Study on the failure mechanism of geopolymeric recycled concrete using digital image correlation method

Abstract

In this study, an experimental investigation was conducted to understand the failure mechanism of geopolymeric recycled aggregate concrete (GRAC) under compression. GRAC specimens with different recycled aggregate (RA) replacement ratios were prepared and tested. A digital image correlation (DIC) system was used to monitor the displacement field and strain distribution over the surface of the specimen. The results revealed that RA replacement adversely affected the mechanical properties of geopolymeric concrete, including compressive strength, elastic modulus, and splitting tensile strength. For all the specimens, cracks mainly initiated near the interfacial transition zones, and usually nucleated around natural aggregate (NA) rather than RA. As observed from the final crack patterns, it was more frequent for the RA that cracks passed through the aggregate particles, in comparison with the NA. The location of strain concentration region detected by the DIC method was closely consistent with that of the formed macro cracks.

Keywords:

• geopolymeric recycled aggregate concrete
• uniaxial compression
• failure process
• crack propagation
• digital image correlation (DIC)

Disclosure statement

The author declare that there is no conflict of interest

Additional information

Funding

All the authors appreciate the support of Australian Research Council (DE150101751), University of Technology Sydney Research Academic Program at Tech Lab (UTS RAPT), and University of Technology Sydney Tech Lab Blue Sky Research Scheme.