Determination of Elastic Constants of Frozen Rubber-Sand Mixes by Ultrasonic Testing

Abstract

This technical note presents measurements of ultrasonic velocities of compressional and shear waves in frozen ground-rubber-sand mixtures at various mixing ratios and subfreezing temperatures. Test results showed that ultrasonic velocities of compressional and shear waves increased with descending temperature, while the addition of rubber decreased both the compressional- and shear-wave velocity; namely, the higher the rubber content in the mixture, the lower the measured ultrasonic wave velocity. Based on the elastic wave theory and measured ultrasonic wave velocities, the dynamic elastic properties were determined. The results indicate that the elastic properties of rubber-mixed sand change with temperature and rubber-mixing ratio. The dynamic elastic modulus and dynamic shear modulus increased with a decrease in temperature. The deformation characteristics and rigidity of the frozen mixtures can be controlled with the addition of ground rubber to sand. The Poisson’s ratios ranged between 0.34 and 0.20.