Influences of Rebar Design Parameters on Flexural Properties of Prestressed Beam-column Nodes.

The beam-column node is an important component of structures and is vital to structural safety. However, existing standards lack design formulas and structural requirements of the Precast Prestressed Efficiently Fabricated Frame (PPEFF) nodes. To investigate mechanical properties of PPEFF nodes deeply, a low-cycle reciprocating load test was conducted on five PPEFF side-node species Factors such as the failure mode, hysteretic skeleton curve, and ductility of PPEFF nodes were analysed to study their influences on the mechanical properties of the nodes. A previous calculation formula of unbounded prestressed tendon stress growth was modified according to the results of the low-cycle reciprocating load test. Results demonstrate that the hysteretic curves of PPEFF nodes are generally full, and the bearing capacity of the nodes increases significantly with the rise of the reinforcement ratio of unprestressed tendon and initial prestress. However, the energy consumption performance of the nodes declines when the initial prestress is too high. During the modification of the previous calculation formula, it is discovered that when the reduction factor of positive loading (k1) is 0.28 and the reduction factor of negative loading (k2) is 0.13, calculation values of the formula agree well with measured values. The obtained conclusions provide a significant reference for the design formula of PPEFF nodes. [ABSTRACT FROM AUTHOR]