Seismic Performance of Assembled Precast High-Strength Concrete Beams

The seismic performance of assembled precast high-strength concrete beams in high-rise buildings is discussed. The proposed various connections, located at beam's mid-span zone, are suitable for precast frames and intended to reduce the amount of cast-in-place concrete as well as construction time. Four half-scale precast beam-specimens are presented. Two beams use transversal bolts. One beam uses sleeved parallel bars and another beam uses sleeved crossed bars. The gap between the assembled precast parts and other voids are grouted with very high-strength cement mortar. Seismic tests, carried out on these assemblies, confirmed their adequacy. They proved to be ductile and failure occurred outside the connection zone similarly to monolithic ordinary beams. Assumed mechanisms were also pictured for the evaluation of the strength of the different connections.