The　half-grouted　sleeve　connection　(HGSC)　is　widely　used　to　connect　reinforcement　in　precast　concrete　(PC)　structures.　While　some　studies　have　examined　the　mechanical　behavior　of　the　HGSC,　there　is　still　a　lack　of　research　on　uncertain　factors　with　large-diameter　high-strength　reinforcement.　To　fill　this　gap,　an　extensive　experimental　study　was　conducted　to　investigate　the　mechanical　properties　of　the　HGSC　under　monotonic　tensile　loads.　The　impact　of　various　uncertain　factors,　including　the　embedded　length,　water-binder　ratio　(w/b)　of　the　grouting　material,　eccentricity　of　rebar,　thread　diameter,　and　thread　length,　was　investigated.　It　was　found　that　the　HGS　connected　with　large-diameter　high-strength　reinforcement　has　four　damage　modes,　i.e.,　thread　fracture,　thread　pullout,　reinforcement　fracture,　and　bond-slip　failure.　Notably,　to　obtain　the　target　of　equivalent　reinforcement,　the　dispersion　ratio　of　the　w/b　should　be　controlled　within　0.3,　the　embedded　length　should　be　greater　than　6d,　and　the　thread　diameter　and　the　thread　length　should　not　be　less　than　1d.　Based　on　the　HGSC　investigated　in　this　paper,　a　model　for　predicting　the　axial　force　and　circumferential　confining　strain　was　presented,　and　a　method　was　provided　to　calculate　the　elastic　and　plastic　lengths　for　the　embedded　reinforcement.　This　study　provides　valuable　guidance　for　the　application　of　large-diameter　high-strength　rebar　in　PC　structures.　©　2024　Elsevier　Ltd