August 2013
CONSTRUCTION WORLD
22
In June 2012 work commenced on a new bunded
storage facility for an oil tank project for GPS
Chemoil, situated at the major bunkering port
of Fujairah on the Gulf of Oman in the United
Arab Emirates. Riaan Rademeyer of Kaytech
was instrumental in supplying and installing
Kaytech’s EnviroFix Geosynthetic Clay Liners
(GCL) as lining for the bunded storage facility.
environment
AS APRECAUTION
to contain leakage or breakage of the oil tanks,
the bunded storage facility had previously been lined with HDPE.
Installation and welding of this lining was carried out by a local
specialist contractor, which proved difficult and costly. After careful
consideration of all other alternatives, the construction engineers
concluded that geosynthetic clay liners (GCLs) would be more
effective and simpler to install thanHDPE lining.While investigating
various alternatives, the company discovered that the supply and
installation of Kaytech’s EnviroFix GCLs fromSouth Africa was more
economical than similar products. This is due to HDPE requiring a
specialist contractor to repair any tears bywelding patches over the
damaged areas on site, but a GCL can be repaired by a generalist or
in-house maintenance worker. Using a GCL also obviates the need
for a cushioning geotextile to protect the HDPE liner.
Manufactured in SouthAfrican, EnviroFixThermal Lock GCLs are
needle-punched, reinforced composites that combine two durable
geotextile outer layers with a uniform core of natural sodium ben-
tonite clay to form a hydraulic barrier. By needle-punching fibres
through the sodiumbentonite clay layer, a completely uniformGCL
is produced. A proprietary heat-treating process (Thermal Lock)
is then used to modify and more permanently lock the needle-
punched fibres into place, resulting in increased internal shear
resistance and long term creep resistance. This unique product
is more durable over a wider range of installation conditions and
can significantly reduce the adverse effects of premature hydration
during installation.
EnviroFix is suitable in several applications; due to the efficiency
of the high swelling sodium bentonite clay, it can completely or
partially replace thick, multi-lift compacted clay layers in composite
landfill liners and caps; it provides exceptional liquid containment,
for instance, in reservoirs and irrigation canals and can also be
used as a secondary containment barrier in above-ground tank
impoundments such as at GPS Chemoil.
The engineering contractors who were awarded the construc-
tion contract for Phase IV of the oil storage terminal at GPS Chemoil,
employed local labourers and two local contractors to begin lining
site tank 1008 with Kaytech’s EnviroFix. The local contractors had
previous experience with installation of HDPE linings.
EnviroFix is a naturally heavy product due to its bentonite
powder content and thus it usually necessitates the use of a TLB
(Tractor Loader Backhoe). In this instance it was not possible to
employ a TLB due to the many pedestals supporting overhead oil
transfer pipes. As a result, rolls of EnviroFix were placed as near as
possible to the areas being covered, and then manually unrolled.
This time-consuming labour was exacerbated by the extremely
high summer temperatures prevailing in the Middle East. Another
challenge experienced on site was the time consuming effort of
ensuring the GCL was properly sealed with bentonite paste.
By June 2013, 70 000 m
2
of oil storage was lined with
EnviroFix X800 GCL, providing an efficient, cost effective solution
to the challenge of lining the oil tank for long-term stability and
easy maintenance.
●
Oil tank containment
The area is protected by Envirofix.
Ensuring correct overlap area is set.
Manually rolling out the Envirofix X800 GCL.
Sealing the overlaps with bentonite.
