Assessing road repair materials via digital image correlation

Abstract

This study investigates the performance of road repair materials using digital image correlation (DIC). Cementitious mortar prisms were produced for slant shear testing and repaired using a commercial belitic calcium sulfoaluminate (BSCA) mortar or polyurethane-based repair material. The repaired prisms were subjected to a slant shear test under repeated loading and unloading, and DIC was utilised to measure and compare the strain developed across the repaired prisms. The DIC-generated strain maps show clear differences in the strain between the two repair materials: the prisms repaired with the BCSA mortar showed less pronounced strain under loading across the prisms until the final loading, whereas the prisms repaired with the polyurethane-based materials exhibited a pronounced but consistent positive and negative strain. These differences in the strain across the samples are attributed to the difference in the elastic modulus of the two repair materials. This work highlights the potential of using DIC to assess the performance of road repair materials for their development in the laboratory and contributes to the longer-term objective of digitising road networks towards safer and longer-lasting roads.