15 July 2021

TILTEX – An Innovative Cementitious Geocomposite With Multiple Applications

In recent years, we have seen the emergence of geosynthetic solutions for a very large number of applications, generally related to soil reinforcement or water management. SOPREMA, through its civil applications product range, innovates by proposing the market a new type of materials - a cementitious geocomposite called TILTEX. It can be used in multiple applications and opens up new areas of use for geosynthetics.

TILTEX: Concrete In Roll The principle of TILTEX is simple: deliver and implement concrete in a different way.

It is now a question of delivering on site only textile rolls. They contain a mixture of sand and cement, once set up and hydrated, the geocomposite will turn into a thin cement slab reinforced with polypropylene fibers.

Indeed, the product is manufactured as follows:
 A non-woven geotextile made of polypropylene fibers (100%) is placed on a specific production line.
- The dedicated amount of dry mixture of sand/cement is poured on this first layer.
- The assembly is covered with a second layer of non-woven geotextile made of polypropylene fibers.
- The whole then passes inside a needle punching machine: a machine with several thousand needles with hooks that will cross the geosynthetics allowing part of the fibers of the two geotextiles to connect and create a mesh between the different layers.
- The product is finally rolled up and packaged.

The interest of the needling is to allow the cohesion between layers and thus give an excellent hold to the product. The mixture of sand and cement cannot circulate between the geotextiles because it is caught in the mesh. Thus, even applications in an upright position are possible.

Fig.1: Sectional View of a Cement Geocomposite  Fig.2: 2.5m Rolls Delivered on Site

The amount of sand/cement mixture placed between the geotextiles is chosen according to the required applications for the product: mechanical resistance - dynamic or static puncture, erosion resistance ... For conventional applications, TILTEX is offered in 4 versions: 7kg/m², 9kg/m², 10kg/m² and 12kg/m².

The geocomposite is produced in 5m wide and different dimensions are proposed in order to best suit to the project -
- 5m x 20ml for large flat surfaces or embankments
- 2.5m x 20ml for ditches or embankment heads
- 1m x 5ml for small or manual applications and difficult accesses

Easy Implementation

TILTEX rolls are delivered directly on site. They are individually packed by a double wrap: a film tightened around the roll and an additional plastic protection closed at the ends. Depending on the weight of the rolls, they are discharged through predisposed straps on the rolls - for large rolls or in pallets - for small rolls. The handling of large rollers must be done using the appropriate equipment with lifting beam. For small rolls, it is possible to handle them with 2 or 3 people using an axis placed in the roll mandrel.

Once unpacked, the products are unrolled and positioned by giving the desired shape. An overlap of the ends of 10 to 20cm is created to ensure the continuity of the protection and possibly the flow of water - placement in tile. Fasteners are implemented in such a way that the geocomposite is kept on the ground avoiding folds. Screw fasteners made of galvanized steel can be used - a small tool to be mounted on a screwing machine is designed specifically. Different shapes and lengths allow their use in hard or soft grounds.

Fig.3: Installation on a Ditch in a Mine in Germany        Fig.4: Watering a TILTEX Used on a Railway Project in France

The product can be easily cut to fit specific dimensions or shapes. While not hydrated, it remains flexible and can be repositioned. Once the TILTEX layer has been positioned correctly, hydration by abundant watering is necessary for the concrete to harden. Watering is done by spraying without pressure and with the water quantities prescribed for the product - at least 0.5l of water per m² and per kg of sand/cement mixture. 

In case of strong wind or sunshine, further watering may be necessary. It is essential that the surface geotextile is kept wet for 48 hours. In certain case, the hydration of the geocomposite can also be carried out by complete immersion, for example in the case of the installation of a protection of the banks of a channel.

About 48 hours after the start of hydration, the concrete will have hardened enough for the geocomposite to work on its protective role. It should be noted that the surface geotextile is made of polypropylene. Once the geocomposite is hardened, this geotextile no longer has a role. As it is therefore not UV resistant, it will disintegrate over time and let the concrete layer appear.

Properties 

TILTEX is designed to meet two main functions: mechanical protection and erosion protection. As for mechanical protection, it is particularly interesting when the product is used as protection of a geomembrane in a basin or under embankments. The presence of fibers in the concrete gives it both a good hold and an excellent resistance to punching - dynamic and static.

With regard to protection against erosion, the installation of a cement geocomposite ensures a good flow of water in a sustainable way while protecting the ground. Anyway, TILTEX geocomposite is not waterproof. The TILTEX PLUS version consists of coupling to the TILTEX a 0.2mm polyethylene film to increase its waterproofing properties, for example for water flows. In addition, TILTEX is non-flammable and can ensure a good level of fire protection. On the other hand, cement geocomposites should not be used in structural applications.

Fig. 5: Setting Up in a Ditch  Fig.6: Protection of a Basin Sealed in HDPE Geomembrane

 

Examples Of Applications 

TILTEX can be used in very different cases. In many real cases, this solution offers both an economic interest compared to conventional solutions in poured concrete but also a speed of installation while maintaining a very interesting durability.

Road Ditches 

The use of cement geocomposite for the construction of road ditches lining limits very significantly the quantities of concrete used and is carried out very quickly. For this application, the ditch will have to be dug in its final form and the embankments will have to be regular. The geocomposite, of suitable width, is then unrolled above the ditch in the direction of its length and the fasteners are put in place on both sides. The presence of wrinkle or occasional irregularity should be avoided to ensure the proper flow of future water. Connections to the outlets will be made only by natural adaptation of the geocomposite to the profile. After hydration, the geocomposite will harden to offer a regular and resistant lining to the ditch - good flow of water, easy cleaning and resistance over time.

In this case, geocomposite allows, versus cast or prefabricated concrete solutions, a rapid setting and a strong limitation of the quantities of concrete used. The solution is thus synonymous with saving time, saving money and respecting the environment.

Protection In A Basin

Many basins are subject to deterioration on the edges and slopes due to mechanical (animals, maintenance) or atmospheric (UV, erosion) aggressions. The use of TILTEX in a mechanical protection layer is an effective and durable solution.

For example, the project in Fig.5. is located in Australia. The HDPE geomembrane of this basin was degraded by kangaroos who came to drink. The problem is singular but it joins a much more classic case study encountered in all regions. Indeed, the fauna present near our roads very often comes to the basins and regularly degrades the slope heads and banks. The installation of a cement geocomposite on the geomembrane avoids any damage. In addition, the presence of this type of product ensures protection against UV and allows easy maintenance and cleaning.

Protection Of The Land Under A Temporary Life Base

The use of a geocomposite as a base layer directly installed on the existing flattened land can significantly limit the input of materials and facilitate rehabilitation at the end of the work. Indeed, under the containers and cabins and if the ground is sufficiently carrier, the presence of the product without any other layer of materials serves as a base for the containers by protecting them from mud and water. Under the pedestrian parts, TILTEX can remain exposed and will avoid the appearance of muddy areas. Under the circulated or parking areas, the supply of crushed materials will be necessary but may be limited. 

During the dismantling of the life base and the restoration of the ground, it will be easy to remove the materials used as the hardened layer will be easy to cut and discharged into plates.

Fig.7: Temporary Protection for Base Installation in a School Garden

 

Cementitious Geocomposites In A Few Arguments

Quick And Easy To Implement 

Delivered in rolls, the products are flexible and adapt to all shapes in an easy way. Once set up, it is enough to water them so that they harden.

Environmentally Friendly 

By limiting the quantities transported and the thicknesses of concrete used, they offer a real alternative to conventional solutions.

Safe And Stable Over Time

The use of cement in geocomposite allows it to have an unparalleled stability over time. The presence of fibers inside the concrete ensures the good resistance of the product to cracking.

For further information,

Paul Guinard
Director of Civil Engineering
SOPREMA
www.soprema.com