Seismic Behavior of Dowel Type Precast Panel-Foundation Connection

Precast concrete panels are a popular construction technique due to their increased construction speed, low cost and the ability to use the precast concrete elements for structural walls to provide high strength and stiffness when used for structural purposes. Slender precast concrete wall panels are a common construction method for single storey warehouse type buildings. Following the Canterbury earthquake sequence Christchurch from 2010 – 2014, damage was observed in precast concrete wall buildings that resulted in out-of-plane collapse of wall panels. . This project seeks to investigate the behaviour of precast reinforced concrete walls designed for limited ductility under gravity and quasi-static in-plane loading. The main point of interest in this thesis research is to understand the seismic behaviour of the connection as well as the out-of-plane stability of slender panels. To investigate the behaviour of this panel and connection type, three slender precast concrete walls, representing full scale panel geometry were subjected to quasi-static cyclic loading. Two common panel to foundation connection types were studied: 1) threaded inserts and 2) traditional starter bars as well as one alternative connection which was developed as a means to improve the out-of-plane response and understand the impact of this design choice on the in-plane behavior of the wall. For all the three units, the dowel connection performed well and the thin wall failed under flexural failure due to loss of strength cause by fracturing of longitudinal rebars after being buckled under the effects of lateral cyclic loading. Significant horizontal cracking occurred on each of the tests at dowel level except unit threaded insert with 50mm cover behind the head of the insert (TI12-C50-IP) which suffered a secondary horizontal crack at 500mm above the main crack and a diagonal crack at the center of the wall. Moreover, this unit was able to undergo more deformation due to a secondary crack.