Design Aids

of 28 /28
Design Aid J.1-1 Areas of Reinforcing Bars Design Aid J.1-2 Approximate Bending Moments and Shear Forces for Continuous Beams and One- way Slabs Design Aid J.1-3 Variation of φ with Net Tensile Strain in Extreme Tension Steel ε t and c / d t Grade 60 Reinforcement and Prestressing Steel Design Aid J.1-4 Simplified Calculation of A s Assuming Tension-Controlled Section and Grade 60 Reinforcement Design Aid J.1-5 Minimum Number of Reinforcing Bars Required in a Single Layer Design Aid J.1-6 Maximum Number of Reinforcing Bars Permitted in a Single Layer Design Aid J.1-7 Minimum Thickness h for Beams and One-Way Slabs Unless Deflections are Calculated Design Aid J.1-8 Reinforcement Ratio ρ t for Tension-Controlled Sections Assuming Grade 60 Reinforcement Design Aid J.1-9 Simplified Calculation of b w Assuming Grade 60 Reinforcement and ρ = 0.5 ρ max Design Aid J.1-10 T-beam Construction Design Aid J.1-11 Values of φV s = V u - φV c (kips) as a Function of the Spacing, s Design Aid J.1-12 Minimum Shear Reinforcement A v, min / s Design Aid J.1-13 Torsional Section Properties Design Aid J.1-14 Moment of Inertia of Cracked Section Transformed to Concrete, I cr Design Aid J.1-15 Approximate Equation to Determine Immediate Deflection, Δ i , for Members Subjected to Uniformly Distributed Loads Design Aids J.2 Two-Way Slabs – Direct Design method, includes the following: • Conditions for Analysis by the Direct Design Method • Definitions of Column Strip and Middle Strip • Definition of Clear Span, • Design Moment Coefficients used with the Direct Design Method • Effective Beam and Slab Sections for Computation of Stiffness Ratio, α f • Computation of Torsional Stiffness Factor, β t , for T- and L-Sections • Moment Distribution Constants for Slab-Beam Members without Drop Panels • Stiffness and Carry-Over Factors for Columns

Embed Size (px)

Transcript of Design Aids

  • Design Aid J.1-1 Areas of Reinforcing Bars

    Design Aid J.1-2 Approximate Bending Moments and Shear Forces for Continuous Beams and One-way Slabs

    Design Aid J.1-3 Variation of with Net Tensile Strain in Extreme Tension Steel t and c / dt

    Grade 60 Reinforcement and Prestressing Steel

    Design Aid J.1-4 Simplified Calculation of As Assuming Tension-Controlled Section and Grade 60 Reinforcement

    Design Aid J.1-5 Minimum Number of Reinforcing Bars Required in a Single Layer

    Design Aid J.1-6 Maximum Number of Reinforcing Bars Permitted in a Single Layer

    Design Aid J.1-7 Minimum Thickness h for Beams and One-Way Slabs Unless Deflections are

    Calculated

    Design Aid J.1-8 Reinforcement Ratio t for Tension-Controlled Sections Assuming Grade 60 Reinforcement

    Design Aid J.1-9 Simplified Calculation of bw Assuming Grade 60 Reinforcement and = 0.5 max

    Design Aid J.1-10 T-beam Construction

    Design Aid J.1-11 Values of Vs = Vu - Vc (kips) as a Function of the Spacing, s

    Design Aid J.1-12 Minimum Shear Reinforcement Av, min / s

    Design Aid J.1-13 Torsional Section Properties

    Design Aid J.1-14 Moment of Inertia of Cracked Section Transformed to Concrete, Icr

    Design Aid J.1-15 Approximate Equation to Determine Immediate Deflection, i, for Members Subjected to Uniformly Distributed Loads

    Design Aids J.2 Two-Way Slabs Direct Design method, includes the following:

    Conditions for Analysis by the Direct Design Method

    Definitions of Column Strip and Middle Strip

    Definition of Clear Span, Design Moment Coefficients used with the Direct Design Method

    Effective Beam and Slab Sections for Computation of Stiffness Ratio, f

    Computation of Torsional Stiffness Factor, t, for T- and L-Sections

    Moment Distribution Constants for Slab-Beam Members without Drop Panels

    Stiffness and Carry-Over Factors for Columns

  • DESIGN AID J.1-1 Areas of Reinforcing Bars

    Total Areas of Bars (in.2)

    Bar Size

    Number of Bars 1 2 3 4 5 6 7 8 9 10

    No. 3 0.11 0.22 0.33 0.44 0.55 0.66 0.77 0.88 0.99 1.10 No. 4 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 No. 5 0.31 0.62 0.93 1.24 1.55 1.86 2.17 2.48 2.79 3.10 No. 6 0.44 0.88 1.32 1.76 2.20 2.64 3.08 3.52 3.96 4.40 No. 7 0.60 1.20 1.80 2.40 3.00 3.60 4.20 4.80 5.40 6.00 No. 8 0.79 1.58 2.37 3.16 3.95 4.74 5.53 6.32 7.11 7.90 No. 9 1.00 2.00 3.00 4.00 5.00 6.00 7.00 8.00 9.00 10.00 No. 10 1.27 2.54 3.81 5.08 6.35 7.62 8.89 10.16 11.43 12.70 No. 11 1.56 3.12 4.68 6.24 7.80 9.36 10.92 12.48 14.04 15.60

    Areas of Bars per Foot Width of Slab (in.2/ft)

    Bar Size

    Bar Spacing (in.) 6 7 8 9 10 11 12 13 14 15 16 17 18

    No. 3 0.22 0.19 0.17 0.15 0.13 0.12 0.11 0.10 0.09 0.09 0.08 0.08 0.07 No. 4 0.40 0.34 0.30 0.27 0.24 0.22 0.20 0.18 0.17 0.16 0.15 0.14 0.13 No. 5 0.62 0.53 0.46 0.41 0.37 0.34 0.31 0.29 0.27 0.25 0.23 0.22 0.21 No. 6 0.88 0.75 0.66 0.59 0.53 0.48 0.44 0.41 0.38 0.35 0.33 0.31 0.29 No. 7 1.20 1.03 0.90 0.80 0.72 0.65 0.60 0.55 0.51 0.48 0.45 0.42 0.40 No. 8 1.58 1.35 1.18 1.05 0.95 0.86 0.79 0.73 0.68 0.63 0.59 0.56 0.53 No. 9 2.00 1.71 1.50 1.33 1.20 1.09 1.00 0.92 0.86 0.80 0.75 0.71 0.67 No. 10 2.54 2.18 1.91 1.69 1.52 1.39 1.27 1.17 1.09 1.02 0.95 0.90 0.85 No. 11 3.12 2.67 2.34 2.08 1.87 1.70 1.56 1.44 1.34 1.25 1.17 1.10 1.04

    mrsTypewritten Text

    mrsTypewritten Text

    mrsTypewritten Text

    mrsTypewritten Text

    mrsTypewritten Text

    pfs314 Design Aid

  • PositiveMoment

    NegativeMoment

    Shear

    n n n n

    Prismatic members

    n

    nuw nuw nuw

    nuw avgnuw avgnuw nuw nuwSpandrelSupport

    ColumnSupport

    nuw

    nuw nuwnuw nuwnuw nuw

    nuw

    nnavgn

    Note A nuw avgnuw avgnuw nuw nuw

    Two or more spans

    Uniformly distributed load wu (L/D 3)

    nuw

    DESIGN AID J.1-2

    pfs314 Design Aid

  • DESIGN AID J.1-3

    pfs314 Design Aid

  • DESIGN AID J.1-4

    Simplified Calculation of sA Assuming Tension-Controlled Section and Grade 60 Reinforcement

    cf (psi) sA (in.2)

    3,000 d

    M u84.3

    4,000 d

    M u00.4

    5,000 d

    M u10.4

    uM is in ft-kips and d is in inches

    In all cases, d

    MA us 4= can be used.

    Notes:

    d

    ff

    f

    MA

    c

    yy

    us

    =

    '85.05.0

    1

    For all values of < 0.0125, the simplified As equation is slightly conservative. It is recommended to avoid > 0.0125 when using the simplified As equation.

    pfs314 Design Aid

  • DESIGN AID J.1-51

    Assumptions:

    yf

    cc

    sf

    Bar Size

    Beam Width (in.)

    Minimum number of bars, nmim:

    1)5.0(2

    sdcb

    n bcwmin

    where

    s

    cs

    f

    cf

    s

    000,4012

    5.2000,4015

    1 Alsamsam, I.M. and Kamara, M. E. (2004). Simplified Design Reinforced Concrete Buildings of Moderate Size and Heights, EB104, Portland Cement Association, Skokie, IL.

    db

    pfs314 Design Aid

  • DESIGN AID J.1-61

    Assumptions:

    yf

    sc

    Bar Size

    Beam Width (in.)

    Maximum number of bars, nmax:

    1space)(Clear

    )(2

    b

    sswdrdcb

    nmax

    1 Alsamsam, I.M. and Kamara, M. E. (2004). Simplified Design Reinforced Concrete Buildings of Moderate Size and Heights, EB104, Portland Cement Association, Skokie, IL.

    db

    pfs314 Design Aid

  • 1 2 3

    5.18/1h 21/2h 8/3h

    1 2 3

    24/1h 28/2h 10/3hSolid One-way Slabs

    Applicable to one-way construction not supporting or attached to partitions or other construction likely to be damaged by large deflections.

    Values shown are applicable to members with normal weight concrete ( 145cw lbs/ft3) and Grade 60

    reinforcement. For other conditions, modify the values as follows:

    For structural lightweight having cw in the range 90-120 lbs/ft3, multiply the values by

    .09.1005.065.1 cw

    For yf other than 60,000 psi, multiply the values by .000,100/4.0 yf

    For simply-supported members, minimum slabsway -one ribbedor beamsfor 16/

    slabsway -one solidfor 20/h

    Beams or Ribbed One-way Slabs

    DESIGN AID J.1-7h

    pfs314 Design Aid

  • DESIGN AID J.1-8

    Reinforcement Ratio t for Tension-Controlled Sections Assuming Grade 60 Reinforcement

    cf (psi) t when t = 0.005 t when t = 0.004

    3,000 0.01355 0.01548

    4,000 0.01806 0.02064

    5,000 0.02125 0.02429 Notes:

    1. ( )bcfC c 1'85.0 = ys fAT =

    ( ) ysc fAbcfTC == 1'85.0

    a. When t = 0.005, c/dt = 3/8. ( ) ystc fAbdf =83'85.0 1

    y

    c

    t

    st f

    f

    bdA )8

    3(85.0 1 ==

    b. When t = 0.004, c/dt = 3/7.

    ( ) ystc fAbdf =73'85.0 1

    y

    c

    t

    st f

    f

    bdA )7

    3(85.0 1 ==

    2. 1 is determined according to 10.2.7.3.

    mrsTypewritten Text

    mrsTypewritten Text

    mrsTypewritten Text

    pfs314 Design Aid

  • DESIGN AID J.1-9

    Simplified Calculation of wb Assuming Grade 60 Reinforcement and max= 5.0

    cf (psi) wb (in.)*

    3,000 26.31

    d

    M u

    4,000 27.23

    d

    M u

    5,000 20.20

    d

    M u

    * uM is in ft-kips and d is in inches

    In general:

    ( ) 211 2143.01600,36

    df

    Mb

    c

    uw

    =

    where max= / , cf is in psi, d is in inches and uM is in ft-kips and

    003.0004.0003.085.0 1+

    =

    y

    cmax f

    f (10.3.5)

    pfs314 Design Aid

  • 1s

    fhh =

    +

    +

    +

    2443

    612lengthSpan

    121

    1

    1

    1sbb

    hb

    b

    b

    ww

    w

    w

    e

    1eb

    2s 1wb 2wb

    2eb

    ++

    +

    +

    242

    164lengthSpan

    21312

    22ssbbb

    hbb

    www

    we

    3wb

    2w

    fbhh =

    wb

    we bb 4

    Isolated T-beam

    DESIGN AID J.1-10 T-beam Construction

    8.12

    pfs314 Design Aid

  • DESIGN AID J.1-11

    Values of cus VVV = (kips) as a Function of the Spacing, s*

    s No. 3 U-stirrups No. 4 U-stirrups No. 5 U-stirrups d/2 19.8 36.0 55.8

    d/3 29.7 54.0 83.7

    d/4 39.6 72.0 111.6 * Valid for Grade 60 ( 60=ytf ksi) stirrups with 2 legs (double the tabulated values for

    4 legs, etc.).

    In general:

    sdfA

    V ytvs

    = (11.4.7.2)

    where ytf used in design is limited to 60,000 psi, except for welded deformed wire reinforcement, which is limited to 80,000 psi (11.4.2).

    pfs314 Design Aid

  • DESIGN AID J.1-12

    Minimum Shear Reinforcement */, sA minv

    cf (psi) sA minv,

    in.in.2

    500,4 wb00083.0

    5,000 wb00088.0

    * Valid for Grade 60 ( 60=ytf ksi) shear reinforcement.

    In general:

    yt

    w

    yt

    wc

    minv

    fb

    fb

    fs

    A 5075.0, = Eq. (11-13)

    where ytf used in design is limited to 60,000 psi, except for welded deformed wire reinforcement, which is limited to 80,000 psi (11.4.2).

    pfs314 Design Aid

  • DESIGN AID J.1-13 Torsional Section Properties

    Section* Acp pcp Aoh phEdge

    bwh + behf 2(h + bw + be) x1y1 2(x1 + y1)

    x1 = bw - 2c - dsy1 = h - 2c - ds

    Interior

    bw(h - hf) + behf 2(h + be) x1y1 2(x1 + y1)

    x1 = bw - 2c - dsy1 = h - 2c - ds

    L-shaped

    b1h1 + b2h2 2(h1 + h2 + b2) x1y1 + x2y2 2(x1 + x2 + y1)x1 = b1 - 2c - dsy1 = h1 + h2 - 2c - dsx2 = b2 - b1y2 = h2 - 2c - ds

    Inverted tee

    b1h1 + b2h2 2(h1 + h2 + b2) x1y1 + 2x2y2 2(x1 + 2x2 + y1)x1 = b1 - 2c - dsy1 = h1 + h2 - 2c - dsx2 = (b2 - b1)/2y2 = h2 - 2c - ds

    * Notation: xi, yi = center-to-center dimension of closed rectangular stirrup c = clear cover to closed rectangular stirrup(s) ds = diameter of closed rectangular stirrup(s)

    hf

    h

    hf

    yo

    yo

    xo

    h

    bw

    hf

    be = bw + 2(h - hf) bw + 8hf

    h

    bw

    hf

    be = h - hf 4hf

    x1

    y1

    y1

    x1

    b1

    y1

    b1

    h1

    h2

    b2

    y1

    y2

    x1

    x2

    h1

    h2

    b2

    y2

    b1x1

    x2

    y1

    Note: Neglect overhanging flanges in cases where cpcp pA /2 calculated for a beam with

    flanges is less than that computed for the same beam ignoring the flanges (11.5.1.1).

    pfs314 Design Aid

  • Gross Section Cracked Transformed Section Cracked Moment of Inertia, crI

    23

    )(3

    )( kddnAkdbI scr +=

    where

    BdBkd 112 +=

    2

    23

    )()1(

    )(3

    )(

    dkdAn

    kddnAkdbI

    s

    scr

    +

    +=

    where

    ( ) ( )

    B

    rrddrdB

    kd+++

    ++

    =1112 2

    ---continued next page--- 12/3bhI g =

    cs EEn /= )/( snAbB =

    )/()1( ss nAAnr =

    b

    As

    As

    b d

    n.a.

    nAs

    kd

    d

    b

    n.a.

    b

    As

    DESIGN AID J.1-14

    Moment of Inertia of Cracked Section Transformed to Concrete, crI

    h

    h

    nAs

    kd

    d (n 1)As

    pfs314 Design Aid

  • Gross Section Cracked

    Transformed Section

    Cracked Moment of Inertia, crI

    2

    2

    33

    )(

    2)(

    3)(

    12

    )(

    kddnA

    hkdhbb

    kdbhbbI

    s

    ffw

    wfwcr

    +

    +

    +

    =

    where

    C

    fffhdCkd

    f )1()1()2(2 ++++

    =

    22

    2

    33

    )()1()(

    2)(

    3)(

    12

    )(

    dkdAnkddnA

    hkdhbb

    kdbhbbI

    ss

    ffw

    wfwcr

    ++

    +

    +

    =

    where

    C

    frfrdrfhdCkd

    f )1()1()22(2 +++++++

    =

    ]})/[(])[(5.0{ 22 hbhbbhbhbbhy wfwwfwt ++=

    2233 )5.0()5.0()(12/12/)( hyhbyhhhbbhbhbbI twtffwwfwg +++=

    cs EEn /= )/( sw nAbC =

    )/()( swf nAbbhf = )/()1( ss nAAnr =

    nAs

    kd

    b

    n.a.

    d b

    As

    hf

    bw

    As

    nAs

    kd d

    b

    n.a.

    b

    As

    hf

    bw

    DESIGN AID J.1-14

    Moment of Inertia of Cracked Section Transformed to Concrete, crI (continued)

    h

    h yt

    d (n 1)As

    pfs314 Design Aid

  • DESIGN AID J.1-15

    Approximate Equation to Determine Immediate Deflection, i , for Members Subjected to Uniformly Distributed Loads

    ec

    ai IE

    KM48

    5 2=

    where =aM net midspan moment or cantilever moment

    = span length (8.9)

    =cE modulus of elasticity of concrete (8.5.1)

    = cc fw 335.1 for values of cw between 90 and 155 pcf

    =cw unit weight of concrete

    =eI effective moment of inertia (see Flowchart A.1-5.1)

    =K constant that depends on the span condition

    Span Condition K

    Cantilever* 2.0

    Simple 1.0

    Continuous **)/(2.02.1 ao MM

    * Deflection due to rotation at supports not included

    ** 8/2wM o = (simple span moment at midspan)

    pfs314 Design Aid

  • DESIGN AID J.2-1

    f

    f

    scs

    bcbf IE

    IE

    cE

    cc fw cw

    sb II

    Page 1 of 11

    pfs314 Design Aid

  • DESIGN AID J.2-2

    -Middle strip

    -Middle strip

    1

    Column strip

    Minimum of 1/4 or ( 2)A/4

    Minimum of 1/4 or ( 2)B/4( 2)A

    ( 2)B

    Page 2 of 11

    pfs314 Design Aid

  • DESIGN AID J.2-3

    n

    n

    Page 3 of 11

    pfs314 Design Aid

  • DESIGN AID J.2-4

    Flat Plate or Flat Slab

    Flat Plate or Flat Slab with Spandrel Beams

    t

    Page 4 of 11

    pfs314 Design Aid

  • DESIGN AID J.2-4

    Flat Plate or Flat Slab with End Span Integral with Wall

    Flat Plate or Flat Slab with End Span Simply Supported on Wall

    Page 5 of 11

    pfs314 Design Aid

  • DESIGN AID J.2-4

    Two-Way Beam-Supported Slab

    f t

    Page 6 of 11

    pfs314 Design Aid

  • DESIGN AID J.2-5

    f

    CC2

    ha

    b

    beff = b + 2(a h) b + 8h

    Beam, Ib

    Slab, Is

    2

    ha

    b

    Beam, Ib

    Slab, Is

    CL

    beff = b + (a h) b + 4h

    Interior Beam Edge Beam

    scs

    bcbf IE

    IE

    cE

    cc fw cw

    hIs

    beffeffbb yhahbhbhayhabhabI

    habhb

    habhahby

    eff

    eff

    b

    Page 7 of 11

    pfs314 Design Aid

  • DESIGN AID J.2-6

    t

    CC2

    ha

    b

    beff = b + 2(a h) b + 8h

    Interior Beam

    Case A

    yxyx

    yxyxCA

    Case B

    yxyx

    yxyxCB

    C AC BC

    scs

    cbt IE

    CE

    hIs cc fwE cw

    x2x1

    y1

    y2y2

    x2x1

    y1

    y2

    Page 8 of 11

    pfs314 Design Aid

  • 2

    ha

    b

    CL

    beff = b + (a h) b + 4h

    DESIGN AID J.2-6

    t

    Edge Beam

    Case A

    yxyx

    yxyxCA

    Case B

    yxyx

    yxyxCB

    C AC BC

    scs

    cbt IE

    CE

    hIs cc fwE cw

    x2x1

    y1

    y2

    x2x1

    y1

    y2

    Page 9 of 11

    pfs314 Design Aid

  • DESIGN AID J.2-7

    Nc NcNFk NFC NFm

    sbcsNFsb IEkK

    uFN qmFEM

    FN cc FN cc uqPCA Notes on ACI 318-11

    Nc

    Nc

    Fc

    Fc

    Page 10 of 11

    pfs314 Design Aid

  • DESIGN AID J.2-8

    cHABk ABC

    ccccBABAc

    ccccABABc

    IEkK

    IEkK

    PCA Notes on ACI 318-11

    H c

    Page 11 of 11

    pfs314 Design Aid

    TOC.pdf