Cb : Cement content of the base mix (lb/yd3)
The relationship between ap and Pr is determined as follows:
Prp=(Tcm- Tpm)/ Tcm > Prp= 1 Tpm/ Tbm Equation 5-6
According to ACI 207.1R-96, there is a linear relationship between the
cementitious material content and the peak temperature so:
Tpm/ Tcm = (Cc + pCp )/ Ct Equation 5-7
Where:
Ct : Cement content of the control mix which is equal to the summation of the
amounts of Cc and Cp in lb/yd3 (Ct = Cc + Cp)
Therefore:
Tpm/ Tcm = (Cc + pCp )/ (C + Cp ) Equation 5-8
Equations 5-7 and 5-8 -> Pr = 1 (Cc + pCp )/ (Cc + Cp ) > Pr = C,(1- ap)/( Cc +
Cp) >
(1- ap) = Pr( Cc + Cp )/ Cp : (1- ap) = Pr( Cc /Cp ) + Prp Equation 5-9
Rp = Cp / (C + Cp) > Cc/ Cp = 1/Rp -1 Equation 5-10
Combining Equations 5-9 and 5-10 results:
(1- ap) = Prp (1/ R -1) + Pr :> ap = 1- Pr/ Rp Equation 5-11
From Equations 5-3 and 5-11 it is concluded that:
p = 1 a(Rp) b c/Rp Equation 5-12
Using the constant factors from Table 5-6 the equations to calculate ,p would be as
follows:
For mixes with fly ash and 73F placing temperature: ap= 0.59 0.59Rp
For mixes with fly ash and 95F placing temperature: ap= 0.83 0.59Rp