Influence of traffic loads on permanent deflections of prestressed concrete bridges
Z. Smerda Technical University Brno, VIAPONT Ltd, Brno, Czech Republic
J. Smerda VIAPONT Ltd, Brno, Czech Republic
The rising volume of traffic on concrete road bridges has caused designers to consider the problem of permanent deflections caused by repeated traffic loading. However, it should be stated that the correct method for calculating such deflections is currently unclear and consequently gives rise to unrealistic estimations. Moreover, a lack of knowledge regarding the full spectrum of traffic loads and the effects of repeated loads upon concrete deformation exacerbate the problem. This paper attempts to determine the permanent deflection of prestressed concrete bridges without cracks.
Minimum cost design of concrete sandwich panels made of HPC faces and PAC core: the case of in-plane loading
Catherine G. Papanicolaou, University of Patras, Greece
Thanasis C. Triantafillou, University of Patras, Greece
This paper presents a minimum cost design procedure for precast structural sandwich panels made of HPC (high-performance concrete - i.e. high-strength and fibre-reinforced) faces and a pumice aggregate concrete (PAC) core, which might also include a layer of thermal insulating material. Attention has been focused on the selection of materials' strength and members' geometrical parameters, as well as on the material cost functions for both concrete types. The strength-based design case study resides with the format of Eurocode 2 and takes into consideration failure modes associated with in-plane loading, such as flexure, shear and local buckling of the compressed faces, with respect to the presence of the insulating layer. The solution of the optimisation problem is attained through the development of a computer program using available algorithm codes provided by Matlab®. The optimisation procedure results in the derivation of design recommendations, which encompass the objective of minimum cost for the elements under investigation.