Response of precast prestressed concrete hollowcore slabs under fire conditions

• Results from fire tests on six prestressed hollowcore slabs are presented.
• Critical factors influencing fire response of hollowcore slabs are discussed.
• Different failure modes in hollowcore slabs under fire conditions are identified.
• A numerical model for tracing fire response of hollowcore slabs is presented.

This paper presents results from experimental and numerical studies on the behavior of precast prestressed concrete (PC) hollowcore slabs under fire conditions. Six PC hollowcore slabs were tested under simultaneous application of thermal and structural loads. The test variables included type of aggregate in concrete, load level, fire exposure and restraint conditions at the supports. The hollowcore slabs did not experience any fire induced spalling and the failure of all slabs occurred through temperature on unexposed side of slab reaching limiting temperature criteria. Data generated from fire tests show that aggregate type, fire scenario, load level and end support condition have significant effect on the fire performance of PC hollowcore slabs. Further, results from fire tests indicate that typical hollowcore slabs can sustain service loads for at least two hours under standard and design fire conditions. Data generated from fire tests is utilized to validate a numerical model developed for evaluating fire performance of PC hollowcore slabs. Predicted cross-sectional temperatures and deflections of the slab, generated from the numerical model, compare well with measured data from fire tests indicating that the proposed model is capable of tracing the behavior of PC hollowcore slabs under standard and design fire conditions.