Tensile properties of grout-anchored rebar butt connection for precast concrete component
To enhance the process and performance of precast concrete component rebar connections,a grout-anchored rebar butt connection was proposed.Uniaxial tensile tests were conducted on the new type of rebar connection specimens,to assess the reliability of force transmission,considering variations in rebar diameter,concrete strength,and grouted length.The experimental results indicated that the tensile performance of the grout-anchored rebar butt connection was governed by both the grouted length of the rebar and the load-bearing capacity of the splice bars,with no significant correlation to the concrete strength.Under identical splice rebar configurations,specimens with 12 mm and 14 mm diameter rebars fractured with grouted lengths of 0.5la(basic anchorage length of the tensile steel bar)and 0.6la,respectively,while those with 16 mm diameter rebars fractured at grouted lengths of 0.6la.By data analysis suggested that the grouted length for connecting rebars with diameters ranging from 12 to 16 mm should be controlled to the value of 0.6la.Under the condition that the splice rebars and the connecting rebars are of the same grade,the splice rebars for 12~14 mm connecting rebars should be designed as 4(#)8,and those for 16 mm diameter connecting rebars as 6(#)8.Additionally,the rebar heading structure could ensure full anchorage of the rebars,and its specific dimensions could guide the rebar processing.The spiral reinforcement has no significant effect on the tensile performance of the rebar connection and can be designed with reference to the parameters of this test.