Compressive strength of calcium aluminate mortar determined by ultrasonic non-destructive test method

Abstract

The early-age hydration of a number of calcium aluminate cement pastes and mortar materials was investigated using compressive strength and ultrasonic through-transmission measurements. Ultrasonic signals obtained were successfully described in the temporal domain by a single Gaussian wave packet equation giving five characteristic parameters – amplitude A, angular frequency ω, phase shift, wave centre arrival time and signal width. The group velocity of ultrasonic wave propagation (vG) is suggested to be a more sound parameter characterising the material under study than the generally employed ultrasound velocity determined from the ‘time of flight' parameter. The combination of parameters AωρvG showed a linear correlation with the measured compressive strengths for all the samples tested. The physical meaning of the AωρvG group of parameters is given and its application is further discussed in relation to other testing procedures.