and
the global search with glowworm swarm optimization (GSO). The solution is defined by 40 variables, including
the geometry, materials and reinforcement of the beam and the slab. Regarding thematerial, high strength concrete
is used as well as self-compacting concrete in beams. Results provide engineers with useful guidelines to
design PC precast bridges. The analysis also revealed that reducing costs by 1 Euro can save up to 1.75 kg in
CO2 emissions. Finally, the parametric study indicates that optimal solutions in terms of monetary costs have
quite a satisfactory environmental outcomeand differ only slightly fromthe best possible environmental solution
obtained.