3604Precast Articulated Concrete

3604.1SCOPE

Provide manufactured articulated concrete block and mat revetment systems to protect embankment slopes, river channels, spillways, and vehicle accesses where the soil may erode.

3604.2REQUIREMENTS

A Revetment Systems A.1 Articulated Block Mat Provide closed cell or open cell articulated block mat consisting of blocks cabled together into a prefabricated mat placed on a geotextile fabric meeting ASTM D6684, Standard Specification for Materials and Manufacture of Articulating Concrete Block (ACB) Systems . Place the mats side-by-side, and clamp and anchor to provide one homogeneous erosion protection system. Provide blocks for the mats ranging in thickness and weight meeting the bed shear requirements in accordance with Table 3604.2-1. Determine the type in accordance with Table 3604.2-1 for Type A, Type B, Type C, Type D, and Type E. Table 3604.2-1 Bed Shear Requirements Type Minimum Bed Shear, pounds/square foot A 10 B 15 C 20 D 25 E 30 A.2 Articulated Interlocking Block Mat Provide closed cell or open cell articulated interlocking block consisting of hand placed concrete blocks placed on a geotextile fabric and locked together to form a soil protecting paver system. Provide blocks ranging in thickness and weight meeting the bed shear requirements in accordance with Table 3604.2-1. Determine the type in accordance with Table 3604.2-1 for Type A, Type B, and Type C. Provide open cell units with an open area of at least 20 percent when measured at the bottom of the block in the system. Provide closed cell systems with an open area no greater than 10 percent when measured at the bottom of the block in the system.

B Concrete Provide blocks meeting Specification 2461, “Structural Concrete” and the following:

ASTM C1262, Standard Test Method for Evaluating the Freeze-Thaw Durability of Dry- Cast Segmental Retaining Wall Units and Related Concrete Units, using a distilled water solution or less than 1.0 percent loss in 50 freeze/thaw cycles when tested in accordance with ASTM C67, Standard Test Method for Sampling and Testing Brick and Structural Clay Tile

Standard Test Methods for Sampling and Testing Concrete Masonry Units and Related Units

ASTM C140, Standard Test Methods for Sampling and Testing Concrete Masonry Units and Related Units:

C Cable For systems using cables, provide stainless steel or coated high-strength polyester cables compatible with the system and designed to meet a 5:1 factor of safety in accordance with ASTM D6684, Standard Specification for Materials and Manufacture of Articulating Concrete Block (ACB) Systems . Use stainless steel cable at least 3/16 inches thick and use high-strength polyester cable at least 1/4 inches thick. D Geotextile Filter Provide geotextile appropriate for the soil conditions in accordance with the manufacture’s recommendations and 3733, “Geosynthetic Materials.” The Engineer will make the final approval of the geotextile type. E Clamps Use stainless-steel wire rope clamps and sleeves to secure loops of adjoining mats. F Anchors Use helical or duckbill anchors with a pull resistance of 4,000 pounds to secure the top and exposed sides of the articulating block system.

3604.3SAMPLING AND TESTING

Submit to the Engineer a manufacture’s Certificate of Compliance for the revetment system and components that meets the requirements of ASTM D7277, Standard Test Method for Performance Testing of Articulating Concrete Block (ACB) Revetment Systems for Hydraulic Stability in Open Channel Flow , and ASTM D7276, Standard Guide for Analysis and Interpretation of Test Data for Articulating Concrete Block (ACB) Revetment Systems in Open Flow Channels.