Mixed-Mode cracking behavior of cold recycled mixes with emulsion using Arcan configuration

• A newly developed Arcan test was utilized to investigate Mixed-Mode cracking behavior of CIR mix.
• Using Digital Image Correlation allowed for full-field displacement/strain fields to be captured.
• The proposed indicators can reflect the characteristics of CIR mixtures in Mixed-Mode cracking.

Cold In-place Recycling (CIR) has gained popularity in recent years and it shows a good resistance to reflective cracking from underlying concrete pavement. The objective of this research is to investigate the Mixed-Mode cracking behavior of CIR mixtures, as there are indications that reflective cracks do not form in a 100% Mode I fashion. A newly developed Arcan configuration was utilized to simulate five levels of Mixed-Mode cracking. The peak load, crack angle, and three types of fracture energies were obtained to compare the Mixed-Mode cracking characteristics of CIR mixture. Utilizing Digital Image Correlation (DIC) allowed for full-field displacement/strain fields to be captured, along with the more traditional readings from attached gauges. The accuracy of DIC was verified and the effect of rigid displacement in Arcan test was eliminated. The results of this study indicates that crack initiation in 100% Mode II cracking produces the highest peak load, but it propagates rapidly once the crack is initiated. The peak load is more sensitive than fracture energy to temperatures. A strong correlation was found between crack angle and the level of Mixed-Mode cracking: it increases as the percentage of Mode II increases. A common feature of the five strain maps for Mixed-Mode cracking is that the strains near crack tip are higher than other strains, which results in the crack initiation. However, the crack path formed along higher strains changes significantly with five levels of Mixed-Mode cracking. Overall, this research provides a solid foundation for future research in exploring reflective cracking characteristics of CIR mixtures.