Influence of the constraint condition of column ends on seismic performance of a novel prefabricated concrete frame beam - An experimental and numerical investigation

摘要

A novel prefabricated concrete frame beam with an innovative assembling pattern is developed and studied in this paper, and it is characterized by simple operation, economical and good fault-tolerance performance. Quasi-static tests were carried out on one monolithic beam and two PC beams to investigate the influence of the constraint condition of column ends on the hysteretic behavior of the proposed beams. Analyses and comparisons were conducted in terms of the cracking propagation pattern, the failure mode, the load-bearing capacity, the beam ductility, the beam stiffness and the plastic energy dissipation ability. It is concluded that the constraint condition of column ends had a great influence on the failure mode of the proposed beams. Furthermore, the PC frame beam with restricted column ends had relatively higher load-bearing capacity and stiffness, slightly lower ductility and energy dissipation ability compared with that of PC frame beam with free column ends. In general, the seismic performance of the proposed PC beams was similar with that of the monolithic one under the same constraint condition of column ends. Note that the results of the evolution of the crack width versus the cyclic load were obtained and especially a significant increasing of the crack width after the beam yielded. Finite element analysis method was introduced to conduct a further analysis of the PC beams. The parametric analysis results recommended a reasonable and relatively small stirrup spacing for application of the proposed novel PC frame beams.