Self-healing of clay desiccation cracks by biopolymeric microcapsules – sharing good and bad results

Department of Civil Engineering, The University of Hong Kong, Hong Kong SAR, China

^* Corresponding author: lourenco@hku.hk

Abstract

We explored the utilization of polymeric microcapsules to mitigate desiccation cracking in clayey soils, drawing from successful applications in cementitious materials. Microcapsules were synthesized with gum Arabic gelatine shells and cement cargo through the complex coacervation method. The internal structure and shell thickness of these microcapsules are characterized using optical microscopy. Experimental results demonstrate the effectiveness of microcapsules in reducing the width and depth of cracks in desiccated clay, highlighting a significant decrease in cracking penetration depth. However, on the opposite, the number and length of cracking segments increased. Overall, the findings suggest that microcapsule-based self-healing approaches hold some promise for mitigating desiccation cracking in clay, with further work needed.