Frp rebar are materials formed by high-performance fibers, synthetic resin matrix, and curing agent using an appropriate molding process; high-performance fibers are reinforcing materials, and synthetic resin is the matrix material. Fiber has high tensile strength and is the main provider of fiber-reinforced composite material strength.   The matrix material has the function of bonding and transmitting shear force, and its physical properties can affect the physical properties of fiber reinforced materials.

    FRP has high load-bearing capacity and strong tensile strength. The strength of the rod body is twice that of the same diameter threaded steel bar, but the mass is only 1/4 of the steel bar; the elastic modulus is stable, about 1/3 to 2/5 of the steel bar; , Electrical insulation, thermal expansion coefficient closer to cement than steel bars, etc. It is mostly used in shield tunneling through underground diaphragm walls, column piles, and anti-pull piles, including the entrance and exit walls of subway station end wells. Many of them must be used fiberglass ribs.

The performance of frp rebar is basically similar to that of steel rebar. It has good adhesion to concrete, and at the same time has high tensile strength and low shear strength. It can be easily directly cut by a composite shield machine. Without causing abnormal tool damage. However, the biggest difference between frp and steel reinforcement is that the elastic modulus of glass fiber reinforcement is small, which is a typical brittle material. The stress-strain curve shows an obvious linear relationship before breaking, which greatly affects the lifting of the glass fiber reinforcement cage. The stability of the foundation pit and the bending and shear bearing capacity of the glass fiber reinforced continuous wall during the excavation stage of the foundation pit.

    The glass fiber reinforcement is non-corrosive, light in weight, strong in tensile strength, convenient to transport, and easy to operate. The disadvantage is that the bending is not strong; the steel is easy to corrode, heavy in weight, and inconvenient to transport. The advantage is that the bending is better and the flexibility is greater.