Geofoam, also known as expanded polystyrene or EPS for short, is the perfect material for bridge abutments. This material is used for bridge abutment approach fills. Highlighted by an inherently high level of compressive resistance, geofoam serves as a reliable, secure, safe, and low-cost fill that adequately supports heavy loads above.
Though geofoam is lightweight, it holds up without flaw amidst stress from above. The material’s lightweight is also beneficial in that it does not stress the soil below the bridge as occurs with other materials used for backfill. The result is a decrease in the differential movement along the interface between the approach and bridge, serving to decrease project costs and also reduce the maintenance budget across posterity.
Aside from providing compressive resistance benefits, geofoam also decreases lateral forces along the bridge foundation and abutment walls as well as other retaining structures. The decrease in lateral force is the result of the lateral force being directly proportional to the backfill weight used in the construction of the abutment. While the buildup of lateral pressure will cause stress on bridge abutments made without geofoam over the long haul, those that rely on geofoam will benefit from comparably high levels of compressive strength that allow for the absorbing of wall displacement for long-term stability.
Geofoam is quite light compared to other materials used for backfill, ensuring the designing of the bridge abutment proves affordable as there is no longer any need for the use of extensive horizontal forces. Though it might be hard to believe, the truth is geofoam is primarily comprised of air. Air is environmentally-friendly and sets the stage for the recycling of this building material. In short, using geofoam for bridge abutments saves you money, bolsters bridge reliability and helps save our planet.
