Design specifications for headed bars were recently amended in ACI 318 and KCI 2012. These specifications have limitations on bar strength, bar diameters, concrete strength, and so on, due to lack of test data. Experiments of lap splices with high-strength…
Design specifications for headed bars were recently amended in ACI 318 and KCI 2012. These specifications have limitations on bar strength, bar diameters, concrete strength, and so on, due to lack of test data. Experiments of lap splices with high-strength headed bars were conducted to investigate the anchorage behavior of high-strength headed reinforcement. Headed bars of Grade 600 MPa were used and main variables include splice length, spacing between bars, bar diameter, concrete strength, and confinement. Observations of cracking behavior, strain measurements of reinforcement, and strength are reported. The strengths of lap splices with Grade 600 MPa are compared with design codes and previous models. The behavior of unconfined laps is compared to the behavior of confined laps. Test results show that the current codes do not provide a conservative design for high-strength headed bars and transverse reinforcement is more important than cover thickness to confine splice laps.