LOAD CAPACITY OF TUNNEL LINING CONCRETE STRENGTHENED WITH CARBON-FIBER COMPOSITE CABLE (CFCC)

Abstract

Efficient strengthening systems for tunnel lining concrete (TLC) have not been sufficiently discussed while various systems are available for other structures. The study aims at development of a strengthening system applicable for TLC. In particular, the present study focused on an NSM-FRP strengthening system which is often employed in deck-slabs and girders of bridge. Most of FRP materials used in such supra-structures are laminates and rods. It may be hard to embed FRP materials into inner surface of arched tunnels. Flexible FRP must be a favorable material for strengthening of TLC. The study focused on a carbon-fiber composite cable (CFCC) which is often used in prestressed concrete structures. The CFCC is embedded in inner surface of TLC by using a polymer cementitious mortar and epoxy resin. Fundamental loading test using mock-up TLC models was conducted to examine the strengthening effect of the proposed system. The paper reports the load-carrying capacity of the strengthened TLC models.