『Abstract
We hypothesize that the weathering of building stones can be
attributed to surface dissolution processes. We assume that chemical
interactions occur on grain boundaries and/or microcracks and
that diffusion is the controlling process. A dissolution layer
(rind) develops adjacent to the weathering surface. We quantify
the extent of dissolution by introducing a damage variable f
; f = 0 for pristine rock, and when f = 1 the rock
disintegrates. We assume that the variations of the damage variable
are given by the diffusion equation. We solve two problems. The
first is for the structure of the transient dissolution boundary
layer prior to surface disintegration. We find an incubation time
ti, before active weathering (disintegration)
begins. The second is the solution for steady-state weathering
with a constant weathering velocity vw.
Our results are entirely consistent with weathering studies on
Carrara marble gravestones in the United Kingdom. Typical incubation
times are ti = 20-30 years, and typical
steady-state weathering velocities are vw
= 5-50μm year-1.
Keywords: Weathering; Damage; Dissolution; Gravestones』
Introduction
Weathering solution
Comparisons with weathering data from gravestones
Discussion
Acknowledgments
References