geocell cellular confinement system industry geotechnical and civil engineering landscape architecture infrastructure website www.prs med.com prs neoweb is a cellular confinement system geocell developed and manufactured by prs mediterranean ltd. composed of ultrasonically welded strips the neoweb geocell is opened up on site to a form a 3d honeycomb like matrix and then infilled with soil material to stabilize and reinforce soil . in addition to the reinforcement of the subgrade subbase or base layer of roads and railways cellular confinement is also used for soil stabilization and erosion control in slopes channels retention walls reservoirs and landfills . neoweb is manufactured from neoloy a novel polymeric alloy npa which provides a higher modulus creep resistance and tensile strength to geocells than commonly available hdpe high density polyethylene pokharel et al. 2009 . 1 research has shown a stiffer geocell wall retains the cell geometry dimensional stability better and therefore confinement and reinforcement . 2 neoweb is a sustainable solution for road construction as it enables the use of locally available but marginal soils for infill thereby saving virgin aggregate ; reduces the pavement layer thicknesses ; and extends the service life of pavements and thereby lowers operating and maintenance costs . 3 contents 1 history 2 research 3 applications 4 design methodologies 5 sustainable transportation 6 how it works 7 environmental durability 8 see also 9 references 10 external links history edit the geocell concept was originally developed by the us army corps of engineers in the 1970s as sand grids to improve the soft subgrades of unpaved roads for short term use by heavy military vehicles webster and alford 1977 . 4 subsequent production of geocells for civilian use began several years later using hdpe for slope stabilization and erosion control and in temporary and low volume roads . prs mediterranean est. 1996 began manufacture of the neoweb brand of geocells . however in order to improve the stiffness and long term durability suitable to long term use 5 prs developed neoloy a novel polymeric alloy npa based on a polyolefin matrix reinforced by polyamide nano fibers . this npa as it is termed in the research literature 6 7 8 is used to create a multi layered geocell featuring durable outer layers in between a high strength inner core layer for optimal performance . geocells made from neoloy are suitable for long term structural reinforcement in critical applications such as the structural pavements embankments and high retention walls . research edit extensive research on exploring geocell reinforcement for roadway applications has been ongoing at the university of kansas 6 as well as at other geotechnical civil engineering research institutes such as the indian institute of technology madras 9 university of delaware 5 clausthal university germany 10 and colombia university ny 11 in the past few years . the objectives of this comprehensive research was to understand the mechanisms and influencing factors of geocell reinforcement evaluate its effectiveness in improving roadway performance and develop design methods for roadway applications . this research included laboratory box tests accelerated moving wheel tests field demonstration and development of design methods . 6 the research summarized in over 40 published papers demonstrated that not all geocells are equal . comparative test results that neoweb made from npa had a greater improvement in stiffness bearing capacity stress distribution and reduced deformation when compared with conventional hdpe based geocells pokharel et al. 2011 and 2009 . 1 12 applications edit neoweb with npa neoloy is suitable for use in the base layer reinforcement of asphalt paved roads where high tensile strength dimensional stability low creep and resistance to high temperatures are required to retain the geocell geometry even under repeated dynamic & cyclical load stresses . 6 applicable for new road construction as well as for rehabilitation neoweb is typically used to reinforce the base and subbase layers of pavement types such as highways railways intermodal ports storage yards and unpaved haul access and service roads . one notable unpaved road project was undertaken by the uk royal engineering corps route trident under difficult conditions in afghanistan to create a secure patrol roads that aided troops and civilians alike . 13 14 design methodologies edit research includes the development of road design methodologies for neoweb geocells . 15 in particular a modulus improvement factor mif verified in research and field demos was developed as a reliable method for quantifying the neoweb contribution to a pavement structure . the mif value obtained from field tests laboratory tests and finite element studies varies between 1.5 5 dependent upon the material of infill subgrade and location of reinforced layer . 9 sustainable transportation edit neoweb can be considered a sustainable road construction method as by improving the structural properties of low strength materials it enables the replacement of quarry aggregate with lower cost lower quality granular infill materials . these lower quality materials include locally available but weak soils sand ; recycled and reclaimed construction materials such as recycled concrete and industrial byproducts such as fly ash and furnace slag . not only does the use of such materials in road construction conserve quarry resources and recycle waste . it also reduces quarry haul and infill activities which in turn decreases the amounts of fuel pollution and the carbon footprint . neoweb reinforcement can also increase the lifespan of pavement structures 6 which means less repairs and maintenance further enhancing sustainability . how it works edit when neoweb is deployed and compacted with soil aggregate a cellular confinement composite structure is created from the geotechnical interaction of the material soil and geometry . soil confinement retains infill materials in three dimensions providing high tensile strength on each axis . under loading neoweb generates lateral confinement while soil to cell wall friction reduces vertical movement . the high hoop strength of the cell walls together with the passive earth and passive resistance of adjacent cells also increases soil strength and stiffness . aggregate abrasion is minimized by the cell confinement thereby reducing attrition of the base material . 10 vertical loading on neoweb with compacted infill creates a semi rigid slab or beam effect in the structure . this distributes the load evenly and effectively over a wider area thereby increasing bearing capacity and decreasing differential settlement . extensive research of the reinforcement mechanisms in geocells shows that the stiffness of the geocell material and geometry are the most important confinement parameters . 7 16 environmental durability edit neoweb is a non corrosive inert engineering thermoplastic resistant to extreme environmental conditions heat cold water wind and dust . it operates in temperature extremes of 60 c to 60 c and has been successfully used in environments from deserts to saturated peat bogs to the arctic tundra . special additives and manufacturing processes make neoweb highly resistant to environmental influences such as uv radiation and oxidation during long term outdoor storage installation as well for long term project design life . see also edit cellular confinement systems geocells route trident geosynthetics references edit a b pokharel s.k. han j. leshchinsky d. parsons r.l. halahmi i. 2009 . experimental evaluation of influence factors for single geocell reinforced sand transportation research board trb annual meeting washington d.c. january 11 15 pokharel s.k. han j. manandhar c. yang x.m. leshchinsky d. halahmi i. and parsons r.l. 2011 . accelerated pavement testing of geocell reinforced unpaved roads over weak subgrade journal of transportation research board the 10th international conference on low volume roads july 24 27 lake buena vista florida usa thakur j.k. han j. leshchinsky d. halahmi i. and parsons r.l. 2010 creep deformation of unreinforced and geocell reinforced recycled asphalt pavements . advances in geotechnical engineering geotechnical special publication no. 211 proceedings of geofrontiers 2011 han j. and alzomora d.e. editors dallas texas march 13 16 4723 4732 webster s.l. & watkins j.e. 1977 investigation of construction techniques for tactical bridge approach roads across soft ground . soils and pavements laboratory u.s. army corps of engineers waterways experiment station vicksburg ms technical report s771 september 1977 . a b leshchinsky d. 2009 research and innovation seismic performance of various geocell earth retention systems geosysnthetics no. 27 no. 4 46 52 a b c d e han j. pokharel s.k. yang x. and thakur j. 2011 . unpaved roads tough cell geosynthetic reinforcement shows strong promise . roads and bridges . july 49 7 40 43 a b yang x. han j. pokharel s.k. manandhar c. parsons r.l. leshchinsky d. and halahmi i. 2011 . accelerated pavement testing of unpaved roads with geocell reinforced sand bases transportation research board trb annual meeting washington d.c. january 23 27 pokharel s.k. j. han r.l. parsons qian y. d. leshchinsky and i. halahmi 2009 . experimental study on bearing capacity of geocell reinforced bases 8th international conference on bearing capacity of roads railways and airfields champaign illinois june 29 july 2 a b 23 . kief o. and rajagopal k. 2011 modulus improvement factor for geocell reinforced bases . geosynthetics india 2011 chennai india a b emersleben a. meyer m. 2010 . the influence of hoop stresses and earth resistance on the reinforcement mechnism of single and multiple geocells 9th internationational conference on geosynthetics brazil may 23 27 leshchinksy b. 2011 enhancing ballast performance using geocell confinement advances in geotechnical engineering publication of geo frontiers 2011 dallas texas usa march 13 16 4693 4702 pokharel s.k. han j. manandhar c. yang x.m. leshchinsky d. halahmi i. and parsons r.l. 2011 . accelerated pavement testing of geocell reinforced unpaved roads over weak subgrade . journal of transportation research board the 10th international conference on low volume roads july 24 27 lake buena vista florida usa pannell ian 28 january 2010 . progress slow and messy in afghanistan . bbc news . harding thomas 2009 . afghanistan glimmers of hope in helmand . daily telegraph . han j. pokharel s.k. yang x. and thakur j. 2011 . unpaved roads tough cell geosynthetic reinforcement shows strong promise . roads and bridges . july 49 7 40 43 emersleben a. meyer m. 2009 . interaction between hoop stresses and passive earth resistance in single and multiple geocell structures gigsa geoafrica 2009 conference cape town south africa september 2 5 external links edit prs company website retrieved from https en.wikipedia.org w index.php title neoweb & oldid 725729339 categories geotechnical engineeringhidden categories pages using infobox company with unsupported parameters navigation menu personal tools not logged intalkcontributionscreate accountlog in namespaces article talk variants views read edit view history more search navigation main pagecontentsfeatured contentcurrent eventsrandom articledonate to wikipediawikipedia store interaction helpabout wikipediacommunity portalrecent changescontact page tools what links hererelated changesupload filespecial pagespermanent linkpage informationwikidata itemcite this page print export create a bookdownload as pdfprintable version languages add links this page was last modified on 17 june 2016 at 13 43 . text is available under the creative commons attribution sharealike license ; additional terms may apply . by using this site you agree to the terms of use and privacy policy . wikipedia is 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