Mechanical properties of new bolted nodes of ultra-high performance concrete assembly wall panels

Assembled building is the key development area of the current construction industry. The assembled wall panels made of ultra-high performance concrete (UHPC) have many advantages compared with ordinary lightweight wall panels. However, most of the existing connection nodes are based on the design of ordinary lightweight concrete wall panels, which cannot effectively bring out the performance advantages of UHPC wall panels. This paper proposes two new types of connection nodes that can better bring out the performance advantages of assembled UHPC wall panels: broken line steel plate bolt connection node and T-sleeve bolt connection node. Based on the different strengths of concrete, the design reference values of the thickness of the broken line steel plate, the bending angle, and the thickness of the T-sleeve are given for the new connection nodes. Under uniaxial tensile, uniaxial compression, and unidirectional shear conditions, three kinds of bolted node specimens including ordinary connection nodes and two new types of connection nodes were loaded to study the damage characteristics and mechanical properties. In conclusion, the mechanical properties of the two newly proposed connection nodes demonstrate significant improvements. For instance, under the unidirectional shear test, the ultimate loads of the two new connection node specimens were increased by 156.20 % and 105.33 %, respectively, compared with the ordinary connection node specimens. In addition, the formula for calculating the ultimate tensile load capacity of the new bolted nodes of assembled UHPC wall panels was provided.