AN OPTIMIZATION DESIGN PROCEDURE FOR PRESTRESSED REACTIVE POWDER CONCRETE BRIDGE

摘要

Reactive Powder Concrete (RPC) has been developed rapidly in material field. However, a great deal study work is to be desired on structure design. RPC200, which can be used under job site conditions similar to those for conventional high performance concretes, also can be used in the construction of prestressed structures, and its special strength character sets it free from the conventional reinforcement. The failure criterion is defined in this paper according to the strength performance. It is very different from the existing concrete failure criteria, which allow the concrete to crack and ignores the tensile area concrete effect. The tensile strength of RPC is very high and we regard the reactive powder concrete to be a failure if there is crack on the beam. The optimization design method on the PRC bridge is discussed based on the enumerative method, in which the objective function is the engineering cost, the design variables are the size of the cross-section and the quantity of the prestressed strand, the constraint conditions are strength and displacement. A T-beam optimization design is carried out according to the enumerative method. The optimized result proves that the design method is effective and the optimized price of 24m T-beam is 88.9% compared with the original design. Furthermore, the optimized beam height, the quantity of strand and the price curves are fitted on the optimized results and the simplified formulas of the T-beam are advised.