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Field studies show that glass fiber-reinforced polymer offers a low life-cycle cost option for reinforcement in concrete pavements.
Glass fiber-reinforced polymer rebar is one of the new products on the market that could offer a number of benefits to the transportation industry. Because it is lightweight and free of corrosion, construction costs should be lower and pavements should last longer. However, laboratory studies offer limited help in determining the real-world performance of glass fiber-reinforced polymer (GFRP) reinforcing bars in continuously reinforced concrete pavements (CRCPs). The reasons: the difficulties in modeling field boundary conditions, such as friction from the subbase and restraints from the shoulders or adjoining pavements; environmental changes; traffic loads; and possible variations in construction work. To overcome these limitations and gain a better understanding of GFRP-CRCP behavior, researchers turned to field investigations.
With support and cooperation from the Federal Highway Administration CFHWA), the West Virginia Department of Transportation (WVDOT), and contractors, West Virginia University (WVU) researchers recently completed the Nation's first GFRP-CRCP test section, along with a steel-CRCP test segment, to study the performance of the two rebar materials. The GFRP and steel test segments are located on Route 9 in Martinsburg, in the northeastern corner of West Virginia.
"The use of GFRP reinforcing bars in lieu of conventional steel reinforcement in CRCP, as demonstrated last fall [2007] in West Virginia, offers some interesting performance considerations," says Sam Tyson, concrete pavement engineer, FHWA. "First, the corrosion resistance of GFRP bars makes them attractive for obvious reasons, particularly in a State where winter conditions require frequent applications of deicer chemicals. In addition, the high tensile strength and low unit weight of GFRP, its matching thermal and matching stiffness characteristics, provide for a unique approach to the design and construction of CRCP. Finally, because GFRP is not magnetic, its use in concrete pavements where various traffic- and toll-monitoring devices are to be installed could be advantageous."
These qualities are clear advantages of GFRP, but the WVU study has not reached a conclusion regarding performance, including corrosion resistance, because not enough time has passed to obtain sufficient results. However, the study did show that GFRP-reinforced CRCPs can be constructed at low cost and without added construction time.
Overview of the Study
WVDOT allocated a 610-meter...