The increasing demand for rehabilitating and strengthening existing reinforced concrete (RC) beams has led to new advances in materials beyond conventional fiber-reinforced polymers (FRP). This paper reviews existing research focused on inorganic, cementitious composites, including fabric-reinforced cementitious mortar (FRCM), textile-reinforced mortar (TRM), mineral-based composites (MBC), textile-reinforced concrete (TRC), and fiber-reinforced concrete (FRC) as sustainable alternatives to organic, epoxy-based FRP for flexural strengthening of RC beams under static and fatigue loading. The study reviews a consolidated experimental and numerical database to quantify the performance of these materials, with a focus on the key performance indicators: ultimate and yield loads, failure modes, stiffness, ductility, and fatigue life. The results indicate that advanced composites significantly improve flexural capacity by 91%, stiffness by almost 29%, and fatigue resistance by 2×106 cycles; however, the increase in ductility depends on type and configuration of the reinforcing material. Furthermore, the superior fire performance and affordability of inorganic strengthening systems are emphasized. The review finds that cementitious composites are promising alternatives for reinforcing reinforced concrete beams effectively and sustainably.
GaoPGuXMosallamAS. Flexural behavior of preloaded reinforced concrete beams strengthened by prestressed CFRP laminates. Compos Struct2016; 157: 33–50.
2.
DuYXShaoXChuSH, et al.Strengthening of preloaded RC beams using prestressed carbon textile reinforced mortar plates. Structures2021; 30: 735–744.
3.
RaoofSMKoutasLNBournasDA. Textile-reinforced mortar (TRM) versus fibre-reinforced polymers (FRP) in flexural strengthening of RC beams. Constr Build Mater2017; 151: 279–291.
4.
Sharifi GhalehnoeiM. Numerical analysis of safety distances of reinforced concrete structures subjected to blast loading by Perform-3D. World J Eng2023; 20(3): 544–558.
5.
Sharifi GhalehnoeiMJavanmardiAIzadifarM, et al.Finite element analysis of shear reinforcing of reinforced concders, rete beams with carbon fiber reinforced polymer grid-strengthened engineering cementitious composite. Buildings2023; 13(1034): 1–23.
6.
KhorasaniAMMEsfahaniMRSabziJ. The effect of transverse and flexural reinforcement on deflection and cracking of GFRP bar reinforced concrete beams. Composites Part B2019; 161(January): 530–546.
7.
ArabshahiATavakolMSabziJ, et al.Prediction of the effective moment of inertia for concrete beams reinforced with FRP bars using an evolutionary algorithm. Structures2022; 35: 684–705.
8.
LiDZhouJOuJ. Damage, nondestructive evaluation and rehabilitation of FRP composite-RC structure: a review. Constr Build Mater2021; 271: 121551.
9.
TangL. Maintenance and inspection of fiber-reinforced polymer (frp) bridges: a review of methods. Materials2021; 14(24): 7826. DOI: 10.3390/ma14247826.
10.
ShiJWWuQQLiB, et al.Fatigue bond behavior of FRP-to-concrete joints with various bonding adhesives. Eng Struct2024; 301: 117311.
11.
Sharifi GhalehnoeiMNoormohammadiN. Finite element investigation of the flexural performance of RC beams with various dimensions strengthened using prestressed CFRP sheets. Int J Concr Struct Mater2025; 19(93): 93.
12.
PeledA. Confinement of damaged and nondamaged structural concrete with FRP and TRC sleeves. J Compos Construct2007; 11(5): 514–522.
13.
DaiJ-GYokotaHIwanamiM, et al.Experimental investigation of the influence of moisture on the bond behavior of FRP to concrete interfaces. J Compos Construct2010; 14(6): 834–844.
14.
KoutasLNTettaZBournasDA, et al.Strengthening of concrete structures with textile reinforced mortars: state-of-the-art review. J Compos Construct2019; 23(1): 03118001.
15.
Di TommasoAFocacciFMantegazzAG. Rinforzo a flessione di travi in calcestruzzo armatto com reti di carbonio e matrice cementizia. Proceedings of the national AICAP conference. 2004.
16.
SatoYFujiiSSetoY, et al.Structural behavior of composite reinforced concrete members encased by continuous fiber-mesh reinforced mortar permanent forms. Am. Concr. Institute, ACI Spec. Publ1999; SP-188: 113–124.
17.
TäljstenBBlanksvärdT. Mineral-based bonding of carbon FRP to strengthen concrete structures. J Compos Construct2007; 120(April): 120–128.
18.
CurbachMJesseF. High-performance textile-reinforced concrete. Struct Eng Int1999; 9(4): 289–291.
19.
WuHCSunP. Fiber reinforced cement based composite sheets for structural retrofit. In Proceedings of the international symposium on bond behavior of FRP in structures (BBFS’05). International Institute for FRP in Construction, 2005, pp. 351–356.
20.
OmbresL. Flexural analysis of reinforced concrete beams strengthened with a cement based high strength composite material. Compos Struct2011; 94(1): 143–155.
21.
Al-LamiKD’AntinoTColombiP. Durability of fabric-reinforced cementitious matrix (FRCM) composites: a review. Appl. Sci2020; 10(5): 1714.
JabrAEl-RagabyAGhribF. Effect of the fiber type and axial stiffness of FRCM on the flexural strengthening of RC beams. Fibers2017; 5(1): 2.
24.
KantarciFMaraşMM. Fabrication of novel geopolymer grout as repairing material for application in damaged RC beams. Int J Civ Eng2022; 20(4): 461–474.
25.
KantarciMMarasMMAyazY. Experimental performance of RC beams strengthened with aluminum honeycomb sandwich composites and CFRP U-Jackets. Exp Tech2023; 47(4): 767–786.
26.
ZhangWKangSLiuX, et al.Experimental study of a composite beam externally bonded with a carbon fiber-reinforced plastic plate. J Build Eng2023; 71(April): 106522.
27.
HamidiKBouziadiFBoulekbacheB, et al.Finite element analysis of interfacial shear behavior for CFRP flexural-externally strengthened reinforced concrete beams using a modified CZM model. J Compos Mater2025; 59(14): 1755–1773.
28.
BournasDATriantafillouTCPapanicolaouCG. Textile reinforced mortars (TRM) versus fiber reinforced polymers (FRP) as strengthening materials of concrete Structures. ACI Struct J2005; 6(ii): 740–748.
29.
ElsanadedyHMAlmusallamTHAlsayedSH, et al.Flexural strengthening of RC beams using textile reinforced mortar - experimental and numerical study. Compos Struct2013; 97: 40–55.
30.
GieseACHGieseDNDutraVFP, et al.Flexural behavior of reinforced concrete beams strengthened with textile reinforced mortar. J Build Eng2021; 33: 101873.
31.
EbeadUShresthaKCAfzalMS, et al.Effectiveness of fabric-reinforced cementitious matrix in strengthening reinforced concrete beams. J Compos Construct2017; 21(2): 04016084.
32.
Yadollahi OmranHOmranHYYadollahi OmranH. Long-term flexural performance of Prestressed-NSM-CFRP strengthened RC beams. Doctoral thesis, University of Calgary.2013.
33.
FlemingCJKingGEM. The development of structural adhesives for three original uses in South Africa. RILEM International Symposium, Synthetic Resins in Building Construction. The International union of laboratories and experts in construction materials, systems and structures, 1967, pp. 241–251.
34.
L’hermiteRBressonJ. Concrete reinforced with glued plates. RILEM International Symposium, Synthetic Resins in Building Construction. The International union of laboratories and experts in construction materials, systems and structures, 1967, pp. 175–203.
ToutanjiHAGómezW. Durability characteristics of concrete beams externally bonded with FRP composite sheets. Cem Concr Compos1997; 19(4): 351–358.
37.
BabaeidarabadSLoretoGNanniA. Flexural strengthening of RC beams with an externally bonded fabric-reinforced cementitious matrix. J Compos Construct2014; 18(5): 04014009.
38.
HashemiSAl-MahaidiR. Investigation of bond strength and flexural behavior of FRP strengthened RC beams using cement-based adhesives. Struct. Congr2010; 2010: 689–700.
39.
AmbrisiADFocacciF, Flexural strengthening of RC beams with cement-based composites. Journal of Composites for Construction2011; 15(5): 707–720.
40.
EscrigCGilLBernat-MasoE. Experimental comparison of reinforced concrete beams strengthened against bending with different types of cementitious-matrix composite materials. Constr Build Mater2017; 137: 317–329.
41.
HashemiSAl-MahaidiR. Investigation of bond strength and flexural behaviour of FRP-Strengthened reinforced concrete beams using cement-based adhesives. Aust J Struct Eng2010; 11(2): 129–139.
42.
HashemiSAl-MahaidiR. Experimental and finite element analysis of flexural behavior of FRP-strengthened RC beams using cement-based adhesives. Constr Build Mater2012; 26(1): 268–273.
43.
Akbari HadadHEricksonBNanniA. Flexural analysis and design of FRCM-strengthened RC beams. Constr Build Mater2020; 244: 118371.
44.
JungKHongKHanS, et al.Prediction of flexural capacity of RC beams strengthened in flexure with FRP fabric and cementitious matrix. Int J Polym Sci2015; 2015: 1–11.
45.
WeiLUedaTMatsumotoK, et al.Experimental and analytical study on the behavior of RC beams with externally bonded carbon-FRCM composites. Compos Struct2021; 273(May): 114291.
46.
ShengJYinSYueJ, et al.Bending performance of ECC-RC composite beam reinforced with textile. Constr Build Mater2021; 287: 123079.
47.
OmbresL. Structural performances of PBO FRCM-strengthened RC beams. Proc. Inst. Civ. Eng. Struct. Build2011; 164(4): 265–272.
48.
KoutasLNPapakonstantinouCG. Flexural strengthening of RC beams with textile-reinforced mortar composites focusing on the influence of the mortar type. Eng Struct2021; 246(August): 113060.
49.
ParkJParkSKHongS. Experimental study of flexural behavior of reinforced concrete beam strengthened with prestressed textile-reinforced mortar. Materials2020; 13(5): 1137.
50.
OmbresL. Debonding analysis of reinforced concrete beams strengthened with fibre reinforced cementitious mortar. Eng Fract Mech2012; 81: 94–109.
51.
ElghazyMEl RefaiAEbeadU, et al.Corrosion-damaged RC beams repaired with fabric-reinforced cementitious matrix. J Compos Construct2018; 22(5): 04018039.
52.
El-MaaddawyTEl RefaiA. Innovative repair of severely corroded T-Beams using fabric-reinforced cementitious matrix. J Compos Construct2016; 20(3): 04015073.
53.
MandorAEl RefaiA. Flexural response of reinforced concrete continuous beams strengthened with fiber-reinforced cementitious matrix (FRCM). Eng Struct2022; 251(PB): 113557.
54.
FengRLiuYZhuJH, et al.Flexural behaviour of C-FRCM strengthened corroded RC continuous beams. Compos Struct2020; 245(March): 112200.
55.
ElghazyMEl RefaiAEbeadU, et al.Fatigue and monotonic behaviors of corrosion-damaged reinforced concrete beams strengthened with FRCM composites. J Compos Construct2018; 22(5): 04018040.
56.
ElghazyMEl RefaiAEbeadU, et al.Experimental results and modelling of corrosion-damaged concrete beams strengthened with externally-bonded composites. Eng Struct2018; 172(June): 172–186.
57.
AljazaeriZRMyersJJ. Fatigue and flexural behaviour of reinforced concrete beams strengthened with a fibre reinforced cementitious matrix. Adv. Compos. Constr. ACIC 2015 - Proc. 7th Bienn. Conf. Adv. Compos. Constr2016; 3: 128–134.
58.
PinoVHadadHADe CasoF, et al. Performance of FRCM strengthened RC beams subject to fatigue. Sustain. Constr. Mater. Technol. 2016; 2016: 1–11.
59.
Akbari HadadHNanniAEbeadUA, et al.Static and fatigue performance of FRCM-strengthened concrete beams. J Compos Construct2018; 22(5): 04018033.
60.
ParkJParkSKHongS. Evaluation of flexural behavior of textile-reinforced mortar-strengthened rc beam considering strengthening limit. Materials2021; 14(21): 6473.
61.
IrshidatMRAl-ShannaqA. Using textile reinforced mortar modified with carbon nano tubes to improve flexural performance of RC beams. Compos Struct2018; 200: 127–134.
62.
ParkJHongSParkSK. Experimental study on flexural behavior of TRM-Strengthened RC beam: various types of textile-reinforced mortar with non-impregnated textile. Appl. Sci2019; 9(10): 1981.
63.
SongSDengMZhangM, et al.Flexural strengthening of reinforced concrete beams using textile-reinforced mortar improved with short PVA fibers. Structures2023; 56(July): 104824.
64.
AlhoraniRARabayahHSAbendehRM, et al.Assessment of flexural performance of reinforced concrete beams strengthened with internal and external AR-Glass textile systems. Buildings2023; 13(5): 1135.
65.
Al-SaidyAEl-GamalSAbu SohailK. Strengthening of reinforced concrete (RC) beams using textile reinforced mortars (TRMs). Int J Civ Eng2023; 21(12): 2023–2035.
66.
MoyCKSRevannaN. Experimental and DIC study of reinforced concrete beams strengthened by basalt and carbon textile reinforced mortars in flexure. Buildings2023; 13(7): 1765.
67.
KhalilAAEtmanEEBehiryR. Comparative study of flexure strengthening of RC beams using mineral based composite mortar. In proceedings of the eight Alexandria international conference on structural and geotechnical engineering. 2014; 27–40.
68.
AliNMWangXWuZ, et al.Basalt fiber reinforced polymer grids as an external reinforcement for reinforced concrete structures. J Reinforc Plast Compos2015; 34(19): 1615–1627.
69.
SiddikaAShojibMHHHossainMM, et al.Flexural performance of wire mesh and geotextile-strengthened reinforced concrete beam. SN Appl Sci2019; 1(11): 1324.
70.
HeWWangXWuZ. Flexural behavior of RC beams strengthened with prestressed and non-prestressed BFRP grids. Compos Struct2020; 246(October 2019): 112381.
71.
ZhangZQinH. Study on flexural performance of reinforced concrete beams strengthened with FRP Grid–PCM composite reinforcement. Appl. Sci2024; 14(19): 9013.
72.
YinSXuSLvH. Flexural behavior of reinforced concrete beams with TRC tension zone cover. J Mater Civ Eng2014; 26(2): 320–330.
73.
YinSPLüHXuSL. Properties and calculation of normal section bearing capacity of RC flexural beam with skin textile reinforcement. J Cent South Univ2013; 20(6): 1731–1741.
Si LarbiAContamineRHamelinP. TRC and hybrid solutions for repairing and/or strengthening reinforced concrete beams. Eng Struct2012; 45: 12–20.
76.
Si LarbiAAgbossouAHamelinP. Experimental and numerical investigations about textile-reinforced concrete and hybrid solutions for repairing and/Or strengthening reinforced concrete beams. Compos Struct2013; 99: 152–162.
77.
VerbruggenSTysmansTWastielsJ. TRC or CFRP strengthening for reinforced concrete beams: an experimental study of the cracking behaviour. Eng Struct2014; 77: 49–56.
78.
NguyenCHNgoQD. Flexural and shear behavior of reinforced concrete beams strengthened with carbon textile reinforced concrete. Arch Civ Eng2020; 66(3): 407–426.
79.
TruongBTBuiTTLimamA, et al.Experimental investigations of reinforced concrete beams repaired/reinforced by TRC composites. Compos Struct2017; 168: 826–839.
80.
SenTJagannatha ReddyHN. Strengthening of RC beams in flexure using natural jute fibre textile reinforced composite system and its comparative study with CFRP and GFRP strengthening systems. Int J Sustain Built Environ2013; 2(1): 41–55.
81.
XieWShengJYuZ, et al.Flexural behavior of corroded RC beams strengthened by textile-reinforced concrete. Buildings2023; 13(12): 2902.
82.
XieWShengJYuZ, et al.Investigation of flexural bearing behavior of corroded RC strengthened with U-Type TRC. Materials2024; 17(5): 1154.
83.
RossiERandlNMészölyT, et al.Effect of TRC and F/TRC strengthening on the cracking behaviour of RC beams in bending. Materials2021; 14(17): 4863.
84.
GopinathSMurthyARIyerNR, et al.Behaviour of reinforced concrete beams strengthened with basalt textile reinforced concrete. J Ind Text2015; 44(6): 924–933.
85.
YinS-PShengJWangX-X, et al.Experimental investigations of the bending fatigue performance of TRC-strengthened RC beams in conventional and aggressive chlorate environments. J Compos Construct2016; 20(2): 04015051.
86.
HeWCaiFWangX, et al.Fatigue performance of RC beams strengthened with non-prestressed and prestressed BFRP grids. Eng Struct2024; 304(September 2023): 117594.
87.
CaiGTsavdaridisKDYoshizawaM, et al.Flexural behaviors of high-performance trm-retrofitted RC beams under cyclic loading. コンクリート工学年次論文集2019; 41(2): 1297–1302.
88.
CaiGTsavdaridisKDSi LarbiA, et al.A simplified design approach for predicting the flexural behavior of TRM-Strengthened RC beams under cyclic loads. Constr Build Mater2021; 285: 122799.
89.
AielloMALeoneMOmbresL. Structural analysis of reinforced concrete beams strengthened with externally bonded FRP (fiber reinforced polymers) sheets. In Proceedings of the third international conference on composites in constructions. Université Lyon I, Laboratoire Mécanique Matériaux et Structures, 2005, pp. 11–18.
90.
OmbresL. Failure modes in reinforced concrete beams strengthened with PBO fiber reinforced mortars. In Proc. Fiber-Reinforced Polym. Reinf. Concr. Struct. FRPRCS-9. 2009.
91.
SabziJEsfahaniMRRamezaniA, et al.A comparison between the behavior of beams strengthened by FRP sheets and FRCM composites. Eng Struct2024; 306(November 2023): 117796.
92.
TriantafillouTC. Textile-reinforced mortars (TRM) versus fibre-reinforced polymers (FRP) as strengthening and seismic retrofitting materials for reinforced concrete and masonry structures. Int. Conf. on advanced composites in construction (ACIC07). 2007.
93.
ZhengYZWangWWBrighamJC. Flexural behaviour of reinforced concrete beams strengthened with a composite reinforcement layer: BFRP grid and ECC. Constr Build Mater2016; 115: 424–437.
94.
Yang XuYK-QGaoW-YDaiJ-G, et al.Flexural strengthening of RC beams with CFRP grid-reinforced ECC matrix. Compos Struct2018; 189; 9–26.
95.
ShilangXShipingYXinhuaC. Investigation on the flexural behavior of reinforced concrete beam strengthened with textile-reinforced concrete. China Civ Eng J2011; 44(4): 23–34.
96.
YinSPXuSLWangF. Investigation on the flexural behavior of concrete members reinforced with epoxy resin-impregnated textiles. Mater Struct2015; 48(1–2): 153–166.
97.
VerbruggenSTysmansTWastielsJ. Bending crack behaviour of plain concrete beams externally reinforced with TRC. Mater Struct2016; 49(12): 5303–5314.
AlrshoudiF. Behaviour of textile-reinforced concrete beams versus steel-reinforced concrete beams. Adv Civ Eng2021; 2021: 6696945.
100.
AlrshoudiF, Textile-Reinforced Concrete Versus Steel-Reinforced Concrete in Flexural Performance of Full-Scale Concrete Beams. Crystals2021; 11(11), 1272.
101.
KimDNaamanAEEl-TawilS. Comparative flexural behavior of four fiber reinforced cementitious composites. Cem Concr Compos2008; 30(10): 917–928.
102.
WuH-CSunPTengJ. Development of fiber-reinforced cement-based composite sheets for structural retrofit. J Mater Civ Eng2010; 22(6): 572–579.
103.
El GhadiouiRWagnerJKleinJ, et al.RC members with a flexural-strengthening layer of CFRP textile-reinforced concrete under monotonic and cyclic long-term loading. Struct Concr2022; 23: 939–953.
104.
D’AntinoTCarloniCSneedLH, et al.Matrix-fiber bond behavior in PBO FRCM composites: a fracture mechanics approach. Eng Fract Mech2014; 117: 94–111.
105.
OmbresL. Analysis of the bond between fabric reinforced cementitious mortar (FRCM) strengthening systems and concrete. Composites Part B2015; 69: 418–426.
106.
GuoRHuWLiM, et al.Study on the flexural strengthening effect of RC beams reinforced by FRP grid with PCM shotcrete. Compos Struct2020; 239: 112000.
107.
MarasMMKantarciF. Structural behavior of RC beams strengthened using fiber-reinforced polymer U-jackets. Struct Concr2023; 24(2): 2384–2401.
108.
HawilehRAMhannaHHAl RashedA, et al.Flexural behavior of RC beams externally bonded with polyethylene terephthalate (PET) fiber reinforced polymer (FRP) laminates. Eng Struct2022; 256: 114036.
109.
BisbyPLStratfordTHartC, et al.Fire performance of well-anchored TRM, FRCM and FRP flexural strengthening systems, In Advanced Composites in Construction. Network Group for Composites in Construction, pp. 98–109, 2013.
110.
AskouniPDPapanicolaouCGAzdejkovicL. Experimental investigation of the trm-to-masonry bond after exposure to elevated temperatures: cementitious and alkali-activated matrices of various densities. Materials2022; 15(1): 140.
111.
LiWSunPLiuY, et al.Tensile damage mechanisms of carbon fiber composites at high temperature by acoustic emission and fully connected neural network. Mater Test2022; 64(6): 893–901.
YangXGaoWYDaiJG, et al.Flexural strengthening of RC beams with CFRP grid-reinforced ECC matrix. Compos Struct2018; 189(January): 9–26.
114.
LampropoulosAPPaschalisSATsioulouOT, et al.Strengthening of reinforced concrete beams using ultra high performance fibre reinforced concrete (UHPFRC). Eng Struct2016; 106: 370–384.
115.
SafdarMMatsumotoTKakumaK. Flexural behavior of reinforced concrete beams repaired with ultra-high performance fiber reinforced concrete (UHPFRC). Compos Struct2016; 157: 448–460.
116.
PaschalisSALampropoulosAPTsioulouO. Experimental and numerical study of the performance of ultra high performance fiber reinforced concrete for the flexural strengthening of full scale reinforced concrete members. Constr Build Mater2018; 186: 351–366.
117.
Al-OstaMAIsaMNBaluchMH, et al.Flexural behavior of reinforced concrete beams strengthened with ultra-high performance fiber reinforced concrete. Constr Build Mater2017; 134: 279–296.
118.
ZhangYLiXZhuY, et al.Experimental study on flexural behavior of damaged reinforced concrete (RC) beam strengthened by toughness-improved ultra-high performance concrete (UHPC) layer. Composites Part B2020; 186(December 2019): 107834.
119.
TurkerKTorunIB. Flexural performance of highly reinforced composite beams with ultra-high performance fiber reinforced concrete layer. Eng Struct2020; 219(August 2019): 110722.
120.
PremPRMurthyAR. Acoustic emission and flexural behaviour of RC beams strengthened with UHPC overlay. Constr Build Mater2016; 123: 481–492.
121.
ZhangYHuangSLiuY, et al.Flexural behavior of damaged RC beams strengthened with prestressed UHPC layer. Eng Struct2023; 283(July 2022): 115806.
122.
AhmadSSharifAMAAl-OstaMA, et al.Flexural performance of pre-damaged RC beams strengthened with different configurations of UHPFRC layer –experimental and analytical investigation. Structures2023; 48(November 2022): 1772–1787.
123.
YuanFPanJWuY. Numerical study on flexural behaviors of steel reinforced engineered cementitious composite (ECC) and ECC/Concrete composite beams. Sci China Technol Sci2014; 57(3): 637–645.
124.
AfefyHMKassemNHusseinM. Enhancement of flexural behaviour of CFRP-strengthened reinforced concrete beams using engineered cementitious composites transition layer. Struct. Infrastruct. Eng2015; 11(8): 1042–1053.
125.
ZhangPSuYLiuY, et al.Flexural behavior of GFRP reinforced concrete beams with CFRP grid-reinforced ECC stay-in-place formworks. Compos Struct2021; 277(September): 114653.
126.
MaalejMLeongKS. Engineered cementitious composites for effective FRP-strengthening of RC beams. Compos Sci Technol2005; 65(7–8): 1120–1128.
127.
HuBZhouYXingF, et al.Experimental and theoretical investigation on the hybrid CFRP-ECC flexural strengthening of RC beams with corroded longitudinal reinforcement. Eng Struct2019; 200(September): 109717.
128.
ZhangZLiuDAbdallaJA, et al.Flexural behavior of reinforced concrete beams externally strengthened with ECC and FRP grid reinforcement. Constr Build Mater2024; 446(July): 137964.
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