Recommendations for the Installation of
The Concrete Block Revetment (CBR) System

Overview:
The installation of a Concrete Block Revetment System (CBR) offers the owner or contractor a quick and cost effective solution to erosion control and/or soil stabilization.  Some of its many advantages and uses are; ease of installation, versatile applications, it allows vegetation to re-establish, a viable alternative when local resources are not available, the option to immediately drive on the mat, re-usability for temporary applications and cost

The 16 X 8 X 4.5” mats can be delivered to the jobsite by either a conventional flatbed trailer or boom truck.  When possible, the CBR mats should be placed directly from the delivery truck to the prepared foundation to minimize handling and maximize installation efficiency.

The following guidelines are provided for general use, it is incumbent upon the installer to assure that specific contract specifications and provisions are also being complied with. Where there is a conflict between these guidelines and the contract specifications, the installer shall seek written clarification from the proper authority before proceeding.

Subgrade Preparation:
The Concrete Block Revetment (CBR) shall be placed on the slopes, sides and bottoms of channels in substantial compliance with the specifications and at the locations shown on the plans or established by the Owner.

Unless otherwise provided, moisture and density control will not be required for the surface upon which the CBR will be placed and only moderate equipment compaction is expected.

The ground foundation upon which the CBR is to be placed shall be cut or filled and graded in accordance with the details shown in the contract or established by the Owner. Obstructions that may interfere with the installation shall be removed and foundation voids shall be filled with material approved by the owner. The ground shall be contoured so that sudden or sharp variations in contour are eliminated. When embankment material is required it shall consist of materials approved by the owner.  When the application is expected to experience traffic loading, further engineering may be required for the specific application to assure the structural integrity of the installation.

The CBR shall be placed so that the weight is carried by the slope material and not by the adjoining blocks. CBR shall be placed to form a continuous blanket. The finished surface of CBR will follow the finished foundation grade, so every effort should be made to ensure a uniform foundation. The Owner shall approve the condition of the completed ground surface foundation prior to the placement of the CBR.

Installation:
It is recommended that the contractor have a technician provided by Erosion Block Supply experienced in the installation of the CBR at the start of an installation to assist in any special techniques needed to assure a proper installation.

On Pipe Culvert, Concrete Box and Flume locations the installation will be per the recommendations contained here unless otherwise shown on construction drawings.

Where CBR is used as an alternative for Riprap, the same details for elevations and contours as shown for Riprap will be utilized for the CBR.

A layer of geotextile filter fabric shall be placed at the interface between all slope and erosion protection structures and the supporting soil or backfill material, or placed as shown in the contract.

The geotextile fabric shall be laid from the downstream end of project to the upstream end, perpendicular to the major direction of flow so that the geotextile joints are shingled to direct flow over the joint and also to prevent undermining. Intimate contact with the subsurface is critical to the systems performance in the field.

A minimum fabric overlap of 2 feet shall be used.  More overlap may be required depending on conditions and the geotextile manufacturer's recommendations may prevail as determined by the owner.