Industry Sector & Application:
Central Vancouver Island, British Columbia
Erosion and Sediment Control
In this application, over 11,000m2 Concrete Canvas® (CC) GCCM* was installed as a protective liner for a large diversion channel at an underground zinc and copper mine on Central Vancouver Island, Canada.
The diversion channel, which conveys clean water from the hillside above to a lower creek, was originally lined with shotcrete but the material had begun to degrade over time. It was recommended that the diversion channel should be enlarged and realigned to effectively handle the high-water volume and velocities.
Higher Performing Solution
Alternative options such as replacement shotcrete were considered, however Concrete Canvas® was specified due to its ability to cope with high water velocities, its ability to accommodate variance in profile and the ease of repair if future damage occurred due to falling trees or large boulders from the above hillside.
Since the water was diverted away from the channel during installation, the speed of installation was key as the diversion pipes wouldn’t be able to handle the high-water volume expected to begin in early October.
The use of CC meant measures could be in place much faster than using conventional concrete or shotcrete. The fibre reinforcement inherent in CC gives a durability and design life well above competitor geomembrane products, whilst the integral PVC backing ensures minimal water loss in the diversion channel.
The channel was designed to handle water velocities of up to 20m/s with slopes as steep as 16% and 20% in some sections.
Mine Diversion Channel Repair: The Technical Breakdown
Prior to Excavation
- The main contractor completely removed and disposed of all trees, brush and other vegetation growth in the area. Any standing water was drained away from the exposed excavated areas to prevent pooling and infiltration.
Prior to Installation
- A new channel was created which was significantly wider than the original shotcrete lined channel.
- The final channel measured 735m in length, 5-8.5m wide with an average depth of 1.5m with a 2:1 side slope.
- Due to the anticipated flow velocities, 8mm thick Concrete Canvas (CC8TM, now reformulated and known as CCT8) was specified.
- The 125m2 CC8TM bulk rolls were delivered to site and positioned strategically along the channel to save time and minimise handling and vehicle movement during installation.
- To account for the variation in profile width, a transverse layup was specified and bulk rolls of CC8TM were deployed from a spreader beam mounted from an excavator to unroll the material across the width of the channel.
- Adjacent layers of CC8TM were overlapped by 100mm in the direction of water flow and secured using 1.5m earth percussion anchors with 3mm stainless steel cables every meter along the overlaps in conjunction with 8 stainless steel 1” screws at 150mm intervals.
- The Canvas was pinned into 300mm deep anchor trenches on either side of the channel using the 1.5m earth percussion anchors.
- The trenches were then backfilled with material to provide a neat termination and to prevent water ingress underneath.
- When fixing the Canvas to rock in some sections of the channel, Hilti rock anchors and 600mm rock bolts were used.
- The material was hydrated using a water truck and due to CC having a very low wash out rate and low alkaline reserve, treatment of the runoff from installation was not required.
CC has a working time of approximately two hours from hydration, meaning that work can continue even in very wet conditions. This can reduce programme disruption typically caused by bad weather when using traditional solutions.
- The installation took 6 weeks to complete with an average crew size of 6 men and daily temperatures up to 34°C.
- The client was satisfied with the product and the minimal amount of specialist training or equipment required.
- The speed of installation meant the project was completed before the heavier precipitation arrived at the mine in early October which may have caused significant project delays.
What is Concrete Canvas ®?
Concrete Canvas ® is part of a new class of construction material known as a Geosynthetic Cementitious Composite Mat (GCCM). A GCCM is a factory-assembled geosynthetic composite consisting of a cementitious layer contained within one or multiple layers of geosynthetic materials. The cementitious portion of the GCCM becomes hardened when properly hydrated to be used for erosion control and weed suppression.
CC® is a flexible, concrete-filled impregnated fabric that hardens on hydration. Essentially, it’s concrete on a roll and allows concrete construction without the need for plant or mixing equipment: just add water. The product is typically used to replace conventional concrete (in-situ, precast, or sprayed) for erosion control, remediation, and construction applications.
Benefits of CC®
- Rapid Install – CC can be laid at a rate of 200m2/hour, up to 10 times faster than conventional concrete solutions.
- Easy to Use – CC is available in man portable batch rolls for applications with limited access. The concrete is pre-mixed so there is no need for mixing, measuring or compacting.
- Lower Project Costs – quick and easy to install, Concrete Canvas® is more cost-effective than conventional concrete, with less logistical complexity.
- Eco-friendly – CC is a low mass, low carbon technology which uses up to 95% less material than conventional concrete for many applications.
- Durability – CC offers up to 120 years of performance life. Click here for durability certificate.
Features of CC®
- Waterproof – The PVC backing on one surface of the CC ensures that the material has excellent impermeability.
- Strong – CC has a 24-hour compressive strength of 50MPa. The fibre reinforcement prevents cracking, absorbs energy from impacts and provides a stable failure mode.
- Durable – CC is twice as abrasion resistant as standard OPC concrete, has excellent chemical resistance, good weathering performance and will not degrade in UV.
- Flexible – CC has good drape characteristics and will closely follow the ground profile and fit around existing infrastructure. Unset CC can be cut or tailored using basic hand tools.
- Fire & Chemical Resistant – CC has excellent high temperature performance and has been tested for reaction to fire. It is also more resistant to aggressive compounds than standard OPC concrete.
Concrete Canvas ® is used across a range of sectors including mining, oil & gas, agriculture and civil construction for a variety of applications.
- Channel/Ditch Lining
- Slope Protection and stabilization
- Bund Lining
- Concrete Remediation
- Weed Suppression
- Culvert Lining
- Outfall/Spillway Protection
- Gabion Protection
- Mining Vent Walls
- Pipe Protection
Concrete Canvas ® comes in three formats, man-portable Batched Rolls, Bulk Rolls, and Wide Rolls.
- Minor works.
- Restricted site access.
- Unavailability of plant.
- Stocking for reactive work.
- Man portable.
- Major works.
- Material efficient (zero waste).
- Cost efficient.
- Transport efficient.
- Staggered production and delivery for specific projects.
- Major works.
- Straight uniform channels of constant profile.
- Increased installation rates.
- Reduced jointing.
- Reduced ancillary requirement.
All Titan product solutions are backed by comprehensive engineering and specialized technical support. Using the latest and advanced design software, we work with engineers and consultants all over the world.
Our skill sets go far beyond product supply and installation. We are happy to provide complimentary application specific preliminary designs. We can also provide detailed designing and working calculations including construction drawings, and crucial specification and installation details.
Explore what Concrete Canvas ® can do for you. Request a Project Consultation below to discuss the best solution for your next project.
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