CCX-M® Canal Remediation

Location:  Tzaneen, South Africa

Project Type:  Product Supply

Product Used: Concrete Canvas® CCX-M®

 

Project 

In October 2020, Concrete Canvas CCX-M® (CCX-M®) was installed on a trial basis at a site in Tzaneen, South Africa.

The objective of the project was to provide a rapidly installable and non-erodible remediation solution for an existing concrete lined canal. The client, Pusela Irrigation Board (PIB) opted to trial CCX-M® in order to determine its ease and speed of installation as well as to demonstrate and monitor material strength and durability.

The section of canal being lined in this trial was part of PIB’s feeder canal to a local avocado farm. The existing concrete lined canals are approximately 50 years old and require regular remediation by crack sealing, panel replacement and joint reinstatement. As a result of the current condition, the canals leak with a significant amount of water loss in a very water-sensitive region.

The section of canal being lined measured 25m in length, with a parabolic profile measuring approximately 1.7m wide.
CCX-M® was installed by Kingdo

 Concrete Canvas® (CC) is a Geosynthetic Cementitious Composite Mat (GCCM), a factory-produced material combining cement within geosynthetic layers that hardens when hydrated for erosion control and weed suppression.

Installation of CCX-M®

The 1.95m wide CCX-M® rolls were delivered to site by Hiab truck without any logistical complications due to the availability of an access road directly adjacent to the canal. The rolls were lifted from the truck using a spreader beam and unrolled longitudinally along the length of the chosen canal section.

A single overlap was formed at the end of the roll to demonstrate the proposed future mechanism for jointing. The overlap joint created was 100mm wide and thermally bonded using a hand-held hot air welder. This consisted of the LLDPE backing being bonded to the Polyester top surface of the underlying lap at a temperature of approximately
450°C and speed of 1.5m/min.

Once the overlaps had been bonded, the CCX-M® was anchored to the concrete canal using shot-fired nails. In order to reinstate a high degree of impermeability at the position of these nails, an expoy covering was applied measuring approximately 50mm in diameter. Shot-fired nails were also used to fix the CCX-M® internally at 400mm spacing,
100mm from the top of the canal to the underlying concrete substrate. These nails were again covered with an epoxy.

The CCX-M® edges were terminated in a shallow anchor trench directly behind the top of the existing 50mm thick concrete. These edges were secured using 250mm long anchor pegs created and bent on site from 12mm thick high tensile steel straight bar. The shallow anchor trenches were backfilled with in situ material and compacted by hand.

The CCX-M® was hydrated by hose pipe attached to a generator pump. Water was pumped from the main canal just upstream from the installation. CCX-M® was hydrated 3 times at 15-minute intervals to saturation and then one last time prior to completion of the installation.

Project Outcome

A total of 50m² of CCX-M® were installed in around three hours by a team of six in moderate heat and humidity conditions.

The trial was very successful and is currently under consideration by the PIB for use as a remediation solution for the full scope of their canal scheme.

The 50m length of canal lined with CCX-M® is noticeably more efficient than the unlined sections. CCX-M® provides a more durable, erosion resistant solution with considerably reduced permeability than those currently incorporated on the canal network and is fit for purpose for all future canal linings of similar terrestrial conditions.