Cuttable Concrete Reinforcement High Strength Fiberglass Reinforced Polymer FRP Composites Rebar For

Glass Fiber Reinforced Polymer (GFRP) bars have high strength primarily along the length of the bar but can be easily abraded or "consumed" by tunnel boring machines (TBM) or tunneling equipment. This unique "anisotropic" property of these high strength reinforcing bars offers many benefits simplifying TBM launch and reception chambers as well as pre-consolidation in New Austrian Tunneling Method/Sequential Excavation Method (NATM/SEM) tunneling. In places where the TBM needs to pass through a diaphragm wall, GFRP bars are incorporated in the "soft-eye" opening.This significantly speeds up the construction process and eliminates the need to stop the TBM, lower workers in the area between the TBM and the concrete face, remove the concrete and steel so the TBM can pass.  
 The result is typically a "hybrid" Steel/FRP cage with GFRP bars used with appropriate tolerance around the TBM diameter. Tolerance adjusted to variation in TBM breakout and variation in placement of cage.Since they are strong primarily along the main axis of the bar, FRP rebar can be "consumed" by the TBM which greatly increased the speed and safety to begin and end the tunnel run.  
 Benefits of Pulwell GFRP Rebar in Soft-eye Openings:
 Used in place of steel rebar, Pulwell GFRP Rebar cuts easily, permitting the boring machine to penetrate a station wall, cut a tunnel and bore through the wall in the next station down the line in a continuous process, eliminating much of the delay. In addition, this continuous process yields a cost savings even though the cost of the GFRP Rebar is higher than conventional steel rebar. Main benefits as the following:
 ★ No Grout Block
 ----Time and Construction Cost Saving
 ★ TBM passes directly through the diaphragm wall
 ----Speeds up construction