Volume fraction	Volume concentration of particles in the unit volume of material: e.g., suspension, concrete
Maximum volume fraction	Ratio of the true volume of particles to the volume occupied by them in a maximally compacted state
Random loose packing fraction	Ratio of the true volume of particles to the volume occupied by them in a random loose state, i.e., without compaction
Surface area of aggregate per unit volume of cement paste	Total area of surfaces of all aggregate particles distributed in the unit volume of cement paste
Sphericity	Ratio of the surface area of a sphere to the surface area of an actual, irregularly shaped particle of equivalent volume
Intrinsic viscosity	Measure of the effect of individual particles on the viscosity of suspensions; dependent on particle shape and concentration
Static yield stress	Stress which is required to initiate flow
Structural build-up	Evolution of rheological properties of a cementitious material over time due to flocculation and early hydration
Structural build-up rate	Rate of increase in the static yield stress of a cementitious material over time
Relative static yield stress	Ratio of the static yield stress of suspension, e.g., concrete, to the static yield stress of suspending medium, e.g., cement paste
Relative structural build-up rate	Ratio of the structural build-up rate of suspension, e.g., concrete, to the structural build-up rate of suspending medium, e.g., cement paste
Constant shear rate test	Rheometry method for measuring static yield stress; a low, constant shear rate is applied until shear stress reaches its peak or plateau value
Single-batch approach	A technique used to determine the evolution of static yield stress over time, in which the measurements of peak torque at all ages are performed on a single sample of material
Multi-batch approach	A technique used to determine the evolution of the static yield stress over time, in which measurement of peak torque at each particular age is performed on a discrete, individually prepared sample of the same material