressive Membrane Action (CMA) on the out‐of‐plane load capacity of shotcrete panels. The results demonstrate that the in‐plane restraint against dilation around a localized failure in a wall could contribute to at least a doubling of out‐of‐plane load resistance compared to estimates based on standard unrestrained beam and panel tests. Results of the experimental study have been used to develop an approximate mathematical model that describes the observed behavior with regard to the flexural strength enhancement associated with membrane compression and the contribution to load resistance associated with the development of inclined membrane struts and arching action. [ABSTRACT FROM AUTHOR]

The increasing demands of sustainable design and construction with economical sections, reduced cover, and more efficient time schedule require more flexibility in the design methodologies. The development of ultra‐high performance concrete (UHPC) have gained increasing interests as an attractive option for structural members with lightweight and superior performances. Concrete members reinforced with steel bars and fibers, generally known as hybrid reinforced concrete (HRC), offer a feasible solution in terms of reducing reinforcing materials and achieving desired structural performance. This paper proposes an analytical model to predict the flexural behavior of hybrid reinforced UHPC with steel reinforcements. Moment–curvature solutions are derived for reinforced sections based on parameterized tension‐compression constitutive models. The approach is applicable to customized cross section and derivation of T‐section is demonstrated. The moment–curvature response is further simplified as a tri‐linear model, which is used for the development of full‐range displacement solutions in analytical form. The proposed model is validated with the experimental data from literature covering a range of materials and member sizes. The full‐range solutions may provide insights into the serviceability design approach based on the criterion of maximum crack width or allowable deflection. [ABSTRACT FROM AUTHOR]

Anchorage systems have been proven to efficiently prevent or postpone debonding of reinforced concrete structures strengthened in flexure with fiber‐reinforced polymer (FRP) laminate or sheet. Although extensive studies on the effect of anchorage systems on intermediate crack debonding and end debonding of strengthened members have been performed, the effect of U‐shaped anchorages on commonly faced concrete cover separation remains unclear, and a corresponding design proposal has not been completed, which limits the practical use of anchorage systems for strengthening. In this study, carbon fiber‐reinforced polymer (CFRP)‐strengthened beams with notches at the sheet end and CFRP U‐shaped anchorages of various widths and heights were specially designed to investigate the effects of anchorages on strength of concrete cover separation. The height of the U‐shaped anchorage was proved more important than its width to improve concrete cover separation strength, and the related mechanism was discussed. Furthermore, an analytical model was developed to predict the initial and full separation load of concrete cover with U‐shaped anchorages. The reliability and accuracy of the proposed analytical procedure were verified against the test results. [ABSTRACT FROM AUTHOR]

Confinement with fiber‐reinforcement polymer (FRP) materials is a technique, which can increase adequately the axial strain ductility of concrete. Plain and reinforced concrete columns, with circular, square and rectangular cross sections, confined with FRP materials, subjected to monotonic or cyclic compressive load, have been extensively studied over the last 35 years. Also, a lot of predictive expressions for peak and ultimate axial strength and strain, suitable for the available concrete sections, have been proposed. However, it is proven that it is difficult to accurately model and predict the behavior of the noncircular confined concrete columns, especially in the presence of internal longitudinal and transverse steel reinforcement, which is the real case for the majority of existing reinforced concrete structures. The presented study gathers all the available test results on square and rectangular reinforced or plain concrete columns confined with FRP materials and other novel techniques, subjected only to cyclic axial loading. It also assesses the performance of four significant expressions published in literature for the prediction of column load and deformation, proposed for the peak and ultimate conditions. [ABSTRACT FROM AUTHOR]

This study has been undertaken for the assessment of steel/glass fiber reinforced polymer (GFRP) reinforced concrete mechanical behavior at an early stage. We developed a numerical model to describe the hydration process by using a chemo‐thermo‐mechanical scheme in ABAQUS finite element software. Mechanical properties of early age concrete versus hydration degree were determined using De Shutter's laws. The thermal and the autogenous strains are numerically implanted. Mazars elastic model was used to describe the concrete cracking. In addition, experimental validation of the established numerical model was performed and compared to the available literature. These data are selected for both plain and steel reinforced early age high‐strength concrete (HSC). Moreover, two mechanical boundary conditions were taken into account in accordance with the numerical simulations. Thermal conditions were considered in isothermal (20°C) and semiadiabatic conditions. Steel rebars were substituted by the GFRP under the same reinforcement percentages and configurations. The Interface between the steel and the GFRP reinforcement, and HSC was considered a perfect surface condition. Numerical predictions of the GFRP reinforcement were compared to those of steel reinforcement. Our results prove that the GFRP rebars restrain the concrete strains more than steel rebars. The GFRP rebar postpones concrete cracking compared to steel reinforcements. Furthermore, the concrete stress in the GFRP reinforced element is lower than the concrete stress in the RC steel. [ABSTRACT FROM AUTHOR]