Specific surface area (SSA) is a property of solids defined as the total surface area (SA) of a material per unit mass, (with units of m/kg or m/g). Alternatively, it may be defined as SA per solid or bulk volume (units of m/m or m).
It is a physical value that can be used to determine the type and properties of a material (e.g. soil or snow). It has a particular importance for adsorption, heterogeneous catalysis, and reactions on surfaces.
Pozzolanic activity is a measure of the reaction rate between a pozzolan and Ca or calcium hydroxide (Ca(OH)2) in the presence of water. The rate of the pozzolanic reaction is dependent on the intrinsic characteristics of the pozzolan such as the specific surface area, the chemical composition, and the active phase content.
Physical surface adsorption is not considered as being part of the pozzolanic activity, because no irreversible molecular bonds are formed in the process.
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