New Generation Neoweb® Geocell is Transforming Infrastructure Construction Innovative N technology developed by PRS has strength and durability that meets the needs of a sustainable transportation future Introduction Cellular confinement systems (geocells) were invented by the US Army Corps of Engineers construct temporary roads for heavy military vehicles over problematic soils Several years later their commercial production was allowed and production for civilian use began However, unlike the original application, development of geocells in the civilian engineering market focused mainly on soil erosion control for slope and channel protection The use of geocells for load support road and rail applications became a secondary function, limited to the reinforcement of temporary pavement structures Geocells were typically deployed in the lowest structural layers, usually the subbase, in order to improve the load bearing of weak subgrade Unfortunately, this approach ignores the potential of geocells to reinforce other structural layers of the pavement and provide long term applications PRS Professional Reinforcement Solutions has been producing three-dimensional cellular confinement systems since 1996 These honeycomb geocells filled with soil create a composite system as a result of the unique 3D interaction of the cell material, geometry and soil PRS has focused on understanding and advancing cellular confinement technology The result is a completely new concept N based Neoweb® This new generation of geocell from PRS offers performance and design life aligned to the same time, driving the transition from slope and channel protection to load support applications for highways, railways and ports Unpaved Access Road, Topen Oil & Gas, Columbia Cellular Confinement Neoweb is a three-dimensional, cellular confinement system in a honeycombed structure When filled with granular infill, a new composite geosynthetic entity is created from Neoloy is a patented polymeric the complex interaction of cell, geometry and soil on three planes, alloy with long-term resistance ideal for soil confinement, stabilization and reinforcement solutions to creep, stress-cracking, high Neoweb improves the performance of infill materials, while temperatures, oxidation and increasing the bearing capacity of structural pavement layers UV light that substantially Stiffness of the infill and cell is increased by the hoop stresses extends the design life of developed on the cell wall as well as by passive resistance from geocells and the performance surrounding cells Confinement prevents movement and shearing of of the project as well soil infill under cyclic loading, maintains compaction and reduces aggregate attrition The confinement system maintains soil PRS Article for Geosynthetics Magazine March 18, 2010 compaction, thereby providing long term soil reinforcement and increased structural strength Typical applications include: Load support for roads, rails and ports Slope and channel erosion protection Earth stabilization and retention walls Landfill & reservoir geomembrane protection Beam Effect Vertical loading on Neoweb infilled with compacted granular material creates a semiThis distributes the load evenly and effectively over a wider area, thereby increasing bearing capacity and decreasing differential settlement The zone of influence created by the geocell is slightly higher than the cell wall height and applicable to any structural layer The beam effect was verified by extensive testing at Kansas State University (KSU) and confirmed by unpublished results at the Indian Institute of Technology (ITT) Chennai, India Vertical Pressure Isobars Comparing Load Pressures in Unreinforced Vs Neoweb Reinforced Subgrade Typical Road Pavement Structure Sections The enhanced 3D properties of Neoweb and its reinforcement capabilities enable a reduction in the thickness of structural pavements both the substrata and surface (e.g., asphalt) layers while at the same time improving the performance of non-cohesive, inferior fill, such as fine granular soils and recycled materials Reinforcement with Neoweb also increases the service life of pavement structures, thereby reducing their operational and maintenance cost requirements This enables transportation management professionals to allocate the budgets from maintenance and repair to the construction of new roads and infrastructure Neoweb Confinement Enables Use of Less Expensive Infill Neoweb 3D cellular confinement system exhibit clear advantages over 2D planar solutions (geotextiles, geogrids) A major advantage of Neoweb is its ability to utilize inferior granular materials that cannot be used by 2D geogrids The 3D vertical confinement zone enables the use of less expensive local and/or ungraded granular materials for infill This includes native soil, quarry waste, sand, RAP (Recycled Asphalt Pavement) and recycled construction waste for load support applications Depending on the project-specific soil Particle Size of Geogrid vs Geocell conditions and traffic loading parameters, Neoweb can offer very large cost savings by using these local and/or inferior infill sources PRS Article for Geosynthetics Magazine Page 21-Mar-10 Neoweb vs Geogrids The reinforcement capabilities of Neoweb 3D cellular confinement system are another significant advantage over 2D geogrids Geogrids require a specific graded aggregate which has a particle size 1/2 the size of the grid aperture, limiting their confinement zone to a maximum of cm The Neoweb fully confined vertical zone is equivalent to the cell height (10-20 cm), while the infill particle size can be up to 1/3 of the cell diameter (50 cm), approximately 17 cm Unpublished results from KSU show that the structural contribution of Neoweb (20 cm width x 10 cm ht) is equivalent to three geogrid layers Breakthrough in Polymer Technology The Time Dimension The widespread acceptance of geocells for reinforcement in load support applications is dependent on its dimensional stability over time Preservation of cell geometry in all three planes is essential to preserve the stiffness, beam effect and resilient modulus to maintain soil confinement and compaction Even minimal expansion of the cell geometry under dynamic loading will dramatically weaken the pavement structure Long-term dimensional stability under thermal cycling throughout the design life of the project is mission critical This dimension of time is based on several factors: Resistance to permanent plastic deformation over time (creep) Dimensional stability under thermal cycling: thermal expansion coefficient vs the loss of strength and stiffness at high temperatures Resistance to environmental influences, oxidation and UV degradation over time New Railway Line Over Soft Soil, Northern Province, Russia Although HDPE is the conventional polymer in geocells, lab test and field trials have demonstrated that HDPE based geocells deform plastically over time and are dramatically impaired by high temperatures HDPE is therefore suitable for short-term use only and not appropriate for long-term structural applications The following polymers typically used for geocells exhibit the following characteristics: HDPE lacks stiffness, low dimension stability and loses strength above 55°C, limiting long-term use Polypropylene (PP) very sensitive to high and low temperatures and UV radiation Polyester lacks elasticity for geocell geometry and is too brittle Neoweb with Neoloy Extends Design-life To create a new cellular confinement system that meets the engineering requirements for long-term performance, PRS embarked on an ambitious and intensive five-year R&D program The result was the synthesis of a completely new proprietary material for Neoweb, called NeoloyNeoloy is a unique polymeric nano-composite alloy based on dimensionally stable polymer nano fibers (polyester or nylon) in a polyolefin matrix PRS Article for Geosynthetics Magazine Page 21-Mar-10 Reinforced Heavy Duty Pavement with Paving Blocks Neoloy polymeric alloys used in Neoweb providing the long term stiffness and dimensional stability required for long-term confinement in earth retention and road and rail pavements applications Unlike HDPE, Neoweb geocells with Neoloy maintain their engineering properties over time and under elevated temperatures These properties can be measured by accepted testing procedures and verifiable scientific testing methods Essentially PRS has added the dimension of time to conventional 3D geometry of geocells to create an entirely new generation geocells: 3D plus design-life time Neoweb based Neoloy geocells offers significant advantages over HDPE-based geocells include: Significantly stiffer and stronger and resistant to stress-cracking Very high plastic deformation (creep) resistance Much more dimensionally stable, for reliable confinement in wide temperature range Far more resistant to oxidation and UV light degradation for very long periods N N well beyond conventional geocell technology and provide a clear value proposition compared to other geocells, geogrids and other reinforcement geosynthetics Mr O E PR“ W PR“ R D the only way to advance beyond the basic geocell technology, and redefine the geocell performance according to the highest professional standards to satisfy the needs of t The ability to predict and guarantee the long term performance of Neoweb aligns it with the typical life-span required by civil engineering projects This makes Neoweb the most suitable reinforcement solution for a wide range of load support applications including roads, railways, airports, parking, pipelines, and working platforms, in addition to traditional earth stabilization applications PRS Article for Geosynthetics Magazine Page 21-Mar-10 Sustainable from Start of Project to End of Life Neoweb is a green solution that makes civil infrastructure projects more sustainable As a sustainable construction technique for land support applications, it uses less than 50% of the aggregate infill than other unreinforced solutions, and can utilize sand, locally available soils and recycled materials for infill By reducing the amount and type of infill required, the usage of haul and earthmoving equipment is reduced This in turn decreases fuel use, pollution and the carbon footprint, and at the same time minimizes on-site disruption from dust, erosion and runoff When used for slope applications, perforated geocells provides excellent soil protection, water drainage and growth stratum for plants The long-term design life of advanced Neoweb technology means that repairs and maintenance are significantly reduced, as are long-term economic costs The bottom line is that Neoweb provides significant economic, engineering and environmental benefits both during initial construction and over the long term Olympic Canoe and Kayak Stadium, Greece 2004 About PRS PRS is the world’s leading supplier of cost-effective soil stabilization solutions Combining unique, proprietary technology with specialized engineering expertise, PRS delivers proven solutions for load support, slope and channel protection, earth retention, reservoir and landfill applications With a global network of fully owned subsidiaries and independent local distributors, PRS provides a full range of end -to-end support services Since its establishment in 1996, PRS has implemented thousands of successful projects in over 40 countries worldwide PRS Article for Geosynthetics Magazine Page 21-Mar-10 ... has a particle size 1 /2 the size of the grid aperture, limiting their confinement zone to a maximum of cm The Neoweb fully confined vertical zone is equivalent to the cell height (10 -20 cm),... for Neoweb, called Neoloy Neoloy is a unique polymeric nano-composite alloy based on dimensionally stable polymer nano fibers (polyester or nylon) in a polyolefin matrix PRS Article for Geosynthetics... Geosynthetics Magazine Page 21 -Mar-10 Neoweb vs Geogrids The reinforcement capabilities of Neoweb 3D cellular confinement system are another significant advantage over 2D geogrids Geogrids require