Experimental Studies of Beam-to-Column Dowel Connections in RC Precast Buildings
Tatjana Isaković1, Blaž Zoubek1, Miha Kramar2, Matej Fischinger1
1 University of Ljubljana, Faculty of Civil and Geodetic Engineering
Jamova 2, 1000 Ljubljana, Slovenia
tatjana.isakovic@fgg.uni-lj.si
blaz.zoubek@fgg.uni-lj.si
matej.fischinger@fgg.uni-lj.si
2 ZAG
Dimičeva 12, 1000 Ljubljana, Slovenia
miha.kramar@zag.si
Abstract. The load-carrying capacity and failure mechanisms of beam-to-column dowel connections in precast industrial buildings were studied experimentally and analytically. The main objective of the experimental research was to obtain the strength and the deformation capacity of the dowel connections under “realistic conditions”, in contrast to other experiments, which were available in the literature and were considerably idealized. For this purpose, three most frequently used types of dowel connections were studied. The full-scale specimens were analysed. To obtain realistically large relative rotation between columns and beams, the dimensions and reinforcements in some columns were reduced comparing to that which is required in the codes.
The experiments revealed that dowel connections can be subjected to the two potential failure mechanism: (a) local failure – characterized by the simultaneous yielding of the dowel and crushing of the surrounding concrete, and (b) global failure – characterized by spalling of the concrete between the dowel and the edge of the column or the beam. Using the strut-and-tie model, an entirely new design procedure for estimation of the global response has been defined. The existing procedure, which defines the local capacity has been slightly modified.
Large relative rotations between beams and columns reduced the strength of dowel connections. In the cases, presented in the paper, the strength was reduced for about 20% comparing to those where these rotations were small. The analytical procedure for estimation of the dowel’s strength reduction under the large relative rotations between columns and beams has been proposed.
Keywords: RC precast stuctures, Dowel connections, Seismic Response, Strength, Failure Mechanisms.
