The pore structure of Salem limestone is investigated,
and conclusions regarding the effect of the pore
geometry on modeling moisture and contaminant
transport are discussed based on thin section
petrography, scanning electron microscopy, mercury
intrusion porosimetry, and nitrogen adsorption
analyses. These investigations are compared to and
shown to compliment permeability and capillary
pressure measurements for this common building
stone. Salem limestone exhibits a bimodal pore size
distribution in which the larger pores provide routes
for convective mass transfer of contaminants into the
material and the smaller pores lead to high surface
area adsorption and reaction sites. Relative
permeability and capillary pressure measurements of
the air/water system indicate that Salem limestone
exhibits high capillarity and low effective permeability
to water. Based on stone characterization, aqueous
diffusion and convection are believed to be the
primary transport mechanisms for pollutants in this
stone. The extent of contaminant accumulation in
the stone depends on the mechanism of partitioning
between the aqueous and solid phases. The
described characterization techniques and modeling
approach can be applied to many systems of interest
such as acidic damage to limestone, mass transfer of
contaminants in concrete and other porous building
materials, and modeling pollutant transport in
subsurface moisture zones.