Articulated concrete blocks are revetment systems that can be made in a wide variety of shaped and thickness. It also can be defined as a grid of interconnected concrete block units used for erosion protection of embankments or slopes. The articulated blocks are connected by cables, geotextiles or geogrids, including typically a geotextile membrane underlayment that allows hydraulic infiltration and exfiltration to occur while providing particle retention. The blocks are made of precast concrete and cast into interlocking or non-interlocking shapes.
Where to Use Articulated Concrete Blocks
Articulated concrete blocks can be installed in the following locations:
Shoreline Protection
Bridge Abutments
Slopes
Embankments
Canals
Channels
Landfill Downshutes
Boat Ramps
Pipeline Protection
Residential Waterways
Retention Basins
Wetland Protection
Articulated Concrete Block Systems
Articulated concrete block cabled systems are formed by individual blocks that are connected into a grid by ropes, polyester cables or stainless steel cables. Individual concrete block systems may be built off-site and the transported to the project location, or they can also be completed on-site by hand. Some manufactured blocks have tapered tops preventing protrusions, the most common failure of articulated concrete blocks.
Articulated Concrete Block Installation Tips
Articulated concrete block systems are easily assembled but their installation must have a good quality control to avoid further problems. Here are some installation tips:
Final grade should be clean and block must be in full contact with geotextile underlayment.
Subgrade should be compacted at least 90-95 percent of standard Proctor.
Geotextile membrane should be overlapped at least 3 feet for wet locations
When placing blocks against a structure, fill all voids and gasps with grout or sealer
The protrusion tolerance must not be greater than the design tolerance.
If articulated concrete blocks are going to be installed under water, install heavier blocks at the toe of the slope to keep them in place
Articulated Concrete Blocks: Factors to Consider
Several factors must be considered when analyzing which erosion protection system is going to be used. Articulated concrete blocks can be used in the following situations:
Where heavy flow is expected
Areas where flash or high flow velocities (20 fps) are occurring
The interlocking properties allow for expansion and contraction.
Can be used around trees and over storm water pipes
If maintenance cost is an issue, articulated concrete blocks are almost maintenance-free
Variations of articulated concrete blocks provide for areas that can be planted
If infiltration of storm water is allowed, articulated concrete blocks might be a feasible solution
If a site is not easily accessible, articulated concrete blocks can be hand-placed.
Articulated concrete blocks can provide greater strength than rocks or soft solutions
