Punching shear reinforcing using studs with steel plates in reinforced concrete flat plates

Flat plate structures of reinforced concrete buildings have many advantages. However, a drawback of flat structures is that they are vulnerable to punching shear failure at the column-slab connections. This study proposes a new novel technique to improve the punching shear resistance capacity in new flat plate structures using the studs with perforated steel plate reinforcement at column-slab connections. Tests were carried out on specimens of 3 4 scale, which were designed to fail as a result of punching shear. The specimen variables were as follows: the first case used a stud rail and a base specimen; the second case used four stud specimens with perforated steel plates with different lengths; and the third case used a perforated steel plate with the same length as the stud with the steel plate. From the test results, the following conclusions were drawn: (a) the ultimate strengths of specimens have been designed to resist punching shear based on ACI 421 and Eurocode 2-04, and shear reinforcement for slabs has been compared with the results from the structural experiments; (b) the studs contributed substantially to the increase of ultimate strength; (c) the studs with steel plates contributed to the increase of the ultimate strength. The ratio of ductility in the specimen was larger than that of the total increase in strength.This research was supported by a grant (Code No. 06 Chumdan-eunghapE01) from Virtualmighty Program by the Ministry of Construction and Transportation of the Korean Government (MOEHRD)(R05-2004-00010591-0)