Ultrasonic pulse velocity (UPV) is a non-destructive measurement technique with which
the quality of any concrete element can be evaluated. It provides information on concrete health
and for assessing the need for repair in a straightforward manner. In this paper, the relationship
is studied between UPV readings and the mechanical behavior of self-compacting concrete (SCC)
containing coarse, fine, and/or powdery RA. To do so, correlations and simple- and multipleregression relationships between compressive strength, modulus of elasticity, splitting tensile strength,
flexural strength, and UPV readings of nine SCC mixes were assessed. The correlations showed that
the relationship of UPV with any mechanical property was fundamentally monotonic. The inverse
square-root model was therefore the best-fitting simple-regression model for all the mechanical
properties, although for bending-tensile-behavior-related properties (splitting tensile strength and
flexural strength) the estimation accuracy was much lower than for compressive-behavior-related
properties (compressive strength and modulus of elasticity). Linear-combination multiple-regression
models showed that the properties related to bending-tensile behavior had a minimal influence on
the UPV value, and that their introduction resulted in a decreased estimation accuracy. Thus, the
multiple-regression models with the best fits were those that linked the compressive-behavior-related
properties to the UPV readings. This therefore enables the estimation of the modulus of elasticity
when the UPV and compressive strength are known with a deviation of less than ±20% in 87% of the
SCC mixes reported in other studies available in the literature.
