6 minute read
Geosynthetics: An African perspective
Geocells are an example of geosynthetic technology uniquely suited to the African environment. Geocells are a 3D mechanical soil stabilization and road reinforcement method. The honeycombed cells create a new composite entity when filled with soil materials due to the unique interaction of geometry, soil and the cell-wall material. The stiff 3D mattress restrains the lateral movement of soil particles and maximizes the distribution of lateral and vertical stresses. The main advantage of geocells is the creation of a layer with significantly increased compressive, shear and bending stiffness (slab effect). This results in higher bearing capacity, lower stress/strain fields, resulting in lower deformations and extended service life.
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However, as Zeev Strahl of PRS – the veteran Israeli manufacturer of geocells – states, this is where Neoloy, a nano-polymeric alloy comes into play. “In the end, it is the stiffness and durability properties of material (beside the cell geometry) that the geocell is manufactured from that determines the level of engineering performance. Neoloy is an innovative alloy developed by PRS specifically for geocells. Studies and field trials by leading civil engineering faculties and engineering companies around the world have validated that geocells made from Neoloy show significantly better ultimate bearing capacity, stiffness, and reinforcement relative to geocells made from conventional HDPE geocells, particularly for the entire life span of the roads pavements,” he adds.
The Neoloy Geocells’ stiffness, resistance to deformation (creep)and long-term design strength make geocells more suitable for the demanding requirements of infrastructure projects. Projects undertaken in Africa for the Neoloy Geocell include: weak subgrade stabilization and reinforcement for paved and gravel roads, railroad embankments, terminal storage, container yards, airfields and landfills from Northern to Southern Africa and from the Gold Coast to the Horn of Africa. Clients include UNOPS, mine owners , energy companies, railway authorities , port authorities, and government agencies and municipalities.
Dimiter Alexiew an international Geosynthetic Consultant from Germany, explains that in the African context, it is important to note that the 3D Neoloy Geocell confinement enables the use of sands or other locally available inferior fills, in place of gravel aggregate. And as it works for sands, finer-grained, partially cohesive soils, such as Laterite, can also be used for structural infill. This is of great benefit in many regions in Africa, where even sand is rare.
Besides the lack of gravel and sand, expansive soils are a common geotechnical problem in Africa that can be resolved economically by Neoloy Geocells, as a proven solution to equalize heave deformations. In addition, cement stabilization can be replaced in many projects with geocell mechanical reinforcement, as it is more cost-effective, does not crack over time and does not have negative environmental impacts.
“The high improved modulus factor from Neoloy Geocell reinforcement typically reduces pavement thickness by 50%, even with marginal infill, with no decrease in performance or service life. Neoloy optimized pavements do not crack, thereby significantly decreasing repairs and maintenance, even under heavy loading/trafficking and harsh environmental conditions. So, both construction and maintenance costs can be lowered at the same time. The end result is a sustainable construction solution with significant economic advantages, enabling countries to maximize their infrastructure investments in the most costeffective and environmentally-friendly manner,” says Zeev Strahl of PRS.
Blum’s plinth solution creates storage below and provides easy access up high
Cabinet plinths offer undreamt-of possibilities. Space Step by Blum brings multi-functionality to areas that are frequently left unused. The plinth solution consists of a step which extends with a single touch and a pull-out underneath for seldom used items.
Space Step delivers multiple benefits to an area that is frequently left unused: the cabinet plinth. The plinth solution by Blum extends with a single touch and can be used as a step. Good for everyone. Children, for example, can reach kitchen worktops more easily and lend a helping hand with cooking and baking. Space Step also makes little ones more independent in bathrooms: they can reach the washbasin and wash their hands and brush their teeth by themselves. As for “big” users, the step gives them easy access to higher levels, be it wall cabinets in kitchens or hat racks in hallways. But that’s not all. The clever plinth solution by Austrian manufacturer of fittings, Blum fulfils another function: the top of the step can be simply pushed back into the cabinet to reveal a pull-out underneath. This is where Space Step creates extra storage space for seldom used storage items.
Broad field of application
The plinth solution lowers when a weight of 8 kg or more is applied, thus securely locking the step in position, making it safe even for the smallest of users. It can withstand loads of up to 150 kg, provided the recommended construction is used. Space Step can be used for step heights of 150 to 250 mm and is suitable for cabinet widths of 400 to 1200 mm. Be it recessed plinths, recessed low plinths or flush plinths, the plinth solution by Blum can be implemented for all standard plinth types. For supreme user convenience, combine the solution with the Servo-Drive electrical opening support system by Blum. But it can also be easily implemented with mechanical motion technologies such as Tip-On Blumotion and Tip-On. Space Step closes softly and effortlessly with Blumotion.
New
SPACE STEP – Taking storage to new levels
Benefit from easy access to high cabinets and create unexpected storage space. SPACE STEP brings multi-functionality to cabinet plinths and gives you the design freedom to deliver innovative furniture solutions – from floor to ceiling. Now that’s clever!
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ZEDEX FABRICATORS LTD.
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