Table 1 Various durability estimators reported in the literature
From: A review of theoretical salt weathering studies for stone heritage
Durability estimator | Parameters used in durability estimation | Comments (merits and demerits for determination of index) | |
|---|---|---|---|
Richardson (1991) | Durability factor, \( D={C}_s^2P \) | Saturation coefficient (Cs) and total porosity (P) | For determination of this index, only easy-measurement parameter (porosity) of solid (rocks) is enough, although chemical analysis of saline solution is necessary. |
Moh'd et al. (1996) | Durability estimator, x = [(P. Pmircro)Cs]0.5 | Total porosity (P), microporosity (Pmicro), and saturation coefficient (Cs) | Fairly complex methods (determination of pore size distribution and chemical analysis of saline solution) are necessary. |
Matsukura and Matsuoka (1996) | Weathering susceptibility index, \( WSI=\frac{P_c}{S_t} \) | Calculated crystallization pressure based on pore size distribution and pore radius (Pc) and tensile strength (St) | No chemical analyses for saline solution but strength test of solids (rocks) are necessary. The parameter can consider variable tensile strength of rocks. |
Ordóñez et al. (1997) | Durability dimension estimator, \( DDE=\sum \frac{v(r)}{r}{P}_{conc} \) | Pore size distribution, pore radius (r), and connected porosity (Pconc) | Only one method (porosimetry) is enough to determine this index. |
Benavente et al. (2004a) | Petrophysical durability estimator, \( PDE=\frac{X}{\sigma } \) | Estimators based on pore structure (X) and various rock strengths (σ) | It is easy to consider because of simple equation. |
Angeli et al. (2007) | Alteration index (AI) estimator, \( {AI}_{estim}=\ln \left(\frac{100C}{E\sqrt{\sigma_T}}\right) \) Alteration velocity (AV) estimator, P-wave velocity | AI: Capillary coefficient (C), evaporation coefficient (E), and tensile strength (σT) AV: P-wave velocity (vp) | This parameter reflects three kinds of conditions (pore size, evaporation, and rock strength) of salt weathering. |
Salt Susceptibility Index, SSI, SSI = (Ipc + Ipm0.1)(Pms/Pc) | Ipc: Index of total connected porosity Ipm0.1: Index of microporosity of pores smaller than 0.1 μm in radius Pms: Total connected porosity Pc: Microporosity of pores smaller than 5 μm in radius | Only one method (porosimetry) is enough to determine this index. |