Stirrup Reinforcement Research Articles

ANALISIS STRUKTUR BANGUNAN HOTEL 17 LANTAI DAERAH KEMAYORAN JAKARTA DENGAN PERMODELAN 3D SOFTWARE SAP2000

There are lots of skyscrapers in Indonesia, especially in the Jakarta area. In designing the building, of course, it needs to be designed with appropriate earthquake loads for the location and conditions around the building. Regulations that can be used in the design of skyscrapers are regulations developed by the Indonesian National Standard (SNI), including earthquake loads, gravity loads, and design standards. The method of collecting data in research includes 2 things, namely, (1). primary data, in the form of style output in the SAP2000 version 20 application, Spcolumn v.6.0 column interaction diagrams, and the results of Microsoft Excel calculation analysis. (2) the secondary data obtained is in the form of an image of the structure of the 17 Floor Hotel Kemayoran Area Building.Secondary and primary data processing is in the form of remodeling the redesigned building structure design in SAP2000 version 20 and Spcoloumn v.6.0, determining the seismic design category, analyzing and making changes to the original building structure design that are not in accordance with SNI 1726: 2019 and SNI 2847: 2019. The results of the study found differences in the year versions in SNI 2847:2013 and 2847:2019, SNI 1726:2012 and SNI 1726:2019. In SNI 2847:2019 concerning structural concrete there is a change or addition of special detailing and stirrup reinforcement in columns, beams and floor slabs, while in SNI 1726:2019 concerning earthquake loads there is an increase in seismic forces.

Shear performance of reinforced expansive concrete beams utilizing aluminium waste

Shear damage is a catastrophic failure in the design of reinforced concrete structural elements. To prevent it, the effect of aluminum wastes on reinforced concrete shear beams was investigated in this study. There is a gap in the scientific field on the expanding concrete with aluminium waste, and no research has been done on the utilizing of aluminum waste to produce expandable concrete. Moreover, there is a gap in expandable concrete usage with aluminum waste reinforcing, which is crucial for engineering applications especially beams, slabs and columns. For this purpose, experimental investigations were performed on a total of 12 Reinforced Concrete Beams (RCB) with different aluminum waste ratio (0, 1, 2 and 3 vol.%) and different shear reinforcement spacing (270, 200 and 160 mm). The depth span ratio was chosen as 1.6, 2.0 and 2.7. RCB was simply supported on the loading frame and subjected to four-points bending. As a result of experimental tests for each sample, the maximum load, stiffness, ductility and energy dissipation capacity were calculated. It was observed that the load capacity of the Al refuse combined RCBs raises as the vacancy of the stirrup reinforcement reductions compared with reference RCBs. Furthermore, it was found that the load capacity of the RCBs reduced as the Al refuse quantity in the concrete mixture was increased from 0% to 3%. However, it was found that the decrease in load capacity for 1 vol.% aluminum waste could be tolerated. For this reason, it can be stated that aluminum waste (AW) in reinforced concrete shear beams will contribute to the beam up to 1%.

Experimental Investigation on Shear Capacity of Steel-Fiber-Reinforced High-Strength Concrete Corbels.

As short cantilever members, corbels are mainly used to transfer eccentric loads to columns. Because of the discontinuity of load and geometric structure, corbels cannot be analyzed and designed using the method based on beam theory. Nine steel-fiber-reinforced high-strength concrete (SFRHSC) corbels were tested. The width of the corbels was 200 mm, the cross-section height of the corbel column was 450 mm, and the cantilever end height was 200 mm. The shear span/depth ratios considered were 0.2, 0.3, and 0.4; the longitudinal reinforcement ratios were 0.55%, 0.75%, and 0.98%; the stirrup reinforcement ratios were 0.39%, 0.52%, and 0.785%; and the steel fiber volume ratios were 0, 0.75%, and 1.5%. According to the test results, this paper discusses the failure process and failure mode of corbel specimens with a small shear span/depth ratio and analyzes the effects of variables such as shear span/depth ratio, longitudinal reinforcement ratio, stirrup reinforcement ratio, and steel fiber volume content on the shear capacity of corbels. The shear capacity of corbels is significantly affected by the shear span/depth ratio, followed by the longitudinal reinforcement ratio and the stirrup reinforcement ratio. Moreover, it is shown that steel fibers have little impact on the failure mode and ultimate load of corbels, but can enhance the crack resistance of corbels. In addition, the bearing capacities of these corbels were calculated by Chinese code GB 50010-2010 and further compared with ACI 318-19 code, EN 1992-1-1:2004 code, and CSA A23.3-19 code, which adopt the strut-and-tie model. The results indicate that the calculation results by the empirical formula in the Chinese code are close to the corresponding test results, while the calculation method based on the strut-and-tie model of a clear mechanical concept yields conservative results, and hence the related parameter values must be further modified.

A contribution to resource-efficient construction: Design flow and experimental investigation of structurally optimised concrete girders

In view of the current global climate challenges, the urgency for reduction of material consumption in the construction sector becomes clear. In this context, the present study concentrates on enhancing resource efficiency in concrete construction via the use of structural optimisation software tools as a guide for finding the geometry of optimised, mass-reduced concrete girders. Within a test series of eight specimens, varying parameters regarding the consulted optimisation strategy, the stirrup reinforcement type and concrete coverage were assessed. The experimental investigation was followed by a profound structural analysis, identifying peculiarities in the load-bearing behaviour and stiffness as well as two main failure modes characteristic of the optimised girder geometries. The comparison with full concrete girders illustrates the achieved reduction in concrete mass, the decrease of the Global Warming Potential of the production phase as well as the increase in the overall performance.

Study on Shear Behaviors and Damage Assessment of Circular Concrete Short Columns Reinforced with GFRP Bars and Spiral Stirrups.

This study investigated the shear resistance and damage evolution of glass fiber-reinforced polymer (GFRP)-reinforced concrete short columns. Five circular concrete short columns reinforced with GFRP bars and spiral stirrups were fabricated and tested under lateral thrust in the laboratory. The test variables involved the stirrup reinforcement ratio, the longitudinal reinforcement ratio and the type of stirrups. The failure modes, load-displacement curves, strain responses and crack characteristics of these columns were documented and discussed. The accuracy of shear design equations in predicting shear capacity of such columns was evaluated. In addition, the digital image correlation (DIC) instrument was used to identify the full-field strain and damage zones of circular concrete short columns. Several smart aggregate (SA) transducers coupled to the surface of these columns were used to monitor its damage status. The energy ratio index (ERI) and the damage index based on smart aggregate were established to characterize damage level of such columns. The test results indicate that the shear capacity is improved 5.6% and 31.1% and the lateral ultimate displacement is increased 67.7% and 400% as the stirrup reinforcement ratio of the concrete short column is increased from 0 to 0.19% and 0.47%, respectively. The shear capacity equation proposed by Ali and his co-workers, considering a strain limit of 0.004Efv, gives accurate predictions of the shear capacity of circular concrete short columns reinforced with GFRP bars and spiral stirrups. The variation in ERI values is explained by the development of damage zones of the column obtained with DIC technology and with the proposed damage index based on the smart aggregate it is feasible to evaluate the damage level of circular short concrete columns.

Perencanaan Pondasi Borepile Pada Jembatan, Studi Kasus : Jembatan Utama Cisadane

The most important part in a bridge construction is the foundation. Bore pile foundation is planned for 2 abutments and 5 piers. The entire foundation uses a diameter of 1 meter with a depth of 20-30 meters. Calculation of axial bearing capacity using the reese and wright method produces a single pile axial bearing capacity of 268.090 - 470.697 tons. The efficiency of the pile group using the Converse-Labarre method and the axial bearing capacity of the pile group is 5870,246 - 33176,233 tons. Single pile settlement using a semi-empirical method and resulted in a decrease of 50,100 - 59,490 mm. The settlement of the pile group used the vesic method and resulted in a decrease of 6,627 - 13,302 cm. consolidation decrease using the coefficient of volume change and resulted in a decrease of 104,024-576.047 mm with a time of 5,694-26,731 years. The calculation of lateral bearing capacity and pile deflection using the Broms method resulted in the lateral bearing capacity of the pile group of 3024-20580 tons and deflection of 1.485-5.888 mm. foundation reinforcement using the reference of SNI 2847-2019. Longitudinal reinforcement using 10D32 and stirrup reinforcement D16-50 and D16-75. Pile cap planning refers to SNI 2847-2019, resulting in a pile cap thickness of 1.5-4 meters. The X direction and Y direction reinforcement used are D32-150 for the pier and D32-150 and D25-150 for the abutment. The calculation of the cost budget plan uses the unit price analysis method and the resulting total cost is 73.574.031.053.

Numerical simulation of heavy rail transit vehicle collision and analysis of collision force characteristics

The collision force of a heavy rail transit vehicle hitting a bridge pier is affected by many factors. In order to investigate the characteristics of the collision force when a heavy rail transit vehicle hits a bridge, the finite element software LS-DYNA is used to simulate the impact of a heavy rail transit vehicle on a bridge. The influence of the vehicle speed of heavy rail transit vehicles, the strength of bridge pier concrete, the spacing of pier stirrups, the ratio of pier stirrup reinforcement, and the eccentric distance between the vehicle and the bridge pier on the characteristics of the collision force. The simulation analysis results show that the total deformation frequency around the impact point of the bridge pier and the heavy rail transit vehicle decreases as the distance from the impact point increases, and the deformation frequency in the vicinity of the impact point is the largest. The speed of the heavy rail transit vehicle, the concrete strength of the bridge pier, the reinforcement ratio of the pier stirrup, the larger the eccentric distance between the vehicle and the bridge pier, and the smaller the spacing between the stirrups, the greater the collision force when the heavy rail transit vehicle hits the bridge pier.

Study on the intermediate crack-induced debonding strain of FRP-strengthened concrete members using the updated BP neural network

Fiber reinforced plastics (FRP) are often used to enhance the capacity of the reinforced concrete beam (RC beam). However, the debonding failure is often observed due to the effect of the complex environment and the random loads. The debonding failure includes three types: plate end interfacial debonding (PE debonding), critical diagonal crack-induced debonding (CDC debonding), and intermediate flexural crack-induced interfacial debonding (IC debonding). In order to investigate the IC debonding strain of RC beam strength by FRP, this paper proposed some data-driven models to explore the IC debonding strain, based on the machine learning approaches The concrete strength, shear span proportion, the proportion of anchorage length to shear width, tensile reinforcement proportion, steel yield strength, stirrup reinforcement ratio, FRP stiffness, and the proportion of sheet span to beamwidth were regarded as the input parameters. The IC debonding strain was regarded as the output. It was found that the BP model can predict the IC debonding strain well. However, the BP data-driven model is easy to fall into a local minimum, and it is very difficult to converge, which has a negative effect on the accuracy of the model. The Sparrow Search Algorithm (SSA) was proposed to update it. The results indicated that the neural network optimized by SSA with lowest relative error, which can predict the IC debonding strain well. In addition, a study on the importance of each input found that the concrete strength, shear span proportion, and reinforcement yield strength will have a big impact on the IC debonding strain.

Experimental Study on Steel Fiber Reinforced Concrete

Abstract: As of today, there are no official set of rules for designing fiber reinforced structures, but there are several suggestions for rules which are described in the report. Mechanical properties of concrete and mortar reinforced with randomly distributed smooth steel fibers were investigated to understand the mechanism of fiber reinforcing. Different volumes, lengths, orientations and types of fibers were used. Fibers were compared with conventional reinforcement in flexure, tension and compression. It was observed that the significant reinforcing effect of fibers is derived after the cracks are initiated in the matrix, just as with conventional tensile and stirrup reinforcement. The post-cracking resistance of fibers is considerably influenced by their lengths, orientation, and stress-strain relationship. The spacing of reinforcement appears to have little influence on crack propagation below a certain length. This Project consist of M20 Grade concrete where the compression test and split tensile test are done. The cubes and cylinders are casted for 7,14 and 28 days of curing. Steel fibers are used in this project with three different volume percentage of fibres (0.50%,0.75% and 1.0%). The inclusion of fiber showed improvement of compression strength and tensile strength.

The Behavior of Reinforced Concrete Beams Added Cold-Formed-Steel as Shear Reinforcement

This paper presents an experimental study of concrete beams with cold-formedsteeladded as shear reinforcement. Cold-formed steel (CFS), also called light gauge steel or metal studs, is cold-formed into “C” or “Z” shaped members, capable of holding heavy loads. “Cold-Formed” means the sections are shaped at room temperature by guiding the steel through a series of rollers. Previous researchers have shown that CFSgenerally has a yield stress of 350 MPa to 550 MPa, but its use is mostly focused on anticipating beam bending. The purpose ofthis study was to determine the behavior of concrete beams with CFS added as a stirrup to increase the shear capacity of the beam. Two beams have been made with a size of 150x250x860 mm using the same 6D10 flexural reinforcement. One as a control beam (SB-C) using steel bar stirrups ∅5-200mm, the other as a beam added to CFS as stirrup reinforcement (SB-CFS) with a CFS cross section 20 mm wide, 0.75 thick mm and 120 mm CFS stirrup spacing. The test is carried out by applying a one-point loadingin the middle of the span of the beam so that the a/d ratio is 1.36. The parameters to be recorded are the capacity of the beam, the deflection that occurs, and the stiffness of the beam. The test data have been compared with the theoretical analysis results using the numerical software Response-2000. The resultshave shown that the increase in the shear capacity of the beam with the addition of CFS is 12.7% even though,according to Response-2000 analysis,it is 38.7%. The failure that occurs is shear failure according to the predetermined a/d ratio.

A new method to investigate the intermediate crack-induced debonding strain

In order to investigate the interfacial debonding (IC) strain of the reinforced concrete structures strengthened by fiber-reinforced polymer (FRP), this paper proposed some data-driven models to explore it, considering the effect of random factors both in material and environment. The concrete strength, shear span proportion, the proportion of anchorage length to shear width, tensile reinforcement proportion, steel yield strength, stirrup reinforcement ratio, FRP stiffness, the proportion of sheet span to beamwidth, ratios of environmental temperature to the maintenance standard temperature, and ratios of environmental humidity to the relative humidity were regarded as the inputs, the IC debonding strain was regarded as the output. The results indicate that the neural network optimized by the sparrow search algorithm not only has a relatively small error but also has stronger robustness. In addition, a study on the importance of the inputs on the IC debonding strain indicates that the concrete strength, FRP stiffness, and ratios of environmental temperature to the maintenance standard temperature are the most significant factor to influence the IC debonding strain.

Enhanced Torsion Mechanism of Small-Scale Reinforced Concrete Beams with Spiral Transverse Reinforcement

The nonlinear torsional behaviour of small-scale reinforced concrete (RC) beams with continuous staggered spiral as transverse reinforcement stirrups is experimentally investigated. Twelve miniatures RC beams were tested under torsion load considering the closed shape of stirrups and compared with continuous staggered spiral ones. All miniatures beams were scaled down to be one-eighth the prototype beam size. The main parameters considered in this research are stirrup spacing and its configurations. Small scale RC beams were taken into account in the existing study because of their construction simplicity and financial feasibility. Mortar without coarse aggregate was applied instead of concrete to reduce the size effect of applying small scale models. Ongoing research trials have been carried out to obtain an efficacious approach to boost torsion failure mechanisms because brittle torsion failure of RC structural elements should be avoided. This study emphasized boosted torsion capacity, dissipated energy, and helical crack propagation. During testing, the primary cracking torsion moment, ultimate torsion moment, peak twist angle, and failure mechanism of the beams were inspected. The use of spiral stirrups showed great enhancement of the torsional behaviour of samples. It was observed that using spiral stirrups rather than closed stirrups could result in a substantial increase in torsion capacity and dissipated energy of 87.7% and 89.8%, respectively. As a result, the predicted capacities of the RC beams prototype were estimated in detail, taking account the scale down factor implemented by the authors. Values obtained based on international specifications and guidelines were used to compare the experimental results. Doi: 10.28991/CEJ-2022-08-11-019 Full Text: PDF

PERENCANAAN PEMBANGUNAN GEDUNG BARU BALAI NIKAH DAN MANASIK HAJI KUA KECAMATAN AUR BIRUGO TIGO BALEH KOTA BUKITTINGGI

: The structure of this building uses reinforced concrete construction. The structure analysis goes through stages starting from Preliminary Design, structural loading, earthquake loading using the latest method, namely the response spectrum, analysis of the forces that occur in the structure using SAP2000 Version 20 by selecting the network system structure system (Grid System). The materials used are K-250 quality concrete (f'c = 20.75 MPa), screw reinforcement (fy = 400 MPa), plain reinforcement (fy = 240 MPa). For floor slab reinforcement, reinforcement is used for the x = 10-150 direction, while the y direction = 10-170. The column design uses steel quality fy = 400 MPa and concrete quality fc' = 20.75 MPa for columns 1 and 2 with a size of 35cm x 35cm. For the design of the beam using steel quality fy = 400 MPa and concrete quality fc' = 20.75 MPa with beam size 1 30cm x 50cm and beam 2 25cm x 45cm. And for stirrup reinforcement using steel quality fy = 240 MPa.Keywords: Preliminary Design, SAP2000 Analysis, Foundation, Loading ReinforcedConcrete, Reinforcement

Deep HystereticNet to predict hysteretic performance of RC columns against cyclic loading

This article attempts to reproduce hysteretic performance of HRB600 bar reinforced concrete columns under cyclic loading by adopting multivariate deep learning methods. Bidirectional long short-term memory (BiLSTM) and bidirectional gated recurrent units network (BiGRU) have been modified for temporal sequence related strength prediction with the consideration of multivariate parameters. To this end, a database with a 79,244 (row) × 12 (column) matrix is prepared for training, validation, and testing purposes. The inputs to the model include time intervals, loading displacement, concrete strength, axial compression ratio, longitudinal reinforcement tensile grade, longitudinal reinforcement diameter, longitudinal reinforcement ratio, stirrup tensile strength, stirrup diameter, spacing, and stirrup reinforcement ratio while the target is the cyclic load. By comparing the energy dissipation, accumulated energy dissipation, stiffness degradation and backbone curve of the hysteretic performance, the capacity of the adopted methods is compared with that of the finite element analysis. The comparison shows that the adopted method can recovery the hysteretic curves very well and the GRU method exhibits the most accurate prediction performance because of the highest R2 and the lowest MAE, MSE, and RMSE. The originality and innovation are mainly reflected in the use of time series data-driven deep learning model to replace the existing empirical formula and finite element method to reconstruct the nonlinear hysteretic behavior, so as to predict the seismic performance of the structure.

Research on the General Failure Law of a CTRC Column by Modeling FEM Output Data.

In this paper, a finite element model (FEM) is developed based on a set of circular steel tube reinforced concrete (CTRC) columns with axial compression and eccentric compression tests. The stressing state characteristics of the FEM are modeled in the form of characteristic pairs (mode-characteristic parameters) based on the structural stressing state theory and the proposed correlation modeling method. The slope increasing criterion is applied to the correlation characteristic parameter curve to obtain the characteristic point Q where the CTRC stressing state undergoes a qualitative change, and the characteristic point Q is defined as the new failure load point of the CTRC column. By selecting the element strain energy density at different locations of the FEM for correlation stressing state modeling and dividing the correlation stressing state sub-modes (concrete, steel tube, vertical reinforcement, and stirrup reinforcement), the structural stressing state theory and the rationality of the proposed correlation stressing state modeling method are verified. In addition, the certainty and reasonableness of the failure load points of the CTRC columns are revealed and verified.

Experimental Study and Calculation Methods of Shear Capacity for High-Strength Reinforced Concrete Full-Scale Deep Beams.

The shear behavior of 8 high-strength concrete full-scale deep beams with high-strength steel bars was studied. The depth beam size was 100 mm × 900 mm × 2200 mm, the test parameters included the shear span-to-depth ratio ( = 0.9, 0.6, 0.3), longitudinal reinforcement ratio (.66%, 1.06%, 1.26%) and stirrup reinforcement ratio ( = 0, 0.26%, 0.34%, 0.5%). The ratio of the cracking load of the inclined section to the ultimate load is between 30% and 50%, and the bending deformation of the deep beam is small, showing the characteristics of brittle failure for deep beams. Under the action of a concentrated load, the failure mode of deep beams with a small shear span ratio is the failure of the diagonal compression struts, which is very different from that of shallow beams with a large shear span ratio. With the increase of shear span ratio from 0.3 to 0.9, the ultimate shear capacity of deep beams decreases by 19.33%. With the increase of longitudinal reinforcement ratio from 0.67% to 1.27%, the ultimate shear capacity of deep beams increased by 45.02%. With the increase of vertical stirrup reinforcement ratio from 0% to 0.5%, the ultimate shear capacity of deep beams increased by 8.93%. Increasing the area of longitudinal bars or stirrups limited the transverse tensile strain of the compression struts, which is conducive to improving the compressive strength of the compression struts of deep beams and then improving the bearing capacity of deep beams. The strut-and-tie model (STM) is more suitable for analyzing the shear capacity of deep beams. The calculation methods for calculating the shear capacity of deep beams were compared with ACI 318-19, CSA A23 3-19, EN 1992-1-1:2004, Tan–Tan model, Tan–Cheng model, softened STM (SSTM) and simplified SSTM (SSSTM). The results showed that the shear capacity of deep beams could be well predicted by reasonably determining the STM parameters.

Simulation of Shear Capacity of Reinforced Concrete Column with Variation of Stirrups Using Finite Element Method Analysis

Shear failure of column causes the column to have shear reinforcement that cannot withstand shear forces so that it loses of lateral strength quickly. This research aims to see the effect of the configuration with the addition of shear reinforcement in the direction and perpendicular to the direction of the shear force on the capacity of reinforced concrete columns that are loaded with axial and lateral loads. The test was carried out by providing a constant axial load (0.3 P0) followed by a shear load until the test object failed. The numerical analysis was carried out using software based on the finite element method, namely ATENA Version 5 and GID Version 13.0.1 developed by Cervenka Consulting. This study used reinforced concrete with three variables of shear reinforcement. It can be the normal columns without stirrup reinforcement (S0P2), the addition three (3) stirrups in the direction of the shear reinforcement (S4P2) and the addition of two (2) stirrups in the direction of the shear reinforcement and one (1) stirrups perpendicular to the shear reinforcement (S5P2). After the numerical analysis is carried out, the results are verifies using experimental testing. The numerical analysis and experimental results give the load and deflection relationship results that are almost close. Therefore, the difference in shear loads compared to the experiments results and numerical analysis on columns S0P2, S4P2, and S5P2 is 0.11%, 3.95% and 1.16%, respectively, with a deflection ratio of 4.72%, 37.80% and 9.44%. The pattern of column destruction in the numerical model resembles the destruction pattern of the experimental results, both of which indicate that the column has shear cracks.

Confinement behavior and stress–strain response of square concrete columns strengthened with carbon textile reinforced concrete (CTRC) composites

In this study, with the aim of investigating the confinement behavior and stress–strain response of concrete columns strengthened with carbon textile reinforced concrete (CTRC) under a uniaxial load, a total of 20 column specimens with square cross-sections were cast and subjected to monotonic axial compression. Next, the effects of the number of textile layers, stirrup reinforcement ratio, concrete strength and short fibers on the efficiency of CTRC confining system were evaluated. The experimental results indicated that the CTRC-confined columns obtained a maximum improvement of up to 67.3% in bearing capacity and 65.2% in displacement ductility compared to the un-strengthened reference columns, and exhibited a more significant ductile failure characteristic. Moreover, the bearing capacity and displacement ductility of the confined columns were characterized by increasing with an increase in the number of textile layers and stirrup ratio, and a decrease in the concrete strength. The short fibers mixed in the strengthening layers also made a beneficial contribution to the bearing capacity and displacement ductility, particularly to the cracking load of the confined columns. Finally, a semi-empirical model was proposed to predict the axial stress and strain of concrete column specimens strengthened with CTRC based on the experimental results and theoretical analysis. The results calculated by the proposed model were evidenced to be fundamentally consistent with the experimental results. Therefore, the proposed model in this study could effectively predict the stress–strain response of square RC columns confined with CTRC composites.

Experimental modal analysis of RC beams strengthened with SHCC subjected to shear under impact strain rates

Strain Hardening Cement-based Composites (SHCC) holds great potential to be a remarkably effective material for shear strengthening of reinforced concrete beams in case of impact scenarios due to its great energy dissipation capability through the formation of multiple very fine cracks (∼100 μm of width). The effectiveness of this technique is investigated in the paper at hand through the observation of the changes in the dynamic properties in terms of natural frequencies, mode shapes, and damping ratios. Considering a non-destructive free vibration excitation of the specimens before the experiment (undamaged/intact state) to their condition after the destructive impact of an accelerated steel projectile. In this sense, two types of reinforcement configurations and two types of strengthening layers were investigated: reinforced concrete beams with and without stirrups were strengthened with SHCC made with polyvinyl alcohol (PVA) and ultra-high molecular weight polyethylene (UHMWPE) and tested under increasing levels of kinetic energy varying between 2.1 kJ and 6.4 kJ by using an accelerated impactor inside a drop tower facility. The parameter variation enabled conclusions with respect to the influence of the stirrup reinforcement and the SHCC strengthening contributions in the case of dynamic scenarios.

Data-driven model for predicting intermediate crack induced debonding of FRP-strengthened RC beams in flexure

There are a kinds of failure modes in flexurally strengthened RC beams using externally bonding FRP sheets. To evaluate the flexural strength of FRP-strengthened RC beam, the failure mode of the strengthened beam must be determined first. Intermediate crack (IC) induced debonding is the main failure mode in flexurally FRP-strengthened RC beams. In this study, a Back-Propagation Neural Network (BPNN) model is proposed to predict the intermediate crack (IC) induced debonding of FRP-strengthened RC beams. A database of 101 beams from different researchers are used to train and test the BPNN model. This model established in this study has eight inputs, including concrete strength, shear span ratio, tensile reinforcement ratio, the yield strength of reinforcement, stirrup reinforcement ratio, FRP stiffness, the ratio of sheet width to beam width, and the ratio of anchorage length to shear span, the output is FRP strain at the initial debonding, that is, the ultimate debonding strain of FRP reinforcements. The importance and sensitivity of the parameters are studied by the BPNN model and collected data. Based on the parametric study and Levenberg-Marquardt algorithm for nonlinear fitting, a design model is established for the prevention of IC debonding failure. The BPNN model and design model established in this study can accurately predicted the IC debonding of FRP-strengthened RC beams.