ASTM C1818, Standard Specification for Synthetic Fiber Reinforced Concrete Culvert, Storm Drain, and Sewer Pipe, has recently been approved as a performance-based ASTM specification based on multiple tests conducted by the authors on synthetic fiber reinforced concrete pipes (SYN-FRCP). The initial testing included the production and three-edge bearing testing of SYN-FRCP pipes, ranging in diameter from 18 to 36 in. (450 to 900 mm) with varying fiber dosages. More than 250 tests were conducted, and fiber dosages for different diameters and wall thicknesses were identified for achieving certain pipe class strengths. Material testing, including cylinders (ASTM C39, Standard Test Method for Compressive Strength of Cylindrical Concrete Specimens) and beams (ASTM C1609, Standard Test Method for Flexural Performance of Fiber-Reinforced Concrete [Using Beam With Third-Point Loading]), was also performed at different fiber dosages. Due to the time-dependent behavior of synthetic fibers, long-term field and laboratory tests were conducted for 10,000 hours’ duration to determine the long-term serviceability factor for the synthetic fiber concrete pipes. This long-term property was introduced as a part of ASTM C1818 and is required to be determined by fiber producers through long-term laboratory tests using their respective fibers in concrete pipes. This paper will present the concept behind the ultimate load, which is the load at the vicinity of the first crack. This paper will also introduce reasons behind the tests and design concepts described in the specification.