1. Scope

Keywords

Rationale

Results from splice tests of reinforcing bars serve as the basis for the development length and bar splice length requirements incorporated in the ACI 318-Building Code and the AASHTO LRFD Bridge Specifications for reinforced concrete, including the effects of epoxy coatings on the bond strength of reinforcing bars to concrete. Splice tests are used because they have been shown to provide strengths equal to those obtained in development tests in realistic full-scale structural members. Good practice is generally understood within the research community (ACI Committee 408 2003), but the test method has not been standardized. The accuracy of the beam-end test in ASTM A944 is discussed by ACI Committee (20023), but the application of the results of the A944 test to structures is not widely understood. For example, the current ASTM requirement (A775, A934, and A1055) is that epoxy-coated reinforcement must provide a relative strength of 85% with respect to uncoated reinforcement. The value of 85% was established based on multiple tests with bars of difference sizes, deformation patterns, and epoxy suppliers that showed that for splices producing relative strengths of 65 to 70%, the range of values used to establish the ACI Code and AASHTO requirements for increases of development length, had to provide a relative strength in beam-end test of at least 85%. It makes sense that such a widely-used test be standardized. A standardized test method that can directly measure development and splices strength as a function of factors, such as member geometry, bar size, and bar coating, will be valuable to both the industry and to the quality and consistency of results from research studies of reinforced concrete structures.