The Application of Steel Fiber Concrete Technology in Bridge and Road Construction

In recent years, China's economy has developed vigorously, urbanization has advanced rapidly, and people's requirements for building construction quality have reached new levels. With the advancement of public infrastructure construction and the progress of building technology, steel fiber concrete technology has emerged. Steel fiber concrete technology involves adding short steel fibers to concrete to enhance tensile strength and load-bearing capacity. Due to the random distribution of steel fiber concrete, which can significantly improve the toughness and strength of concrete, it is widely used in the construction of road bridges and other infrastructure, having significant importance.

Application of Steel Fiber Concrete Technology in Road Construction

Steel fiber concrete can reduce pavement thickness and the number of longitudinal joints, with advantages of good frost resistance and abrasion resistance, and extension of pavement service life. Thus, it is widely used in road construction. The main application forms include composite steel fiber concrete pavement, full-section steel fiber concrete pavement, roller-compacted steel fiber concrete pavement, and steel fiber concrete overlay.

Composite Steel Fiber Concrete

Composite steel fiber concrete pavement typically consists of two-layer or three-layer structures. The two-layer structure places 40%~60% full-thickness steel fiber concrete on ordinary concrete; the three-layer structure has a layer of ordinary concrete between the upper and lower layers of steel fiber concrete. This structure is durable but complex in construction, suitable for areas with high mechanization levels, and has higher construction costs.

Full-section Steel Fiber Concrete Pavement

The thickness of full-section steel fiber concrete can be 70-80% of ordinary concrete, with a steel fiber content of 0.5%~0.8%. This type of pavement usually does not have longitudinal joints, and the spacing between transverse joints is best controlled within 20cm.

Roller-compacted Steel Fiber Concrete Pavement

Roller-compacted steel fiber concrete pavement adopts the construction method of asphalt concrete, rolling the steel fibers into the concrete mixture. This method can improve the mechanical properties of roller-compacted concrete, enhance the toughness and strength of the pavement, but achieving compaction and smoothness still poses certain difficulties.

Steel Fiber Concrete Overlay

Steel fiber concrete overlay is used to repair damaged concrete pavement, having good tensile, flexural, and crack resistance, effectively improving pavement performance and extending its service life. Its main types include bonding type, direct type, and separation type. Bonding type combines the new and old concrete layers to enhance the overall structural strength; separation type acts independently with an isolation layer in between; direct type adds the steel fiber concrete directly to the old cement concrete surface, mostly used for repairing slightly damaged old cement concrete pavement.

Application of Steel Fiber Concrete Technology in Bridge Construction

Improving Bridge Deck Overlay

Steel fiber concrete can be used as a bridge deck overlay layer, enhancing the rigidity and bending strength of the bridge, improving the comfort and crack resistance of the bridge, and extending its service life. The deck overlay can be a two-layer or three-layer structure. The two-layer structure has a steel fiber concrete top layer and ordinary concrete bottom layer; the three-layer structure has steel fiber concrete top and bottom layers, with ordinary concrete in the middle. This structure is complex to construct, with two-layer overlay being more commonly used.

Reinforcing Parts of the Bridge Structure

Due to long-term load effects, bridges may develop cracks and surface spalling. Steel fiber materials can effectively control cracks, enhance earthquake resistance, and meet structural requirements. To improve surface area falling off issues, steel fiber concrete can be used to reinforce parts of the structure, such as sandblasting or chiseling on the concrete surface to enhance the integrity of new and old concrete.

Strengthening Steel Fiber Concrete

Using steel fiber concrete on pile tops or pile tips can significantly improve the penetration ability of piles, enhance impact resistance and toughness, prevent pile tip breakage, and increase soil penetration depth and striking speed. Due to the high cost of using steel fiber concrete overall, pre-stressed or non-pre-stressed reinforced concrete can be used for the pile body to save construction costs.

In summary, steel fiber concrete technology has significant advantages in the construction of bridges and roads, effectively improving project quality and extending service life, with important economic and social benefits.