25 500 1608 1000 h= 550 d= 492 Minimum cover to tension reinforcement " CO " = 40 Maxmum bar spacing " S " = 125 Bar dia " DIA " = 16 " acr " =(((S/2)^2+(CO+DIA/2)^2)^(1/2)-DIA/2) as default or enter other value = 70.8 "acr " is distance from the point considered to the surface of the nearest longitudinal bar Applied service moment " Ms "= 189.6
N/mm2 N/mm2 2 mm mm mm mm mm mm mm mm KNm
CALCULATIONS moduli of elasticity of concrete " Ec" = (1/2)*(20+0.2*fcu) = moduli of elasticity of steel " Es " = Modular ratio " a " = (Es/Ec) = " r " = As/bd = depth to neutral axis, "x" = (-a.r +((a.r)2 + 2.a.r)0.5.d =
12.5 200.0 16.00 0.003 135
KN/mm2 KN/mm2
mm
" Z " = d-(x/3) = 447 2 Reinforcement stress " fs " = Ms/(As*Z) = N/mm 264 Concrete stress " fc " = (fs*As)/(0.5*b*x) = N/mm2 6.27 Strain at soffit of concrete beam/slab " e1 " = (fs/Es)*(h-x)/(d-x) = 0.001534 Strain due to stiffening effect of concrete between cracks " e2 " = e2 = b.(h-x)2/(3.Es.As.(d-x)) for crack widths of 0.2 mm Used 2 e2 = 1.5.b.(h-x) /(3.Es.As.(d-x)) for crack widths of 0.1 mm n/a e2 = 0.000500 Average strain for calculation of crack width " em "= e1-e2 = 0.001035 Calculated crack width, " w " = 3.acr.em/(1+2.(acr-c)/(h-x)) CALCULATED CRACK WIDTH, 'w' =
0.19
33
mm
Notes
Disclaimer All advice or information from the British Cement Association and/or Reinforced Concrete Council is intend those who will evaluate the significance and limitations of its contents and take responsibility for its use an application. No liability (including that for negligence) for any loss resulting from such advice or informatio accepted by the BCA, RCC or their subcontractors, suppliers or advisors. Users should note that all BCA and publications are subject to revision from time to time and should therefore ensure that they are in pos of the latest version.
This spreadsheet should be used in compliance with the accompanying publication 'Spreadsheets for con design to BS 8110 & EC2' available from British Cement Association, Telford Avenue, Crowthorne, Berks RG45 6YS. Status of spreadsheet Public release version. Revision history RCC14 Crack Width.xls
Date
Version
Action
04-Aug-99
RCC14 v0.1
Renamed
Page 2
Notes
Page 3
Notes
Reinforced Concrete Council is intended for s and take responsibility for its use and sulting from such advice or information is sors. Users should note that all BCA software therefore ensure that they are in possession
ing publication 'Spreadsheets for concrete n, Telford Avenue, Crowthorne, Berkshire
