Dekohesjon

Dekohesjon is a term used in materials science, geology and geotechnical engineering to describe the loss or weakening of internal cohesive bonds within a material. It refers to the process by which a structure that relies on cohesive forces—such as cementation between grains, bonding in concrete, or interfacial bonds in composites—loses its ability to resist shear and maintain integrity. Dekohesjon is an internal failure mechanism and can precede or accompany fracture, fragmentation, or flow.

The causes of dekohesjon are multifaceted. Mechanical overloading beyond the material’s cohesive strength can initiate bond breakage. Environmental factors such as moisture, chemical attack, temperature changes, and freeze–thaw cycles can degrade bonding agents or cementation. Aging, radiation, irradiation, and sustained chemical exposure may also reduce bond strength. In soils, dekohesjon often manifests as a reduction in cohesion, which can change the effective shear strength and stability of slopes or foundations.

In practice, dekohesjon is relevant to a range of materials and settings, including cemented soils and rocks, concrete subjected to aggressive environments, coatings and laminates, and fiber-reinforced composites where matrix or interface degradation occurs. It is typically considered alongside erosion and wear as a mechanism of material degradation, and it can lead to changes in mechanical properties such as reduced cohesion and altered friction behavior.

Assessment and mitigation rely on laboratory testing and field monitoring. Shear tests, triaxial tests, and direct shear tests help quantify changes in cohesion and friction angle. Monitoring of moisture, chemical exposure, and temperature, along with appropriate design measures—drainage, protective coatings, material selection, and stabilization—are used to manage dekohesjon risks.