Common Types of Road Cracks

Cracks in road construction are one of the most common and noticeable road construction defects. Common crack types, depending on their cause and form, include:

Longitudinal cracks

• Longitudinal cracks are distributed along the road centerline and are often caused by uneven roadbed settlement, thermal shrinkage, or poor construction joints.

Transverse cracks

• Vertical or nearly perpendicular to the road centerline and are primarily caused by thermal stress changes or subgrade shrinkage.

Network cracks (tortoise shell cracks)

• Cracks interlock and connect to form a tortoise shell pattern, often seen during the fatigue failure stage of a pavement.

Block cracks

• Cracks that divide the pavement into large areas are typically caused by thermal shrinkage or aging.

Reflective cracks

• Pre-existing cracks in the subgrade or existing pavement gradually extend upward under load and temperature, eventually reflecting onto the new paving layer.

Fiberglass Geogrid

This new geosynthetic material is made primarily of high-strength fiberglass yarn, knitted or warp-knitted into a grid-like structure, and coated with asphalt. Fiberglass geogrid offers unique advantages, including high strength, low elongation, high-temperature resistance, aging resistance, and good compatibility with asphalt.

Glass Fiber

• Raw Materials: Alkali-free or medium-alkali glass fiber

• Features: High strength, high modulus, corrosion resistance, and no elongation

Woven or warp-knitted structure

Glass fiber filaments are arranged in a grid pattern in the warp and weft directions to ensure balanced load distribution in both the horizontal and vertical directions.

• Coating (usually asphalt or a modified polymer)

• Enhanced compatibility with asphalt mixtures

• Improved high temperature resistance and durability

• Provides protection to prevent damage to the glass fiber during construction

Performance Indicators

• Basic performance parameters of fiberglass geogrids typically include:

• Tensile strength: ≥50–200 kN/m (uniform in both longitudinal and transverse directions) 

• Elongation: ≤3% (much lower than materials like polyester)

• High temperature resistance: Long-term resistance above 200°C 

• Compatibility: Excellent bonding with asphalt 

• Durability: Acid and alkali resistant, aging-resistant, and long service life

The Role of Glass Fiber Geogrids in Treating Reflective Cracks in Pavements

Stress Diffusion and Dispersion

• When vehicle loads or temperature stresses act on a pavement, significant stress concentrations occur at the crack tip, directly causing the crack to propagate upward. 

• The high modulus and strength of glass fiber geogrids enable them to quickly distribute and diffuse stress within the stress-bearing area, transforming concentrated stress into a larger, lower-intensity stress zone, thereby mitigating the stress peak at the crack tip.

Crack Blocking and Propagation Delay

• Glass fiber geogrids have a low elongation (≤3%). When cracks in the base layer propagate upward, they act as a barrier, physically preventing further crack growth.

• Even if cracks reach the grid, they are slowed or blunted by the grid, preventing them from penetrating directly into the pavement surface. Laying glass fiber geogrids can delay the onset of reflective cracks by 2–4 times.

Constraint and Interlocking Effect

Fiberglass geogrids have a regular mesh structure that tightly interlocks with the asphalt mixture after installation.

• Constraint: Limits lateral displacement of the asphalt mixture, reducing shear deformation caused by repeated wheel action.

• Interlocking: Creates a cohesive "skeleton-matrix" structure within the asphalt mixture, improving the overall strength and stability of the pavement.

Typical Applications of Glass Geogrids

• Highway Resurfacing and Maintenance Projects

• Airport Runways and Helipads

• Urban Roads and Municipal Engineering Projects

• Heavy-Duty Roads and Industrial Sites

• Roads in Cold and High-Temperature Regions

• Bridge Pavements and Tunnel Pavements

Glass fiber geogrids, with their high strength, low elongation, high-temperature resistance, and good compatibility with asphalt, offer a comprehensive solution for pavement structures.

Effectively slow the development of reflective cracks – Glass fiber geogrids significantly slow the upward propagation of base cracks through stress diffusion, crack isolation, and interlocking constraints.

Improve overall pavement performance – The reinforcement provided by the geogrid not only enhances the pavement's tensile and shear strength, but also improves its fatigue resistance and thermal shrinkage resistance.

Widely applicable – Whether resurfacing existing roads, constructing new highways and airport runways, or paving urban roads and bridges, as well as projects in unique climates, these geogrids can benefit.

Significant economic and social benefits – The use of glass fiber geogrids can extend the service life of roads by 2–3 times, reduce maintenance frequency, and lower lifecycle costs, while ensuring traffic safety and operational efficiency.

Glass fiber geogrids are a key material for managing reflective cracks in roads, making infrastructure safer, more durable, and more sustainable.