GEOSYNTHETICS ENGINEERING: IN THEORY AND PRACTICE

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2 GEOSYNTHETICS ENGINEERING: IN THEORY AND PRACTICE Prof. J. N. Mandal Department of Civil Engineering, IIT Bombay, Powai, Mumbai , India. Tel

3 Module-13 LECTURE- 58 Designing with Geofoam

4 OUTLINE Introduction to geofoam Classification of geofoam Manufacturing of geofoam Applications, Advantages and Disadvantages, Cost, and Functions of geofoam Geofoam test methods Design function of geofoam Installation of geofoam Design of embankment using geofoam

5 Cont List of tests on geofoam Development of a new geomaterial using EPS beads and fly ash Triaxial test on expanded polystyrene (EPS) geofoam Poisson s ratio of geofoam Geofoam application for roadway widening and repairing, problems

6 GEOSYNTHETICS FOR GEOFOAM STRUCTURES

7 Compression of conventional and geofoam embankment (BASF, 1995) Conventional (Increase in surcharge pressure) Geofoam (No increase surface pressure)

8 Geofoam Retaining Wall

9 Drink a cup of coffee or tea

10 As per ASTM D 4439, the Geofoam can be defined as block or planar rigid cellular foamed polymeric used in geotechnical engineering applications. In textile term, the geofoam is called as Expended Polystyrene (EPS) or Extruded Polystyrene (XPS). The geofoam is a cellular plastic material. We say it a thermocal used for packaging the electronic goods, making cup container to drink coffee or tea and others. The geofoam is a super light material which is available in the form of blocks or cellular honeycomb form. It provides easy of handling. It is an emerging geomaterial

11 Size of block-molded geofoam is about 600 mm x 1200 mm x 2400 mm. The block size can vary from country to country. The other minimized sizes can be made by cutting and trimming at site. Weight of the block varies from 11 kg/m 3 to 40 kg/m 3. Its density is very less (about 100 times less) compared to the conventional fill materials in geotechnical engineering. Geofoams have been used in many structures around the world for the last forty-five years. The life time of geofoam is about 70 to 100 years.

12 Full Size EPS block in temporary storage after moulding

13 Block-molded Geofoam

14 Square Geofoam-geocell Honeycomb Geofoam-geocell

15 Norwegian Public Road Administration (1972) used geofoam as light weight material for the construction of road embankment. Lots of research works have been carried out on geofoam by various researchers i.e. Thonpsett et al. (1995), Aaboe (1987), Duskov (1991), Horvath (1992), Stark et al.(2004), Horvath (1997), Mandal (1998), Nimbalkar (1999), Hazarika(2006), Waghdhave (2006), Mandal and Nimbalkar (2004), and Horvath (1995). It was reported that the temperature of geofoam should not exceed of 95 o C.

16 Geofoam has been exclusively used in Belgium, Canada. Finland, France, Germany, Japan, The Netherland, Norway, Sweden, United Kingdom and U.S.A though its use in India is in infant stage. Frydenlund and Aaboe (1994) reported that geofaoms have been used over 150 projects in Norway. Bearing capacity of clay or silt can be considered equivalent to compressive strength of EPS i.e. 100 kpa. Arellano and Stark (2009) recommended to provide lower density of geofoam at lower portion and higher density of geofoam at upper portion of the roadway embankment for economical design solutions.

17 Huang and Negussey (2011) reported modified test methods to determine California Bearing Ratio (CBR), resilient modulus and modulus of subgrade reaction of geofoam. Aytekin (1998) reported that the cost related to damage because of swelling is double of the cost related to damage from earthquakes, floods, tornadoes and hurricanes. Since the early 1990 s, geofoam has been a generic term for any synthetic geomaterial created in an expansion process using a gas (blowing agent) resulting in a texture of numerous closed cells. Geofoam is not just one material or product but a very diverse family of many different kinds of materials.

18 Development of geofoam in geosynthetic family (Padade, 2010)

19 Formation stages of geofoam block

20 Scanning Electron Microscopy (SEM) picture of a geofoam bead

21 A modified geofoam has been prepared by mixing geofoam beads, fly ash, cement and water in proper proportions. (a) (b) (a) Mix of geofoam beads, fly ash, cement and water in proper proportion (b) Prepared modified geofoam

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23 EPS Geofoam Manufacturing Process (After BASF, 1995)

24 Embankment and Pavements, Retaining walls and abutments, Road widening, Railways, Foundation, Side-hill fill, Landscape Dike/ Berms Below ground walls of structures Applications Geofoam can effectively be used in various engineering applications, Tunnels and buried pipes Tunnels Clay Liners Flood Control Levees Parking Clay Heave Protection Sound barriers Landfills, and Gas Venting

25 In conventional method, good quality granular materials are used as backfill behind retaining structures. Sometimes the materials are scarce. The inclusion of geofoam reduces the lateral earth pressure dramatically Geofoam as an alternative backfill material behind retaining wall

26 Geofoam as an alternative filling material for embankment

27 Some major applications of geofoam Geofoam retaining wall

28 Placement of Geofoam as backfill material behind reinforced concrete retaining wall

29 Placement of Geofoam as drainage behind reinforced concrete retaining wall

30 Placement of Geofoam as compressible inclusion behind reinforced concrete retaining wall Geofoam as compressible inclusion with reinforcements behind reinforced concrete retaining wall

31 Geofoam application in retaining wall for extension of existing pavement Application of Geofoam behind bridge abutment (after Stark et al., 2004) Geofoam wall as noise barrier

32 Geofoam as filling material beneath the pavement Embankment made of geofoam as filling material

33 Road widening using geofoam Embankment made with geofoam Geofoam beneath the slabs or beams at foundation (After Frydenlund et al., 1987) Slope side fills of geofoam

34 Geofoam application in hilly terrain Different density geofoam used for road construction

35 Geofoam beneath the bridge abutment (After Frydenlund and Aabфe, 1996) Geofoam above canal

36 Geofoam at the basement for thermal insulation Geofoam as compressible inclusion beneath a grade beam or structural slab

37 Geofoam as compressible inclusion for underpass (After Frydenlund et al., 1987) Geofoam as compressible inclusion above pipes or culverts Geofoam as compressible inclusion for railway

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39 Bridge Ramp Construction With Geofoam Geofoam Check After 25 Years In Service No deformation No damage

40 Please let us hear from you Any question?

41 Prof. J. N. Mandal Department of civil engineering, IIT Bombay, Powai, Mumbai , India. Tel