Fracture behavior of 3D printed geopolymer concrete containing waste ceramic

This study systematically investigates the fracture behavior of 3D printed geopolymer concrete containing waste ceramic. Based on three-point bending tests, the effect of waste ceramic aggregate (CWA) content and printing direction on the cracking patterns of 3D printed geopolymer concrete (3DGPC) were investigated with the help of digital image correlation (DIC) and acoustic emission (AE) techniques. The test results showed that the addition of 40 % CWA significantly enhanced the mechanical properties, fracture toughness and fracture energy of concrete. Compared to inter-strip cracking, inter-layer cracking was verified to be more effective in mitigating stress concentrations which further improves the performance of concrete. DIC analysis revealed that CWA incorporation and interlayer fracture had significantly increased the crack opening displacement, effectively inhibiting crack propagation and alleviating stress concentration at the crack tip. AE analysis further indicated that the incorporation of CWA and interlayer fracture can reduced shear cracks and enhanced the fracture toughness effectively. This research not only provides optimal mix proportions and printing parameters for 3D printed geopolymer concrete, but also holds the potential to promote the sustainable development of 3D printing technology.