Advantages and uses of fiberglass rebar

Fiberglass rebar is a new type of composite material, which is a product made of glass fiber as a reinforcing material and synthetic resin and auxiliary materials as a matrix material.

Compared with ordinary steel rebar, fiberglass rebar have many advantages:

1. Higher tensile strength than steel rebar;
2. The shear strength mainly depends on the resin properties, and its shear strength is often very low;
3. The tensile modulus of elasticity is much lower than that of steel bars, generally 40 to 55GPa, which is about 1/4 of that of steel bars, and the compressive modulus of elasticity is less than the tensile modulus of elasticity;
4. Fiberglass rebar is a composite material composed of glass fiber filaments and resin materials. It has good electrical and magnetic insulation and will not affect the magnetic field and electromagnetic waves. It is very suitable for the situation where reinforced concrete components cannot be used due to the consideration of electrical and magnetic effects;
5. Good resistance to chloride ions and other chemical corrosion;
6. Has excellent creep resistance;
7. Have good fatigue resistance;
8. Light weight, only 1/4 of the steel bar, which is convenient for transportation and installation;
9. Poor thermal stability.

Fiberglass rebar

Fiberglass rebar replace the steel bars in the shield enclosure structure, which can ensure the safety of the working well enclosure structure, and the shield does not need to manually break the door when it starts and arrives for construction, which reduces the safety risk of shield construction. In the past, the traditional method of using steel bars was to reinforce the soil behind the shaft wall with measures such as grouting or temporary retaining piles, and then manually chisel it under precipitation conditions. In fact, this construction method often results in structural damage. , uncontrolled groundwater and other serious problems. The use of glass fiber reinforcement in the shield tunnel allows the shield to directly cut the retaining wall for excavation when entering and exiting the tunnel. From the perspective of many construction site conditions, the cost of using glass fiber reinforcement is lower and the construction process is simpler. At the same time, it also reduces construction risks, improves construction efficiency, and reduces capital investment.

In the actual use of fiberglass rebar, attention should be paid to the vertical hoisting of the connection between the fiberglass reinforcement and the steel bar, because the fiberglass reinforcement cannot be welded. The connection between the reinforcement and the reinforcement is undertaken. In the construction design, the construction error when the reinforcement cage of the enclosure wall is lowered should be fully considered, so as to avoid the influence of the positioning error of the reinforcement cage on the cutting of the shield.