The optimized design of the T5 roundabout on the State road received the approval of the Estonian Transport Administration and contractor AS TREV-2 Grupp.
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THE CHALLENGE
Contractor needed cost-effective and long-term load bearing pavement for new T5 roundabout road. They found the solution together with EM Infra OÜ and used for that Neoloy Tough Cell.
CONVENTIONAL SOLUTION
Conventional construction on this road is based on removal and replacement of clay subgrade. The cost of importing replacement infill along with the installation of drainage systems proved prohibitively expensive.
Due to the requirements of the reinforced intersection the contractor would need to build four layers of asphalt.
NEOLOY TOUGH CELLS SOLUTION
Client chose Neoloy Tough Cells due to its ability to distribute vertical loads laterally and increase the bearing capacity. Neoloy Tough Cell solution gave the opportunity to eliminate clay subgrade excavation and one layer of asphalt.
The Neoloy Tough Cell solution was based on reclamation of the reusable materials. It provided maximum engineering at the lowest economic and environmental cost. Neoloy Tough Cells were filled with onsite reclaimed asphalt (RAP).
The Neoloy mattress “floats” provides a high modulus improvement factor (MIF) for asphalt surface road. This is due to Neoloy’s unique properties – low permanent deformation (<3% at 75 years); high tensile strength (>19 kN/m perforated); and high (elastic) stiffness (>525 MPa @60°C) – that create a beam (slab) effect.
The reinforced road successfully supported the traffic of heavy construction and haul vehicles in all weather conditions. Solution was cost-effective, installed quickly and environmentally friendly.
NEOLOY TOUGH CELLS DESIGN
BENEFITS
Neoloy improved the bearing capacity of soft subgrade, and created a high modulus base layer that ‘floats’ over the peat layer subject to seasonal volumetric changes.
Read moreTHE CHALLENGE
Vapo needed cost-effective and long-term load bearing pavements for roads and platforms for the extraction and processing a steady supply of renewable energy for domestic, municipal and industrial use. They found the solution with PRS Neoloy Tough Cells.
CONVENTIONAL SOLUTION
Conventional construction on peat bogs is based on subgrade replacement, drainage systems and large amounts of gravel. Beyond the unsustainability of hauling large amounts of gravel to remote regions, the weight of such pavement structures results in additional settlements, due to consolidation and creep.
NEOLOY TOUGH CELLS SOLUTION
Vapo chose Neoloy due to its ability to distribute vertical loads laterally and increase the bearing capacity of soft, saturated peat soil. The Neoloy mattress “floats” over the soft soil and provides a high modulus improvement factor (MIF) for the gravel or asphalt surface road and yard pavements. This is due to Neoloy’s unique properties – low permanent deformation (<3% at 75 years); high tensile strength (>19 kN/m perforated); and high (elastic) stiffness (>525 MPa @60°C) – that create a beam (slab) effect.
In addition, Neoloy performed extraordinary (or very well)in the freeze-thaw cycle of the Finnish extreme climate and was unaffected by the volumetric changes in the soil moisture. Drainage systems and soil replacement were unnecessary.
Vapo was very satisfied with both the unpaved and paved pavements, with low surface degradation reported over a 14-year period of intensive use. The surface gravel layer was recently renewed to provide many more years of heavy-duty use.
BENEFITS
A saturated Muskeg peat access road with extreme weather conditions was stabilized using Neoloy® Geocell reinforcement for all-weather access.
Read moreIn 2012, MEG Energy’s oil sand mining operations at the Christina Lake complex in northern Alberta were expanding. Plans included new wells, processing, operations, storage, and treatment facilities, as well as constructing the roads needed to interconnect them. The existing soil in the area consisted of deep muskeg, 3-4 meters deep, with a moisture content greater than 800%. The client needed an access solution that would increase the bearing strength of the road base, provide a durable, all-weather road that was economically feasible, and could be completed before winter. Paradox Access Solutions proposed a design for the road using ToughCell® geocells. Utilizing locally available materials for infill, this innovative geosynthetic cellular confinement system increased the modulus of the existing subgrade and built a road, virtually over water, capable of supporting. 500,000 ESALs. The project delivered:
Approach
The saturated, organic soil in this region combined with harsh climate conditions made normal road-building difficult at best. Freezing in winter combined with heavy rains and poor drainage in summer typically impeded construction efforts almost year-round. Conventional construction methods necessitated the removal and replacement of the muskeg material. The cost of importing replacement infill along with the installation of drainage systems proved prohibitively expensive. Paradox Access Solutions provided a design utilizing two layers of Tough Cell® geocells. Instead of replacing the problematic muskeg, a layer of non-woven geotextile was placed directly over it. An initial layer of Tough Cell® was then installed over the geotextile and infilled with up to 1m of clean sand from a nearby borrow pit.
Construction
Paradox Access experts designed a reinforced road using one to three layers of Neoloy (Category-D tensile strength >22 kN/m) depending on the saturation level. The existing peat subgrade was covered with geotextiles for drainage and to prevent further mixing with the Neoloy layers.
The Neoloy Geocells were infilled with sand from locally available borrow pits and compacted. The strong hoop strength of the cells creates a “beam effect”, or semi-rigid mattress. This effect distributes vertical loads widely, reduces stress and settlement and extends the road life. The capping wearing course layer was filled with a thin layer of crushed gravel.
The end result was a reliable road that MEG Energy’s heavy rigs and other construction equipment could easily traverse.
Benefits
Video about using Neoloy® Tough Cell solution in extreme soil conditions
Neoloy® Geocells double the lifespan of highway using locally available sandy soil.
Read moreChallenge
The Western High-Speed Diameter Road (WHSD) is a 40 km North-South 4-8 lane motorway built to relieve congestion in St. Petersburg. It was the first urban high-speed toll road in Russia, with a planned traffic capacity of 1,000,000 vehicles monthly.
The original plan for the 26 km northern section called for a conventional pavement design on top of a road embankment and 1.0m thick working platform of sandy soil. This was comprised of a 70 mm subbase layer, 410 mm thick granular base layer and a 230 mm thick asphalt layer.
Neoloy Solution – Verification
An alternative design was presented to the NHC consortium responsible for the project, and a proof of concept project was implemented on a section of the A-118 Motorway. Based on Neoloy® Geocells, the goal of the design was to replace the expensive imported granular materials with locally available infill..
Stress monitoring by cyclical plate load tests (Russian standard: GOST 20276-99) of pre-installed pressure cells on sand subgrade verified that the Neoloy Geocell design improves the granular subbase modulus by a factor of 2.45. It also reduced vertical stress by ~50% and allowed a 13% reduction in asphalt thickness.
The demonstration project convinced the project’s commercial and technical experts to adopt and implement the Neoloy Geocell based design for the WHSD road project.
Why Neoloy
The Neoloy Geocell is a 3D mechanical stabilization technology which stiffens the confined layer. The unique properties – high dynamic stiffness, creep resistance and tensile strength – of the Neoloy novel polymeric alloy (NPA) enable the following design benefits:
Neoloy® Geocells selected for reliable soil stabilization in South Sudan for long-term road infrastructure.
Read moreChallenge – Creating a Reliable Lifeline for the Neediest
One of the least developed countries in the world, the new country of South Sudan faces enormous challenges. Large parts of the country lack basic road infrastructure, which severely impacts all aspects of life: from farming to economic opportunities, the perilous political-security situation, and a mounting refugee and food crisis. One vital strategy to address the chronic food insecurity, improve livelihoods and stimulate rural development is to improve the rural road infrastructure and provide access to markets. This would also enable critical aid to get in to those in need.
Neoloy Geocells – Best Road Performance Achieved Using Locally Available Resources
The United Nations Office of Project Services (UNOPS) worked with the Engineering firm of WSP|Parsons Brinckerhoff to provide an optimized pavement design for 225 km of roads in four regions. Conditions included poor subgrade, high traffic loading, and a lack of quality aggregate.
The solution was to build permanent roads with guaranteed long-term performance. This was not just another engineering challenge – it was literally creating a new lifeline for the country. After extensive investigations, WSP proposed the only fast, strong, durable and cost effective solution Neoloy Geocells. UNOPS then submitted the proposed solution for an independent engineering evaluation by ARUP Engineering Consultants to validate the design.
Engineering Design Assumptions Confirmed: Only Neoloy Geocell Provides Long-Term Stabilization For Permanent Roads
The bid specifications for the geocells issued by UNOPS were based on the following design considerations:
PRS was awarded the UNOPS bid for the the Supply and Delivery of Neoloy or approved equivalent for the manufacturer and delivery of 1½ million sqm of geocells within 16 weeks. Neoloy is the only geocell that met the project requirements for elastic stiffness, creep resistance and tensile strength.
The road design includes a wearing course, a formation level and in-situ material roadbed. The Neoloy Geocells are incorporated in the wearing course with significant overfill. The road is basically constructed from sand, with the higher quality sandy-gravel infill limited to the wearing course.
Key Benefits
Paved service road in Poland with poor load-bearing capacity was upgraded by Neoloy®Geocells, drastically reducing pavement thickness and costs. Costs Reduced by 30% on Paved Service Road
Read morePoland is at an important crossroads in the European Union due to its physical location and its developing economy.Signifcant investments are being made by the government and the EU to upgrade the Polish highway system, and a large number of international engineering and contracting firms have ofces and representation in Poland.
In the feld of geosynthetics, there is widespread awareness, acceptance and accreditation of the PRS Neoloy Cellular Confnement System. Neoloy is a well known brand name in the professional academic, contractor and civil engineering community for to its outstanding properties and performance.
Costs Reduced by 30% on Paved Service Road
The S22 upgrade of 28.8 km of the national express road between Elblag and Grzechotki on the northern border of Poland included a service road for heavy construction vehicles. Much of the route was over clay soil with a poor load-bearing capacity (30-40 MPa). Neoloy Geocells were tested and selected by MSF-TGA engineers to meet their requirements for a 140 MPa load bearing capacity.
20 cm Neoloy Geocells were deployed with sandy soil infill, overfilled by 5 cm of sand and 10 cm of recycled concrete construction waste and 6 cm of asphalt. The reinforced road successfully supported the traffic of heavy construction and haul vehicles in all weather conditions. The temporary section was cost-effective, installed quickly, and removed without damage to the environment.
Benefits
More objects from Poland: PDF
Neoloy® Geocells provide foresters with a novel solution that is revolutionizing the way forestry roads are built and timber harvested.
Read moreThe Challenge
Coillte Forestry company required a logging road over deep upland-peat in the in a remote mountainous area of South West Ireland. The existing peat has poor bearing capacity and very saturated, uncapable of handling the 45-tonne vehicles required for timber harvesting.
The conventional solution is a “corduroy road” a portion of the tree harvest is sacrificed, cut and laid perpendicular across the road for a working platform. This is filled with layers of stone in depths of up to 1.2 metres. This method means a loss of part of the harvest as well as a limited construction pace of about 40-50 linear meters per day and requires availability of reasonable quality stone of suitable size to achieve some interlock.
PRS Neoloy Solution
PRS Neoloy Geocells enabled Coillte to build a cost-effective access road across this area using locally dug, poor-quality stone, which could support heavy loading and frequent passes for a 40-year lifespan!
The Neoloy solution was for a single layer of 200 mm height Neoloy Geocells with a 50 mm overfill directly over a non-woven geotextile separation layer. No subgrade excavation was required. Construction proceeded smoothly in a continuous stream. The customer reported complete satisfaction with the road performance several years after construction.
Why Neoloy
Neoloy Geocells provided a completely innovative solution to a forestry company that built logging roads the same way for decades. The Neoloy Geocell was chosen due to its resistance to fatigue and rutting, even over the softest of soils – and guaranteed to continue its performance with permanent degradation for the 40 year design life of the road.
The solution was developed by PRS Engineering in consultation with the customers technical staff to provide an optimized and cost-effective solution for their unique road engineering requirements.
Benefits
Neoloy®Geocells provided ideal solution to reinforce recycled asphalt pavement, significantly increasing modulus, saving costs.
Read moreThe Institute of Urban Development (IDU) of Bogota decided to rehabilitate run-down road infrastructure. The plan called for reclamation of large existing stockpiles of waste asphalt collected from resurfacing programs to repave the streets. However, the low strength of the reclaimed asphalt (200-300 MPa) required processing to improve its modulus (to 900 MPa) for use in conventional pavement design.
After consulting with the geosynthetic experts at Pavco Geosystems and PRS engineers on-site, Incoplan SA engineering consultants were convinced of the suitability of cellular confinement systems for RAP, despite any prior familiarity with geocells.
Although permanent deformation or rutting is one of the concerns in the use of RAP as a base course due to creep deformation, Incoplan engineers learned that the lateral confinement provided by Neoloy Geocells to granular materials would significantly reduce creep deformation of RAP. In particular, the engineers were impressed by the high-modulus performance of the Neoloy Geocell, based on novel polymeric alloy, which has been tested and proven in studies and field trials around the world.
Conventional Solution
Conventional use of RAP required processing with bitumen to improve strength in reclaiming the existing milled asphalt. This increased hauling costs to the asphalt processing facility, as well as indirect costs, such as pollutants, energy and bitumen used in the processing.
The conventional pavement design proposed 4 layers of 15 cm processed RAP for a combined 60 cm base/subbase, with a new asphaltic concrete wearing course of 8.4 cm thickness.
However, tests comparing unconfined vs. PRS-Neoloy-confined RAP in the base of pavements carried out under Dr. Jie Han of the University of Kansas show that the unconfined RAP is subject to significantly higher creep deformation resulting in permanent surface deformation and rutting.
Neoloy Geocell Solution
Unprocessed RAP was used as infill in the Neoloy Geocell reinforced base layer, comprised of 12.5 cm height Neoloy 330 size cell plus 5-8 cm overfill (depending on each street alignment). The same unprocessed RAP was also used for the 30 cm subbase infill as well. The wearing course was a new 8.4 cm asphalt layer.
The Neoloy Geocell reinforcement mechanism (Modulus Improvement Factor – MIF) increased the existing low strength infill from 200-300 MPa to 1000 MPa modulus for the existing milled asphalt stock RAP infill without processing.
These savings enabled the contractor to increase the number of streets in the rehabilitation. The improved modulus of RAP also enabled a reduction in the overall thickness of the pavement structure. In addition to the 10% net savings, the project construction was faster as excavation, infill and compacting were all reduced.
The municipal road authority, the engineering consultants and the contractor were all so satisfied that the program is being extended to another 50 streets.
Benefits
Sustainable highway reinforcement with Neoloy®Geocells on section of Israel’s Highway 6 reduced asphalt layer by 23%, infill by 37%
Read moreThe Challenge
The Cross Israel Highway (Highway 6) is a 140 km national electronic toll road traversing the country’s long North-South corridor. Highway 6 is a DBOT (Design, Built, Operate, Transfer) project built by AECON Canada’s largest construction and infrastructure development company, at a cost of $1.4 billion. The Highway 6 concessionaire, Derech Eretz Group, needed to add a third lane in each direction in response to increased traffic intensity, and decided to test the Neoloy Geocell cellular confinement system in pavement sections. The goal was to demonstrate how Neoloy could be integrated in a cost-efficient design by reducing the cost of infill and asphalt while maintaining long-term performance, within the following guidelines:
Neoloy Geocell Design
While the unreinforced conventional design for the Highway 6 pavement consists of: 200 mm asphalt, 200 mm crushed stone base and 170 mm subbase (670 mm total thickness), the alternative design with Neoloy Geocells included two key improvements:
Neoloy 330 small size 140 mm height geocells (4 m wide sections) were installed in the base layer. The Neoloy Geocells serve as a reinforcing inter-layer in the upper pavement directly under the asphalt (contrary to conventional geocell use in the subgrade). This maximizes the 3D reinforcement mechanism, thereby increasing the pavement structure bearing capacity and load distribution.
The road design was based on the empirical-mechanistic methodology and Flex-Design pavement design software. The use of Neoloy Geocells resulted in a 2.7x higher elastic modulus for each pavement layer.
Neoloy®Geocells were deployed to construct a wind farm access road over a Scottish peat bog, ultimately reducing project costs by 72%.
Read moreChallenge
An access road was required for transporting a wind-turbine generator to a construction site and for installing power lines within a Scottish nature reserve. The site was in mountainous terrain, while the access road crossed peat bogs. Local nature authorities required a sustainable solution with minimal environmental impact, including dismantling of the road to restore the area to its previous natural state.
Conventional Approach
The original plan required several 60-80 cm thick granular infill layers; however, this solution was expensive, complicated and irreversible.
Neoloy Geocell Solution
The use of Neoloy Geocells was proposed for fortifying road segments running over peat. The client decided to conduct a test of the performance of Neoloy Geocells on muddy soil, to verify: minimal environmental damage during installation, sufficient load-bearing capacity, and test its removal. Neoloy successfully passed the test and was selected for project implementation. The client deployed Neoloy Geocells utilizing locally won borrow pit soils for infill.
Benefits
Using Neoloy Geocells the required granular infill was reduced by as much as 120,000 cubic meters, which greatly reduced project costs and minimized the need for granular infill excavation that damages the environment. The road was easily dismantled and the land returned to its natural state.