6 major methods of bridge crack reinforcement and repair

Editor: Qin and Han Engineering Ye Ziyan Compiled

With the development of our country's economy, the increase of traffic flow, the increase of traffic pressure, the bridge is often due to the actual traffic load is greater than the original design standard level, the traffic traffic volume far exceeds the design, resulting in the imbalance of supply and demand, resulting in serious congestion of the bridge, often causing damage to the bridge components, in order to ensure its safety, it is necessary to carry out frequent maintenance to meet its use function and extend its service life.

The working procedure for bridge structure reinforcement is:

Bridge verification - determination of reinforcement plan - construction drawing design - construction organization design - construction one by one project acceptance. The choice of bridge structure reinforcement scheme is very important, and the quality of the scheme will not only affect the investment of funds, but also affect the quality of bridge reinforcement. A reasonable reinforcement scheme should achieve good reinforcement effect, little impact on performance, reliable technology, simple and economical construction.

For bridges with cracks, in order to restore the durability and waterproof performance of the bridge structure, it is necessary to fill the concrete cracks, and the technical methods used are as follows:

(1) Surface repair method. When small bridge cracks appear, the surface of the crack can be treated by applying waterproof coating and filler to enhance the durability and waterproofness of the cracked bridge. If there is a large crack and the crack has a tendency to expand, it is necessary to choose a material with strong elasticity to repair it.

(2) Grouting method. The grouting method refers to filling the bridge cracks with cement or resin substances when cracks appear to enhance the durability and waterproof performance of the bridge. The primary materials that can usually be selected are:Epoxy。 During repair, the low-speed and low-pressure injection method should be chosen. If steel nails are used together with epoxy resin injection method, they can greatly enhance the integrity of the bridge crack orientation and are a good way to avoid the deterioration of cracks.

(3) Filling method. In the specific operation, a deep groove should be chiseled along the bridge crack, and then filled with various viscous materials in the deep groove. For example, asphalt, epoxy resin, expanded cement, cement mortar and a variety of chemical reinforcements.

(4) Spraying method. The grouting repair method refers to the repair method of applying high viscosity and dense cement mortar on the surface layer of the bridge crack after chiseling the cracks to maintain the cracks. It is necessary to be vigilant that before spraying, the peeling on the surface of the crack should be removed, and then washed and cleaned with clean water, and the base layer must be sprinkled with water and moistened before spraying, so that the slurry can easily adhere to the surface of the crack and play a very good protective role.

（5）Bonded steel plate method。 When the steel bar construction of the bridge shows stress cracks, when the bridge is reinforced and repaired, the cracks should be disposed of first, and then the bonding plate should be pasted at the crack, and the steel plate should be reinforced with expansion bolts. Structural reinforcement technology The reinforcement technology for bridge structure includes: external pasting, increasing the section, adding longitudinal beams, changing planning and external stress and other reinforcement methods.

(6) Repair of cracks in concrete cracked by alkali aggregate

causeAlkali aggregate reactionThe cracks generated are generally extendable, especially when the amount of steel bars is small, the constraints on expansion are smaller, so the crack width becomes significantly larger. For such cracks, epoxy resin can be injected or waterproof materials can be applied to prevent moisture from penetrating from the outside, thereby controlling the alkali aggregate reaction.

Crack repair is an important link in bridge maintenance and renovation, determine its construction technology before construction, and ensure its construction quality during construction. As a hidden project, defects and cracks need to be strictly verified in the process of on-site engineering quantity and construction quality, which plays an important role in the structural and durability of the bridge.

Keywords: building reinforcement engineering, structural reinforcement engineering, house safety appraisal, villa renovation, factory reinforcement, elevator installation, seismic isolation engineering, photovoltaic reinforcemen