GOVPUB C13 8620f9e60cbfd1c3ac9e0bf55ba3770c

This report provides five types of mechanical properties for steels from the World Trade Center (WTC): elastic, room-temperature tensile, room-temperature high strain rate, impact, and elevated-temperature tensile. Specimens of 29 different steels representing a combination of mechanical damage, natural variability, and differences in testing methodology were tested. High-strain-rate properties for selected perimeter and core column steels include yield and tensile strength, total elongation, and strain rate sensitivity for rates up to 400 s−1. Measured properties were consistent with literature reports on other structural steels. Impact properties were evaluated with Charpy testing, and the impact toughness at room temperature of nearly all WTC steels tested exceeded 15 ft·lbf at room temperature. Elevated-temperature stress-strain curves were collected for selected perimeter, core column, and truss steels. The report also presents a methodology for estimating high-temperature stress-strain curves for the steels not characterized based on room-temperature behavior and the behavior of other structural steels from the literature. The measured elevated-temperature stress-strain behavior of WTC steels is consistent with other structural steels from that era. For the truss steels, it presents a complete constitutive law for creep deformation based on experimental measurements, along with a methodology for estimating the creep deformation law for the steels not characterized.