This report presents the results of an investigation into four aspects of the corrosion behavior of steel fibrous concrete: (1) The behavior of cracked and uncracked metallic and nonmetallic fibrous concrete subjected to a natural wet-dry, freeze-thaw saltwater environment; (2) The effect of crack width on the corrosion of fibers bridging the crack; (3) The effect of various durations of exposure to a corrosive environment on constant-crack-width and uncracked steel fibrous concrete specimens; and (4) The effect of fatigue. Results indicate that good quality, air-entrained, uncracked steel fibrous concrete does not experience any undesirable strength changes when subjected to a seawater environment for up to 1.5 years. Results also indicate that unworking cracks less than 0.01 in. (0.25 mm) wide do not provide sufficient passageway for corrosive liquids to cause corrosion of the fibers bridging the crack, while fibers bridging larger cracks can be expected to corrode. The fatigue behavior of uncracked, good quality, air-entrained steel fibrous concrete at 65 percent of the first cracked stress level was found to be unaffected by exposure to a saltwater environment.