ACI 318-08 allows the required splice length in compression to exceed the required length in tension as the concrete strength becomes higher. This study investigates the effects of concrete strength, splice length, and transverse reinforcement in an experimental study. A total of 72 specimens were tested for developing the design equations for the compression lap splices with concrete compressive strengths of 80 and 100 MPa (11,600 and 14,500 psi). Two equations were developed to predict the splice strength using findings from regression analyses of 94 tests that failed in splitting, including data from the literature. Using a 5% fractile coefficient, two design equations for the splice length were derived. The proposed equations provide shorter lengths than the splice length in tension, as given by ACI 318-08. In addition, there is no significant difference between the lengths calculated by the two equations. The simple equation developed here was found to be practical within the tested ranges. The proposed equation also has a sufficient safety margin.
