Conceptual design and investigation of an innovative joint for the rapid and precise assembly of precast UHPC elements

Buildings assembled on site from precast concrete elements have several advantages compared to monolithic structures, such as fabrication in flow production, rapid and precise erection as well as controlled disassembly. The joints of segmental structures have a significant influence on the design of the structure, the assembly and the load transfer of the bearing elements. In this study, the mechanism of shear force transmission of a developed ultra-high performance concrete (UHPC) mortise in conjunction with a steel tenon under additional post-tensioning forces was investigated. Numerical investigations and experimental tests were conducted focusing on the shear behavior of planar surfaces, the load–displacement behavior of the developed dry joint and the failure modes under different normal stresses. The results show that the Coulomb friction law is not fully applicable to the friction of plane UHPC surfaces with micro-roughness under high normal stresses. The data obtained from FE simulations show good agreement with the results from full-scale experimental tests and the characteristic shear capacities are adequate for further design of the developed dry joint.