grdslab kevin

8/10/2019 Grdslab Kevin

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"GRDSLAB" --- CONCRETE SLAB ON GRADE ANALYSIS

Program Description:

"GRDSLAB" is a spreadsheet program written in MS-Excel for the purpose of analsis of concrete sla!s on

grade Specificall# a concrete sla! on grade ma !e su!$ected to concentrated post or wheel loading %hen

for the gi&en parameters# the sla! flexural# !earing# and shear stresses are chec'ed# the estimated crac' width isdetermined# the minimum re(uired distri!ution reinforcing is determined# and the !earing stress on the dowels

at construction $oints is chec'ed Also# design charts from the )ortland *ement Association +)*A, are included

to pro&ide an additional method for determiningchec'ing re(uired sla! thic'ness for flexure %he a!ilit to

anal.e the capacit of a sla! on grade su!$ected to continuous wall +line-tpe, load as well as stationar#

uniforml distri!uted li&e loads is also pro&ided

%his program is a wor'!oo' consisting of eight +/, wor'sheets# descri!ed as follows0

or!seet Name Description

Doc %his documentation sheet

Sla! on Grade *oncrete Sla! on Grade Analsis for *oncentrated )ost or 1heel Loading

)*A 2ig 3-1heel Load )*A 2igure 3 - Design *hart for Single 1heel Loads

)*A 2ig 4a-)ost Load )*A 2igure 4a - Design *hart for )ost Loads +' 5 67 pci,

)*A 2ig 4!-)ost Load )*A 2igure 4! - Design *hart for )ost Loads +' 5 877 pci,

)*A 2ig 4c-)ost Load )*A 2igure 4c - Design *hart for )ost Loads +' 5 977 pci,

1all Load *oncrete Sla! on Grade Analsis for 1all Load

:nif Load *oncrete Sla! on Grade Analsis for Stationar :niform Li&e Loads

Program Ass#mptions an$ Limitations:

8 %his program is !ased on the following references0

a "Load %esting of ;nstumented )a&ement Sections - ;mpro&ed %echni(ues for Appling the 2inite Element

Method to Strain )redition in )** )a&ement Structures" - ! :ni&ersit of Minnesota# Department of *i&il

Engineering +su!mitted to M# 9779,

! ")rinciples of )a&ement Design" - ! E? @oder and M1 1itc.a' +?ohn 1ile Sons# 846, c "Design of *oncrete Structures" - ! 1inter# :r(uhart# =CRour'e# and


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g Load at interior and corner of sla! distri!uted uniforml of a circular contact area

h 2ull contact +support, !etween the sla! and foundation


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3 =ther !asic assumptions used in the flexural analsis of the "Sla! on Grade" wor'sheet are as follows0

a Sla! &iewed as a plate on a li(uid foundation with full su!grade contact +su!grade modeled as a series

of independent springs - also 'nown as "1in'ler" foundation,

! Modulus of su!grade reaction +"'", is used to represent the su!grade

c Sla! is considered as unreinforced concrete !eam# so that an contri!ution made to flexural strength !

the inclusion of distri!ution reinforcement is neglected

d *om!ination of flexural and direct tensile stresses will result in trans&erse and longitudinal crac's e Supporting su!!ase andor su!grade act as elastic material# regaining position after application of load

> %he "Sla! on Grade" wor'sheet allows the user to account for the effect of an additional post or wheel load

%he increase in stress# CiC# due to a 9nd wheel +or post, load expressed as a percentage of stress for a single

wheel +or post, load generall &aries !etween 86 to 37 as is to !e input ! the user

6 All four +>, wor'sheets pertaining to the )*A 2igures 3# 4a# 4!# and 4c from Reference +f, in item F8 a!o&e are

!ased on interior load condition and other similar assumptions used in the "Sla! on Grade" wor'sheet

=ther assumed &alues used in the de&elopment of the 2igures 3# 4a# 4!# and 4c are as follows0

a Modulus of elasticit for concrete# Ec 5 >#777#777 psi

;n the four +>, wor'sheets pertaining to the )*A 2igures 3# 4a# 4!# and 4c# the user must manuall determine

+read, the re(uired sla! thic'ness from the design chart and must manuall input that thic'ness in the

appropriate cell at the !ottom of the page An interation or two ma !e re(uired# as when the sla! thic'ness

is input# it mama not change the effecti&e contact area


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"GRDSLABxls" )rogramHersion 8>

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CONCRETE SLAB ON GRADE ANALYSIS%or S&a' S#'(ecte$ to Interior Concentrate$ Post or ee& Loa$ing

Ass#ming ACI-)*+ "T,pe B" Design - Reinorce$ or Srin!age an$ Temperat#re On&,

?o! formed $oint t3 or 9"

6777 deg

;ncrease for 9nd 1heel# i 5 86 f!8+actual, 5

f!8+actual, 5

5

Res#&ts: T,pica& Constr#ction .oint or Loa$ Transer

5

Cec! S&a' %&e/#ra& Stress: +assuming unreinforced sla! with interior load condition, 5

Effecti&e Load Radius# a 5 79> in

>9//9 psi

Modulus of Rupture# MR 5 3>7 psi fp+actual, 5

4 ft-'ft 2p+allow, 5

7863/6 in

E(ui&alent Radius# ! 5 6>/ in ! 5 SR%+8aK9NtK9,-746t # for a O 849>t !o 5

946/ psi f&+actual, 5

37449 psi f!8+actual,+8Ni877, 2&+allow, 5

38/97 psi %'0a&&o12 34 '0act#a&25 O676

Cec! S&a' Bearing Stress: +assuming wor'ing stress, +Ref >,

876 psi 1 5

949/ psi 2p+allow, 5 >9MR %p0a&&o12 34 p0act#a&25 O676 fs 5

As 5

Cec! S&a' P#ncing Sear Stress: +assuming wor'ing stress, +Ref >,

>947/ in978 psi fr 5

848/3 psi %80a&&o12 34 80act#a&25 O676 fs 5

Srin!age an$ Temperat#re Rein6: +assuming su!grade drag method, +Ref 3,

2riction 2actor# 2 5 867 2 5 86 +assumed friction factor !etween su!grade and sla!,As 5

Sla! 1eight# 1 5 87777 psf

>6777 psi fs 5 746f

7733 inK9ft fr 5

*oncrete Strength# f Cc5

*onc :nit 1eight# wc5

Reinforcing @ield# f5

*ontact Area# Ac5

Dowel Bar Dia# d!5

%emperature Range#% 5

a 5 SR%+Ac,

Modulus of Elasticit# Ec5 Ec5 33wcK86SR%+f Cc,

MR 5 SR%+f Cc,

*rac'ing Moment# Mr5 Mr5 MR+89tK9,89777 +per 8C 5 89" width,

)oissonCs Ratio# 5 5 786 +assumed for concrete,Radius of Stiffness# Lr5 Lr5 +EctK3+89+8-K9,',,K796

8 Load0 f!8+actual,5 f!8+actual,5 3)+8N,+9tK9,+LSR%+A

c, +assumed shear perimeter,f&+actual,5 f&+actual,5 )+t+!oN>t,,

2&+allow,5 2&+allow,5 794MR

5

1 5 wc+t89,

Reinf Allow Stress# fs5

As5 As5 2L1+9fs,

t

+Su!grade,

t9

*ontact Area# Ac

3>")lain Dowels P 89"

) )

1heel)ost

Direction of pour


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+continued,


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As 5

Determine Estimate$ Crac! i$t: +assuming no use of sta!ili.ed or granular su!!ase,

Sla!-!ase 2rict Ad$ust# * 5 877 * 5 87 +assumed &alue for no su!!ase, As 5

77777766 inindeg As 5

77779 inin As 5

789/> in

Cec! Bearing Stress on Do1e&s at Constr#ction .oints 1it Loa$ Transer: +Ref 9,

A 5

Ecm 5

L 5

As 5

* 5

ss#me$ Loa$ Transer Distri'#tion or Do1e&s at Constr#ction .oin

3/6 in Le 5

388 !ars

96777 l!s

9788// l!s Dow

8677777 psi

9777777 psi

77866 inK>

7// 84 psi %$0a&&o12 34 $0act#a&25 O676)c 5'c 5

E! 5

Reerences:

8 "Load %esting of ;nstumented )a&ement Sections - ;mpro&ed %echni(ues for Appling the 2inite Element

Method to Strain )redition in )** )a&ement Structures" - ! :ni&ersit of Minnesota# Department of *i&il

Engineering +su!mitted to M# 9779, 2d+allow, 5

9 "Dowel Bar =pimi.ation0 )hases ; and ;; - 2inal Report" - ! Max L )orter +;owa State :ni&ersit# 9778,

3 "Design of Sla!s on Grade" - A*; 37R-9 - ! American *oncrete ;nstitute +from A*; Manual of *oncrete

)ractice# 8, ;teration F

> "Sla! %hic'ness Design for ;ndustrial *oncrete 2loors on Grade" +;S8678D, - ! Ro!ert G )ac'ard

+)ortland *ement Association# 84,

Comments:

%hermal Expansion# 5 5 66x87K+-, +assumed thermal expansion coefficient,

Shrin'age *oefficient# 5 5 36x87K+->, +assumed coefficient of shrin'age,

Est *rac' 1idth# L 5 L 5 *L89+%N,

5

5

5

L 5

Le5 Le5 87Lr5 applica!le dist each side of critical dowel

Effecti&e Dowels# K3E!I!,,

2d+allow,5 2d+allow,5 +>-d!,3f Cc

I! 5

5

fd+actual, 5

87)c

s

LeLe

)t

d8d9 d3d9d3d> d> didi

+8-+9-8,sLe,)c

7)c7)c

+8-+9-8,sLe,)c

+8-+3-8,sLe,)c+8-+3-8,sLe,)c

+8-+>-8,sLe,)c+8-+>-8,sLe,)c


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CONCRETE SLAB ON GRADE T9IC7NESS ANALYSIS%or S&a' S#'(ecte$ to Sing&e ee& Loa$ing rom eic&es 1it Pne#matic Tires

Per PCA "S&a' Tic!ness Design or In$#stria& Concrete %&oors on Gra$e" - %ig#re )5 page ;

?o!


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CONCRETE SLAB ON GRADE T9IC7NESS ANALYSIS%or S&a' S#'(ecte$ to Concentrate$ Post Loa$ing 0or ! 4 ;+ pci2

Per PCA "S&a' Tic!ness Design or In$#stria& Concrete %&oors on Gra$e" - %ig#re 77 inK9 $. Move to right to slab thic'ness( t

2actor of Safet# 2S 5 377

Res#&ts:

43> inK9

*oncrete 2lexual Strength# MR 5 3>7 psi

*oncrete 1or'ing Stress# 1S 5 98983 psi 1S 5 MR2S

Sla! Stress8777 l! )ost Load 5 839 psi

Sla! %ic'ness# t 5 87/77 in t 5 determined from 2igure 4a a!o&e

*oncrete Strength# f Cc5 Instructions for Use of Figure 7a:

Load *ontact Area# Ac5

Effecti&e *ontact Area# Ac+eff,5 Ac+eff,5 determined from 2igure 6# page

MR 5 SR%+f Cc, +Modulus of Rupture,

Ss5 1S+)8777,

%ig#re


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CONCRETE SLAB ON GRADE T9IC7NESS ANALYSIS%or S&a' S#'(ecte$ to Concentrate$ Post Loa$ing 0or ! 4 >++ pci2

Per PCA "S&a' Tic!ness Design or In$#stria& Concrete %&oors on Gra$e" - %ig#re 7 psi

*oncrete 1or'ing Stress# 1S 5 98983 psi 1S 5 MR2S

Sla! Stress8777 l! )ost Load 5 839 psi

Sla! %ic'ness# t 5 /77 in t 5 determined from 2igure 4! a!o&e

*oncrete Strength# f Cc5 Instructions for Use of Figure 7b:




Ss5 1S+)8777,

%ig#re ++ pci


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CONCRETE SLAB ON GRADE T9IC7NESS ANALYSIS%or S&a' S#'(ecte$ to Concentrate$ Post Loa$ing 0or ! 4 ?++ pci2

Per PCA "S&a' Tic!ness Design or In$#stria& Concrete %&oors on Gra$e" - %ig#re >

?o! 77 inK9 $. Move to right to slab thic'ness( t

2actor of Safet# 2S 5 377

Res#&ts:

/79 inK9

*oncrete 2lexual Strength# MR 5 >96 psi

*oncrete 1or'ing Stress# 1S 5 8>39 psi 1S 5 MR2S

Sla! Stress8777 l! )ost Load 5 89> psi

Sla! %ic'ness# t 5 977 in t 5 determined from 2igure 4c a!o&e

*oncrete Strength# f Cc5 Instructions for Use of Figure 7c:




Ss5 1S+)8777,

%ig#re


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CONCRETE SLAB ON GRADE ANALYSIS%or S&a' S#'(ecte$ to Contin#o#s Line Loa$ing rom a&&

?o! 777 psi

Su!grade Modulus# ' 5 877 pci

1all Load# ) 5 /7777 l!ft

)c 5

Concrete S&a' Loa$e$ Near Center or at .oint

)e 5

%opSla!

;teration F

Res#&ts:

Concrete S&a' Loa$e$ Near %ree E$ge

Design Parameters:

Modulus of Rupture# MR 5 698 psi MR 5 SR%+f Cc,

8788 psi 2! 5 8SR%+f Cc, +as recommended in reference !elow,

2actor of Safet# 2S 5 696 2S 5 MR2!

Section Modulus# S 5 89/77 inK3ft S 5 !tK9

37>4 psi Ec 5 64777SR%+f Cc,1idth# ! 5 8977 in ! 5 89" +assumed,

68977 inK>

77978

7399>

a&& Loa$ Near Center o S&a' or 7e,e$@Do1e&e$ .oints:

Allowa!le 1all Load# )c 5 87>737 l!ft

5 89/SR%+f Cc,tK9+'+8777SR%+f Cc,tK3,,K+796,

Pc0a&&o12 34 P5 O676

a&& Loa$ Near %ree E$ge o S&a':

Allowa!le 1all Load# )e 5 /7/ l!ft

5 96SR%+f Cc,tK9+'+8777SR%+f Cc,tK3,,K+796,Reerence: Pe0a&&o12 34 P5 O676

"*oncrete 2loor Sla!s on Grade Su!$ected to ea& Loads"

Arm %echnical Manual %M 6-/7-89# Air 2orce Manual A2M //-3# *hapter 86 +8/4,

Comments:

*oncrete Strength# f Cc5 5

Bx 5

Allow Bending Stress# 2! 5

Modulus of Elasticit# Ec 5

Moment of ;nertia# I5 I5 !tK389

Stiffness 2actor# 5 5 +'!+>EcI,,K+796,

*oefficient# Bx 5 Bx 5 coef for !eam on elastic foundation

)c 5 >2!S

)e 5 2!SBx

t

+Su!grade,

)

1all

)

1all

t

+Su!grade,

)

1all

Dowel+at ?oint,


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CONCRETE SLAB ON GRADE ANALYSIS%or S&a' S#'(ecte$ to Stationar, niorm&, Distri'#te$ Li8e Loa$s

?o! 96 psi MR 5 SR%+f Cc,

Allow Bending Stress# 2! 5 9>>/ psi 2! 5 MR2S

Modulus of Elasticit# Ec 5 389978 Ec 5 64777SR%+f Cc,

786

83 in*ritical Aisle 1idth# 1cr 5 36 ft 1cr 5 +997Lr,89

Stationar, niorm&, Distri'#te$ Li8e Loa$s:

wLL+allow, 5 94/3 psf

1LL0a&&o12 34 1LL5 O676

Reerence:

8 "*oncrete 2loor Sla!s on Grade Su!$ected to ea& Loads"

Arm %echnical Manual %M 6-/7-89# Air 2orce Manual A2M //-3# *hapter 86 +8/4,

9 "Sla! %hic'ness Design for ;ndustrial *oncrete 2loors on Grade" +;S8678D,

! Ro!ert G )ac'ard +)ortland *ement Association# 84,

Comments:

wLL+allow,5

*oncrete Strength# f Cc5


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grdslab kevin

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