Monotonic Loading Tests of RC Beam-Column Subassemblage Strengthened to Prevent Progressive Collapse

Abstract

In this study the progressive collapse resisting capacity of a RC beam-column subassemblage with and without strengthening was investigated. Total of five specimens were tested; two unreinforced specimens, the one designed as gravity loadresisting system and the other as seismic load-resisting system, and three specimens reinforced with: (i) bonded strand, (ii) unbonded strand, and (iii) side steel plates with stud bolts. The two-span subassemblages were designed as part of an eight-story RC building. Monotonically increasing load was applied at the middle column of the specimens and the force-displacement relationships were plotted. It was observed that the gravity load-resisting specimen failed by fractures of re-bars in the beams. In the other specimens no failure was observed until the maximum displacement capacity of the actuator was reached. Highest strength was observed in the structure with unbonded strand. The test result of the specimen with side steel plates in beam-column joints showed that the force-displacement curve increased without fracture of re-bars. Based on the test results it was concluded that the progressive collapse resisting capacity of a RC frame could be significantly enhanced using unbonded strands or side plates with stud bolts.

Progressive Collapse of Exterior Reinforced Concrete Beam–Column Sub-assemblages: Considering the Effects of a Transverse Frame

“…Tsai and Huang (2015) tested the collapse resistance of six reinforced concrete sub-assemblages designed with different span-to-depth ratios and varied stirrup spacings under gravitational loading. Farhang Vesali et al (2013), Choi and Kim (2011) and Kim and Choi (2015) presented other notable studies that focused on the collapse behavior of RC sub-assemblages. Qian et al (2014) investigated the contribution of secondary load-carrying mechanism, including transverse beams and membrane action of the slabs in RC assemblies.…”

Strengthening of Precast RC Frame to Mitigate Progressive Collapse by Externally Bonded CFRP Sheets Anchored with HFRP Anchors

“…About the numerical simulation, Pan et al [8] studied the behavior of beamcolumn joints and the progressive collapse performance of unbonded posttensioned precast concrete frame structures with finite element models which were established in OpenSEES, and Feng et al [9] presented a numerical investigation of the progressive collapse behavior of the precast RC frame subassemblages. Some researchers have also conducted tests on strengthening against the progressive collapse of structures [10][11][12][13][14][15][16][17][18]. Qian and Li [10,11] tested a series of flat slab substructures to assess the effectiveness of proposed CFRP and GFRP strengthening schemes for improving the progressive collapse behavior.…”

Experimental Cyclic Behavior of Precast Hybrid Beam-Column Connections with Welded Components

“…There has been a great deal of research by means of experimental and numerical studies on reinforced concrete beam-column joints (Ronagh and Baji 2014;Kim and Hyunhoon 2015;Kassem 2015;Rashidian et al 2016;Lim et al 2016). However, there are a limited number of experimental studies on the behavior of hybrid (emulativewelded) connections in the literature.…”