Table 3.

Stoichiometry and assumed thermodynamic and kinetic parameters for simulated reactions. Except where noted, the collection of reactions and the parameter values are taken from Reference [36] and references therein. The reactions and solubilities for C–S–H are based on a newer solid solution model in Reference [47], and the kinetic parameter values were chosen to give approximately the same rates of nucleation and growth as simulated in Reference [36].

Reaction	k+/μmol m−n s−1(a)	ln K	$I_0^B/{\mathrm{m}}^{-n}{\mathrm{s}}^{-1}$ (a)	q/K3
${\text{Ca}}_3{\text{SiO}}_5+4{\mathrm{H}}_2\mathrm{O}\rightleftharpoons 3{\text{Ca}}^{2+}+{\mathrm{H}}_3{\text{SiO}}_4^{-}+5{\text{OH}}^{-}$	112.5(b)	−39.0(b)
${\mathrm{C}}_2{\mathrm{S}}_3{\mathrm{H}}_{12}\rightleftharpoons 2{\text{Ca}}^{2+}+3{\mathrm{H}}_3{\text{SiO}}_4^{-}+{\text{OH}}^{-}+7{\mathrm{H}}_2\mathrm{O}$	1.5 × 10−7	−37.43	1.1 × 1027(b)	2.0 × 109(b)
${\mathrm{C}}_5{\mathrm{S}}_3{\mathrm{H}}_{12}\rightleftharpoons 5{\text{Ca}}^{2+}+3{\mathrm{H}}_3{\text{SiO}}_4^{-}+7{\text{OH}}^{-}+4{\mathrm{H}}_2\mathrm{O}$	1.5 × 10−7	−80.43	7.3 × 1026(c)	1.7 × 1010(c)
$\text{Ca}{(\text{OH})}_2\rightleftharpoons {\text{Ca}}^{2+}+2{\text{OH}}^{-}$	7.2	−11.97	7.35 × 1026(d)	2.5 × 109(d)
${\text{CaOH}}^{\text{+}}\rightleftharpoons {\text{Ca}}^{2+}+{\text{OH}}^{-}$	6 × 105	−2.81
${\mathrm{H}}_3{\text{SiO}}_4^{-}+{\text{OH}}^{-}\rightleftharpoons {\mathrm{H}}_2{\text{SiO}}_4^{2-}+{\mathrm{H}}_2\mathrm{O}$	1.5 107	1.91

^(a)n = 2 or 3 for heterogeneous or homogeneous processes, respectively.

^(b)Based on linear regression of measurements in Ref. [28].

^(c),(d)Heterogeneous nucleation on Ca₃SiO₅ and C−S−H, respectively.