Degradation of rock under marine conditions can be ascribed to three general mechanisms; spalling, abrasion and large scale, catastrophic fracture. The physical disaggregation of a rock fabric can be assessed in terms of the forces of ‘attack’, such as salt crystallization pressure and rock impact forces, acting against the coherence of the rock fabric.
This coherence (and hence durability) is examined in terms of fracture toughness (K1C) and the Griffith fracture criteria for brittle solids which relate the maximum length of discontinuities present in a rock to its tensile strength. The relationship of tensile to compressive strength is reviewed and their relative merits are discussed. The use of standard engineering tests in the assessment of potential rock durability is also examined.