|
Canada's “Rock to Road”
Magazine
|
|
What is Reinforced Earth?
Reinforced Earth is a patented soil retention system that combines an approved backfill and flexible metal reinforcing strips to create a unique composite construction material. The interleaving of the backfill and reinforcement develops friction at their points of contact, resulting in a permanent and predictable bond. According to the manufacturers, more than 25,000 Reinforced Earth structures, including 3000 bridge abutments have been completed on five continents in varied applications including roads, motorways, airports, railways, sea and river walls, dams, industrial projects, silos as well as civil and military applications. The system is used in conjunction with precast concrete facing panels, and following the placement of the base course of facing panels, each additional layer of panels interlocks with the previous course. Reinforcing strips and backfill are then placed and compacted in successive layers in a similar manner similar to the placement of traditional earthen embankments. A light crane is utilised to place the facing panels, which are attached to the reinforcing strips by a single high strength bolt. Strict specifications are set for the physical and chemical properties of the backfill, to ensure good overall performance of the system. These include upper and lower gradation limits of 100 per cent passing a 150 mm sieve and, with certain exceptions, a 15 per cent limit on the percentage passing the 0.075 mm (200 mesh sieve). In addition, limits are set on electrochemical properties including Chlorides, Sulphates, Resistivity and pH (acidity), for both above water and underwater applications.
|
