Prediction of Chloride Ion Penetration in Concrete.

Keyword

Prediction of Chloride Ion Penetration in Concrete,Water/Cement weight ratio,Chloride Ion Content on the Concrete Surface,Initial Chloride Ion Content inside Concrete,Depth from Concrete Surface to Rebar,Age of Concrete,Error Function,Hastings Approximation.

Reference

[1]:『鉄筋コンクリート造建築物の耐久設計施工指針(案)・同解説 2004年制定』(社団法人日本建築学会).
[2]:『2007年制定 コンクリート標準示方書 維持管理編』(社団法人土木学会).
[3]:『原子力施設における建築物の維持管理指針・同解説 2008年制定』(社団法人日本建築学会).
[4]:大野豊・磯田和男:『新版数値計算ハンドブック』,オーム社,1990.

Remarks

・w/c:Water/Cement weight ratio.
・C0:Chloride Ion Content on the Concrete Surface.
・Cinit:Initial Chloride Ion Content inside Concrete.
・x:Depth from Concrete Surface to Rebar.
・t:Age of Concrete.
・C(kg/m^3)=(C0(kg/m^3)-Cinit(kg/m^3))*(1-erf(x(mm)/(2*(D(mm^2/year)*t(year))^0.5)))+Cinit(kg/m^3).(Reference[1])
・erf(x)=2/π^0.5*∫[0~x]e^(-u^2)・du≈1-1/(1+a1*x+a2*x^2+a3*x^3+a4*x^4+a5*x^5+a6*x^6)^16.(Reference[4])
a1=0.0705230784
a2=0.0422820123
a3=0.0092705272
a4=0.0001520143
a5=0.0002765672
a6=0.0000430638
・log10D(cm^2/year)=-3.9*(w/c)^2+7.2*(w/c)-2.5.:Ordinary Portland Cement.(Reference[2])
・log10D(cm^2/year)=-3.0*(w/c)^2+5.4*(w/c)-2.2.:Blast-Furnace Slag Cement Concrete,Silica Fume.(Reference[2])
・The value of "Apparent Diffusivity(D)" begins to decrease in the calculation when "Water/Cement weight ratio" exceeds almost 0.9.Be careful when you use this page.

History

・2010/02/23:Renewal.
・2009/03/15:Upload.