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Non-destructive characterization of cementitious materials is essential to ensure structural integrity and longevity in civil engineering. This study presents an advanced approach using singular value decomposition (SVD) to analyze ultrasonic dispersion curves, thereby improving the clarity and precision of ultrasonic characterization of cement slabs. We focused on the impact of different water/cement ratios on ultrasonic properties, revealing how these ratios influence the material's microstructure and mechanical properties. Our results show that higher water/cement ratios increase porosity and reduce density, thus slowing down the propagation of ultrasonic waves and potentially reducing mechanical strength. The application of SVD allowed for the isolation of significant signal components, providing a better understanding of the acoustic behavior and mechanical properties of the material. These findings highlight the importance of precise control over the water/cement ratio in the development of durable and robust cementitious structures. The study suggests that SVD can significantly improve the reliability of non-destructive testing methods, making it a valuable tool in materials science and engineering. This research advances current methodologies by offering enhanced accuracy in characterizing the internal structure and mechanical properties of cementitious materials. [ABSTRACT FROM AUTHOR]

A newly developed ultrasound method that acquires at the same time both reflected and transmitted P-waves, at different angles, using two immersion transducers of 0.5 MHz central frequency, is described in this present study. This non-destructive method allows calculating the longitudinal and transverse velocities, and thus, the Young modulus, so that its evolutions is followed in time domain. The closely correlation between the evolution in time domain of those calculated parameters and hydration properties of cement based materials was used to characterize the effects of different water-cement ratio and curing temperatures on early age hydration behaviour of cement pastes. To do so, cement samples were prepared by mixing Portland cement and freshwater. Results indicates that lower water to cement ratio reduces the workability and increases the Young modulus of resulted cement medium. Also, both ultrasound velocities and Young modulus values increases linearly with increasing curing temperature. [ABSTRACT FROM AUTHOR]