Page:4SIGHT manual- a computer program for modelling degradation of underground low level waste concrete vaults (IA 4sightmanualcomp5612snyd).pdf/139

63. CHLORIDE PENETRATION 63. Chloride penetration.

The ratio of the mass of chloride ions to the mass of concrete equal to 0.0004 is the depth of chloride penetration. The ration equals $$10^-3 \left [ \textit{Cl}^- \right ] A_{Cl}/\phi/((1-\phi)2.5)$$. $$A_{\textit{Cl}}(\textit{gm}/\textit{mole})$$ is the gram atomic mass of chlorine, $$\phi$$is porosity, and 2.5 is the density of concrete.

⟨Global variables 4⟩ $$+\equiv$$ real CLratio [NUM.SURFACES]; 64. ⟨Assess chloride penetration 64⟩ $$\equiv$$ for (k = FIRST_CELL; k < NUM.SURFACES; k++); CLratio[k]=35.5 * anion[Cl].moles[k]/(2.b * (1.0-$$\phi'^n$$[k] * Vsample);  k= NUM.SURFACES - 1;   while (k $$\ge$$ 0 \land Cl.ratio[k] < 0.0004) k--   if k < 0) chloride. depth = 0.0;   /* k at lower limit */ else { if (k$$\equiv$$ FIRST_CELL) {  /* account for distance equals $$\Delta X$$ */ chloride.depth = $$\Delta X$$[FIRST_CELL] * (CLratio[k] — 0.0004)/(CLratio[k]—CLratio[k+1]); chloride.depth += (real) FIRST_CELL; }   else chloride.depth = (real) k + ( Cl.ratio[k] —0.0004)/(Cl_ratio[k] - Cl.ratio[k+1]); }

This code is used in section 10.