1. High drainage efficiency: The three-dimensional space provides a large water-passing cross-section.
2. High compressive strength: Withstand heavy loads.
3. Lightweight: Easy and quick to transport, carry and install.
4. Save space and cost: The thickness is much thinner compared to traditional gravel drainage layer, which can save excavation and material costs.
5. Convenient construction: It is in the form of a roll material and can be laid quickly.
Introduction
Geocomposite Dimple Drainage Sheet is a drainage material made of a high-strength plastic convex core layer and a permeable geotextile filter layer. It provides strong pressure resistance and efficient drainage through its structure, and realizes the filtering protection function through the geotextile. It can drain water, protect the waterproof layer, and reduce hydrostatic pressure effectively. It is widely used in various civil engineering and construction projects that require drainage and waterproofing.
Features
1. Core structure - Dimpled Core:
Usually made of high-density polyethylene (HDPE) or polypropylene (PP).
The surface is covered with regularly arranged conical or dome-shaped convex dots (Domes/Dimples).
These convex dots support each other to form a solid three-dimensional space structure.
Core function: The gaps between the convex dots form a continuous, high-water conductivity drainage channel, allowing water (liquid water or water vapor) to flow horizontally quickly and smoothly between them. At the same time, the convex dot structure gives the board extremely high compressive strength, which can withstand the pressure of the upper covering soil, concrete or traffic load without being flattened, ensuring that the drainage space is effective for a long time.
2. Filter layer:
Usually bonded or hot-melted to the top of the core layer convex dots (sometimes also on the bottom surface).
Made of non-woven geotextile with good water permeability.
Core function:
Filtration: Prevent soil and silt particles above or around from invading and blocking the drainage channel of the core layer, keeping the drainage unobstructed.
Isolation: Isolate the drainage layer from the soil to prevent them from mixing with each other.
3. Optional - Bonding Surface for Waterproofing:
The bottom surface (flat surface) of the core layer is usually designed to be smooth or with a special texture.
Core Function: Facilitates a strong hot melt bonding or bonding with the waterproof membrane below (such as asphalt-based, PVC, TPO, etc.). This layer of bonding is crucial because it:
Fixes the drainage board to the waterproof layer.
Forms a reliable protective layer between the waterproof layer and the drainage board.
Even if there are minor defects in the waterproof layer, water will enter the drainage board and be quickly drained away, and no hydrostatic pressure will be formed at the defect, thereby protecting the waterproof layer (Secondary Protection).
Application
1. Building underground engineering:
Outside of foundation wall (vertical application): protect the waterproof layer of side wall and drain groundwater.
Under the building floor (horizontal application): form a drainage layer to prevent the floor from being subjected to groundwater pressure.
Underground garage roof (planting roof): drain excess moisture from the planting soil layer, protect the waterproof layer of the roof, and reduce the load.
Behind the tunnel lining: drain water that has infiltrated behind the lining.
Retaining wall and slope: drain water behind the wall to reduce soil pressure and protect the wall structure.
2. Green roof: as a drainage layer, it can store a certain amount of water for plants to use, and drain excess rainwater to protect the roof structure.
3. Square, road subgrade: enhance subgrade drainage to prevent frost heave and softening.
4. Sports venue: venue foundation drainage.
5. Landfill: Leachate collection layer.
Techinical Parameters
1. Physical Properties:
Parameter | Typical Range/Unit |
Dimple Height | 8mm/10mm/16mm/20mm/25mm |
Core Material | HDPE, PP |
Filter Material | PET non-woven fabric, PP non-woven fabric |
Roll Width | 2.0m/2.5m/3.0m |
Weight Per Unit Area | 700-2000g/m² |
2. Mechanical Properties:
Parameter | Typical Range/Unit |
Compressive strength at 10% strain | 200-1000kN/m² |
Compressive strength at 25% strain | 400-1500kN/m² |
CBR bursting strength | 1.5-5.0kN |
Mandatory tensile strength (MD) | 8-25kN/m |
Transverse tensile strength (CD) | 8-25kN/m |
3. Hydraulic Properties:
Parameter | Typical Range/Unit |
Water conductivity (θ) at Specific pressure/gradient | ≥ 5×10⁻⁴ m²/s at 50kPa |
Water flow (Q) at Specific pressure/gradient | ≥ 0.5 L/s/m @ i=0.1, 50kPa |
Filter layer permeability/water permeability | 0.1 - 2.0 cm/s or k×10⁻² - 10⁻³ cm/s |
Filter layer equivalent pore size (O₉₀ / AOS) | 0.06 - 0.25 mm |
4. Durability:
Parameter | Typical Range/Unit |
Root Penetration Resistance Certification | Passed FLL and other standard tests |
UV Stability (Strength Retention Rate) | ≥ 70% after 1500h UV |
Chemical Stability | Good (HDPE/PP/PET) |
About Us
Haoyang Environmental Technology engineers high flux geocomposite dimple drainage sheets since 2008 our patented thermoplastic dimpled core bonded to nonwoven filtration layers achieves 5100 m² day in plane flow capacity under 500 kPa compression loads exceeding ASTM D4716 standards the 20mm dome height creates efficient capillary break channels while 120 g m² geotextile prevents soil clogging proven in foundation drainage green roof systems and tunnel lining applications across 28 countries including Singapore MRT subterranean networks and Dubai vertigo skyscraper foundations these sheets replace 300mm thick gravel layers reducing vertical space consumption 90 and installation costs 65 request pressure flow curves for your specific hydraulic load requirements.
