Rate of Decay of Marble in Laboratory and Outdoor Exposure

Marble structures are deteriorating rapidly in industrial environments due to the attack of ${\mathrm{SO}}_2\text{.}$ The sulfation reaction is produced from the attack upon calcite by sulfuric acid or sulfur dioxide in the presence of moisture. This paper characterizes four common types of marble on the basis of petrofabrics, describes the kinetics and the mechanism of the ${\mathrm{SO}}_2$ reaction with marble, and applies the reaction constants developed in the previous paper in this issue to the weathering of the Georgia and Carrara marble exposed for nearly 60 and 100 yr in Chicago and Louisville, respectively. The calculated values are in general agreement with the observed crust thickness and the surface reduction at these two sites, although additional information concerning several kinetic and thermodynamic factors is needed to accurately predict the weathering rates of marble over a wide range of environmental conditions.