A review on freeze-thaw action and weathering of rocks

Freeze-thaw weathering is an important surface process and the complex underlying processes can be understood as an interplay between rock properties and its dynamic environment. Multiple researchers coming from different scientific disciplines have contributed to the present-day knowledge on the matter and misconceptions still prevail. In a changing climate, the multidisciplinary insights into freeze-thaw action are crucial for a better understanding of rock weathering in natural and anthropogenic environments. In this review, a series of laboratory and in-situ field tests are presented to illustrate the present-day methods to assess freeze-thaw weathering. Over the last century, these methods led to insights and the development of theories on damage mechanisms. Presently, it is accepted that crystallization pressure is responsible for the majority of stresses in the material's pores. Damage is induced when these stresses overcome the local tensile strength. Since most of the methods used to derive and validate stress build-up theories are indirect observations of parameters related to the phase transition, it is hard to reach a consensus on the exact explanation for stress development. Direct observations, which require actual real-time observation of the pore space during a freeze-thaw cycle, are therefore favoured to reach agreement. Eventually, the goal is to achieve a better insight on which processes potentially occur, how these vary with different environmental, temporal and spatial conditions and under which circumstances damage is inflicted.