スプライススリーブ工法による異形鉄筋継手について

抄録

The rebar splicing method discussed in this report consists of a double-tapered frustum-shaped cylinder with an annular-grooved inner wall, which is filled with high-strength non shrink grout, LL-602, to effect splicing between separate bars butted in the sleeve. It can be applied with best advantage to connections between precast structural members in the vertical direction. This report covers a part of our development research on the Splice Sleeve method, including the tests on isolated rebar splices and structural columns containing splice sleeve connections in them.
It was found from the testing of sleeve length vs. splice strength and compressive strength of grout vs. splice strength, that the sleeve length (L) must be 10 fold of nominal diameter (D) in order to obtain the 125% of the nominal yielding load of the bar used. It was also found that, to obtain the splice strength higher than JIS specified tensile strength, L must be about 14D and the minimum compressive strength of grout must be higher than 650kg/cm². No adverse effects were recognized on the sleeve properties according to the fire-resistance tests. No difference in the splice strength was observed between the pre- and post-grouting. Misalignment between upper and lower rebar did not affect on the splice strength.
Structural member tests were performed to evaluate the effectiveness of the splice sleeve connection in reinforced concrete columns in comparison with the column monolithically casted without splicing of reinforcing bars. The tests were conducted on Y-Type and U-Type column specimens, each provided with different combinations of the factors such as axial forces, types of transverse reinforcement around splice sleeves, shear keys at connections, grouting methods, etc.
The results of these tests showed equal or superior performance of the splice sleeve connections as compared with the columns without connections.