Effect of Water-to-Cement Ratio on Acoustic Nonlinearity of a Hardened Mortar
We present the results of experimental and theoretical studies of nonlinear acoustic phenomena (amplitude-dependent losses, resonant frequency shifts, generation of the second and third harmonics of a low-frequency (LF) wave, and self-action of ultrasonic finite-amplitude pulses) in rod resonators made of cement and river sand with various values of water–cement ratios (w/cs; 0.5, 0.6 and 0.9). We have also provided an analytical description of the observed phenomena within the frameworks of the phenomenological equations of state that contain LF hysteretic and high-frequency elastic nonlinearities. By analyzing the experimental and theoretical amplitude dependences of the nonlinear phenomena we determined values of the nonlinearity parameters of test materials. Comparison of changes in the measured nonlinear acoustic and strength properties of these materials demonstrates that an increase in the w/c, which leads to a decrease in the strength of the resulting mortars, also leads to an increase in its acoustic nonlinearity.
KeywordsCement-based materials Nonlinearity Resonance Hysteresis Water-to-cement ratio
This work was supported by Program No. 7 “Topical Issues of Photonics and Sounding of Inhomogeneous Media and Materials” of the Presidium of the Russian Academy of Sciences, within the framework of the state assignment in the field of scientific research (Project No. 2.1433.2017/4.6) and under financial support of the Council for the Grants of the President of the Russian Federation for the State Support of the Leading Scientific Schools of the Russian Federation (Project No. NSh-2685.2018.5).
- 3.Nazarov, V., Radostin, A.: Nonlinear Acoustic Waves in Micro-inhomogeneous Solids. Wiley (2015). https://doi.org/10.1002/9781118698334.
- 17.Reichel, W., Conrad, D.: Beton, B 1. Veb Varfag für Bauwesen, Berlin (1976)Google Scholar
- 20.Benson, R.W., Raelson, V.J.: Acoustoelasticity. Prod. Eng. 30, 56–59 (1959)Google Scholar