Strength of Steel Fiber Concrete in Adverse Environments.

摘要

This report presents the results of an investigation of the strength of cracked steel-fiber-reinforced concrete subjected to a flowing salt water environment. The testing procedure was adapted from the plane strain fracture toughness method of testing metallic materials using a modified wedge opening loading (WOL) specimen. Concrete specimens were cast with 1.0, 1.5, and 2.0 percent concentrations of steel fibers by volume of concrete and cured for 28 days in a moisture room. After 28 days, a notch was sawed in each of the specimens with a masonry saw, and a small crack was propagated from the tip of the notch by mechanical means. Control specimens then underwent a compliance testing procedure to determine the work rate necessary to propagate a crack through the specimens. The remaining specimens were subjected to a flowing saltwater environment for four different exposure intervals. The strain energy release rate of the specimens exposed to saltwater was determined and compared with that of the control specimens. The rate of change of strain energy release rate decreased with increasing time and with increasing steel fiber content. (Author)