3/10/2015 Materials Used in Tall Buildings Dr JiafeiJANG College of Civ Engineering Materials Used in Tall Buildings Higher height Larger bearing capacity Free space Higher requirement on material 本课件版权归作者所有，仅供个人学习使用，请勿转载。 1
3/10/2015 1 Materials Used in Tall Buildings Dr Jiafei JIANG Assistant Professor College of Civil Engineering Tongji University 2015/3/10 Higher height Materials Used in Tall Buildings Free space Larger bearing capacity Higher requirement on materials 本课件版权归作者所有，仅供个人学习使用，请勿转载
3/10/2015 Concrete Most widely used construction material *33 billion metric tons every year *73%of the tall buildings studied in the 2oo0s adopt a core+outrigger structural system.Of these approximately 5o%are constructed with concrete. (CTBUH) Core+outrigger OUTLINE Confined Concrete Mechanism-strength ductility √Application High Strength Concrete √Definition √Mechanism √Property Case Study Taipei101 本课件版权归作者所有，仅供个人学习使用，请勿转载。 2
3/10/2015 2 Most widely used construction material 33 billion metric tons every year Concrete Core+outrigger 73% of the tall buildings studied in the 2000s adopt a core+outrigger structural system. Of these approximately 50% are constructed with concrete. (CTBUH) Confined Concrete Mechanism‐strength & ductility Application High Strength Concrete Definition Mechanism Property Case Study Taipei 101 OUTLINE 本课件版权归作者所有，仅供个人学习使用，请勿转载
3/10/2015 1.Confined Concrete Confined Concrete *Reinforcement and concrete *Hoops/spirals t primary fle shlthemmthemterfthe xural reinforcing bars;b)omm. Why 本课件版权归作者所有，仅供个人学习使用，请勿转载。 3
3/10/2015 3 1. Confined Concrete Reinforcement and concrete Hoops/spirals In static design, the spacing of the hoops shall not exceed the smallest of a) the width of the section ; b) 15 times the diameter of the smallest primary flexural reinforcing bars; c) 400 mm. In seismic design, the spacing of the hoops in densified zone shall not exceed the smallest of a) 6 times the diameter of the smallest primary flexural reinforcing bars; b)100 mm. ‐JGJ 3‐ 2010 (Chinese Code) Confined Concrete Why ? 本课件版权归作者所有，仅供个人学习使用，请勿转载
3/10/2015 Confined Concrete -Mechanism Concrete in triaxial loading -Triaxial testing on cubes *Arbitrary loading path Complete failure surface Triaxial Loading System in DUT,China Willam-Warnke failure surface Confined Concrete -Mechanism *Concrete in triaxial loading --Hydro-pressure confinement testing on cylinder -Richart et al.1928(20 MPa s fs 50 MPa) fcc=f+4.1f Mohr-Coulomb Cirdle aan Ce 本课件版权归作者所有，仅供个人学习使用，请勿转载。 4
3/10/2015 4 Confined Concrete ‐Mechanism Concrete in triaxial loading ‐‐‐‐Triaxial testing on cubes Arbitrary loading path [1]Sun Y.P , He Z. J. Experimental investigation on strength and deformation of plain high‐strength high‐performance concrete under multiaxial compression [J]. Chinese Journal of Rock Mechanics and Engineering, 2008. 1 3 2 Triaxial Loading System in DUT, China [1] Willam‐Warnke failure surface Complete failure surface Confined Concrete ‐Mechanism [1] Richart F E, Brandtzaeg A, Brown R L. A study of the failure of concrete under combined compressive stresses[J]. 1928. cc c l f f f 4.1 Mohr–Coulomb Circle Triaxial Cell[1] c fl Concrete in triaxial loading ‐‐‐ Hydro‐pressure confinement testing on cylinder Richart et al. 1928 (20 MPa ≤ fc ≤ 50 MPa) 本课件版权归作者所有，仅供个人学习使用，请勿转载
3/10/2015 Confined Concrete -Mechanism T f= Confined Concrete -Strength *Arching action *Assumption: 1.2nd degree parabolas 2.Initial tangent slope of 45] Weak section-middle 国 pressure 本课件版权归作者所有，仅供个人学习使用，请勿转载。 5
3/10/2015 5 Confined Concrete ‐Mechanism c fl Rcor Tu=fsyAss1 Tu u sy ss1 l cor cor T f A f q R R ? l f Arching action Assumption: 1. 2nd degree parabolas 2. Initial tangent slope of 45°[1] Weak section‐ middle Confined Concrete ‐Strength [1] Mander, J. B.; Priestley, M. J. N.; and Park, R., “Theoretical Stress‐Strain Model for Confined Concrete,” J. Struct. Eng., ASCE, V.114, No. 8, 1988. q q Spacing Confinement pressure 本课件版权归作者所有，仅供个人学习使用，请勿转载
3/10/2015 Confined Concrete -Strength Arching action(cross-section) Confined Concrete -Strength Arching action(cross-section) *Confinement effective coefficien Equlvalent uniform confinement=Peak strength? 本课件版权归作者所有，仅供个人学习使用，请勿转载。 6
3/10/2015 6 Arching action (cross‐section) Confined Concrete ‐Strength [1] Paultre P, Légeron F. Confinement reinforcement design for reinforced concrete columns[J]. Journal of structural engineering, 2008, 134(5): 738‐749. Arching action (cross‐section) Confinement effective coefficient Confined Concrete ‐Strength [1] Paultre P, Légeron F. Confinement reinforcement design for reinforced concrete columns[J]. Journal of structural engineering, 2008, 134(5): 738‐749. e cc e A k A Ae‐minimum effectively confined core area Acc‐ concrete area enclosed by hoops l el f k f Equivalent uniform confinement Peak strength? 本课件版权归作者所有，仅供个人学习使用，请勿转载
3/10/2015 Confined Concrete -Strength Richart et al.(Chinese Code) f=f+4.1f Wiliam-Warnker(1975) (Mander model) A=2万，a= er.J.B:Prlestley.M.J.N:and Park.R. Confined Concrete -Ductility Ductility()） "The ability of a material,component,connection or structure to undergo inelastic deformations with acceptable stiffness and strength reduction." *Material u->Section u->Member u->Structure u Material ductility is the basis hAs,SmoLD.fndamrekdanhaukeEghemg'womwMeyAors,,ooPy-e 本课件版权归作者所有，仅供个人学习使用，请勿转载。 7
3/10/2015 7 Richart et al. (Chinese Code) Confined Concrete ‐Strength [1] Mander, J. B.; Priestley, M. J. N.; and Park, R., “Theoretical Stress‐Strain Model for Confined Concrete,” J. Struct. Eng., ASCE, V.114, No. 8, 88 fsy=300 Mpa ds=16 mm s=90 mm fc=30 Mpa sm=0.15 cc c l f f f 4.1 Confined strength determination from lateral confining stresses[1] m m 2 01 2 ( ) 60 5 c c bb b f f f Wiliam‐Warnker(1975) (Mander model) compression meridian 1 2 m 2 , 3 c I J Ductility () “The ability of a material, component, connection or structure to undergo inelastic deformations with acceptable stiffness and strength reduction.”[1] Material ‐> Section ‐>Member ‐>Structure Material ductility is the basis Confined Concrete ‐Ductility [1] ] Elnashai A. S., Sarno L. D. “Fundamentals of Earthquake Engineering” [M]. John Wiley & Sons, INC., 2008, P85‐100. 本课件版权归作者所有，仅供个人学习使用，请勿转载
3/10/2015 Confined Concrete -Ductility Material u>Section u>Member u>Structure u Confined Concrete -Ductility The definition of ductility ↑Fore AJA 4 A,Deformation of the gth World 本课件版权归作者所有，仅供个人学习使用，请勿转载。 8
3/10/2015 8 Material > Section >Member >Structure Confined Concrete ‐Ductility [1] [1] ] Elnashai A. S., Sarno L. D. “Fundamentals of Earthquake Engineering” [M]. John Wiley & Sons, INC., 2008, P85‐100. The definition of ductility Confined Concrete ‐Ductility =u/y [1] Park, R. ( 1988). Ductility evaluation from laboratory and analytical testing . Proceedings of the 9th World Conference on Earthquake Engineering , Tokyo ‐ Kyoto, Japan , Vol. VIII, pp. 605 – 616 . y u Force Deformation 本课件版权归作者所有，仅供个人学习使用，请勿转载
3/10/2015 Confined Concrete -Ductility .The definition of ductility =4A .Yielding deformation A,based on] 1.First Yield 2.Equivalent Elasto-Plastic Yield 3.Equivalent Elasto-Plastic Energy Absorption 4.Reduced Stiffness Equivalent Elasto-Plastic Yield Confined Concrete -Ductility The definition of ductility HAJAy Ultimate deformatioeonding 1.A limiting value of strain 2.Apex of the load-displacement relationship 3.80%-85%of the peak load 4.Fracture or buckling k98pmtamooeaataearge 本课件版权归作者所有，仅供个人学习使用，请勿转载。 9
3/10/2015 9 The definition of ductility Yielding deformation y, based on[1] 1. First Yield 2. Equivalent Elasto‐Plastic Yield 3. Equivalent Elasto‐Plastic Energy Absorption 4. Reduced Stiffness Equivalent Elasto‐Plastic Yield Confined Concrete ‐Ductility =u/y [1] Park, R. ( 1988). Ductility evaluation from laboratory and analytical testing . Proceedings of the 9th World Conference on Earthquake Engineering , Tokyo ‐ Kyoto, Japan , Vol. VIII, pp. 605 – 616 . Confined Concrete ‐Ductility =u/y [1] Park, R. ( 1988). Ductility evaluation from laboratory and analytical testing . Proceedings of the 9th World Conference on Earthquake Engineering , Tokyo ‐ Kyoto, Japan , Vol. VIII, pp. 605 – 616 . The definition of ductility Ultimate deformation u, corresponding to[1] 1. A limiting value of strain 2. Apex of the load – displacement relationship 3. 80%‐85% of the peak load 4. Fracture or buckling 本课件版权归作者所有，仅供个人学习使用，请勿转载
3/10/2015 Confined Concrete -Ductility Deformation Suggested ductillty ratio for uniformity t的ea2 l:片 Confined Concrete -Ductility *Material Ductility Typical values for is o.033 for unconfined concrete. With tie confinement,,(hoop rupture)ir三号 8cu=0.004+1.4p,f8m/f ranges from .12 to.,a4-to16-fold increase over the traditionally assumed value for unconfined concrete. 本课件版权归作者所有，仅供个人学习使用，请勿转载。 10
3/10/2015 10 Confined Concrete ‐Ductility Suggested ductility ratio for uniformity[1] [1] Park, R. ( 1988). Ductility evaluation from laboratory and analytical testing . Proceedings of the 9th World Conference on Earthquake Engineering , Tokyo ‐ Kyoto, Japan , Vol. VIII, pp. 605 – 616 . Deformation Bearing Confined Concrete ‐Ductility [1]Mander, J. B.; Priestley, M. J. N.; Park, R., “Theoretical Stress‐Strain Model for Confined Concrete,” J. Struct. Eng., ASCE, V.114, No. 8, 1988. [1] cu 0.004 1.4 / s sy sm cc f f Material Ductility Typical values for cu is 0.033 for unconfined concrete. With tie confinement, (hoop rupture) cu ranges from 0.012 to 0.05, a 4‐ to 16‐fold increase over the traditionally assumed value for unconfined concrete. 本课件版权归作者所有，仅供个人学习使用，请勿转载