Progressive collapse resistance of precast concrete beam-column sub-assemblages with high-performance dry connections

Abstract

Due to its relatively lower integrity, precast concrete structures are considered to be more vulnerable to progressive collapse than cast-in-place concrete structures. However, to date, majority of existing studies on progressive collapse focused on cast-in-place concrete structures, little attentions were paid to precast concrete structures. Among existing precast concrete structures, unbonded post-tensioning precast concrete structure is one of innovation dry connection structural systems, which no casting at the connections on site. Its excellent seismic performance was recognized by many studies, while studies on its progressive collapse resistance were very few. To fill this knowledge gaps, in this paper, eight half-scaled unbonded post-tensioning precast concrete beam-column sub-assemblages with different connection configurations were tested through pushdown tests to investigate their capacities and resistance mechanisms to prevent progressive collapse. The test results demonstrated various behaviors of beam-column sub-assemblages with different connection types. It was found that, as the longitudinal reinforcements were discontinuous across the beam-column joint region in the beams, flexural action observed in the cast-in-place concrete frames was not mobilized for the specimens with purely unbonded post-tensioning connections. When the specimens installed top-seat angles at the beam-column interfaces, considerable flexural action capacity could be mobilized for load resistance. Moreover, it was found that the failure modes of the specimens are distinctly different to that of conventional reinforced concrete frames or precast concrete frames with cast-in-place joints. The characteristic of compressive arch action and tensile catenary action in tested specimens is quite different to that of conventional reinforced concrete frames.

Strengthening of Precast RC Frame to Mitigate Progressive Collapse by Externally Anchored Carbon Fiber Ropes

“…Traditional strengthening methods are used to prevent progressive collapse of RC frame structure, mainly including prestress strengthening method (Qian et al [3,4]), steel Polymers 2021, 13, 1306 2 of 16 bonding strengthening method [5,6], bracing strengthening method [7][8][9], etc. These methods are effective in strengthening of progressive collapse resistance, but the construction is relatively complicated.…”

A Review of Precast Concrete Beam‐to‐Column Connections Subjected to Severe Fire Conditions

“…e precast concrete frame structure developed by the construction industry has resulted in high production efficiency, better product quality, and low labour intensity [1][2][3][4][5][6]. e mechanisation and standardisation of prefabrication methods have made the production of concrete elements sustainable [7][8][9]. Connections are critical in ensuring structural integrity, adequate strength, energy dissipation, stiffness, and ductility of the designed precast concrete structures [1,7,10,11].…”

“…e failure of connections during natural and humanmade disasters has an adverse impact on precast structures. Precast concrete structures have a relatively low integrity and are more vulnerable to progressive collapse than the traditional cast-in-place concrete structures [9]. e design of precast structures must take into account the occurrence of a fire as it is one of the accidental actions [11,19].…”

Assessment of SMC Frames under Different Column Removal Scenarios

“…They concluded that it is essential to provide practical recommendations for enhancing the structural robustness of structural configurations of the form considered in this study. Some studies scope on the precast connection's behavior due to progressive collapse, Al-Salloum et al [11], studied how to strengthen the precast connections using bolted steel plates and Qian et al [12], studied the resistance of high-performance dry connections due to progressive collapse. Tang et al [13], studied and designed an asymmetric double-half-span single-column structure with a fully bolted connection in (RCS) frame structure.…”