In the following thesis there will be an explanation, what integral bridges are, what advantages and disadvantages they have and which characteristics are crucial. Then the idea of building with precast elements will be specified. The production of precast elements and the construction of a deck will be defined. Following the existing bridge made of steel and reinforced concrete is described in detail. Afterwards an alternative draft will be developed and declared. The precast elements as a special feature of the construction will be explained. Then the construction phases for building the deck are clarified and the building materials used for the alternative draft are defined. The time-related parameters are calculated. The concrete cover is determined as a parameter for durability. Subsequently, the loads of the construction phases of the alternative design are calculated. The single loads of the final state are combined to load combinations for the evidence to be formed. Following the required pre-stressing force is calculated from the loads. On the one hand, a design is only slightly pre-stressed and reinforced. On the other hand, a design is developed, which is highly pre-stressed. The calculated force resultants and stresses of the individual phases and the load combinations are diagrammed and explained. Subsequently, with the force resultants and stresses the evidences in the border state of bearing capacity and serviceability are provided. Finally, the connection areas and nodes are constructively formed and shown in details.