Vigas mistas de aço e concreto; Protensão externa; Algoritmo de
otimização; Emissão de CO2; Pré-tração.
Name: KAMILA MADEIRA FIOROTTI
Publication date: 30/08/2023
Examining board:
Name |
Role |
|---|---|
| ADENILCIA FERNANDA GROBERIO CALENZANI | Coorientador |
| ELCIO CASSIMIRO ALVES | Presidente |
| EVANDRO PARENTE JUNIOR | Examinador Externo |
| MARCOS ANTONIO CAMPOS RODRIGUES | Examinador Interno |
Summary: The use of external prestressing has been increasing in recent decades, mainly in the
reinforcement of beams in bridges and viaducts, due to its performance and less
interference in the local traffic. ABNT NBR 6118:2014 deals with the application of
prestressing in concrete structures, and ABNT NBR 8800:2008 presents the
requirements for the design of steel beams as well as composite steel and concrete
beams. However, the use of prestressing applied to these types of structures is not
addressed by Brazilian technical standards. The present study aims to contribute to
filling this gap by formulating the optimization problem of prestressed steel and
concrete composite beams with full interaction in pretension and straight cables, to
minimize CO2 emissions. The dimensions of the doubly symmetric and
monosymmetric profiles, the choice of the steel deck slab, the choice of strength, the
dimensions of the concrete slab and the number of prestressing cables were
considered as the design variables for the optimization problem. To solve the
optimization problem, metaheuristic algorithms, such as the Genetic Algorithm (GA)
and the Particle Swarm Algorithm (PSO), were applied to compare the optimized
solution. Experimental and numerical problems available in the literature were
analyzed in the proposal validation step. A parametric analysis was carried out to
identify which geometric patterns most influence the solution, as well as the final
emissions. From the analysis, it was concluded that the final emissions are strongly
influenced by the shape of the steel of slab and the metallic profileof beam, and that
the use of prestressing is more suitable for beams with larger spans. It was also verified
that the use of concrete with higher resistance in the slabs is more indicated for beams
with larger spans. The final results indicates that the proposed formulation can be used
to design more sustainable structures.
