Fatigue performance of 3D printed reusable concrete slabs for temporary pavements

To explore the fatigue performance of 3D printed reusable concrete slabs for temporary pavements, the effect of varied steel fiber volume ratios and fiber lengths on flexural tensile strength and fatigue performance was studied through the bending fatigue tests on 216 3D printed specimens. Fatigue life calculation methods for various failure probabilities were developed using the two-parameter Weibull distribution, and the related fatigue equation was then derived. Furthermore, the fatigue coefficient suitable for 3D printed reusable prefabricated pavement was developed, followed by a revision to the pavement design procedure. The study found that incorporating steel fibers into 3D printed specimens can effectively prevent the development and expansion of transverse cracks, significantly improve the flexural tensile strength, crack resistance, and fatigue resistance of components, and transition their failure mode from sudden brittle failure to ductile plastic failure. The steel fiber volume ratios and lengths significantly impact component flexural tensile strength and fatigue life. The fatigue life of the component increased by 252 % when the ${\rho }_f{l}_f/d_f$ increased from 0.00 to 0.60 under the same stress ratio S= 0.65. The stress level in the middle of the long side of the new type of 3D printed reusable prefabricated pavement slabs is higher than in the plate's center and corners, and that was the most unfavorable loading position for the slab. The 20-meter field test section shown that the 3D printed slabs could reduce volume by 40 %, weight by 35 %, and manual labor by 50 % while a 3-fold increase in fatigue life compared to traditional C40 concrete slabs. The study's findings are extremely important for further encouraging the use of 3D printing technology in the transportation field, as well as promoting industrial intelligence industrial intelligence and development.