Steel corrosion affects the failure mechanism of deteriorated reinforced concrete (RC) beams. Meanwhile, there is a lack of research on the shear behavior of corroded RC beams, particularly corroded steel fiber reinforced concrete (SFRC) beams. This paper investigates the shear behavior of corroded SFRC beams with a 1.5 shear span-to-depth ratio. All beam specimens included steel fibers with 50 kg/m3.
Journal of Science and Technology in Civil Engineering, HUCE (NUCE), 2022, 16 (3): 97–110 ASSESSING THE SHEAR BEHAVIOR OF STEEL FIBER REINFORCED CONCRETE BEAMS CORRODED UNDER CHLORIDE ATTACKS Nguyen Thi Thanh Thaoa , Tran Phi Son Tunga , Nguyen Duc Nhana , Nguyen Ngoc Tana,∗ a Faculty of Building and Industrial Construction, Hanoi University of Civil Engineering, 55 Giai Phong road, Hai Ba Trung district, Hanoi, Vietnam Article history: Received 12/4/2022, Revised 10/5/2022, Accepted 18/5/2022 Abstract Steel corrosion affects the failure mechanism of deteriorated reinforced concrete (RC) beams Meanwhile, there is a lack of research on the shear behavior of corroded RC beams, particularly corroded steel fiber reinforced concrete (SFRC) beams This paper investigates the shear behavior of corroded SFRC beams with a 1.5 shear span-to-depth ratio All beam specimens included steel fibers with 50 kg/m3 In particular, tensile longitudinal reinforcements were subjected to a corrosion degree of 16.4%, while stirrups were subjected to an approximately 24.1% corrosion degree These results are compared to those obtained on a non-corroded beam The obtained results from the four-point loading tests show that the corroded SFRC beams preserve a softening behavior as opposed to the sudden shear failure of RC beams without steel fibers Keywords: shear behavior; steel fiber reinforced concrete; reinforced concrete beam; steel corrosion https://doi.org/10.31814/stce.huce(nuce)2022-16(3)-08 © 2022 Hanoi University of Civil Engineering (HUCE) Introduction Nowadays, there are undoubtedly several benefits of steel fiber reinforced concrete (SFRC) One of the primary positives of SFRC is that it improves the mechanical properties of traditional concrete, particularly the tensile strength [1, 2] This means that the bridging actions of steel fibers on cracks in SFRC during loading could help to reduce crack width Moreover, one of the advantages of SFRC is crack resistance in enhanced post-crack strength The addition of steel fibers to concrete that may be used to enhance the mechanical properties has been studied experimentally Nguyen et al [3] found the following results after testing sample groups constructed of SFRC with varying steel fiber contents: (i) When the steel fiber content was raised, the tensile strength of SFRC grew from to 97%; (ii) Unlike traditional concrete, the addition of steel fibers enhanced the ductility response Likewise, another research work conducted by Bui et al [4] presented that when added steel fibers splitting tensile strength and flexural tensile strength significantly increased by up to 228% and 145%, respectively Steel fiber addition to beam structures exhibited more ductility than ordinary concrete in the post-peak stage On the other hand, shear failure is a critical issue in the RC beams because of the brittle behavior [5] Shear strength is generally predicted using the geometric theory of the shear resistant mechanism ∗ Corresponding author E-mail address: tannn@huce.edu.vn (Tan, N N.) 97 Thao, N T T., et al / Journal of Science and Technology in Civil Engineering According to the design code ACI 318-19 [6], if a ratio of shear span-to-effective depth (a/d) is less than 2, beams are classified as deep beams with an arch action for the shear resistant mechanism However, a beam action mechanism is a way of load transfer in shear for beams having an a/d ratio of greater than 2.0 Meanwhile, current building constructions in Vietnam have been frequently subjected to harsh environmental conditions, which exacerbate the corrosion of RC structures Steel corrosion is a severe problem that occurs in the loss of bond between concrete and steel reinforcement resulting in a decrease in both flexural and shear capacity of RC structures [7–9] Soltani et al [7] reported that flexural and shear strengths of beam specimens were reduced to 80% in corrosive environments Besides, previous studies have shown that the failure modes of corroded RC structures can change into brittle failure due to a higher degree of corrosion, especially in shear performance [10–14] It was shown in the study of Nguyen et al [15] that steel corrosion may modify the shear transferring mechanism of corroded RC beams For example, beam specimens with an a/d ratio less than 2.0 might have the load transferring mode changing from the combination of beam action and arch action to mainly arch action However, beams with an a/d ratio greater than 2.0 may fail in diagonal tension failure by beam action Numerous researches have investigated the influence of steel fibers on the ability of concrete structures in flexural and shear capacity based on the improved ductile performance in SFRC [16– 21] Particularly, Bui et al [4] further claimed that steel fibers with a high-volume fraction of greater than 1.2% were capable of replacing stirrups to ensure shear capacity because of the similar behavior to traditional RC beams Additionally, Kwak et al [19] investigated that beams with an a/d ratio of 2.0 failed in a combination of shear and flexure, whereas beams with a higher a/d ratio only failed by flexure However, Biolzi et al [21] argued that beams with an a/d ratio of 1.5 still failed by arch action with a ductile post-peak part The steel fibers in concrete not only improve the overall flexural and shear resistance but also is an effective method for corrosion resistance Furthermore, steel fibers could restrain the propagation of corrosion-induced cracks due to the restricted migration and diffusion transport capabilities of concrete [22, 23] Taqi et al [24] carried out experimental works that discussed the influence of corrosion on the shear behavior of SFRC beams having a 2.8 a/d ratio with or without pre-corroded steel fiber They claimed that increasing the steel fiber content causes the failure mode to change from shear to flexural failure Apart from the advantages of steel fibers on concrete properties and structural behavior, the corrosion resistance of SFRC is rarely considered The present experiment in this paper focuses on the shear performance of one control and two corroded SFRC beams with a 0.6% volume fraction of steel fiber hooked-end type (corresponding to 50 kg/m3 ) First, the corroded beam specimens were taken to an accelerated corrosion test with 16.4% and 24.1% average degrees of corrosion for tensile longitudinal reinforcement and stirrups Then, after determining the material properties, three beam specimens constructed entirely of steel fiber reinforced concrete were subjected to a four-point loading test Finally, the findings on the role of steel fibers in the shear behavior of SFRC beams by chloride attacks through the experimental study were discussed Experimental program 2.1 Materials Table shows the designed mixture of SFRC used As with ordinary concrete, Portland cement PCB40 was used as the binder, while river sand and crushed stone were used for fine and coarse 98 kg/m by mass was used in the SFRC 50 mix These steel fibers are manufac stainless steel provided by Bekaert The experimental works used Dramix steel fibers deformed in 3D with hooked ends to increase anchoring in th matrix, as shown in Fig In particular, the elastic modulus of the fiber was Thao, N T T.,GPa, et al /and Journal Science strength and Technology Civil MPa Engineering theoftensile was in1345 The aspect ratio of fiber length (lf/df) was 65 for defining the properties of the fibers (corresponding to a 35mm and a diameter df of 0.55mm) aggregates The steel fibers with a content of 50 kg/m3 by mass were used in the SFRC 50 mix These steel fibers are manufactured from stainless steel provided by Bekaert The experimental works used Dramix 3D 65/35BG steel fibers deformed in 3D with hooked ends to increase anchoring in the concrete matrix, as shown in Fig In particular, the elastic modulus of the fiber was around 210 GPa, and the tensile strength was Figure Dramix 3D 65/35BG hooked-end Fig Dramix 3D 65/35BG hooked-end steel fibers 1345 MPa The aspect ratio of fiber length to disteel fibers ameter (l f /d f ) was 65 for defining the properties The cubes with the dimensions of 150x150x150 mm were cast, cure of the fibers (corresponding to a length l f of 35 conditions of the laboratory, and tested to determine c mm and a diameter d f of 0.55environmental mm) strength As a result, the mean compressive strength of a set of three SFRC Table Concrete mix days was 49.8 MPa, as shown in Table 2, equivalent to the concrete C40/50 Mix SFRC 50 Cement (kg/m3 ) Fine aggregates (kg/m3 ) Coarse aggregates (kg/m3 ) Water (liter/m3 ) 477 596 1250 185 Ratio W/C Steel fiber (kg/m3 ) 0.39 50 The cubes with the dimensions of 150×150×150 mm were cast, cured in indoor environmental conditions of the laboratory, and tested to determine compressive strength As a result, the mean compressive strength of a set of three SFRC cubes at 28 days was 49.8 MPa, as shown in Table 2, equivalent to the concrete C40/50, as defined in Eurocode (EC2) [25] Table Compressive strength of SFRC specimens Sample Maximum compressive load (kN) Compressive strength (MPa) Mean compressive strength (MPa) Standard deviation (MPa) Coefficient of variation (%) M1 M2 M3 1102.0 1112.7 1145.2 49.0 49.5 50.9 49.8 1.0 2.0 In this study, beam specimens used longitudinal reinforcements of 10-mm and 12-mm diameter and stirrups of 6-mm diameter, as illustrated in Fig There are three sets of steel rebars and each of which has three specimens manufactured from the same strength grades of steel The yield and ultimate tensile strengths of steel reinforcements were determined by the tension test The obtained results are synthesized in Table 2.2 SFRC beam specimens According to the SFRC mixture, three beam specimens were conducted The first beam, named B1.1-NC, is the non-corroded SFRC beam as the control beam, while two beams, denoted B2.1-C 99 Thao, N T T., et al / Journal of Science and Technology in Civil Engineering Table Tensile strength of steel reinforcements Mean yield tensile strength (MPa) Ultimate tensile strength (MPa) Mean ultimate tensile strength (MPa) 366.9 380.2 375.8 374.3 534.9 552.6 542.0 543.2 44.2 44.5 44.4 368.3 363.1 369.4 366.9 563.2 566.9 566.0 565.4 14.7 14.5 14.5 335.5 321.6 336.3 331.1 519.1 512.4 513.0 514.8 Sample Diameter/ steel type Yield tensile load (kN) Ultimate tensile load (kN) Yield tensile strength (MPa) M1 M2 M3 ϕ12 mm CB300-V 41.5 43.0 42.5 60.5 62.5 61.3 M1 M2 M3 ϕ10 mm CB300-V 28.9 28.5 29.0 M1 M2 M3 ϕ6 mm CB240-T 9.5 9.1 9.5 and B3.1-C, are subjected to the accelerated corrosion test Fig illustrates the dimension and layout of the beam specimens In more detail, the beam specimens have a width of 150 mm, a height of 200 mm, and a length of 1100 mm Three beams were reinforced with two ϕ10 mm and two ϕ12 mm steel rebars in the top and bottom layers, respectively Additionally, all beam specimens were installed with ϕ6 mm stirrups with a regular spacing of 150 mm The concrete cover is 40 mm in thickness according to the Vietnamese standard TCVN 9346:2012 [26] for RC structures in aggressive conditions Journal of Science and Technology in Civil Engineering HUCE 2022 ISSN 1859-2996 2.3 Accelerated electrochemical corrosion test AnalyzingAccording the load-carrying capacity of corroded RCspecimens beams under service is to the SFRC mixture, three beam werenormal conducted Theconditions first more challenging, depending on the corrosion rate [27] In this study, an accelerated electrochemibeam, named B1.1-NC, is the non-corroded SFRC beam as the control beam, while two cal corrosion test was conducted to produce experimental specimens that exhibit the same corrosion beams, denoted B2.1-C and B3.1-C, are subjected to the accelerated corrosion test Fig behavior as in reality in a shorter period Two beam specimens were immersed in a 3.5% sodium illustrates the dimension and layout of the beam specimens In more detail, the beam solution (NaCl) for 48 hours for concrete total saturation The accelerated electrochemical corrosion specimens have a width of 150 mm,3.a Simultaneously, height of 200 mm, and a ions length of 1100into mm test on the beam specimens is shown in Fig chloride diffused the corroThree beams were reinforced with two ϕ10 mm and two ϕ12 mm steel rebars in the top sion test specimens from the electrolyte solution Each transformer was connected to the longitudinal bottom layer layers,ofrespectively Additionally, all beam specimens werean installed with rebars at and the bottom corroded beams Each longitudinal rebar received electrical current of ϕ6 mm stirrups with a regular spacing of 150 mm The concrete cover is 40 mm in beams 1A maintained constant during the corrosion test process Finally, corrosion testing of SFRC the continuously, Vietnamese standard 9346:2012 for RClaw [28] would bethickness completedaccording after 576 to hours which wasTCVN estimated based on[27] Faraday’s structures in aggressive conditions[26] 1-1 Fig 2.2.Detailed Figure Detailedlayout layoutof ofbeam beam specimens specimens 2.3 Accelerated electrochemical corrosion test 100 Fig Fig Detailed layout of beam specimens Detailed layout of beam specimens Thao, N T T., et al / Journal of Sciencetest and Technology in Civil Engineering 2.3 Accelerated electrochemical corrosion 2.3 Accelerated electrochemical corrosion test Journal of Science Civil Engineering 2022 HUCE 2022 ISSN 1859-2996 Journaland of Technology Science and in Technology in Civil HUCE Engineering ISSN 1859-2996 diagram (a)Testing Testing diagram (a) (a) Testing diagram (b) SFRC beams in solution SFRC beams inthethe solution (b) (b) SFRC beams in the solution Accelerated corrosion test for corroded SFRC process Finally, corrosion of SFRC beams would be completed afterbeams 576 hours process Finally, corrosion testing of SFRC beams would bebeams completed after 576 hours Fig 3.testing Accelerated corrosion test for corroded SFRC beams Fig 3.Figure Accelerated corrosion test for corroded SFRC continuously, which was which estimated on Faraday's [28] law [28] continuously, wasbased estimated based onlaw Faraday's Analyzing the load-carrying capacity of corroded beams under normal service Analyzing the load-carrying capacity of corroded RCRC beams under normal service conditions is more challenging, depending on the corrosion [26] study, conditions is more challenging, depending on the corrosion raterate [26] In In thisthis study, anan Following the corrosion test, an experimental program was carried out on three beam specimens to Following theelectrochemical corrosion ancorrosion experimental program was carried out on three Following the test, corrosion test,test an test experimental program carried out on three accelerated was conducted to produce experimental accelerated electrochemical conducted to was produce experimental assess the mechanical behavior of corrosion non-corroded andwas corroded SFRC beams based on several parambeam specimens specimens tothat assess the behavior of non-corroded corroded SFRC beam specimens tomechanical assess the mechanical behavior of non-corroded corroded SFRC exhibit the same corrosion behavior asreality in and reality aand shorter period Two specimens the same corrosion behavior asbetween in ainshorter period Two eters, such asthat the exhibit load-displacement curves, the relationship loadin and crack width, cracking beams based on several parameters, such as the load-displacement curves, the beams on several parameters, such as thesolution load-displacement curves, thefor pattern, and failurebased mechanism beam specimens immersed a 3.5% sodium (NaCl) hours beam specimens werewere immersed in ain3.5% sodium solution (NaCl) forfor 48 48 hours for relationshiprelationship between load and crack width, cracking pattern, and failure mechanism between load and crack width, cracking pattern, and failure mechanism concrete total saturation The accelerated electrochemical corrosion test on the beam concrete total saturation The accelerated electrochemical corrosion test on the beam specimens is shown in Fig Simultaneously, chloride diffused corrosion specimens is shown in Fig Simultaneously, chloride ionsions diffused intointo thethe corrosion test specimens the electrolyte solution Each transformer connected test specimens fromfrom the electrolyte solution Each transformer waswas connected to to thethe longitudinal rebars at the bottom of corroded beams Each longitudinal rebar longitudinal rebars at the bottom layerlayer of corroded beams Each longitudinal rebar received an electrical current of 1A maintained constant during corrosion received an electrical current of 1A maintained constant during thethe corrosion testtest 2.4.Four-point Four-point loading test testloading test 2.4 loading 2.4 Four-point Corroded beam (b) Corroded beam (b)(b) Corroded beam Fig Experimental set-up forset-up (a) the beam,beam, (b) the Fig set-up for (a) non-corroded the non-corroded beam, (b) thebeam corroded beam Figure Experimental Experimental fornon-corroded (a) the (b) corroded the corroded beam Control (a) beam (a)(a)Control beam Control beam Figs and depict an experimental program of three beams on a four-point loading test The span of beams between the supports was 900 mm The load was distributed on beams in two loading application points by a hydraulic jack at a controlled speed The distance between the two loading points is 450 mm, and the distance between the support and the loading point is 225 mm So, the shear span-to-depth ratio (a/d) of experimental beams is 1.5 Six linear variable differential transformers (LVDT) were arranged to measure vertical displacements and crack width For the vertical displacement, devices I1 and I3 were placed at the position of two supports, device I2 was located on the bottom face and at the middle span, and device ITH was located at the beam’s neutral axis For the crack mouth opening displacement (CMOD) of shear cracks, two devices denoted CR1 and CR2 were perpendicularly located on the diagonal lines between loading point centers and supports, and a 2-cm distance for the bottom face All testing devices were connected to a data logger TDS-530 and Fig Four-point loading testloading configuration Fig Four-point test configuration a laptop computer to automatically record the data Figs andFigs depict program ofprogram three beams on beams a four-point andan5 experimental depict an experimental of three on a four-point loading test The span supports 900 mm loading test of Thebeams span between of beamsthe between thewas supports was The 900 load mm was The load was 101 distributed distributed on beams on in beams two loading points by points a hydraulic at a jack at a in twoapplication loading application by a jack hydraulic controlled controlled speed Thespeed distance between the two loading points is 450 mm, and The distance between the two loading points is 450 the mm, and the distance between the support and the loading point is 225 mm So, the shear span-todistance between the support and the loading point is 225 mm So, the shear span-todepth ratiodepth (a/d)ratio of experimental beams is beams 1.5 Sixis linear variable (a/d) of experimental 1.5 Six linear differential variable differential (a) Control beam (b) Corroded beam Fig Experimental (a) ofthe non-corroded beam, the corroded beam Thao, N T set-up T., et al /for Journal Science and Technology in Civil(b) Engineering Fig.Figure Four-point loading testconfiguration configuration Four-point loading test Figs and depict an experimental program of three beams on a four-point Experimental results loading test The span of beams between the supports was 900 mm The load was distributed beams in shear two behavior loadingofapplication by a SFRC hydraulic at a This studyon focuses on the non-corrodedpoints and corroded beams.jack Therefore, four-point loading tests were conducted on all specimens until failure after two beams (B2.1-C controlled speed The distance between the two loading points is 450 mm, and and the B3.1-C) were subjected to the corrosion process The results of the accelerated corrosion process and distance between the support and the loading point is 225 mm So, the shear span-tothe four-point loading tests are included in this section depth ratio (a/d) of experimental beams is 1.5 Six linear variable differential 3.1 Actual corrosion degree transformers (LVDT) were arranged to measure vertical displacements and crack width thisvertical study, thedisplacement, corrosion degree of each Isteel reinforcement, denoted (%),position is determined by ForInthe devices I3 were placed at cthe of two and Eq (1) Then, the average of on corrosion, denoted cm and (%), at is calculated forspan, all steel supports, device I2 wasdegree located the bottom face the middle andreinforcedevice ments of the same type ITH was located at the beam's neutral axis crack mouth opening displacement mo For − m the∆m c (%) = mo = mo (1) where: mo (in g) is the original weight of the steel rebar before corrosion, which was measured before weight of the rebar after corrosion, which was casting the beam specimens; m (in g) is the final measured after cleaning; ∆m is the mass loss of the steel rebar After completing the four-point loading test, all longitudinal reinforcements and stirrups were removed to determine the mass loss of corroded rebars When the surrounding concrete part of the corroded beams was entirely demolished, corroded rebars were extracted carefully After an accelerated electrochemical corrosion process, longitudinal rebars and stirrups exhibited corrosion attack, but the stainless steel fibers were maintained corrosion-free, as shown in Fig In the following step, longitudinal rebars and stirrups were cleaned using HCl solution according to ASTM G1-03 [29] The residual weights of longitudinal rebars and stirrups were measured, and their corrosion degrees are reported in Table Four longitudinal rebars in each beam specimen are numbered from to with the designation R, while eight stirrups are denoted with the designation S and numbers ranging from to As a result of mass loss, the corrosion degrees of tensile longitudinal rebars and stirrups were 16.4% and 24.1% on average, respectively Meanwhile, the corrosion degree of compressive longitudinal rebars at the top layer of the beam specimens have small corrosion degrees ranging from 5.4% to 7.0% on average In this study, the corrosion degree of corroded SFRC beams is considered equivalent to that of tension longitudinal reinforcement at the bottom layer 102 Journal of Science and Technology in Civil Engineering HUCE 2022 ISSN 1859-2996 Thao, N T T., et al / Journal of Science and Technology in Civil Engineering the bottom layer Fig 6.Figure Stage of a corroded SFRC when extracting Stage of a corroded SFRCbeam beam when extracting rebarsrebars Table Corrosion results ininlongitudinal reinforcements and stirrups Table Corrosion results longitudinal reinforcements and stirrups Beam Steel sample mo (g) m (g) ∆m (g) c (%) cm (%) Beam Steel sample mo (g) m (g) ∆m (g) c (%) cm (%) R2-1 894.7 744.5 150.2 16.8 16.5 R2-1 894.7 744.5 150.2 16.8 R2-2 905.5 758.5 147.0 16.2 16.5 R2-2 905.5 758.5 147.0 16.2 R2-3 625.1 587.5 37.6 6.0 7.0 R2-3 625.1 587.5 37.6 6.0 7.0 R2-4 619.9 570.1 49.7 8.0 R2-4 619.9 570.1 49.7 8.0 S2-1 91.7 65.5 26.2 28.6 S2-1 91.7 65.5 26.2 28.6 S2-2 91.7 68.0 23.7 25.8 B2.1-C S2-2 91.7 68.0 23.7 25.8 B2.1-C S2-3 91.7 68.5 23.2 25.3 S2-3 91.7 68.5 23.2 25.3 S2-4 91.7 67.0 24.7 26.9 S2-4 91.7 67.0 24.7 26.9 25.8 25.8 S2-5 100.4 78.5 21.9 21.8 S2-5 100.4 78.5 21.9 21.8 S2-6 91.7 67.5 24.2 26.4 S2-6 91.7 67.5 24.2 26.4 S2-7 91.7 68.0 23.7 25.8 S2-8 91.7 68.8 22.9 25.0 S2-7 91.7 68.0 23.7 25.8 SR3-1 91.7 6774.0 2120.6 213.5 2-8 8.8 2.9 5.0 894.6 16.3 R3-2 899.1 726.5 172.6 19.2 R3-1 894.6 774.0 120.6 13.5 16.3 R3-3 626.9 587.8 39.0 6.2 R3-2 899.1 726.5 172.6 19.2 5.4 R3-4 624.4 595.5 29.0 4.6 R3-3 626.9 587.8 39.0 6.2 5.4 S3-1 91.7 72.0 19.7 21.5 R3-4 624.4 595.5 29.0 4.6 B3.1-C S3-2 101.5 81.5 20.0 19.7 S3-1 91.7 72.0 19.7 21.5 S3-3 91.7 72.5 19.2 20.9 S3-2 101.5 81.5 20.0 19.7 S3-4 91.7 71.5 20.2 22.0 B3.1-C 22.5 S3-5 91.7 65.0 26.7 29.1 S3-3 91.7 72.5 19.2 20.9 S3-6 91.7 69.5 22.2 24.2 S3-4 91.7 71.5 20.2 22.0 S3-7 91.7 73.5 18.2 19.8 22.5 S3-5 91.7 65.0 26.7 29.1 S3-8 91.7 71.5 20.2 22.0 S3-6 91.7 69.5 22.2 24.2 S3-7 91.7 73.5 18.2 19.8 3.2 Mechanical behavior of the control SFRC beam S3-8 91.7 71.5 20.2 22.0 The mechanical behavior of the control beam B1.1-NC is analyzed based on the load-displacement curves, as shown in behavior Fig Theofsolid shows the mid-span 3.2 Mechanical the line control SFRC beam displacement measured at the bottom face (denoted fb ), while the dotted line presents the mid-span displacement measured at the tested mechanical behavior of the control beam curves B1.1-NC is be analyzed based on main the beam’sThe neutral axis (denoted fn ) These load-displacement could divided into three load-displacement curves, as shown in Fig The solid line shows the mid-span displacement measured at the bottom face103 (denoted fb), while the dotted line presents Journal of Science and Technology in Civil Engineering HUCE 2022 ISSN 1859-2996 the mid-span displacement measured at the tested beam's neutral axis (denoted fn) These load-displacement curves could be divided main of stages At and first,Technology the Thao, N T T.,into et al.three / Journal Science in Civil Engineering stage OA represents the linear behavior of the SFRC beam until the first flexural crack At first, theapproximately stage OA represents the linear appears After stages the cracking load of 80 kN, this beam beginsbehavior to behave of the SFRC beam until the first flexural non-linear in stage due to the formation of flexural cracks between two loading crackAB appears After the cracking load of approximately 80 kN, this beam begins to behave non-linear points, followed shearAB cracks from to the loading point In the next stage inby stage due to the thesupport formation of flexural cracks between two loading points, followed by shear BC, the vertical displacement continues to increase quickly due to the opening of cracks from the support to the loading point In the next stage BC, the vertical displacement conflexural crackstinues and shear cracks while maintaining loadofwith a small to increase quickly due to the the applied opening flexural cracks and shear cracks while maintaining NC ) of 335.87 kN variation The the control beam load reaches the amaximum load (denoted applied with small variation ThePmax control beam reaches NC the maximum load (denoted Pmax ) NC ) and the corresponding displacement measured at the neutral axis (denoted of 5.88 f of 335.87 kN and the corresponding displacement measured at the neutral axis (denoted fn ) of mm Then, the concrete in the the compression zone crushed whilezone the tensile 5.88 mm.ofThen, concrete in theiscompression is crushed while the tensileISSN longitudinal rebars Journal Science and Technology in Civil Engineering HUCE 2022 1859-2996 Journal of Science and Technology in Civil Engineering HUCE 2022 ISSN 1859-2996 longitudinal rebars are yielding Besides, the shear crack CR is significantly opened on are yielding Besides, the shear crack CR2 is significantly opened on one side of the beam, as shown Journal of Science andC,Technology in Civil Engineering HUCE 2022 ISSN 1859-2996 one side of thein beam, as shown in Fig At point the displacement f mm, n is 18.68 Fig At point C, the displacement fn is 18.68 mm, corresponding to 1/50 of the span, and the corresponding to 1/50 of the span, and the tested beam is considered to have failed by expands to almost 0.5 mm width, which is over to acceptable tested beam is considered to have failedquickly by flexural-shear mode Thisin displacement is greater than crack width expands to almost in width, which flexural-shearquickly mode This displacement is greater 0.5 than mm the critical value based on is over to acceptable crack width according to EC [25] At the end of the test, the shear crack CR propagated to the the critical[25]] value based on current design codes [6, 25] Therefore, the SFRC beam exhibits a higher current designaccording codes [6], Therefore, theto SFRC beamend exhibits athe higher ductility quickly expands almost 0.5 mm in width, which is over to acceptable crack width to EC [25] At the of test, the shear crack CR propagated to the compression zone and opened with a 0.8 mm width The cracking pattern due to loading ductility behavior the sudden shear failure of traditional RC beams behavior instead of the sudden shear instead failure ofof traditional RC beams NC n captured for the frontthe andshear back sides of theCR control beam and presented in Fig according EC opened [25] with At theawas end of the test, crack to the propagated compression zonetoand 0.8 mm width The cracking pattern due to loading 400 400 compression zone andand opened 0.8the mmcontrol width beam The cracking pattern due to loading was350captured for the front backwith sidesa of and presented in Fig 350 B C sides of the control beam and presented in Fig was captured for the front and back 300 300 200 300 100 A 50 0 250 Load P (kN) 150 200 Load P (kN) 350 Load P (kN) Load P (kN) 400 250 400 350 P - ffbb P - ffnn 250 CR2 P - w CR2 150 300 100 250 50 10 200 15 150 Displacement f (mm) P - w CR1 CR1 200 20 150 -0.1 0.0 0.1 P - w CR1 CR1 P - w CR1 CR1 CR2 P - w0.4CR2 0.5 0.3 CR2 P - w CR2 0.2 Crack width w (mm) 0.6 0.7 0.8 Fig Load-displacement curves 100of the control beam B1.1-NC Fig Load-CMOD curves curves of the control B1.1-NC Figure Load-displacement curves Figure Load-CMOD of thebeam control beam 100 of the control In this study, the CMOD values of two shear cracks, CR1 and CR2, were measured beam B1.1-NC B1.1-NC 50 505 The load-CMOD curves in Fig using two displacement devices, as illustrated in Fig show that two shear cracks not occur under loading withof thetwo loadshear less than 200 kNCR and CR , were measured using two In this study, the CMOD values cracks, while appearing several flexural cracks After that, shear0.1 crack CR to propagate begins -0.1 0.0 0.2 0.3 0.4 0.5 0.6 0.78 0.7 0.8 that displacement devices, as illustrated in Fig The load-CMOD curves in Fig show -0.1 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.8 two shear diagonally from the support towards the loading point, while shear crack CR1 can be Crack width w (mm) cracks not occur under loading with the loadCrack less width than 200 kN while appearing several flexural observed at the load of 250 kN As the beam reaches the maximum load, the width w (mm) cracks After that, shear crack CR begins to propagate diagonally from the support towards the (denoted w) of the shear crack CR1 grows to around 0.1 mm, while the shear crack CR2 Fig 8.Fig Load-CMOD curves of the beam B1.1-NC Load-CMOD ofcontrol theatcontrol beam B1.1-NC(b) Cracking pattern (a)curves Beam captured the final state Fig Failure mode and cracking pattern of the control beam B1.1-NC 3.3 Mechanical behavior of the corroded SFRC beams (a) Similar to the control beam, the mechanical behavior of corroded SFRC beams B2.1-C and B3.1-C is also evaluated based on the curves of load-displacement and loadCMOD, as shown in Figs 10 – 13 The load-displacement curves demonstrate that the performance of these corroded beams has deteriorated under the effect of steel reinforcement corrosion, but the mechanical behavior in stages from OA to BC is quite equivalent compared to the control beam At first, the corroded beams in stage OA operate a quasi-linear behavior since they had several corrosion-induced cracks At point A,state the first flexural crack occurred at the load values of 130 and 135 kN for beams (a)Beam Beam captured atfinal the (b)(b) Cracking pattern (a) captured at final state final Cracking pattern Beam captured atthethe state (b) Cracking pattern B2.1-C and B3.1-C, respectively Then, these beams begin to increase the vertical displacement stage AB,ofwhich is described by reducing the slope of the loadFig Failure mode and crackinginpattern the control beam B1.1-NC Figure Failure and cracking pattern of beambeam B1.1-NC Fig Failure mode mode and cracking pattern ofthe thecontrol control B1.1-NC 3.3 Mechanical behavior the corroded SFRC beams 3.3 Mechanical behavior of theofcorroded SFRC beams 104 10 the control the mechanical behavior of corroded SFRC beams SimilarSimilar to thetocontrol beam,beam, the mechanical behavior of corroded SFRC beams B2.1-C and B3.1-C is also evaluated based on the curves of load-displacement and loadB2.1-C and B3.1-C is also evaluated based on the curves of load-displacement and loadCMOD, as shown in Figs 10 – 13 The load-displacement curves demonstrate that the Thao, N T T., et al / Journal of Science and Technology in Civil Engineering loading point, while shear crack CR1 can be observed at the load of 250 kN As the beam reaches the maximum load, the width (denoted w) of the shear crack CR1 grows to around 0.1 mm, while the shear crack CR2 quickly expands to almost 0.5 mm in width, which is over to acceptable crack width Journal of Science and Technology in Civil Engineering HUCE 2022 ISSN 1859-2996 according to EC [25] At the end of the test, the shear crack CR2 propagated to the compression zone and opened with a 0.8 mm width The cracking pattern due to loading was captured for the front displacement curves and back sides of the control beam and presented in Fig 250 C B 3.3 Mechanical behavior of the corroded SFRC beams 200 Load P (kN) Similar to the control beam, the mechanical behavior of corroded SFRC beams B2.1-C and B3.1D 150 C is also evaluated based on the curves of load-displacement and load-CMOD, as shown in Figs A 10–13 The load-displacement curves demonstrate that the performance of these corroded beams has 100 fb fb deteriorated under the effect of steel reinforcement corrosion, but the mechanical behavior inP -stages fn P - fn from OA to BC is quite equivalent compared to the control beam At first, the corroded beams in 50 stage OA operate a quasi-linear behavior since they had several corrosion-induced cracks At point A, and 135 kN for beams B2.1-C and B3.1the first flexuralin crack occurred at 2022 the load values of 130 Journal of Science and Technology Civil Engineering HUCE ISSN 1859-2996 10 15 20 25 30 35 40 C, respectively Then, these beams begin to increase the vertical displacement in stage AB, which is Displacement f (mm) described by reducing the slope of the load-displacement curves displacement curves Fig 10 Load-displacement curves of the corroded beam B2.1-C 250 300 C B Load P (kN) Load P (kN) B 250 200 D 150 A 100 fb P - fb fn P - fn 50 C 200 D 150 A P-CV P-fb 100 P-fn P-CVth 50 0 10 15 20 25 Displacement f (mm) 30 35 40 10 15 20 25 Displacement f (mm) 30 35 40 Fig 10 Load-displacement curves of the corroded beam B2.1-CFig 11 Load-displacement curves of the corroded beam B3.1-C Figure 10 Load-displacement curves of the Figure 11 Load-displacement curves of the In the next stage BC, thecorroded behavior of the two corroded beams is referred to in the corroded beam B2.1-C beam B3.1-C 300 250 B C sustaining stage as the control beam The results show that beam B2.1-C has the C Load P (kN) maximum load (denoted ) of 226.58 kNthe at sustaining the corresponding In the next stage BC, the behavior of the two corroded beamsPmax is referred to in stage displacement C C D measured at the neutral (denoted f n )load of 13.18 mm (Fig 10) as the control beam The results show that beam B2.1-C has axis the maximum (denoted Pmax ) ofMeanwhile, the C (denoted f C ) of 13.18 C 150 kN at the corresponding displacement 226.58 measured at the neutral axis mm obtained results of beam B3.1-C are Pmax of 251.90 kN n and f n of 14.75 mm, as shown A P-CV P-fb C C (Fig 10) Meanwhile, the obtained results of beam B3.1-C are P of 251.90 kN and f 14.75beams mm, equals 239.24 in Fig 11 Therefore, the average maximum load of these corroded max n of 100 P-fn P-CVth as shown in Fig 11 Therefore, the averagekN maximum load of these corroded equals kN On the other hand, when the applied beams load reaches 60%239.24 of the maximum load, the 50 shear crack CR does not expand, while the shear crack CR begins to open On the other hand, when the applied load reaches 60%1 of the maximum load, the shear crack CR continuously, asopen can becontinuously, seen in Figs 12 and 13 Inbe stage BC,inthe shear12 crack CR2 grows does 0not expand, while the shear crack CR as can seen Figs begins to 10 the 15 shear 20 crack 25 CR 30 grows 35 40 beyond mm After that, the measured width may be inaccurate due to the separation and 13.0 In stage BC, beyond mm After that, the measured width may be Displacement f (mm) inaccurate due to the separation of the concrete cover near the support Fig 11.InLoad-displacement curves of the corroded the stage CD, the corroded beams beam wereB3.1-C fractured due to the loss of load-carrying capacity On 11 In the next BC, the behavior of the the two shear corroded beams is 1referred to in the the stage corroded beam B2.1-C, crack CR propagates and intersects with the longitudinal crack sustaining stage control beam The results show that crack, beam B2.1-C has the due asto the corrosion to become a web-shear as shown in Fig 14 Besides, the shear crack CR2 C maximum load (denotedto Popen ) of 226.58 kN at the corresponding displacement continues with a significant width Due to the ductility of SFRC, both corroded beams have max C cracking patterns until failure In particular, f n ) of measured at relatively the neutral similar axis (denoted 13.18 mm (Fig 10) Meanwhile, the during the experiment, beam B3.1-C 200 C obtained results of beam B3.1-C are Pmax of 251.90 kN and f nC of 14.75105 mm, as shown in Fig 11 Therefore, the average maximum load of these corroded beams equals 239.24 kN On the other hand, when the applied load reaches 60% of the maximum load, the shear crack CR1 does not expand, while the shear crack CR2 begins to open continuously, as can be seen in Figs 12 and 13 In stage BC, the shear crack CR2 grows 50 ISSN 1859-2996 -0.5 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 Journal of Science and Technology in Civil Engineering HUCE 2022 Crack width w (mm) 250 300 200 250 150 Load P (kN) Load P (kN) of the concrete cover near the support Fig.Technology 12 Load-CMOD of the corroded beam B2.1-C Thao, N T T., et al / Journal of Science and in Civilcurves Engineering CR1 P - w CR1 P - w CR2 CR2 100 50 -0.5 0.0 200 P - w CR1 CR1 P - w CR2 CR2 150 100 50 0.5 1.0 1.5 2.0 2.5 3.0 3.5 Crack width w (mm) 4.0 4.5 5.0 Fig 12 Load-CMOD curves of the corroded beam B2.1-C Figure 12 Load-CMOD curves of the corroded -0.5 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 Crack width w (mm) 4.0 4.5 5.0 Fig 13 Load-CMOD curves of the corroded beam B3.1-C Figure 13 Load-CMOD curves of the corroded beam B2.1-C beam were B3.1-C In the stage CD, the corroded beams fractured due to the loss of load-carrying capacity On the corroded beam B2.1-C, the shear crack CR1 propagates and intersects 250 with the longitudinal crack due to corrosion to become a web-shear crack, as shown in suddenly failed at the load of 200 kN owing the corroded rebarCRrupture, as shown in Fig 15 Fig 14.to Besides, the shear crack continues to open with a significant width Due to 200 After demolition of surrounding concrete, ruptured steel rebar at the tension layer, named the ductility of HUCE SFRC, both corroded beams have1859-2996 relativelyR3-2, similarwas cracking patterns Journal of Journal Scienceofand Technology in CivilPCR1 2022 ISSN -Engineering w CR1 Science and Technology in Civil Engineering HUCE 2022 ISSN 1859-2996 150 measured to obtain a severe corrosion degree of 19.2%, the highest value among all longitudinal steel until failure In particular, during the experiment, beam B3.1-C suddenly failed at the P - w CR2 CR2 load of 200 failure kN owing to thebeam corroded rebar rupture, as shown in Fig 15 After rebars, as indicated in Table Therefore, the final of this is different compared to the 100 demolition of surrounding concrete, ruptured steel rebar at the tension layer, named R3tested is others beam different compared to the tested others beam is different compared to the tested others 50 2, was measured to obtain a severe corrosion degree of 19.2%, the highest value among all longitudinal steel rebars, as indicated in Table Therefore, the final failure of this Load P (kN) 300 -0.5 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 Crack width w (mm) 4.0 4.5 5.0 12 Fig 13 Load-CMOD curves of the corroded beam B3.1-C In the stage CD, the corroded beams were fractured due to the loss of load-carrying capacity On the corroded beam B2.1-C, the shear crack CR1 propagates and intersects with the longitudinal crack due to corrosion to become a web-shear crack, as shown in Fig 14 Besides, the shear crack CR2 continues to open with a significant width Due to the ductility of SFRC, both corroded beams have relatively similar cracking patterns until failure In particular, during the experiment, beam B3.1-C suddenly failed at the (a)captured Beam captured at the final state (b)(b)Cracking pattern (a)the Beam captured at final state Cracking (a) Beam atthe the final patternpattern load of 200 kN owing to corroded rebar rupture, as state shown in Fig 15 After (b) Cracking demolition of surrounding concrete, ruptured steel rebar at the tension layer, named Fig 14 Failure mode and cracking pattern ofcorroded the corroded beam B2.1-C Fig 14 Figure Failure and cracking pattern of R3thethecorroded beamB2.1-C B2.1-C 14.mode Failure and pattern of beam 2, was measured to obtain a severe corrosion degree ofmode 19.2%, thecracking highest value among all longitudinal steel rebars, as indicated in Table Therefore, the final failure of this Additionally, Figs 14 and 15 illustrate the failure mode and cracking patterns on two corroded beams Compared to the control beam, the corroded beams have two types of cracks, including 12 corrosion-induced cracks and cracks due to loading In the beginning, the corrosion-induced cracks were horizontally distributed along the length of the beam specimens After conducting the loading test, the flexural cracks began to appear from the bottom of the beam These cracks tend to develop and intersect with the corrosion-induced cracks as the load increases The failure is initiated by crushing the concrete in the compression zone, while a flexural crack at the middle span in the tension zone is opened with a significant width Besides, the shear cracks intersected with the horizontal cracks due to corrosion and(a) propagated quickly at to the the final loading point or crushed concrete zone The failure mode Beam captured state (b) Cracking pattern (a) Beam captured at the final state (b) Cracking pattern of the corroded beam B2.1-C is shear-tension, which is characterized by the web-shear cracks that Fig.bond 15 loss Failure modecorroded and cracking pattern of the corroded beam B3.1-C occurred due15 to the between longitudinal and concrete Fig Failure mode and cracking pattern of thereinforcement corroded beam B3.1-C Meanwhile, the corroded beam B3.1-C failed theand shear-tension with corroded rebar Additionally, Figs.by14 15 illustrate thethefailure mode andrupture cracking patterns on Additionally, Figs 14 and 15 illustrate the failure mode and cracking patterns on two corroded beams Compared to the106 control beam, the corroded beams have two types two corroded beams Compared to the control beam, the corroded beams have two types of cracks, including corrosion-induced cracks and cracks due to loading In the of cracks, including crackswere andhorizontally cracks duedistributed to loading In the thelength beginning, the corrosion-induced corrosion-induced cracks along beginning, the beam corrosion-induced cracks were horizontally along the length of the specimens After conducting the loadingdistributed test, the flexural cracks began to (a) Beam captured at the statestate (a) Beam captured at final the final (b) (b) Cracking pattern Cracking pattern Thao, N.mode T T., et and al / Journal of Science and Technology in Civil Engineering Fig.Fig 14 14 Failure cracking pattern of the corroded beam B2.1-C Failure mode and cracking pattern of the corroded beam B2.1-C (a) captured at the final (a) Beam captured atthe the final statestate (a) Beam Beam captured at final state Cracking pattern (b) (b) Cracking pattern (b) Cracking pattern Journal Science Technology in Civil Engineering HUCE ISSN 1859-2996 Fig 15 Failure mode and cracking pattern of2022 the corroded beam B3.1-C Fig 15.ofFigure Failure mode and cracking pattern of corroded beam B3.1-C 15.and Failure mode and cracking pattern ofthe the corroded beam B3.1-C Load P (kN) Additionally, 14 and 15 illustrate failure mode cracking patterns Additionally, Figs.Figs 14 and 15 illustrate the the failure mode andand cracking patterns on on beam caused by Compared corrosion damage in first stages (OA AB)beams of loading Intwo order 3.4.two Comparisons between control beam corroded beam corroded beams Compared toand thethe control beam, theand corroded beams have two types two corroded beams to the control beam, the corroded have types to compare the load-carrying capacity of three beams, Table shows the specific values of corrosion-induced cracks due to loading In by the of cracks, including cracks andand cracks duethe tocontrol loading the As cracks, shown in including Fig 16, corrosion-induced the corroded beams have acracks stiffness smaller than beam In caused of load and in displacement for non-corroded and corroded SFRC beams The the maximum corrosion damage the first stages (OA and AB) of loading In order to compare load-carrying beginning, the corrosion-induced cracks horizontally distributed along length beginning, the corrosion-induced cracks werewere horizontally distributed along the the length loads applied to corroded between 67-75% of that the control beam The capacity of three beams, Table beams shows range the specific values of load and to displacement for non-corroded of beam the beam specimens After conducting loading test, the flexural cracks began of the specimens After conducting the the loading test, flexural cracks began to to displacement at maximum the corroded beam's neutral axisthe is 2.24 – 2.51 times higher and corroded SFRC measured beams The loads applied to corroded beams range between 67–75% appear from bottom ofdisplacement the beam These cracks to develop and intersect with appear from theofthe bottom of the beam These cracks to develop andneutral intersect with of that to the control The measured attend the corroded beam’s axisofis 2.24– than that thebeam control beam, as indicated in Table 5.tend Besides, the residual loads the corrosion-induced asasthe load increases failure is initiated by crushing 2.51 times higherbeams than that ofcracks theas control beam, as indicated inThe Table Besides, thethe residual loads of the corrosion-induced cracks the load increases The failure is initiated bycontrol crushing corroded were reported around 43-52% of the maximum load of corroded beams were reported as around 43–52% of the maximum load of the control beam However, thebeam concrete in the compression zone, while a flexural crack at the middle in the However, the corroded SFRC beams still reflect a at ductile behavior inspan the the concrete in the compression zone, while a flexural crack the middle span in the the corroded SFRC beams still reflect a ductile behavior in the serviceability state serviceability tension is state opened a significant width Besides, shear cracks intersected tension zonezone is opened withwith a significant width Besides, the the shear cracks intersected the horizontal cracks to corrosion propagated quickly to the loading point 400 withwith the horizontal cracks due due to corrosion andand propagated quickly to the loading point or crushed concrete failure mode of the corroded beam B2.1-C is shear350 zone or crushed concrete zone TheThe failure mode of the corroded beam B2.1-C is shearB1.1-NC tension, which is characterized by the web-shear cracks occurred to the bond 300 tension, which is characterized by the web-shear cracks thatthat occurred duedue to the bond B2.1-C between corroded longitudinal reinforcement concrete Meanwhile, lossloss between corroded reinforcement andand concrete Meanwhile, the the 250 longitudinal B3.1-C corroded beam B3.1-C failed by the shear-tension corroded rebar rupture corroded beam B3.1-C failed by the shear-tension withwith the the corroded rebar rupture 200 150 Comparisons between control beam corroded beam 3.4 3.4 Comparisons between control beam andand corroded beam 100 As shown in Fig the corroded beams a stiffness smaller control As shown in Fig 16, 16, the corroded beams havehave a stiffness smaller thanthan the the control 50 0 10 15 20 25 30 13 13 Displacement fn (mm) 35 40 Fig 16 Comparison of of load-displacement testedbeams beams Figure 16 Comparison load-displacementcurves curves between between tested Table Experimental results of four-point loading test In addition, recent research conducted by Taqi et al [24] used a similar methodology as the exMaximum RatioA corroded Corresponding Failure mode periment Beam of SFRC beams in this study beam with a Ratio 0.8%NCsteel fiber volume fraction, the C NC C load (kN) Pmax displacement P f f max a 2.8 a/d ratio was tested n n dimensions of 100 × 150 × 1300 mm, and They reported that the maximum (mm) load reached 65.6 kN In spite of the same concrete properties, the maximum load of SFRC beams B1.1-NC 335.87 1.00 240 kN.5.88 1.00 Flexural-shear in this study has a higher value at around Besides, the reference beam with a 7% corrosion B2.1-C 226.58 0.67 107 13.18 2.24 B3.1-C 251.90 0.75 14.75 2.51 Shear-tension with web-shear crack Shear-tension with corroded rebar Thao, N T T., et al / Journal of Science and Technology in Civil Engineering degree failed due to shear and splitting effects, while the beam specimens in this study still failed by shear-tension mode with a softening behavior Table Experimental results of four-point loading test Ratio Corresponding displacement (mm) Ratio fnC / fnNC Failure mode 1.00 5.88 1.00 Flexural-shear 226.58 0.67 13.18 2.24 Shear-tension with web-shear crack 251.90 0.75 14.75 2.51 Shear-tension with corroded rebar rupture Beam Maximum load (kN) NC PCmax /Pmax B1.1-NC 335.87 B2.1-C B3.1-C Conclusions This paper presents the results obtained on the SFRC beam specimens with the dimensions of 150 × 200 × 1100 mm have a shear span-to-effective depth of 1.5 about the shear strength Based on the experimental results, the effect of steel corrosion on the shear behavior has been assessed, and the main conclusions can be drawn as follows: The shear capacity of the non-corroded SFRC beam is improved as evidenced by two features: (i) the shear crack width could be opened to 0.8 mm without brittle collapse; (ii) ductility capacity after post-peak is maintained, corresponding to the development of vertical displacement until 1/50 of the beam span, even with crushing concrete in the compression zone Meanwhile, with 16.4% and 24.1% average degrees of corrosion for tensile longitudinal reinforcement and stirrups, the maximum shear strength of corroded SFRC beams is reduced by 25% to 33% compared to that of the non-corroded beam On the other hand, the residual shear strength of these corroded beams is close to 43–52% of the maximum load of the non-corroded beam Under the effect of reinforcement corrosion, the failure mode of SFRC beams can be shifted from flexural-shear to shear-tension, with the significant values of shear crack width and vertical displacement and potential of the corroded rebar rupture Acknowledgments This research is supported by Hanoi University of Civil Engineering (HUCE) under grant number 25-2022/KHXD The authors would like to thank the Laboratory of Construction Testing and Inspection in HUCE for supporting the experimental works References [1] ACI 544.1 R-96 (2009) State-of-the-art report on fiber reinforced concrete American Concrete Institute, Farmington Hills, MI, USA [2] Lim, W.-Y., Hong, S.-G (2016) Shear tests for ultra-high performance fiber reinforced concrete (UHPFRC) beams with shear reinforcement International Journal of Concrete Structures and Materials, 10 (2):177–188 108 Thao, N T T., et al / Journal of Science and Technology in Civil Engineering [3] Nguyen, N T., Bui, T.-T., Bui, Q.-B (2022) Fiber reinforced concrete for slabs without steel rebar reinforcement: Assessing the feasibility for 3D-printed individual houses Case Studies in Construction Materials, 16:e00950 [4] Bui, T T., Nana, W S A., Doucet-Ferru, B., Bennani, A., Lequay, H., Limam, 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(2021) Experimental study on the effect of corrosion on shear strength of fibre-reinforced concrete beams Structures, 33:2317–2333 [25] EN 1992-1-1 (2004) Design of concrete structures - Part 1-1: General rules and rules for buildings European Committee for Standardization, Brussels, Belgium [26] TCVN 9346:2012 Concrete and reinforced concrete structures - Requirements of protection from corrosion in marine environment [27] Tan, N N., Hiep, D V (2020) Empirical models of corrosion rate prediction of steel in reinforced concrete structures Journal of Science and Technology in Civil Engineering (STCE) - NUCE, 14(2): 98–107 [28] Franc¸ois, R., Laurens, S., Deby, F (2018) Corrosion and its consequences for reinforced concrete structures Elsevier [29] ASTM G1-03 (2003) Standard practice for preparing, cleaning, and evaluating corrosion test American Society for Testing and Materials, West Conshohocken, PA 110 ... stirrups, the maximum shear strength of corroded SFRC beams is reduced by 25% to 33% compared to that of the non -corroded beam On the other hand, the residual shear strength of these corroded beams. .. the findings on the role of steel fibers in the shear behavior of SFRC beams by chloride attacks through the experimental study were discussed Experimental program 2.1 Materials Table shows the. .. of beambeam B1.1-NC Fig Failure mode mode and cracking pattern ofthe thecontrol control B1.1-NC 3.3 Mechanical behavior the corroded SFRC beams 3.3 Mechanical behavior of theofcorroded SFRC beams