Which risk increases to Inca retaining walls in the Andes when poor mortar is used?

💡 Explanation

Water infiltration then freezing expands in voids, driving spalling, because poor mortar leads to cracks, generating freeze-thaw process accelerating material degradation; therefore, spalling increases rapidly, and is much more common than creep with stone rather than erosion.

• Which issue threatens historic Mughal garden waterworks when facing uneven ground settlement?
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