Hyson Cells is a patented system for casting articulated block paving and dam liners in situ. Hyson Cells articulated paving is an alternative to conventional flexible and rigid pavements; irrigation channel and dam liners and waterproof dirty-water dam liners. No reinforcing steel is needed.
SPECIAL ADVANTAGES
The Hyson system especially excels in performance and cost under the following conditions:
01.where underlying material is poor quality such as :
collapsing sands
expanding clay
reclaimed land
02.where quarry stone is scarce and expensive but local river sand is available
03. where heavy duty use is expected
04.in geographically remote areas.
ESPECIALLY SUITABLE APPLICATIONS
Industrial paving
where wheel loading is ultra heavy and wheel slewing and turning is frequent
where heavy static point loads are expected
where soil pore pressures are high
where oil or chemical spills can be expected
Lining dirty water channels, ponds and dams
that must be waterproof and must be periodically cleaned of silts.
Lining stormwater channels, irrigation canals, and earthen dams
where water tables fluctuate due to irrigation
where labour-based construction is intended
Low volume access streets with integral side drains
where the project is expected to employ the unskilled
that can be excavated and reinstated using hand tools to lay extra services
THE PRODUCT
Hyson Cells may be thought of as a vast mould, formwork or shuttering
yson Cells is a patented sacrificial formwork system used to cast 3D interlocking articulated block paving and dam liners in situ.
The Hyson Cells product is a large mat comprising square, hollow cells fabricated from thin plastic film. The mat is equipped with integral laced rigging supplied ex factory.
Hyson Cells mats are easily cut and joined on site.
Hyson Cells “BubbleLock” has a hemispherical dimple on each wall that ensures that each cast block interlocks with its neighbour in all 3 dimensions. The older “Regular” product has planar walls that are deliberately buckled during installation to give interlocking wall contours.
There are currently 2 cell sizes 150mm x 150mm and 200mm x 200mm.
Minimum cell depth is 75mm while maximum depth is 2 m.
The mats are supplied ex factory in compact bales normally weighing about 50 kg (depending on size). Packs are expanded on site. A standard module is 100 m² and "double" modules are 200 m². Mats can be easily cut and joined on site. For large projects mats can be tailor-made to suite the dimensions of a particular site.
Rebar pegs are used as anchors to “soil nail” the articulated structure to the base material.
lasticiser / retarder is included to improve workability and so achieve better finish.
ALL sites receive on-site training of the contractor’s labour to ensure that critical instructions are understood so that quality and speed can be quickly achieved.
Site inspection service available.
PI insurance available if we are appointed as nominated sub-contractors.
HOW HYSON CELLS WORK
LOAD BEARING AND LOAD TRANSFER
The Hyson Cells joint exhibits a 3D lockup mechanism.
This lockup provides shear transfer for wheel loads moving across joints and load transfer to prevent differential faulting of adjacent cast blocks.
The interlock therefore gives:
Load distribution
Pavement flexibility
Shear strength
JOINT GAP
When the Hyson Cells formwork is initially filled with concrete there is no gap between the wet infill and the plastic cell wall.
During curing the concrete shrinks and gaps will form at the edges of the cast blocks. Even using a highly workable concrete with slumps of 150 mm a maximum curing shrinkage of less than 800 microstrain will be expected.
With a cast block of side 150 mm (the most common Hyson Cells size for load support applications) this translates to a maximum gap of only 0.12 millimetres.
The joint is therefore not large enough to allow fines to escape from the underlying material.
WATERPROOFING
Hyson Cells linings are approved by the Department of Water Affairs for use for irrigation canal linings.
Water only penetrates the articulated liner under high pressure such as hydrostatic pressure or excess pore pressures.
Should no seepage at all be allowable, e.g. when lining a toxic pond or landfill, then Hyson Cells can be installed as concrete armouring to an impermeable liner such as bitumen or a geomembrane.
See separate section for the Hyson Cells 100% waterproof bitumen “double liner” which is trafficable for cleaning and is the subject of international patents.
RELEASE OF HYDROSTATIC PRESSURE AND PORE PRESSURE
Water and air may be trapped beneath a cast concrete slab and conventional empty concrete canals or swimming pools may rupture when the water table rises. Empty Hyson Cells canal liners in irrigated lands are, however, observed to weep back into the canal as they release these pressures.
Excess pore pressure, generated by the applied surcharge to Hyson Cells paving, can be sufficiently high to be relieved by upward dissipation through the cell joints.
IMPORTANCE OF THE INTEGRAL RIGGING
The rigging is laced into the cell pack during manufacture.
The rigging is used to attach the cell pack to the “soil nail” anchor pegs. It also generally lends strength to the pack; enables it to be pulled out quickly and easily on site; and makes it easier to achieve square corners on site.
Of particular importance are the following: Lends rigidity for filling
The cells are fabricated from High Density Polyethylene (HDPE) film. The HDPE is suitable for use with the concrete because it is impermeable with a smooth surface and does not stick to the concrete fill. This HDPE film is, however, lightweight and is not rigid.
The rigging pulls the cells very taut and lends temporary rigidity for the filling operation. Note that if rigging is not used and the cells should collapse it is a situation that cannot be rectified. That section of the works must be cleared of the concrete debris and laid from scratch using new cells.
Prevents pooling beneath the cell slab
If the cells are not securely anchored to the underlying material then the lightweight cell mat will tend to "float" on the poured concrete. A continuous slab of concrete will pool beneath the cell mat. The cell matrix now ceases to perform its function of dividing the slab into discrete interlocking blocks. Curing shrinkage no longer results in controlled cracks of only a few microns. Instead, the slab formed from the pooled concrete will result in uncontrolled cracking at its weakest point.
Prevent bridging concave surfaces Anchoring to the underlying material is particularly important with concave surfaces such as with a drain liner. The rigging strings that run along the direction of the drain are attached to anchoring pegs to draw the "flat" mat down into the concave profile.
Critical where Hyson Cells are used to armour a plastic liner The rigging supplies extra strength that allows the cell mat to hold the wet concrete on slopes covered with a plastic liner. The rigging is secured to pegs driven outside the perimeter of the geomembrane
