Evaluation of an Alternative Offset Mechanical Splice System

The objective of this project is to identify and develop a generic testing protocol and test method for the evaluation of offset reinforcing bar splice systems. This protocol/test is intended to ensure the conformance of such offset splice systems with Pennsylvania Department of Transportation (PennDOT) Publication 408, Section 1002.2(c). The resulting generic specification will describe a test method suitable for the future qualification and verification of offset mechanical splice systems. Two commercially available offset mechanical splice systems, the BarSplice Double Barrel Zap Screwlok© and the Lenton QuickWedge©, were evaluated in four series of tests. The performance of each specimen was evaluated in accordance with Publication 408, Section 1002.2(c). The tests conducted on each splice systems were: (1) Direct Tension (DT) tested the reinforcement bar splice in open-air direct tension and allowed the splice to freely rotate. (2) Restrained Tension (RT) tested the reinforcement bar splice in a manner that inhibited the splice from rotation. The test setup resulted in the splices being tested in a manner similar to a "pull-out" method. (3) Fatigue Tension (FT) was modeled after the CT670 testing method which required cycling the specimen through a 50 ksi (345 MPa) stress range. This range was unattainable for offset splices if 10,000 cycles were required. The stress range was reduced to 20 ksi (138 MPa) and the load was cycled from 10 ksi (69 MPa) compression to 10 ksi (69 MPa) tension for 10,000 cycles. (4) Flexural Beam tests were conducted with a single #4 reinforcement bar splice embedded in concrete. One beam of each splice type was tested monotonically to failure. A second beam was subjected to 10,000 cycles of repeated loading intended to result in an applied stress range in the #4 flexural reinforcement bar of 20 ksi (138 MPa), similar to the FT tests.