Aftec Concrete Retaining Wall Quality
Concrete Retaining Walls
Written by GJ Stott
Concrete Retaining Walls are structures designed to enable natural elements to resist breakdown. For example a concrete retaining wall may help rock avoid erosion or keep soil from falling down a slope. When a concrete retaining wall is used to hold water back, it is generally referred to as a dam or a bulkhead. While their purpose is the same, architects have created a number of types of concrete retaining walls including gravity concrete retaining walls, sheet piled concrete retaining walls and cantilever concrete retaining walls and can have a variety of textures, including rock walls.
Gravity Concrete Retaining Walls
Gravity concrete retaining walls are constructed using large boulders or masses of precast concrete. These concrete retaining walls use the concrete wall weight to resist pressure from the opposing side. Short gravity concrete retaining walls use dry-stacked stone retainers with a batter, which enables the wall to lean back toward the retained element. For larger needs, precast concrete, geosynthetics, gabions, crib walls or soil-nailed walls can be used for retaining. These walls are built taller and stronger by including reinforcement and rigid-footing applications. Fortification is often used internally and includes timber, soil, steel or polymer mesh reinforcing.
Geosynthetic walls are steel-reinforced and packed with backfill soil. Gabions are wire baskets which hold heavy rocks to weigh the structure down. Soil-nailed walls reinforce a soil substance with steel or precast concrete rods.
The other methods used for gravity concrete retaining walls involve the use of concrete. Crib walls are concrete block filled with soil.
Masonry Concrete Retaining Walls
When block is used, such as building brick or block concrete retaining walls, the structure is considered a masonryconcrete retaining wall. Masonry concrete retaining walls mean that masonry units (CMU block walls)are utilized to construct the wall. A masonry unit is generally a compressed earth block that is formed to be a specific size and weight. Using such units, a masonry concrete retaining wall can have equal resistance at all points on the structure.
Brick masonry concrete retaining walls use standard 8” x 4” x 2.25” size kiln-fired bricks and mortar. The main drawback from brick masonry walls is that brick has a short lifespan and absorbs large amounts of water.
Block masonry concrete retaining walls are also built to a specified size and weight. Due to their congruence in nature and their large concrete block size, concrete block masonry concrete retaining walls can be built faster than brick masonry concrete retaining walls. They are also often reinforced with steel to improve the lifespan of the concrete retaining wall.
Sheet Piled Concrete Retaining Walls
While generally the last option for concrete retaining walls, sheet piled concrete retaining walls are most effective for soft soils and extremely tight areas. Manufactured from steel, vinyl, fiberglass, plastic planks or wooden planks, sheet piled retaining walls must be pounded at least two-thirds the height of the wall into the ground. Tall sheet piled concrete retaining walls need a tie-back anchor "dead-man" in the soil.
Cantilevered Concrete Retaining Walls
Cantilevered concrete retaining walls are made from steel-reinforced precast concrete or wet masonry. Using structural footing, these concrete retaining walls convert horizontal pressures from behind the wall to vertical pressures on the ground below.
Cantilevered precast concrete retaining walls may be buttressed to improve their strength against pressure. These short wing walls are added at right angles to the main concrete retaining wall. Such concrete retaining walls need rigid concrete footing constructed beneath seasonal frost depth. Cantilevered retaining walls require much less material than gravity retaining walls.
Regardless of the method used, the most important aspect of retaining walls is proper design and installation. The AFTEC Precast Concrete Retaining Wall ensures that pressure can be held behind its steel-reinforced three to eight-foot walls.