The draining geosynthetic most commonly used are the Geocomposites, which are produced by laminating one or two geotextiles, with filter function, on a drainage element.
The range of Maccaferri drainage geocomposites is called MacDrain.
MacDrain geocomposites are made from a plastic drainage core that is thermally bonded to a geotextile, on one or both sides, or to a waterproofing layer, on one side. They are capable of providing one or more main functions: filtration, drainage, separation, barrier and protection.
Principles of the functions afforded by MacDrain geocomposites are:
- Distributes pressure
- Transports water to the collector drain
- Protects waterproofing from damage when trench is backfilled
- Removes excess water from the soil
- Prevents the collector drain from splitting up with fine soil particles
MacDrain geocomposites can be manufactured with different draining cores according to the following technologies:
The core structure is flexible, with high thickness, very high void ratio and low compressive resistance; it is suitable for applications where low pressure is applied and relatively high flow is required
The core is relatively thin with high compressive resistance; it is suitable for applications where high pressure is applied and relatively low flow is required.
The core structure is flexible, with low to medium thickness, very high void ratio and medium – high compressive resistance; due to the channel pattern, the flow capacity is much higher in longitudinal direction than in transversal direction; it is suitable for almost all types of applications.
These geocomposites afford a sleeve at one end, with a rope inside that will simplify the insertion of a drainage pipe inside it; they are designed for trench drainage, and the pipe allows to keep a very long distance between outlets.
Among the many reasons that suggest the use of MacDrain in place of traditional drainage with sand and gravel, the following are the most important:
- Economical and environmental advantages
- Technical advantages
- Easy and quick installation
- Guaranteed performances
Economical and environmental advantages
- The use of MacDrain in place of a traditional solution with mineral draining fills (gravels, sand) results in large cost reductions;
- The construction time is significantly reduced by the use of MacDrain, with positive influence on the economical evaluation of the cost efficiency;
- There is practically no wastage nor any need of discharging materials in a landfill;
- There is an additional positive impact on the environment because the amount of materials to be moved is dramatically reduced in term of volume and weight and therefore in terms of the related pollution into the environment.
- The use of MacDrain in place of a traditional solution is in many circumstances the only possibility, as example on steep slopes where the mineral natural layer would not be stable;
- MacDrain range can be customized by developing very specialized and selected composite to fit any technical/functional requirement.
Easy and quick installation
- MacDrain geocomposites are light and easy to handle;
- Time and numbers of workers needed to install MacDrain are much less compared to a traditional solution;
- There is no need for mineral draining fills (gravels, sand);
- A single worker can handle the MacDrain roll (when 2 m wide);
- No need for specialised workers or specific installation tools: generally just a cutter, nails and a hammer is all that is needed.
- MacDrain geocomposites fully replace gravel blankets as drainage and gas ventilation layers in landfill applications;
- MacDrain geocomposites can provide positive drainage under road and railways embankments;
- The draining capacity of MacDrain geocomposites is measured in laboratory under all practical conditions of use and their performance is guaranteed by strict quality control practices.