24 CHAPTER 2 Nsbg side-face blowout strength of a group of forcement within the length lo, mm, Chapter 21 anchors, N, Appendix D Ss= sample standard deviation, MPa, Chapter 5, Nu= factored axial force normal to cross section ppendix D taken ag simultaneously with Vu or T; to be s2= center-to-center spacing of longitudinal shear as positive for compression and nega- or torsion reinforcement, mm, Chapter 11 tive for tension, N, Chapter 11 snow load. or related internal moments and Nua= factored tensile force applied to anchor or forces, Chapters 9, 21 group of anchors, N, Appendix D Se= moment, shear, or axial force at co N factored horizontal tensile force applied at top corresponding to development of probable of bracket or corbel acting simultaneously with strength at intended yield locations, based Vu, to be taken as positive for tension, N, the governing mechanism of inelastic lateral deformation, considering both gravity and Pcp=outside perimeter of concrete cross section, earthquake load effects, Chapter 21 mm, see 11.6.1, Chapter 11 Sm= elastic section modulus, mm, Chapter 22 perimeter of centerline of outermost closed Sn nominal flexural, shear, or axial strength of transverse torsional reinforcement. mm connection, Chapter 21 Chapter 11 Sy= yield strength of connection, based on fy, for Pb= nominal axial strength at balanced strain con- moment, shear, or axial force, Chapter 21 ditions, N, see 10.3.2, Chapters 9, 10, Appe t= wall thickness of hollow section, mm, Chapter mixes B. c Pc= critical buckling load, N, see 10.12.3, Chapter T= cumulative effect of temperature, creep, nominal axial strength of cross section, N age-compensating concrete, Chapter 9, Chapters 9, 10, 14, 22, Appendixes B, C Appendix C Pn. maxmaximum allowable value of Pn,N,see Tn= nominal torsional moment strength, N-mm 10.3.6, Chapter 10 Po= nominal axial strength at zero eccentricity, N, Tu= factored torsional moment at section, N-mm, Chapter 11 Ppi=prestressing force at jacking end, N, Chapter 18 U=required strength to resist factored loads or factored prestressing force at anchorage related internal moments and forces, Chapter 9 device, N, Chapter 18 Appendix C Ppx= prestressing force evaluated at distance lpx nominal shear stress. MPa. see 11.12.6.2 from the jacking end, N, Chapter 18 Chapters 11, 21 Ps=unfactored axial load at the design( midheight) Vb basic concrete breakout strength in shear of a section including effects of self-weight, single anchor in cracked concrete, N,see D.6.2.2 and D.6.2.3, Appendix D factored axial force; to be taken as positive for Vc=nominal shear strength provided by concrete compression and negative for tension, N N, Chapters 8, Chapters 10, 14, 21, 22 Vcb= nominal concrete breakout strength in shear of qpu= factored dead load per unit area, Chapter 13 a single anchor, N, see D.6.2.1, Appendix D gLu= factored live load per unit area, Chapter 13 nominal concrete breakout strength in shear of qy= factored load per unit area, Chapter 13 a group of anchors, N, see D.6.2.1, Appendix D Q= stability index for a story, see 10.11. 4, Chapter Vci= nominal shear strength provided by concrete 10 when diagonal cracking results from combined radius of gyration of cross section of a com- shear and moment, N, Chapter 11 pression member, mm, Chapter 10 cp= nominal concrete pryout strength of a single R= rain load, or related internal moments and anchor, N, see D.6. 3, Appendix D nominal concrete pryout strength of a group of center-to-center spacing of items, such as lon- anchors, N, see D.6.3, Appendix D gitudinal reinforcement, transverse reinforce- Vw= nominal shear strength provided by concrete ment, prestressing tendons, wires, or anchors, when diagonal cracking results from high prin mm, Chapters 10-12, 17-21, Appendix D ipal tensile stress in web, N, Chapter 11 center-to-center spacing of reinforcement in Va= shear force at section due to unfactored dead the i-th layer adjacent to the surface of the member, mm, Appendix A v shear force corresponding to the devel So= center-to-center spacing of transverse rein- it of the probable moment strength licene with Acl oduction of networking permitted without loene from H ACI 318 Building CcHc s esack satc 5 18928-25sTy
24 CHAPTER 2 ACI 318 Building Code and Commentary Nsbg= side-face blowout strength of a group of anchors, N, Appendix D Nu = factored axial force normal to cross section occurring simultaneously with Vu or Tu; to be taken as positive for compression and negative for tension, N, Chapter 11 Nua = factored tensile force applied to anchor or group of anchors, N, Appendix D Nuc = factored horizontal tensile force applied at top of bracket or corbel acting simultaneously with Vu , to be taken as positive for tension, N, Chapter 11 pcp = outside perimeter of concrete cross section, mm, see 11.6.1, Chapter 11 ph = perimeter of centerline of outermost closed transverse torsional reinforcement, mm, Chapter 11 Pb = nominal axial strength at balanced strain conditions, N, see 10.3.2, Chapters 9, 10, Appendixes B, C Pc = critical buckling load, N, see 10.12.3, Chapter 10 Pn = nominal axial strength of cross section, N, Chapters 9, 10, 14, 22, Appendixes B, C Pn,max=maximum allowable value of Pn, N, see 10.3.6, Chapter 10 Po = nominal axial strength at zero eccentricity, N, Chapter 10 Ppj = prestressing force at jacking end, N, Chapter 18 Ppu = factored prestressing force at anchorage device, N, Chapter 18 Ppx = prestressing force evaluated at distance lpx from the jacking end, N, Chapter 18 Ps = unfactored axial load at the design (midheight) section including effects of self-weight, N, Chapter 14 Pu = factored axial force; to be taken as positive for compression and negative for tension, N, Chapters 10, 14, 21, 22 qDu = factored dead load per unit area, Chapter 13 qLu = factored live load per unit area, Chapter 13 qu = factored load per unit area, Chapter 13 Q = stability index for a story, see 10.11.4, Chapter 10 r = radius of gyration of cross section of a compression member, mm, Chapter 10 R = rain load, or related internal moments and forces, Chapter 9 s = center-to-center spacing of items, such as longitudinal reinforcement, transverse reinforcement, prestressing tendons, wires, or anchors, mm, Chapters 10-12, 17-21, Appendix D si = center-to-center spacing of reinforcement in the i-th layer adjacent to the surface of the member, mm, Appendix A so = center-to-center spacing of transverse reinforcement within the length lo, mm, Chapter 21 ss = sample standard deviation, MPa, Chapter 5, Appendix D s2 = center-to-center spacing of longitudinal shear or torsion reinforcement, mm, Chapter 11 S = snow load, or related internal moments and forces, Chapters 9, 21 Se = moment, shear, or axial force at connection corresponding to development of probable strength at intended yield locations, based on the governing mechanism of inelastic lateral deformation, considering both gravity and earthquake load effects, Chapter 21 Sm = elastic section modulus, mm3, Chapter 22 Sn nominal flexural, shear, or axial strength of connection, Chapter 21 Sy = yield strength of connection, based on fy , for moment, shear, or axial force, Chapter 21 t = wall thickness of hollow section, mm, Chapter 11 T = cumulative effect of temperature, creep, shrinkage, differential settlement, and shrinkage-compensating concrete, Chapter 9, Appendix C Tn = nominal torsional moment strength, N⋅mm, Chapter 11 Tu = factored torsional moment at section, N⋅mm, Chapter 11 U = required strength to resist factored loads or related internal moments and forces, Chapter 9, Appendix C vn = nominal shear stress, MPa, see 11.12.6.2, Chapters 11, 21 Vb = basic concrete breakout strength in shear of a single anchor in cracked concrete, N, see D.6.2.2 and D.6.2.3, Appendix D Vc = nominal shear strength provided by concrete, N, Chapters 8, 11, 13, 21 Vcb = nominal concrete breakout strength in shear of a single anchor, N, see D.6.2.1, Appendix D Vcbg= nominal concrete breakout strength in shear of a group of anchors, N, see D.6.2.1, Appendix D Vci = nominal shear strength provided by concrete when diagonal cracking results from combined shear and moment, N, Chapter 11 Vcp = nominal concrete pryout strength of a single anchor, N, see D.6.3, Appendix D Vcpg= nominal concrete pryout strength of a group of anchors, N, see D.6.3, Appendix D Vcw = nominal shear strength provided by concrete when diagonal cracking results from high principal tensile stress in web, N, Chapter 11 Vd = shear force at section due to unfactored dead load, N, Chapter 11 Ve = design shear force corresponding to the development of the probable moment strength of Copyright American Concrete Institute Provided by IHS under license with ACI Licensee=Black & Veatch/5910842100 No reproduction or networking permitted without license from IHS Not for Resale, 11/28/2005 18:20:15 MST --`,,`,````````,,`,,`,,``,`,,,`-`-`,,`,,`,`,,`---
CHAPTER 2 the member. N. see 21.3.4. 1 and 21 4.5.1 footings, Chapter 11 Chapter 21 ratio of flexural stiffness of shearhead arm to Vi= factored shear force at section due to exter hat of the surrounding composite slab sec- tion, see 11.12.4.5, Chapter 11 with Mmar N, Chapter 11 B= ratio of long to short dimensions: clear spans nominal shear strength, N, Chapters 8, 10, 11 33and22.54; 21, 22, Appendix D sides of column concentrated load or reaction Vnh= nominal horizontal shear strength, N, Chap- area,see.12.2.1; or sides of a footing, see ter 17 1544.2, Chapters9,11,15,22 Ve vertical component of effective prestress force Pb ratio of area of reinforcement cut off to total at section, N, Chapter 11 area of tension reinforcement at section nominal shear strength provided by shear reinforcement, N, Chapter 11 Vsa= nominal strength in shear of a single anchor or columns due to sustained loads see 10.11.1 group of anchors as governed by the steel and 10. 13.6, Chapter 10 strength, N, see D.6.1.1 and D.6.1.2, Appen- Pn= factor to account for the effect of the anchor- dix D age of ties on the effective compressive V factored shear force at section, N, Chapters strength of a nodal zone, Appendix A Vua= factored shear force applied to a single anchor Pp=factor used to compute Vc in prestressed slabs, Chapter 11 or group of anchors, N, Appendix D factor to account for the effect of cracking and Vus= factored horizontal shear in a story, N, Chap- confining reinforcement on the effective com- pressive strength of the concrete in a strut, we= density of concrete, kg/m, Chapters 8, 9 Wu= factored load per unit length of beam or one- Bt ratio of torsional stiffness of edge beam sec way slab, Chapter 8 tion to flexural stiffness of a width of slab equal W= wind load, or related internal moments and to span length of beam, center-to-center of forces, Chapter 9, Appendix C supports, see 13.6.4.2, Chapter 13 x= shorter overall dimension of rectangular part B= factor relating depth of equivalent rectangular of cross section, mm, Chapter 13 compressive stress block to neutral y longer overall dimension of rectangular part of depth, see 10.2.7. 3, Chapters 10, 18, App cross section, mm, Chapter 13 dix B y, =distance from centroidal axis of gross section, y =factor used to determine the unbalanced neglecting reinforcement, to tension face, mm, moment transferred by flexure at slab-column Chapters 9, 11 connections, see 13.5.3.2, Chapters 11, 13, 21 a= angle defining the orientation of reinforce- yp factor for type of prestressing steel, see 18.7.2, ment, Chapters 11, 21, Appendix A Chapter 18 coefficient defining the relative contribution of ys= factor used to determine the portion of rein concrete strength to nominal wall shear strength, forcement located in center band of footing see 21.7. 4.1, Chapter 2 see 15.4. 4.2, Chapter 15 af= ratio of flexural stiffness of beam section to % =factor used to determine the unbalanced flexural stiffness of a width of slab bounded moment transferred by eccentricity of shear at laterally by centerlines of adjacent panels (if slab-column connections. see 11.12.6.1 any) on each side of the beam, see 13.6.1.6 Chapter 11 Chapters 9, 13 8ns= moment magnification factor for frames atm= average value of af for all beams on edges of braced against sidesway, to reflect effects of member curvature between ends of compres an= af in direction of C1, Chapter 13 sion member, Chapter 10 af2= af in direction of 2, Chapter 13 moment magnification factor for frames not ai= angle between the axis of a strut and the bars braced against sidesway, to reflect lateral drift in the ith layer of reinforcement crossing that resulting from lateral and gravity loads, Chap strut, Appendix A ter 10 apx= total angular change of tendon profile from u= design displacement, mm, Chapter 21 tendon jacking end to point under consider Af.= increase in stress in prestressing steel due to ation, radians, Chapter 18 factored loads, MPa, Appendix A as = constant used to compute V in slabs and 41 stress in prestressing steel at service loads licene with Acl oduction of networking permitted without loene from H ACI 318 Building Nor censeenBlack Veatch5910842100 ot for Resale, 11/28/2005 182015ural
CHAPTER 2 25 ACI 318 Building Code and Commentary the member, N, see 21.3.4.1 and 21.4.5.1 Chapter 21 Vi = factored shear force at section due to externally applied loads occurring simultaneously with Mmax, N, Chapter 11 Vn = nominal shear strength, N, Chapters 8, 10, 11, 21, 22, Appendix D Vnh = nominal horizontal shear strength, N, Chapter 17 Vp = vertical component of effective prestress force at section, N, Chapter 11 Vs = nominal shear strength provided by shear reinforcement, N, Chapter 11 Vsa = nominal strength in shear of a single anchor or group of anchors as governed by the steel strength, N, see D.6.1.1 and D.6.1.2, Appendix D Vu = factored shear force at section, N, Chapters 11-13, 17, 21, 22 Vua = factored shear force applied to a single anchor or group of anchors, N, Appendix D Vus = factored horizontal shear in a story, N, Chapter 10 wc = density of concrete, kg/m3, Chapters 8, 9 wu = factored load per unit length of beam or oneway slab, Chapter 8 W = wind load, or related internal moments and forces, Chapter 9, Appendix C x = shorter overall dimension of rectangular part of cross section, mm, Chapter 13 y = longer overall dimension of rectangular part of cross section, mm, Chapter 13 yt = distance from centroidal axis of gross section, neglecting reinforcement, to tension face, mm, Chapters 9, 11 α = angle defining the orientation of reinforcement, Chapters 11, 21, Appendix A αc = coefficient defining the relative contribution of concrete strength to nominal wall shear strength, see 21.7.4.1, Chapter 21 αf = ratio of flexural stiffness of beam section to flexural stiffness of a width of slab bounded laterally by centerlines of adjacent panels (if any) on each side of the beam, see 13.6.1.6, Chapters 9, 13 αfm = average value of αf for all beams on edges of a panel, Chapter 9 αf 1 = αf in direction of l1, Chapter 13 αf 2 = αf in direction of l2, Chapter 13 αi = angle between the axis of a strut and the bars in the i-th layer of reinforcement crossing that strut, Appendix A αpx = total angular change of tendon profile from tendon jacking end to point under consideration, radians, Chapter 18 αs = constant used to compute Vc in slabs and footings, Chapter 11 αv = ratio of flexural stiffness of shearhead arm to that of the surrounding composite slab section, see 11.12.4.5, Chapter 11 β = ratio of long to short dimensions: clear spans for two-way slabs, see 9.5.3.3 and 22.5.4; sides of column, concentrated load or reaction area, see 11.12.2.1; or sides of a footing, see 15.4.4.2, Chapters 9, 11, 15, 22 βb = ratio of area of reinforcement cut off to total area of tension reinforcement at section, Chapter 12 βd = ratio used to compute magnified moments in columns due to sustained loads, see 10.11.1 and 10.13.6, Chapter 10 βn = factor to account for the effect of the anchorage of ties on the effective compressive strength of a nodal zone, Appendix A βp = factor used to compute Vc in prestressed slabs, Chapter 11 βs = factor to account for the effect of cracking and confining reinforcement on the effective compressive strength of the concrete in a strut, Appendix A βt = ratio of torsional stiffness of edge beam section to flexural stiffness of a width of slab equal to span length of beam, center-to-center of supports, see 13.6.4.2, Chapter 13 β1 = factor relating depth of equivalent rectangular compressive stress block to neutral axis depth, see 10.2.7.3, Chapters 10, 18, Appendix B γf = factor used to determine the unbalanced moment transferred by flexure at slab-column connections, see 13.5.3.2, Chapters 11, 13, 21 γp = factor for type of prestressing steel, see 18.7.2, Chapter 18 γs = factor used to determine the portion of reinforcement located in center band of footing, see 15.4.4.2, Chapter 15 γv = factor used to determine the unbalanced moment transferred by eccentricity of shear at slab-column connections, see 11.12.6.1, Chapter 11 δns = moment magnification factor for frames braced against sidesway, to reflect effects of member curvature between ends of compression member, Chapter 10 δs = moment magnification factor for frames not braced against sidesway, to reflect lateral drift resulting from lateral and gravity loads, Chapter 10 δu = design displacement, mm, Chapter 21 ∆fp = increase in stress in prestressing steel due to factored loads, MPa, Appendix A ∆fps= stress in prestressing steel at service loads Copyright American Concrete Institute Provided by IHS under license with ACI Licensee=Black & Veatch/5910842100 No reproduction or networking permitted without license from IHS Not for Resale, 11/28/2005 18:20:15 MST --`,,`,````````,,`,,`,,``,`,,,`-`-`,,`,,`,`,,`---
CHAPTER 2 less decompression stress, MPa, Chapter 18 11, 13, 14, 17-22, Appendixes A-D 4,= relative lateral deflection between the top and bottom of a story due to lateral forces com factor used to modify tensile strength of puted using a first-order elastic frame analysis anchors based on presence or absence of and stiffness values satisfying 10.11.1, mr cracks in concrete, see D.5.2.6, Appendix D Chapter 10 VC.P factor used to modify pullout strength of 4r= difference between initial and final (after load anchors based on presence or absence of removal)deflections for load test or repeat cracks in concrete, see D 5.3.6, Appendix D load test, mm, Chapter 20 v factor used to modify shear strength of As=maximum deflection at or near midheight due anchors based on presence or absence of to service loads, mm, Chapter 14 cracks in concrete and presence or absence 4y= deflection at midheight of wall due to factored loads, mm, Chapter 14 of supplementary reinforcement, see D.6.2.7 for anchors in shear, Appendix D 41= measured maximum deflection during first load test, mm, see 20.5.2, Chapter 20 Vcp, N= factor used to modify tensile strength of post 42= maximum deflection measured during second installed anchors intended for use in load test relative to the position of the struc uncracked concrete without supplementary reinforcement, see D 5.2.7, Ap ture at the beginning of second load test, mm, see 20.5.2, Chapter 20 ve factor used to modify development length Et= net tensile strain in extreme layer of longitudi- based on reinforcement coating, see 12.2.4, nal tension steel at nominal strength, exclud 12 ing strains due to effective prestress, creep, shrinkage, and temperature, Chapters 8-10, Vec n= factor used to modify tensile strength of Appendix C anchors based on eccentricity of applied 8 angle between axis of strut, compression loads, see D 5.2.4, Appendix D diagonal, or compression field and the tension sed to modify shear strength of chord of the member, Chapter 11, Appendix A anchors based on eccentricity of applied modification factor related to density of con- loads, see D.6.2.5, Appendix D crete, Chapters 11, 12, 17-19, Appendix A Ra= multiplier for additional deflection due to long Ved.N= factor used to modify tensile strength of term effects, see 9.5.2.5, Chapter 9 anchors based on proximity to edges of con A= coefficient of friction, see 11.7.4.3, Chapter 11 crete member, see D.5.2.5, Appendix D Ap=post-tensioning curvature friction coefficient, Ved y= factor used to modify shear strength of er 18 anchors based on proximity to edges of con- 5= time-dependent factor for sustained load, see crete member, see D.6.2.6, Appendix D 9.5.2.5, Chapter 9 ratio of As to bd, Chapters 11, 13, 21, Appen s factor used to modify development length based on reinforcement size. see 12.2.4 ratio of As to ba, Chapter 9, Appendix B Chapter 12 Pb= ratio of As to bd producing balanced strain Vt factor used to modify development length conditions, see 10.3.2, Chapters 10, 13, 14, based on reinforcement location see 12.2.4 Appendix B Chapter 12 ratio of area of distributed longitudinal rein o= tension reinforcement index. see 18.7.2 forcement to gross concrete area perpendicu- Chapter 18, Appendix B lar to that reinforcement, Chapters 11, 14, 21 ratio of Aos to bd Chapter 18 @= compression reinforcement index, see 18.7.2, Ps= ratio of volume of spiral reinforcement to total volume of core confined by the spiral('measured @p= prestressing steel index, see B 18.8.1, Appen ut-to-out of spirals), Chapters 10, 21 dix B atio of area distributed transverse reinforcement to gross concrete area perpendicular to that apw=prestressing steel index for flanged sections, see B. 18.8.1, Appendix B reinforcement, Chapters 11, 14, 21 Pv= ratio of tie reinforcement area to area of con- @w= tensions reinforcement index for flanged sec- tact surface, see 17.5.3.3, Chapter 17 tions, see B. 18.8.1, Appendix B Pw= ratio of As to bwd, Chapter 11 w=compression reinforcement index for flanged strength reduction factor, see 9.3, Chapters 8- sections, see B. 18.8.1, Appendix B ACI 318 Building Cc Lc rseeesac 8 eatc5 93028042500
26 CHAPTER 2 ACI 318 Building Code and Commentary less decompression stress, MPa, Chapter 18 ∆o = relative lateral deflection between the top and bottom of a story due to lateral forces computed using a first-order elastic frame analysis and stiffness values satisfying 10.11.1, mm, Chapter 10 ∆r = difference between initial and final (after load removal) deflections for load test or repeat load test, mm, Chapter 20 ∆s = maximum deflection at or near midheight due to service loads, mm, Chapter 14 ∆u = deflection at midheight of wall due to factored loads, mm, Chapter 14 ∆1 = measured maximum deflection during first load test, mm, see 20.5.2, Chapter 20 ∆2 = maximum deflection measured during second load test relative to the position of the structure at the beginning of second load test, mm, see 20.5.2, Chapter 20 εt = net tensile strain in extreme layer of longitudinal tension steel at nominal strength, excluding strains due to effective prestress, creep, shrinkage, and temperature, Chapters 8-10, Appendix C θ = angle between axis of strut, compression diagonal, or compression field and the tension chord of the member, Chapter 11,Appendix A λ = modification factor related to density of concrete, Chapters 11, 12, 17-19, Appendix A λ∆ = multiplier for additional deflection due to longterm effects, see 9.5.2.5, Chapter 9 µ = coefficient of friction, see 11.7.4.3, Chapter 11 µp = post-tensioning curvature friction coefficient, Chapter 18 ξ = time-dependent factor for sustained load, see 9.5.2.5, Chapter 9 ρ = ratio of As to bd, Chapters 11, 13, 21, Appendix B ρ′ = ratio of As′ to bd, Chapter 9, Appendix B ρb = ratio of As to bd producing balanced strain conditions, see 10.3.2, Chapters 10, 13, 14, Appendix B ρl = ratio of area of distributed longitudinal reinforcement to gross concrete area perpendicular to that reinforcement, Chapters 11,14, 21 ρp = ratio of Aps to bdp, Chapter 18 ρs = ratio of volume of spiral reinforcement to total volume of core confined by the spiral (measured out-to-out of spirals), Chapters 10, 21 ρt = ratio of area distributed transverse reinforcement to gross concrete area perpendicular to that reinforcement, Chapters 11, 14, 21 ρv = ratio of tie reinforcement area to area of contact surface, see 17.5.3.3, Chapter 17 ρw = ratio of As to bwd, Chapter 11 φ = strength reduction factor, see 9.3, Chapters 8- 11, 13, 14, 17-22, Appendixes A-D ψc,N= factor used to modify tensile strength of anchors based on presence or absence of cracks in concrete, see D.5.2.6, Appendix D ψc,P= factor used to modify pullout strength of anchors based on presence or absence of cracks in concrete, see D.5.3.6, Appendix D ψc,V= factor used to modify shear strength of anchors based on presence or absence of cracks in concrete and presence or absence of supplementary reinforcement, see D.6.2.7 for anchors in shear, Appendix D ψcp,N = factor used to modify tensile strength of postinstalled anchors intended for use in uncracked concrete without supplementary reinforcement, see D.5.2.7, Appendix D ψe = factor used to modify development length based on reinforcement coating, see 12.2.4, Chapter 12 ψec,N = factor used to modify tensile strength of anchors based on eccentricity of applied loads, see D.5.2.4, Appendix D ψec,V = factor used to modify shear strength of anchors based on eccentricity of applied loads, see D.6.2.5, Appendix D ψed,N = factor used to modify tensile strength of anchors based on proximity to edges of concrete member, see D.5.2.5, Appendix D ψed,V = factor used to modify shear strength of anchors based on proximity to edges of concrete member, see D.6.2.6, Appendix D ψs = factor used to modify development length based on reinforcement size, see 12.2.4, Chapter 12 ψt = factor used to modify development length based on reinforcement location, see 12.2.4, Chapter 12 ω = tension reinforcement index, see 18.7.2, Chapter 18, Appendix B ω′ = compression reinforcement index, see 18.7.2, Chapter 18, Appendix B ωp = prestressing steel index, see B.18.8.1, Appendix B ωpw= prestressing steel index for flanged sections, see B.18.8.1, Appendix B ωw = tensions reinforcement index for flanged sections, see B.18.8.1, Appendix B ωw′ = compression reinforcement index for flanged sections, see B.18.8.1, Appendix B Copyright American Concrete Institute Provided by IHS under license with ACI Licensee=Black & Veatch/5910842100 No reproduction or networking permitted without license from IHS Not for Resale, 11/28/2005 18:20:15 MST --`,,`,````````,,`,,`,,``,`,,,`-`-`,,`,,`,`,,`---
CHAPTER 2 R2.- Commentary notation per unit rotation, see R13. 7.5, Chapter 13 Kos coefficient associated with the 5 percent fractile, The terms used in this list are used in the commentary, but ppendix D not in the code length along which anchorage of a tie must occur. mm, Appe Units of measurement are given in the Notation to assist the lb width of bearing, mm, Appendix A user and are not intended to preclude the use of other cor- R = reaction, N, Appendix A rectly applied units for the same symbol, such as meters or T= tension force acting on a nodal zone, N, Appendix A kilonewtons width of a strut perpendicular to the axis of the c al limiting value of cal when anchors are located less strut, mm, Appendix A effective height of concrete concentric with a tie, than 1.5hef from three or more edges(see Fig RD,6.2.4), Appendix D used to dimension nodal zone, mm, Appendix A C compression force acting on a nodal zone, N, Wmar maximum effective height of concrete concentric with a tie, mm, Appendix A fsi= stress in the i-th layer of surface reinforcement, fps at the section of maximum moment MPa, Appendix A stress in the prestressing steel due to prestressing hanc= dimension of anchorage device or single group of and factored bending moments at the section under closely spaced devices in the direction of bursting consideration, MPa, see R11.6.3.10. Chapter 11 being considered Chapter 18 px= stiffness reduction factor, see R10. 12.3, Chapter 10 h'f= limiting value of hef when anchors are located less =amplification factor to account for overstrength of than 1.5hef from three or more edges(see Fig. the seismic-force-resisting system, specified in RD.5.2.3), Appendix D documents such as NEhRp 21.I SEVASCE 21 48 K= torsional stiffness of torsional member; moment IBC.21.5 and UBC,21.2 Chapter 21 SECTION 2.2, DEFINITIONS BEGINS ON NEXT PAGE licene with Acl oduction of networking permitted without loene from H ACI 318 Building Nor censee-Black veatch ot for Resale. 11/28/2005 a
CHAPTER 2 27 ACI 318 Building Code and Commentary R2.1 — Commentary notation The terms used in this list are used in the commentary, but not in the code. Units of measurement are given in the Notation to assist the user and are not intended to preclude the use of other correctly applied units for the same symbol, such as meters or kilonewtons. ca1 ′ = limiting value of ca1 when anchors are located less than 1.5hef from three or more edges (see Fig. RD.6.2.4), Appendix D C = compression force acting on a nodal zone, N, Appendix A fsi = stress in the i-th layer of surface reinforcement, MPa, Appendix A hanc= dimension of anchorage device or single group of closely spaced devices in the direction of bursting being considered, mm, Chapter 18 hef′ = limiting value of hef when anchors are located less than 1.5hef from three or more edges (see Fig. RD.5.2.3), Appendix D Kt = torsional stiffness of torsional member; moment per unit rotation, see R13.7.5, Chapter 13 K05 = coefficient associated with the 5 percent fractile, Appendix D lanc = length along which anchorage of a tie must occur, mm, Appendix A lb = width of bearing, mm, Appendix A R = reaction, N, Appendix A T = tension force acting on a nodal zone, N, Appendix A ws = width of a strut perpendicular to the axis of the strut, mm, Appendix A wt = effective height of concrete concentric with a tie, used to dimension nodal zone, mm, Appendix A wtmax= maximum effective height of concrete concentric with a tie, mm, Appendix A ∆fpt = fps at the section of maximum moment minus the stress in the prestressing steel due to prestressing and factored bending moments at the section under consideration, MPa, see R11.6.3.10, Chapter 11 φK = stiffness reduction factor, see R10.12.3, Chapter 10 Ωo = amplification factor to account for overstrength of the seismic-force-resisting system, specified in documents such as NEHRP,21.1 SEI/ASCE,21.48 IBC, 21.5 and UBC, 21.2 Chapter 21 SECTION 2.2, DEFINITIONS, BEGINS ON NEXT PAGE Copyright American Concrete Institute Provided by IHS under license with ACI Licensee=Black & Veatch/5910842100 No reproduction or networking permitted without license from IHS Not for Resale, 11/28/2005 18:20:15 MST --`,,`,````````,,`,,`,,``,`,,,`-`-`,,`,,`,`,,`---
CHAPTER 2 CODE COMMENTARY 1 2.2-Definitions I R22-Definitions The following terms are defined for general use in this For consistent application of the code, it is necessary that code. Specialized definitions appear in individual terms be defined where they have particular meanings in the code. The definitions given are for use in application of this code only and do not always correspond to ordinary usage Adimixture-Material other than water, aggregate, or A glossary of most used terms relating to cement manufac hydraulic cement, used as an ingredient of concrete turing, concrete design and construction, and research in and added to concrete before or during its mixing t concrete is contained in"Cement and Co modify its properties gy"reported by ACI Committee 116/ncrete Terminol- Aggregate--Granular material, such as sand, gravel, crushed stone, and iron blast-furnace slag, used with a cementing medium to form a hydraulic cement con- crete or mortar Aggregate, lightweight- Aggregate with a dry, loose density of 1120 kg/m"or less Anchorage device-In post-tensioning, the hard Anchorage device--Most anchorage devices for post-ten- are used for transferring a post-tensioning force from sioning are standard manufactured devices available from the prestressing steel to the concrete commercial sources. In some cases, designers or construc tors develop"special"details or assemblages that combin various wedges and wedge plates for anchoring prestressing steel with specialty end plates or diaphragms. These infor- mal designations as standard anchorage devices or special anchorage devices have no direct relation to the ACI Build ing Code and AASHTO "Standard Specifications for High- way Bridges"classification of anchorage devices as Basic Anchorage Devices or Special Anchorage Devices. Anchorage zone- In post-tensioned members, the Anchorage zone-The terminology"ahead of"and"behind portion of the member through which the concen the anchorage device is illustrated in Fig. R18. 13. 1(b) trated prestressing force is transferred to the con- crete and distributed more uniformly across the ection. Its extent is equal to the largest dimension of the cross section. For anchorage devices located away from the end of a member, the anchorage zone includes the disturbed regions ahead of and behind the anchorage devices Basic monostrand anchorage device- Anchorage Basic anchorage devices- Devices that are so propor- device used with any single strand or a single 15 mm tioned that they can be checked analytically for compliance or smaller diameter bar that satisfies 18 21.1 and the with bearing stress and stiffness requirements without hav anchorage device requirements of ACl 423.6, ing to undergo the acceptance-testing program required of cation for Unbonded Single-Strand Tendons special anchorage devices. Basic multistrand anchorage device- Anchorage device used with multiple strands, bars, or wires, or with single bars larger than 15 mm. diameter, that sat- fies 18.21.1 and the bearing stress and minimum plate stiffness requirements of AASHTO Bridge Speci- fications, Division L, Articles 9.21.7. 2.2 through 9. 4 Bonded tendon- Tendon in which prestressing steel is bonded to concrete either directly or through grouting Building official- See 1.2.3 licene with Acl oduction of networking permitted without loene from H ACI 318 Building CoNot fos gesaer 12e2oo5 1820415 st
28 CHAPTER 2 CODE COMMENTARY ACI 318 Building Code and Commentary R2.2 — Definitions For consistent application of the code, it is necessary that terms be defined where they have particular meanings in the code. The definitions given are for use in application of this code only and do not always correspond to ordinary usage. A glossary of most used terms relating to cement manufacturing, concrete design and construction, and research in concrete is contained in “Cement and Concrete Terminology” reported by ACI Committee 116. 2.1 2.2 — Definitions The following terms are defined for general use in this code. Specialized definitions appear in individual chapters. Admixture — Material other than water, aggregate, or hydraulic cement, used as an ingredient of concrete and added to concrete before or during its mixing to modify its properties. Aggregate — Granular material, such as sand, gravel, crushed stone, and iron blast-furnace slag, used with a cementing medium to form a hydraulic cement concrete or mortar. Aggregate, lightweight — Aggregate with a dry, loose density of 1120 kg/m3 or less. Anchorage device — In post-tensioning, the hardware used for transferring a post-tensioning force from the prestressing steel to the concrete. Anchorage device — Most anchorage devices for post-tensioning are standard manufactured devices available from commercial sources. In some cases, designers or constructors develop “special” details or assemblages that combine various wedges and wedge plates for anchoring prestressing steel with specialty end plates or diaphragms. These informal designations as standard anchorage devices or special anchorage devices have no direct relation to the ACI Building Code and AASHTO “Standard Specifications for Highway Bridges” classification of anchorage devices as Basic Anchorage Devices or Special Anchorage Devices. Anchorage zone — The terminology “ahead of” and “behind” the anchorage device is illustrated in Fig. R18.13.1(b). Anchorage zone — In post-tensioned members, the portion of the member through which the concentrated prestressing force is transferred to the concrete and distributed more uniformly across the section. Its extent is equal to the largest dimension of the cross section. For anchorage devices located away from the end of a member, the anchorage zone includes the disturbed regions ahead of and behind the anchorage devices. Basic monostrand anchorage device — Anchorage device used with any single strand or a single 15 mm or smaller diameter bar that satisfies 18.21.1 and the anchorage device requirements of ACI 423.6, “Specification for Unbonded Single-Strand Tendons.” Basic multistrand anchorage device — Anchorage device used with multiple strands, bars, or wires, or with single bars larger than 15 mm. diameter, that satisfies 18.21.1 and the bearing stress and minimum plate stiffness requirements of AASHTO Bridge Specifications, Division I, Articles 9.21.7.2.2 through 9.21.7.2.4. Bonded tendon — Tendon in which prestressing steel is bonded to concrete either directly or through grouting. Building official — See 1.2.3. Basic anchorage devices — Devices that are so proportioned that they can be checked analytically for compliance with bearing stress and stiffness requirements without having to undergo the acceptance-testing program required of special anchorage devices. Copyright American Concrete Institute Provided by IHS under license with ACI Licensee=Black & Veatch/5910842100 No reproduction or networking permitted without license from IHS Not for Resale, 11/28/2005 18:20:15 MST --`,,`,````````,,`,,`,,``,`,,,`-`-`,,`,,`,`,,`---