Experimental Study on the Behavi An Experimental Study on the Behavior of Precast Concrete Column to Foundation Connections by Bolts Under Cyclic Loads

Abstract

Precast concrete construction systems have become increasingly popular due to their convenience, time efficiency, ease of quality control, and cost-effectiveness. However, in areas with earthquake risks, the connections between precast components are critical and require further research and development, as they often exhibit nonlinear behavior during seismic events. This research focuses on the behavior of dry-process precast concrete connections between columns and foundations that utilize column shoes. These connections are designed in accordance with the Capacity Design approach to minimize damage in the joint area. Reversed cyclic loading conditions under the ACI 374.1-05 structural testing standard were employed to test the column-foundation connections, which were intended to replicate the size of a three-story commercial building in Chiang Rai, Thailand. The precast column specimen featured a cross-section of 0.32 meters by 0.32 meters and a height of 1.70 meters, and they were connected to the foundation using the column shoe system. These precast specimens were also compared to traditional cast-in-place concrete systems of the same dimensions. The tests were conducted under an axial load ratio of 5% and a moment-to-shear ratio of 1 meter to assess and compare damage patterns, strength, stiffness, and energy dissipation capacity. The results indicate that the proposed connection system CS effectively resists lateral forces, reducing the risk of sudden structural collapse. It maintains structural strength and can withstand a drift ratio of 3.5% while retaining more than 25% of its initial stiffness, in compliance with ACI 374.1-05 standards, the performance of the precast concrete connection system demonstrates characteristic closely resembling those of the traditional cast-in-place concrete system. However, when the drift ratio exceeds 3.5%, the energy dissipation capacity of the CS specimen becomes noticeably lower than that of the CIP.