An Experimental Study on Reinforced Concrete Infilled Frames with Openings

Abstract

In the last decade, seven major earthquakes caused significant casualties and extensive structural failures. Thousands of RC buildings were severely damaged or collapsed in Turkey due to various deficiencies. This has initiated experimental studies on strengthening methods and intensive researches regarding the rehabilitation of reinforced concrete structures by introducing reinforced concrete infill walls were carried out. Strengthening of reinforced concrete frames by cast-in-place reinforced concrete infills is commonly used in practice. Many structures were also repaired using this technique after the recent earthquakes. In this experimental research, six, one-bay/two-story, 1/3-scaled non-ductile, undamaged reinforced concrete (RC) frames were constructed and tested to investigate the behavior of frames strengthened by introducing infills with or without openings. The test specimens were subjected to reversed cyclic quasi-static lateral loading. The specimens were constructed with the most commonly observed deficiencies in residential RC buildings in Turkey. The first specimen was the reference bare specimen and contained no strengthening. The other specimens were infilled with RC panels with openings having different ratios and configurations. Strength, stiffness and storey drifts of the test specimens were measured and compared. Test results indicated that infilled RC frames displayed significantly higher lateral strength and stiffness than the non-ductile bare frame considerably.

Investigation of Short Column Behaviors at 1/5 Scaled Reinforced Concrete Frames Using Different Strengthening Methods

“…Because of the brittle behavior of the infill wall and the crushing of the wall, the strength of Specimen 2 and Specimen 3 were lower than expected due to the lack of load transfer from the frame to the infill wall. The test results showed that the size of the window opening has no significant effect on the lateral load carrying capacities of the test specimens (Balik et al, 2013).…”

Behaviour of 3D RC frames placed at different angles on shaking table

“…Test frames were deliberately detailed and constructed with some deficiencies such as low strength concrete, strong beamweak column formation, wide spacing of beam and column stirrups, no column stirrups at the beam-column joints, and no confinement zones at the end of the columns and beams [19][20][21]. In addition to these deficiencies, the stirrups were prepared with hooks placed at 90° at free ends of columns and beams of the test specimens [19][20][21]. The height of one storey was 500 mm (3000 mm at real-size 1:1 scale).…”