Rationale

Reinforcing steel undergoes rigorous third party testing whether a project is publicly or privately funded. Many third party labs continue to use older tensile testing equipment that lacks extensometry. When "roundhouse" stress/strain curves are generated, these go undetected, resulting in artificially high yield strength results and artificially low T/Y ratio results. For Grade 60 reinforcement, this is generally not a problem, but with the increasing use of grade 80 and higher reinforcement, the offset method is increasingly necessary due to the shape of the S/S curves. In order to propose a solution that does not conflict with other ASTM specifications or require every tensile lab in the country to upgrade their equipment, the following clause will be balloted for inclusion into Annex A3 governing product verification testing: "In the event of a dispute where differing yield strength determination methods are used, the 0.2% offset method shall prevail. In the event that only one test facility is able to provide a stress / strain curve generated with an extensometer, this test result shall prevail. In the event that both results were obtained by the same method, a third result from an independent agency shall be obtained. In the event that a resample is impossible, the matter shall go to the Engineer of Record for final consideration." A descriptive note will also be included