Damage due to Ice Crystallization

TL;DR

This study investigates how ice crystallization causes damage in partially saturated materials, revealing that liquid inclusions formed during freezing generate high pressures leading to fractures, and that wetting properties influence damage prevention.

Contribution

The paper provides experimental evidence and thermodynamic analysis of ice-induced damage in partially saturated media, highlighting the role of liquid inclusions and surface wettability in damage mechanisms.

Findings

Damage occurs due to pressure from freezing liquid pockets within ice.

Crystallization pressure is independent of liquid pocket volume.

Wetting properties can prevent formation of damaging liquid inclusions.

Abstract

The freezing of water is one of the major causes of mechanical damage in materials during wintertime; surprisingly this happens even in situations where water only partially saturates the material so that the ice has room to grow. Here we perform freezing experiments in cylindrical glass vials of various sizes and wettability properties, using a dye that exclusively colors the liquid phase; this allows to precisely observe the freezing front. The visualization reveals that damage occurs in partially water-saturated media when a closed liquid inclusion forms within the ice due to the freezing of air/water meniscus. When this water inclusion subsequently freezes, the volume expansion leads to very high pressures leading to the fracture of both the surrounding ice and the glass vial. The pressure can be understood quantitatively based on thermodynamics which correctly predicts that the crystallization pressure is independent of the volume of the liquid pocket. Finally, our results also reveal that by changing the wetting properties of the confining walls, the formation of the liquid pockets that cause the mechanical damage can be avoided.