Design Considerations for the Connection of Precast Concrete Structures

The structural integrity of precast concrete buildings depends mainly on the connections between the precast structural components. Large precast concrete panels are used extensively in North America for low, medium, and highrise construction due to their ease and speed of assembly, and high quality control. This paper presents the results of twenty-two prototype specimens tested to investigate the behaviour and the capacity of typical connections used for precast loadbearing shear wall panels subjected to shear loading. The different configurations include dry-packed for plain surface panels, two sizes of dry-packed multiple shear keys, dry-packed plain surface and continuity bars with and without mechanical shear connectors, and post-tensioned connections. Shear walls supporting hollow-core floor slabs were also included. Different levels of load nomlal to the connection were used to simulate the effects of gravity and permanent loading conditions. Test results were used to refine and calibrate rational mathematical models developed to predict the maximum shear capacity and the nominal shear strength of the connection. Various failure mechanisms are presented and discussed. The findings of this investigation were implemented in the design of three 32-storey apartment buildings in Winnipeg, Manitoba, and provided significant savings in construction time and cost.