The contractor for the Pleasant River Bridge project located in Milo, ME 04463 reached out to UniversalFoam Products for a foam material called Elastic Inclusion.
Elastic Inclusion or Elasticized Polystyrene as it is sometimes also called, is used almost exclusively in new bridge construction. It is used to combat pavement settlement at bridge abutments caused by seasonal freeze thaw conditions.
When the temperature drops below freezing it can cause soils to contract. When temperatures then rise above freezing, they expand. These cycles cause the soil to settle, in turn causing the asphalt paving to drop down as it loses support. This is what causes the “b-bump” sound when you enter and exit a bridge.
Elastic Inclusion is installed vertically up against the face of the bridge abutment prior to backfilling. It is designed to contract when the soils expand and go back to its original thickness when the soils contract, greatly reducing the chance of settlement.