Openings effects on the structural behavior of interior voided slab-column connections: An experimental study

This paper studied the openings' influences on the structural responses of interior voided slab-column connections. Seven specimens were constructed with square slabs measuring 1100 × 1100 × 100 mm and contained voids distributed throughout their entire area. After construction, circular openings were introduced in six specimens; the left one was the control. Two specimens had one opening with a diameter of 100 mm and 150 mm. The others had two openings with a 100 diameter placed in different configurations about the column: on the same side, perpendicular, on the slab diagonal, and parallel. The specimens were tested under concentrated loads till the failure. The test results showed that all connections failed due to punching modes, and the strength declines increased with the opening size to reach an essential limit of 35% when the opening size was 150 mm compared with the control connection. Furthermore, the openings decreased the ability of specimens to absorb energy by about 48.1%− 74% and the specimens' stiffness to 33.5%. Moreover, the ductility of specimens with openings dropped nearly to 34.4%− 51.4%. The best openings arrangement was found when placing two openings on the slab diagonal, where the strength decline was only 4.7%; this reduction was lesser than introducing one opening in the front of the column.