T-beam bridge

Project Overview

The highway bridge located at the Hanzhuang sluice in Weishan County, Shandong Province is the main road of the 104 National Highway. The design standards are Automobile 20 and Hanging 100.

When it was built in early 1958, the gate hole was 17 holes, and the corresponding highway bridge was also 17 spans. The road bridge is 5.3m wide and consists of 5 T-beams simply supported by reinforced concrete. Later, due to the requirements of flood control and flood discharge and the increase in the traffic volume of the 104 National Highway, the expansion was carried out in 1977. The south and north of the gate are increased by 7 holes (ie, 14 holes are newly added). After the expansion, the total length of the gate (bridge) is 435.6m, and the bridge width is increased from 5.3m to 9.0m. The bridge deck structure is a combined section consisting of 5 reinforced concrete T beams and 5 reinforced concrete hollow slabs.

The Hanzhuang Zha Highway Bridge has been built since its establishment. The old bridge has been in operation for more than 40 years, and the widened highway bridge has also been in operation for more than 20 years. In the past 10 years, along with the traffic volume on the 104 National Highway, the vehicle load has been increasing, and the vehicle type has become heavier, and the load on the road and bridge has been increasing. In particular, the overload of the T-beam section of the original highway and bridge was particularly serious, and cracks were common throughout. After inspection, evaluation and analysis, it is concluded that the strength of the T-beam is insufficient and the aging of the concrete of the beam is serious. Therefore, the T-beam of the gate highway bridge must be structurally strengthened.

Structural reinforced materials

The materials used to reinforce and repair the bridge concrete components are 12K unidirectional carbon fiber wrap and adhesive produced by Horse. 

Structural adhesives are mainly epoxy resin, and are equipped with different licking additives to make it have different bonding properties. Among them, the adhesive strength of structural adhesive and concrete are all above 4MPa. The damaged surface of the steel plate and concrete bonding room test occurred on the side of the concrete. The high shear strength of the structural glue can prevent the carbon fiber from shearing and breaking along the repair surface.

Reinforcement requirements and layout

After many years of operation, the Hanzhuangzha highway and bridge are seriously aging and diseased, and its carrying capacity is severely insufficient. Therefore, the requirements of carbon fiber reinforcement make the bearing capacity of highway bridges reach the design requirements of Q-20 and HQ-100. Since most of the T1 beams are under the sidewalk slabs, they do not directly bear the load of the car, so the bottom and side surfaces of the T2 ～ T5 beams are bonded with carbon fiber wrap for reinforcement.

Structural reinforcement effect

After reinforcement, the deflection of the T beam is significantly reduced, and the maximum deflection is reduced by nearly 30% compared with that before the reinforcement. It shows that the stiffness of the reinforced reinforced concrete T beam is greatly improved, and the reinforcement effect is obvious.