Experimental Study on the Structural Performance of Reinforced Truss Concrete Composite Slabs during and after Fire

Standard fire resistance tests and post-fire on residual mechanical properties were carried out two four-edge simply supported reinforced truss concrete two-way composite slabs with wide seam splicing (“integral seam”) close (“separated seam”), the effects of different forms during after exposure to high temperatures explored. The results indicate that there are significant differences in terms crack developments, moisture loss times slab surface, spalling characteristics bottom cross-section temperature gradients steel reinforcement along thickness direction between spliced (referred as “S1 slab”) “S2 test. This is mainly due structural measures prefabricated base at joints, which led changes heat transfer path joints. As can be released quickly, stiffness recovery S2 significantly greater than weakening thermal hysteresis concrete, so deflection recovers immediately stops. Overall, both S1 exhibit deformation characteristics. static load show load-carrying capacity 12.08% higher ultimate displacement 8.74% lower slab. It appropriate calculate capacities a one-way