Ultimate load behaviour of skew slab bridge deck

Abstract

In the study of Ultimate Load Behaviour of Skew Slab Bridge Deck. reinforced concrete double lane skew slab bridge deck model were selected. The study was conducted with 1/ 4th scale models. There were two types of model, one with main reinforcement parallel to the free edge and named model type-I. The other was with main reinforcement perpendicular to the support and named model type-2. Transverse reinforcement for both the type were in the direction parallel to the abutments. Skew angle for both the type of lIlodel were 30 degrees. A total of four models were tested comprising two models of each type. The models were designed by WSD method for AASHTO HS20 highway loading and specification. The overall depth of the slab and quantity of steel were calculated on the basis of the effective right . span of the slab. The slabs designed in this way were subjected to scaled 1.IS20 loading for experimental investigation. The load cycled five times first on one side lane and cycled five times in the other side and then increased to failure in one lane. Deflections and concrete surface strains were recorded at different stages of loading. In the study a greater deflection is recorded at service and at ultimate load level for model type-I than that of model type-2. The ultimate carrying capacity of model type-2 is found to be more than tll:1t of model type-I. For model type-2. carrying capacity is about 8.25 times of service load whereas it is about 7.25 times for model type-I for the load arrangement in one lane (model designed for 2 lane loading) used till ultimate failure of the model. Stiffness of the slab is calculated from the deflection consideration and it is found that stiffness of model type-2 is about 35.23% more than that of model type- I at service load and 25.70% more at double of the service load