Modelling shear mechanisms in FRP-strengthened r/c beams

• Autorzy: Menegotto M. , Monti G. , Liotta M. A.
• Języki publikacji: EN

Abstrakty

EN

In order to obtain a clear understanding of the mechanisms underlying the shear strengthening of concrete beams by fibre reinforced polymers (FRP), an extended experimental work was performed and analytical model has been developed to reproduce rationally the tests' features. In the model, through the definition of (i) the generalised constitutive law of a FRP sheet bonded to concrete, (ii) the compatibility required by the shear crack opening, and (iii) appropriate boundary conditions, depending on the strengthening pattern, the analytical relationships of the stress field in a FRP sheet crossing a shear crack are obtained. These permit to define closed-form equations for the resistance of shear strengthening by FRP strips or sheets, as function of adopted strengthening pattern and of some basic geometric and mechanical parameters. Contribution of the FRP strengthening is then added to those of concrete and reinforcing steel, adequately weighed. The model's accuracy has been verified through correlation studies with experimental results, obtained from the literature and from laboratory tests on purposely under-designed real-scale beam specimens, strengthened with different FRP schemes.

PL

W celu uzyskania pełnego zrozumienia mechanizmów będących podstawą wzmacniania na ścinanie belek za pomocą polimerów zbrojonych włóknami (FRP) podjęto szerokie prace doświadczalne i rozwinięto modele analityczne, aby racjonalnie ująć obserwacje z badań. Na podstawie określenia: (i) uogólnionych praw konstytutywnych dla elementów FRP połączonych przez przyczepność z betonem, (ii) zgodności wymaganej przy wystąpieniu rys od ścinania, i (iii) odpowiednich warunków brzegowych – uzyskano w modelu analityczne zależności, zależnie od układu wzmocnienia, dla rozkładu naprężeń w elemencie FRP przecinającego rysę. To pozwoliło na określenie ścisłej formy równań w odniesieniu do nośności wzmocnienia za pomocą taśm lub mat FRP jako funkcji zastosowanego układu wzmocnienia oraz niektórych podstawowych paramentów geometrycznych i mechanicznych. Udział wzmocnienia z FRP jest wtedy dodawany z odpowiednią wagą do nośności betonu i zbrojenia na ścinanie. Poprawność modelu została zweryfikowana przez porównanie zgodności z wynikami eksperymentalnymi uzyskanymi z literatury oraz z własnych badań laboratoryjnych na elementach w skali naturalnej zaprojektowanych do tego celu i wzmocnionych w różny sposób za pomocą FRP.

Słowa kluczowe

EN

analytical models; experimental tests; fibre reinforced polymers; FRP; shear-resistant mechanisms; strengthening; structural concrete

PL

modelowanie; FRP; naprężenia; beton strukturalny

• Wydawca: Silesian University of Technology
• Czasopismo: Architecture Civil Engineering Environment
• Rocznik: 2009
• Tom: Vol. 2, no. 3
• Strony: 57--68
• Opis fizyczny: Bibliogr. 30 poz.

Twórcy

autor

Menegotto M.

autor

Monti G.

autor

Liotta M. A.

• Sapienza, University of Rome - via A.Gramsci 53, Rome, Italy,

Bibliografia

• [1] Monti G., Santinelli F., Liotta M.A.; Shear strengthening of beams with composite materials. Proc. 2nd International Conference on FRP Composites in Civil Engineering CICE 2004, Adelaide, Australia, December 2004
• [2] Täljsten B.; Strengthening of concrete structures for shear with bonded CFRP-fabrics. Recent advances in bridge engineering, Advanced rehabilitation, durable materials, nondestructive evaluation and management, Eds. U. Meier and R. Betti, Dübendorf, 1997, p.57-64
• [3] Triantafillou, T C.; Shear strengthening of reinforced concrete beams using epoxy-bonded FRP composites. ACI Structural Journal, 95(2), March-April, 1998; p.107-115
• [4] Khalifa A., Gold W.J., Nanni A., Aziz A.M.I.; Contribution of externally bonded FRP to shear capacity of RC flexural members. ASCE Journal of Composites for Construction, 2(4), 1998; p. 195-202
• [5] Chen J.F., Teng J.G.; Shear capacity of FRP strengthened RC beams: FRP debonding., ASCE, Journal of Structural Engineering, Vol. 129, 2003; p.615-625
• [6] Adhikary B.B., Mutsuyoshi H.; Behavior of Concrete Beams Strengthened in Shear with Carbon-Fiber Sheets. ASCE, Journal of Composites for Construction, Vol. 8, 2004; p.258-264
• [7] Deniaud C., Cheng J.J.R.; Simplified shear design method for concrete beams strengthened with FRP. ASCE, Journal of Composites for Construction, Vol.8 (5), 2004; p.425-433
• [8] Triantafillou T.C., Antonopoulos C.P.; Design of concrete flexural members strengthened in shear with FRP. ASCE Journal of Composites for Construction, Vol. 4 (4), 2000; p.198-205
• [9] fib; Design and Use of Externally Bonded FRP Reinforcement (FRP EBR) for Reinforced Concrete Structures. Bulletin no. 14, fib Task Group 9.3 „FRP Reinforcement for Concrete Structures”, 2001
• [10] CNR; Instructions for design, execution and control of strengthening interventions through fiber-reinforced composites. CNR-DT 200/04, Consiglio Nazionale delle Ricerche, Rome, Italy (English version), 2005
• [11] Menegotto M., Monti G.; Strengthening Concrete and Masonry with FRP - A New Code of Practice in Italy. 5th AMCM Conference, Gliwice-Ustroń, Poland, June 2005
• [12] Chen J.F., Teng J.G.; Anchorage strength models for FRP and steel plates bonded to concrete. ASCE, Journal of Structural Engineering, Vol.127, 2001; p.784-791
• [13] Monti G., Renzelli M., Luciani P.; FRP Adhesion to Uncracked and Cracked Concrete Zones. 6th International Symposium on Fibre-Reinforced Polymer (FRP) Reinforcement for Concrete Structures (FRPRCS-6), Singapore, 2003
• [14] Campione G., Miraglia N.; Strength and strain capacities of concrete compression members reinforced with FRP. Cement and Concrete Composites, Elsevier, 25, 2003; p.31-41
• [15] Monti G., Santinelli F., Liotta M.A.; Mechanics of FRP shear strengthening of RC beams. Proc. ECCM 11, Rhodes, Greece, May 2004
• [16] CEN; Eurocode 2: Design of concrete structures -Part 1-1: General rules and rules for buildings. prEN 1992-1-1:2003 E, Comité Européen de Normalisation, Brussels, Belgium, 2003
• [17] Al-Sulaimani G.J., Sharif A., Basunbul I.A., Baluch M.H., Ghaleb B.N.; Shear Repair for Reinforced Concrete by Fiberglass Plate Bonding. ACI Structural Journal, Vol.91 (3), 1994; p.458-464
• [18] Chajes M.J., Januszka T.E, Mertz D.R., Thomson T.A. Jr., Finch W.W. Jr.; Shear Strengthening of Reinforced Concrete Beams Using Externally Applied Composite Fabrics, ACI Structural Journal, Vol. 92 (3), 1995; p.295-303
• [19] Funakawa I., Shimono K., Watanabe T., Asada S., Ushijima S.; Experimental study on shear strengthening with continuous fiber reinforcement sheet and methyl methacrylate resin, III Int. Symp. Non Metallic (FRP) Reinforcement for Concrete Structures, Japan, 1997; p.475-482
• [20] Kamiharako A., Maruyama K., Takada K., Shimomura T.; Evaluation of shear contribution of FRP sheets attached to concrete beams, III Int. Symp. Non Metallic (FRP) Reinforcement for Concrete Structures, Japan, 1997; p.467-474
• [21] Norris T., Saadatmanesh H., Ehsani M.R.; Shear and Flexural Strengthening of R/C Beams with Carbon Fiber Sheets, ASCE, Journal of Structural j Engineering, Vol. 123 (7), 1997; p.903-911
• [22] Taerwe L., Khalil H., Matthys S.; Behaviour of R/C beams strengthened in shear by external CFRP sheets, III Int. Symp. Non Metallic (FRP) Reinforcement for Concrete Structures, Japan, 1997; p.483-490
• [23] Umezu K., Fujita M., Nakai H., Tamaki K.; Shear behavior of RC beams with aramid fiber sheet, III Int. Symp. Non Metallic (FRP) Reinforcement for Concrete Structures, Japan, 1997; p.491-498
• [24] Challal O., Nollet M.J., Saleh K.; Use of CFRP Strips for Flexure and Shear Strengthening of RC Members. 2nd Int. Conference on Composites in Infrastructure, Tucson, AZ, USA, 1998; p.249-260
• [25] Khalifa A., Nanni A.; Improving shear capacity of existing RC T-section beams using CFRP composites. Cement & Concr. Comp., Vol. 22, 2000; p.165-174
• [26] Park S.Y, Naaman A.E., Lopez M.M., Till R.D.; Shear strengthening effect of R/C beams using glued CFRP sheets, Int. Conf. On FRP Composites in Civil Engineering, Hong Kong, China, 1, 2001; p.669-676
• [27] ACI; ACI440.2R-02 - Guide for the Design and Construction of Externally Bonded FRP Systems for Strengthening Concrete Structures. American Concrete Institute, Committee 440; 2002
• [28] Aprile A., Benedetti A.; Coupled flexural-shear design of RC beams strengthened with FRP. Composites Part B: Engineering. Volume: 35, Issue: 1, January, 2004; p.1-25
• [29] Brosens K., Van Gemert D.; Anchorage design for externally bonded carbon fiber reinforced polymer laminates. Proc. 4th Int. Symposium on FRP Reinforcement for Concrete Structures, Baltimore, USA, 1999; p.635-645
• [30] Monti G., Liotta M.A.; Tests and design equations for FRP-strengthening in shear. Journal of Construction and Building Materials. Volume 21, Issue 4, April, 2007; p.799-809