Title: Behavior of Unbonded Post-Tensioned Concrete Slabs Exposed to Fire

Author(s): Siyoung Park and Thomas H.-K. Kang

Publication: Structural Journal

Volume: 120

Issue: 3

Appears on pages(s): 217-229

Keywords: cover thickness; fire-resistance performance; tendon configuration; unbonded post-tensioned (PT) slab

DOI: 10.14359/51738512

Date: 5/1/2023

Abstract:
With the development and commercialization of post-tensioned (PT) concrete structures, concerns pertaining to structural safety for disasters and diverse conditions, such as fire and high temperatures, have emerged. To better understand fire-resistance performance, effects associated with cover thickness and tendon configurations for six unbonded PT concrete slabs were evaluated in regardto temperature changes, deflection, tendon tensile forces, and fire endurance/time. In addition, the factors and relationship between the extent of damage caused by concrete cracking/delamination and tendon force at post-tensioning were evaluated. Thermal resistance and deflection rates for materials such as galvanized steel duct or high-density polyethylene (HDPE) sheathing were also examined. It is the authors’ hope that the aforementioned informationidentifying parameters affecting fire-resistance performanceof PT slabs may be helpful to the practitioner when consideringtendon configurations for unbonded PT concrete structures.