•Uniaxial tension tests were conducted on a group of grouted-sleeve splices.•The influence of splice geometrical parameters was investigated quantitatively by FEA.•The failure modes of the grouted-sleeve splices were studied. Sleeve grouting technology is widely employed in prefabricated building structures. However, the influence of multiple factors on the mechanical properties of grouted-sleeve splices have not been sufficiently investigated. This study attempts to investigate the failure process of the grouted-sleeve splice while loaded in uniaxial tension. A series of tensile loading tests were conducted on a group of grouted-sleeve splices. The failure mode of rebar fracture was observed in the test, and the result reveals that the grouted-sleeve was in elastic stage during the test. Three-dimension finite element analyses are carried out on the tensile loading test, considering grout plasticity and damage as well as the influence of rebar thread on interaction property of material interface. The influence of the clearance between sleeve and rebar, as well as the anchorage-diameter ratio, is investigated by finite element parametric study. The numerical results reveal that an anchorage-to-diameter ratio greater than 7 is sufficient for preventing the slippage failure at the interface between the grout and rebar. In addition, an exponential relationship exists between the anchorage length and the ultimate bearing capacity. The damage zone always initiates from the sleeve port in spite of different failure modes.