PSI - Issue 61

Zili Huang et al. / Procedia Structural Integrity 61 (2024) 252–259 Huang et al. / Structural Integrity Procedia 00 (2019) 000 – 000

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a challenge, due to difficulties in controlling the cracking, especially for the case of 0° loading angle. Therefore, more tests will be conducted to ensure better reproductivity.

Table 2. Comparison of tensile strength for 90° and 0° loading scenario with average density. Loading Angle Average Density (kg/m 3 ) Average Tensile strength ( MPa )

90

2175 2130

2.62 2.58

0

4. Conclusions We have shown the application of AUSBIT to a challenging fracture test, using Brazilian discs made of 3D-printed cement-based mortar in which the effects of printing direction are focused on. Although AUSBIT is able to control the whole fracture process for the case of 90° loading angle, it faces challenges the loading direction induces tensile stress on the weak interface between layers (the case of 0° loading angle). For such cases of 0° loading angle, early snap-back responses can still be successfully captured, and very unstable fracture happens after that due to low fracture toughness of the interfaces compared to the layer. The results show the difference between tensile strengths of the layers and their interfaces. The printing quality should be improved with a more consistent mix design. Nevertheless, due to challenges in carrying out this kind of test even with the control using AUSBIT, the results obtained from a few successful tests are not statistically significant enough to indicate a clear difference between strengths of the layers (90° loading angle) and its interfaces (0° loading angle). In addition, due to challenges in controlling the test for the case of 0° loading angle, it was impossible to obtain the full post-peak curve for the calculation of fracture energy. Better control will be used, and more tests will be carried out in the future for more conclusive outcomes. Acknowledgements Giang D. Nguyen and Murat Karakus acknowledge support from the Australian Research Council (ARC) and OZ Minerals Ltd through Linkage Projects LP200100038 and LP220200792. References Chu, T., Ranson, W., Sutton, M., 1985. Applications of digital-image-correlation techniques to experimental mechanics. Experimental Mechanics 25, no. 3, 232–244. Correlation Solutions., 2009. Vic-2D Reference Manual, pp. 1–59. Gell, E., Walley, S., Braithwaite, C., 2019. Review of the validity of the use of artificial specimens for characterizing the mechanical properties of rocks. Rock Mechanics and Rock Engineering 52 chapter 9, 2949–2961. Hamidi, F., Aslani, F., 2019. Additive manufacturing of cementitious composites: Materials, methods, potentials, and challenges. Construction and Building Materials 281, 582-609. Panda, B., Paul, S., Hui, L., Tay, Y., Tan, M., 2017. Additive manufacturing of geopolymer for sustainable built environment. Journal of Cleaner Production 167, 281-288. Sharafisafa, M., Shen, L., 2020. Experimental Investigation of Dynamic Fracture Patterns of 3D Printed Rock-like Material Under Impact with Digital Image Correlation. Rock Mechanics and Rock Engineering 53 chapter 8 , 3589–3607. Tay, Y., Panda, B., Paul, S., Mohamed, N., Tan, M., Leong, K., 2017. 3D printing trends in building and construction industry: a review. Virtual and Physical Phototyping 12, 261-276. Verma, R., Nguyen, G., Karakus, M., 2019a. Snap back indirect tensile test (AUSBIT) Patent, IP Australia 2019101006. Verma, R., & Fallah, P., Nguyen, G., Bui, H., Karakus, M., Taheri, A., 2020. Analysing localisation behaviour of rocks using Digital Image Correlation technique in 13th International Conference on Mechanical Behaviour of Materials, pp 11-14. Verma, R., Nguyen, G., Bui, H., Karakus, M., 2021. Effect of Specimen Size on Localization using Digital Image Correlation, in Proceedings of the 8th International Conference on Fracture, Fatigue and Wear, Springer Singapore. Singapore, pp. 397–405. Verma, R., Nguyen, G., Karakus, M., Taheri, A., 2021a. AUSBIT: A novel approach to capturing snapback in indirect tensile testing in 55th US Rock Mechanics/Geomechanics Symposium OnePetro. Verma, R., Nguyen, G., Karakus, M., Taheri, A., 2021b. Capturing snapback in indirect tensile testing using AUSBIT - Adelaide University Snap Back Indirect Tensile test International Journal of Rock Mechanics and Mining Sciences (Oxford, England : 1997) 14 7, 104897–. Wu, P., Wang, J., Wang, X., 2016. A critical review of the use of 3-D printing in the construction industry. Automation in Construction 68, 21–31.