If the concrete of a prestressed slab spalls in fire,the reinforcement will be exposed to flame,and the slab would soon lose its bearing capacity due to breaking of reinforcement caused by burning.

• 在火灾下预应力板迎火面的混凝土若发生爆裂,受力钢筋将裸露于火中,板将因钢筋被烧断而很快丧失承载力。