Behavior of Unbonded Post-Tensioned Concrete Slabs Exposed to Fire
Siyoung Park, Thomas H.-K. Kang
Appears on pages(s):
fire resistance performance; tendon configuration; unbonded post-tensioned slab; cover thickness
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 regard to temperature changes, deflection, tendon tensile forces, and fire endurance/time. In addition, factors and the 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 ducts or high-density polyethylene sheathing, were also examined. It is the authors’ hope that the aforementioned information identifying parameters affecting fire resistance performance of PT slabs may be helpful to the practitioner when considering tendon configurations for unbonded PT concrete structures.