Key in predicting stability in sands during dynamic events is gaining a fundamental understanding of the physics of its deformation and failure at high pressures. In this paper are reported results of an experimental investigation into the high-pressure (up to 700 MPa) mechanical response of Quikrete sand. During all triaxial compression tests, the material exhibited hardening up to failure while both compressibility and dilatancy regimes of the volumetric response were observed. Furthermore, the transition from compressibility to dilatancy was found to be highly dependent on confining pressure. By performing triaxial compression tests with several creep stages followed by unloading–reloading cycles, the time influence of the overall response was detected. Using the experimental data, a new model that captures both compressibility and dilatancy has been developed. Comparison between model predictions and data showed that the proposed model describes well the main characteristics of the high-pressure response of sand. Copyright © 2012 John Wiley & Sons, Ltd.