Segmental Retaining Walls (SRWs) are dry-stacked, mortarless walls made of 100%, low-absorption, high-strength concrete units. SRWs are more economical and easier to install than poured-in-place concrete or traditional masonry walls. Their rugged, rock-solid durability enables them to outlast railroad ties and timbers while remaining environmentally safe. SRWs are typically used by commercial entities, homeowners and governmental agencies. VERSA-LOK retaining wall systems deliver these benefits:

• Solid Unit Durability
  Solid VERSA-LOK units offer superior resistance to damage before, during and after construction. Built with high-strength, low-absorption concrete, VERSA-LOK can be modified easily right on the job site.

• Design Flexibility
  VERSA-LOK offers the most design-friendly system on the market. A seemingly endless array of curves, corners, steps, freestanding walls, and columns can be created using only one solid unit.
  
• Environmentally Safe
  Made of high-strength, low-absorption concrete, VERSA-LOK units do not create an environmental hazard like some chemically-treated products. Concrete is the sustainable building material preferred by architects, designers, engineers and other design professionals. The National Concrete Masonry Association has more information on sustainable building using concrete.
  
• Cost-Effective
  Because frost footings are not required, VERSA-LOK walls are more economical than poured-in-place walls and will outlast treated timber walls by many years.
  
• Agency Approved
  Not only are VERSA-LOK retaining walls ideal for residential and commercial projects, but they are also well-suited for government agency jobs. The U.S. Army Corps of Engineers and many state departments of transportation have specified and used VERSA-LOK systems on a variety of projects including critical shoreline structures, freeways, retention ponds and tall walls. The International Conference of Building Officials (ICBO) and the Highway Innovative Technology Evaluation Center (HITEC) have published evaluations of the VERSA-LOK Retaining Wall System.
  
• Geogrid Compatible
  Virtually any geogrid or fabric soil reinforcement is compatible with all VERSA-LOK Retaining Wall Systems, which allows the construction of walls exceeding 50 feet tall. For best results, we recommend using VERSA-Grid geogrid soil reinforcement.
  
• Freeze/Thaw Resistant
  VERSA-LOK units are placed on granular leveling pads, creating flexible structures that can tolerate freeze/thaw movement in northern climates.
  
• Variable Bond
  While other systems will not pin or connect if walls are slightly off bond, VERSA-LOK walls allow variable bond—saving installers time on the job site.
  
• Top-Down Pinning
  Installing VERSA-LOK retaining walls is easy thanks to top-down pinning. Installers simply insert high-strength, glass-reinforced nylon VERSA-TUFF pins into the holes of uppermost units and tap them down into the slots of lower course units to ensure uniform alignment and structural integrity.
  
• Easy, Mortarless Construction
  VERSA-LOK walls are installed without mortar and do not require costly concrete footings below frost depth. Because units are dry-stacked, they can move slightly in relation to each other without damage.
  
• Free-Draining Face
  Because VERSA-LOK walls are built without mortar, water is allowed to pass through wall joints to help eliminate hydrostatic pressure behind walls.

For many projects, VERSA-LOK® Retaining Wall Systems work solely as gravity systems where unit weight provides resistance to earth pressures. Frictional forces between units and tight pin connections hold units together so walls behave as coherent structures. Maximum allowable height for gravity walls varies with site and soil conditions. Generally, with level backfill, good soils no additional loads, VERSA-LOK gravity walls may be constructed up to four feet.When weight of units alone is not enough to resist soil loads, horizontal layers of geosynthetic material such as VERSA-Grid, must be used to reinforce soil behind walls. Proper soil reinforcement and design allows VERSA-LOK walls to be built more than 40 feet tall.

The animated feature below illustrates all the components of a VERSA-LOK retaining wall. Each VERSA-LOK wall course is set back 3/4-inch from the front of the course beneath it. This arrangement causes walls to cant into retained soil at an angle of approximately seven degrees. Canted walls are more stable than vertical walls because gravitational forces "pull" units into retained soil. Remember, when designing a soil-reinforced wall always consider factors such as site, soil, loads and height of the wall.

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Click below to watch how a gravity wall is built

Click below to watch how a soil-reinforced wall is built