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To study the influence of masonry infill walls on the hysteretic performance of reinforced concrete frames, a cyclic experiment was conducted for three two-story and two-span reinforced concrete frame structures, including one reinforced concrete frame without infill walls and two frames with infill walls. Whether the infill walls were constructed in the frames and the type of infilled material were the main parameters of the test. The major results reveal that: the infill walls clearly changed the mechanical mechanism of the frame structure at the early stage of loading, magnified the stiffness and horizontal bearing capacity of the frame structure, and enhanced the energy dissipation capacity of the frame structure, but reduced the deformation performance of the frame structure. In the later stage of loading, the infill walls would no longer work as one with the frame gradually with the failure of the infill walls, and the above performance of the structure would approach the empty frame structure. Moreover, the initial stiffness, energy dissipation capacity, and horizontal bearing capacity of the frame with infill walls of clay hollow bricks were the highest among the three specimens. But due to the strong diagonal bracing effect, the damage to the top of the columns and beam-column joints was serious, the yield displacement was reduced significantly, and the shear failure of the top of the columns and the joints occurred prematurely, which showed poor performance of deformation and ductility. However, the frame with infill walls of relatively soft aerated lightweight concrete blocks showed better performance of deformation and ductility.

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This paper presents the details of fire test on eight prestressed reactive powder concrete (RPC) beams cured with 150°C hot-air condition. The test specimens were varied in load ratios/degree, cover thicknesses of tendons, bonded and unbonded tendons, partial prestressing ratios. The thermal fields, deflections behaviour, effective prestress, fire endurance, failure modes, and crack patterns of the beams were observed and recorded during the tests. The post-fire tests observation reveals that no obvious thermal-induced spalling occurred on the prestressed RPC beams prepared in hot-air curing. The fire tests results indicated that the failure of prestressed RPC beams was driven by direct fire exposure and fracture of tendons and longitudinal rebars after generation of wide cracks in the beams. In extreme fire, prestressed RPC beams that are under-reinforced at ambient temperature may fail as the low-reinforced beams. The load ratios and cover thicknesses of tendons are the key factors affecting the fire resistance of the prestressed RPC beams. With the decrease of the load ratios and increase of cover thicknesses of tendons, the fire resistance is dramatically improved. Bonded prestressed RPC beams showed superior performance to equivalent unbonded prestressed RPC beams in fire. The whole scale transferring effect of prestress loss in unbonded beams should be considered for fire resistance performance design based on structural systems.