A miniaturized testing apparatus to study the chemo-mechanics of porous media

Understanding coupled processes in subsurface systems is critical to assessing and predicting the long-term impacts of natural phenomena, underground industrial activities, and geoengineering. Here, we discuss the capabilities of a new miniaturized chemo-mechanical testing device that allows for concurrent reactive transport, mechanical loading, and microstructural imaging. The apparatus enables a range of combined deformation/flow tests to be performed simultaneously or sequentially. In addition, the device enables controlling reactant mixing, flow rate, and boundary conditions, which is useful to identify key factors in flow-through precipitation and dissolution experiments in porous media. Results of precipitation, oedometric compression, and dissolution tests are presented along with concurrent microstructural analyses based on synchrotron X-ray microtomography imaging. High-resolution 3-D images of evolving microstructural features allow explicit quantification of pore structure changes. The results illustrate the efficiency and versatility of the new multifunctional testing device and emphasize the benefits of quantifying the outcomes of coupled chemo-mechanical processes at pore scale, which is essential to develop and validate multiscale transport-reaction-deformation models.