Summary: The U.S. carpet industry consumes about 1.2 million tons of fibers annually and about 70% of the carpet produced is for replacement. The waste generated by the industry and from used carpet is estimated at about 2 million tons per year, most of which is disposed in landfills at present. A study was carried out to study the use of recycled fibers from the carpet industry waste for reinforcement of concrete at a 2% volume fraction. Compressive and flexural tests for strengths and toughness were conducted, and significant increase in shatter resistance, energy absorption, and ductility were observed. This paper reports on the experimental program and compares the effectiveness of such recycled fibers with that using virgin polypropylene fibers specially made for fiber reinforced concrete (FRC). The paper also discusses the benefits of using such FRC to replace conventional concrete in highway construction, including increased service life and reliability.