To　investigate　the　influence　of　ultra-high　strength　steel　bars　(UHSB)　on　the　seismic　performance　and　repairability　of　recycled　aggregate　concrete　(RAC)　frame　structures,　low　cyclic　loading　tests　were　conducted　on　two　frame　structures.　HRB600-grade　steel　bars　were　used　as　the　longitudinal　reinforcement　in　columns　of　HRB600-reinforced　frame　structure　(HFS),　while　UHSB　were　employed　as　the　longitudinal　reinforcement　in　columns　of　UHSB-reinforced　frame　structure　(UFS).　The　experimental　results　indicated　that　the　damage　evolution　of　specimens　was　similar.　However,　there　was　no　plastic　hinge　forming　at　the　column　ends　in　the　UFS.　The　plastic　hinge　at　the　column　ends　in　the　HFS　led　to　a　greater　energy　dissipation　capacity　compared　to　the　UFS,　particularly　beyond　2.0%　drift.　At　a　horizontal　drift　of　1.0%,　the　HFS　and　UFS　can　be　reused　without　any　repair.　However,　at　a　horizontal　drift　of　2.5%,　the　HFS　can　be　reused　after　repair.　The　residual　drift　of　UFS　was　within　0.5%,　indicating　that　UFS　can　be　reused　after　simple　repair.　When　the　horizontal　drift　reached　3.5%,　the　HFS　was　difficult　to　repair,　whereas　the　residual　drift　of　the　UFS　was　still　less　than　1.0%　and　able　to　repair.　Additionally,　finite　element　models,　considering　the　bond-slip　behavior　between　weakly　bonded　UHSB　and　RAC,　were　established　by　setting　nonlinear　springs.　The　influences　of　varying　UHSB　ratios　and　axial　compression　ratios　of　columns　were　analyzed.　It　is　recommended　to　control　both　the　UHSB　ratio　and　the　axial　compression　ratio　in　resilient　RAC　frame　structures　to　mitigate　the　risk　of　progressive　collapse.　©　The　Author(s),　under　exclusive　licence　to　Springer　Nature　B.V.　2025.