DEFLECTION RECOVERY OF FIRE DAMAGED PRECAST REINFORCED CONCRETE RIBBED ROOF SLAB

This paper discusses deflection recovery of a precast reinforced concrete (RC) ribbed roof slab after the application of a 24 hour loading test in the determination of integrity of the slab that was affected by fire in Dar es Salaam Tanzania. The loading was achieved by using sand filled sacks. The average load recovery was within the BS 8110 acceptable range of above the limit of 75%, with the exception of the middle strip zone which did not attain the limit. From the results, it was observed that the RC precast ribbed slab has to be divided into structural zones in relation to its structural configuration. Therefore, interventions need to be applied by considering each structural zone separately when assigning corrective measures, which will be specific on extent of strengthening for each structural zone instead of general corrective measures to the whole precast RC ribbed slab. Based on the mean deflection recovery test results, the slab was found to be still strong and acceptable for service. precast RC ribbed slab, deflection recovery