Composite drainage net is a new type of drainage geotechnical material. Made from high-density polyethylene (HDPE) as raw material, it is processed through a special extrusion molding technique and features a three-layer structure. The central ribs are rigid and arranged longitudinally to form drainage channels, while the upper and lower cross-arranged ribs provide support to prevent geotextile from embedding into the drainage channels, maintaining high drainage performance even under heavy loads. When combined with permeable geotextile on both sides, it offers comprehensive functions of "filtration—drainage—breathability—protection," making it an ideal drainage material currently available.

Product Applications:

Mainly used in drainage projects for railways, highways, tunnels, municipal engineering, reservoirs, slope protection, etc.

Product Features:

1. Strong drainage capacity (equivalent to one-meter-thick gravel drainage).

2. High tensile strength.

3. Reduces the likelihood of geotextile embedding into the net core, ensuring long-term stable drainage.

4. Capable of withstanding high-pressure loads over the long term (can bear compressive loads of approximately 3000 kPa).

5. Corrosion-resistant, acid and alkali resistant, with a long service life.

6. Easy installation, shortening construction periods.

Functions:

1. Laid between the foundation and subbase to drain accumulated water between them, block capillary water, and integrate into the edge drainage system. This structure automatically shortens the drainage path of the foundation, significantly reducing drainage time, and allows for reduced use of foundation materials, extending the road's service life.

2. Installing a drainage net in the subbase prevents fine subbase materials from entering the foundation layer. The aggregate base will partially enter the top of the geonet to a limited extent. In this way, the composite geotechnical drainage net also potentially restricts lateral movement of the aggregate base, functioning similarly to the reinforcement provided by geogrids.

3. After road aging and crack formation, most rainwater enters the cross-section. In such cases, the drainage net is laid directly under the pavement to replace the drainable foundation. The drainage net can collect moisture before it enters the foundation/subbase. Additionally, a membrane can be wrapped around the bottom of the drainage net to further prevent moisture from entering the foundation. For rigid road systems, this structure allows for designing roads with higher drainage coefficients. Another advantage of this structure is the potential for more uniform hydration of concrete (research on the extent of this advantage is ongoing). Whether for rigid or flexible road systems, this structure can extend the road's service life.

4. In northern climates, laying a drainage net helps reduce the impact of frost heave. If the frost depth is significant, the geonet can be installed at a shallower depth within the subbase to act as a capillary barrier. Additionally, it is often necessary to replace the subbase with non-frost-susceptible granular material extending down to the frost depth. Frost-susceptible backfill can be placed directly on top of the drainage net up to the foundation grade. In this scenario, the system can be connected to a drainage outlet to keep the groundwater level at or below this depth. This can potentially limit the development of ice lenses, eliminating the need for traffic load restrictions during spring thaw in cold regions.