No. 19 of 19

GeoFoam

by

John S. Horvath, Ph.D., P.E.

The information presented in this document has been reviewed by the Education Committee of the International Geosynthetics Society and is believed to fairly represent the current state of practice.

However, the International Geosynthetics Society does not accept any liability arising in any way from use of the information presented.

Lecture Outline

•What is Geofoam?•Geofoam materials•Why Use Geofoam?•Designing with Geofoam•Examples of Geofoam Applications

INTRODUCTION

Construction materials are undergoing significant changes with:

• improvements (e.g. increased strength) to existing, traditional materials

• development of new functions and applications for existing materials e.g GEOFOAM

• development of new materials

• use of recycled waste materials

What is Geofoam?

Generic term for closed-cell foams, used in geotechnical applications, that are manufactured from an expansion process using a blowing agent either in a plant or in situ:

• polymeric (plastic)– expanded polystyrene (EPS) <<< predominant– extruded polystyrene (XPS)– others (polyethylene, polyurethane, polyisocyanurate)

• glass (cellular glass)

• cementitious

Full Size EPS block in

temporary storage after

moulding

Benefits of using Geofoam

• works with the forces of nature, not against them

• useful in both new construction and with existing structures

• provides unique geosynthetic functions

• multifunctional in many applications

• compatible and synergistic with other types of geosynthetics

Overview of designing with Geofoam

• design by function

• generally treat as an equivalent earth material and use conventional geotechnical analytical methods

• obtain appropriate parameters for desired analyses and other relevant technical information

• economic assessment

Geofoam geosynthetic functions:

• thermal insulation (1960s)

• (ultra)lightweight fill (1970s)

• fluid transmission = drainage (1970s)

• noise and vibration damping (1980s)

• compressible inclusion (1980s)

• structural (1990s)

Key material behaviour and other technical issues for design:

• index properties

• mechanical (stress-strain-time) behavior

• thermal properties

• durability

• environmental impact

Factors to consider in an economic assessment

• design aspects of initial construction

• constructability aspects of initial construction

• reduced costs of operation and maintenance

Laying Geofoam under Road

Geofoam under Railway

Winter Working

Protective Facing

Bridge Approach Fill

Geofoam for Failed Road Embankment

Geofoam for Road Embankment

Structural Fill

Backfill to Tied Quay Wall

Nail Plate for Joining Blocks

Underslab Venting

Vibration Damping

tensile reinforcement(optional)

geofoam

Back of Wall Fill

Wall Back Fill

Footing Pressure Reduction

Heave Pressure Reduction fill

geofoam

Pressure Reduction Slabs

Wall Insulation

Facing to Reinforced Soil in a Landfill (UK)

Facing to Reinforced Soil in a Landfill (UK)