SECTION 716 — OPEN CELL CONCRETE BLOCK 700-41 — OPEN CELL CONCRETE BLOCK
716.01 Description of Work.
This work includes furnishing Open Cell Concrete Blocks (OCB) at the required lines and grades and includes preparing the subbase and providing the filter fabric materials.
716.02 Materials.
General. Use open cell concrete blocks that have been pre-manufactured as an assembly of concrete blocks. Ensure that t he open cell of the blocks have vertical openings and a void space ratio equal to as required with a sufficient wall thickness to resist breakage during shipping and installation. Ensure that each block incorporates interlocking surfaces and/or manufacturer requirements that prevent lateral and vertical displacement of the blocks. Ensure that the interlocking surfaces do not protrude beyond the perimeter of the blocks such that they reduce the flexibility or articulation capability or become damaged or broken. Once in place, ensure that the interlocking surfaces prevent the lateral displacement of the blocks. Provide OCB that conforms to SECTION M01 and Subsection M18.17 that conform to the following: • Cementitious Materials. Use materials that conform to the following applicable standards: ○ Portland Cements – ASTM C 150 for Portland cement ○ Blended Cements – ASTM C 595 for blended hydraulic cements ○ Hydrated Lime Types – ASTM C 207 for hydrated lime types ○ Pozzolans – ASTM C 618 for fly ash and raw or calcined natural pozzolans for use in Portland cement concrete • Aggregates. Use aggregates that conform to the following, except that grading requirements may not apply: ○ Normal Weight – ASTM C 33 for concrete aggregates • Porous Media Beds. When applicable, use material layers underlying the OCB, including chocker course, crushed stone, reservoir course, and filter course, that conform to the gradation requirements in the Table in Subsection M01.09. • P hysical Requirements . Provide an OCB that at a minimum meets the loading requirements of H-20 or as specified in the Contract. • Du rability . The manufacturer shall certify that the concrete units have adequate durability when subjected to a freeze-thaw environment. • V isual Inspection. Ensure that all units are sound and free of defects that would interfere with the proper placing of the unit or impair the strength or permanence of the construction. The following will be rejected:
Part 700 — Drainage and Selected Utility Accessories August 2025
700-42 SECTION 716 — OPEN CELL CONCRETE BLOCK ○ Cracks exceeding 0.25 in. in width and/or 1.0 in. (2.54 cm) in depth ○ Chipping resulting in a weight loss exceeding 10 percent of the average weight of the blocks Replace blocks rejected before delivery from the point of manufacture at the manufacturer's expense. Repair blocks rejected at the job site to the satisfaction of the Engineer with structural grout at no additional cost to the Department. • S ampling and Testing. Provide proper access to the Engineer to facilities to inspect and sample the units at the place of manufacture from lots ready for delivery. • E xpense of Tests . Perform any additional testing other than that provided by the manufacturer at no additional cost to the Department. Filter Fabric. Provide filter fabric, if required, as specified in the Contract and as approved by the Engineer. Subbase Material. Provide, prepare, place, and grade the subbase material as required in the Contract.
716.03 Construction Methods.
Submittals.
a.Shop Drawings . Submit the manufacturer’s product data, including installation instructions, to the Engineer. Ensure that the Shop Drawings include the layout, layout sequence, and details for edging, anchoring, junctions, and grade change.
b.R epresentative Samples . Select the sources proposed to obtain in advance of the time when the materials will be required in the work. Submit the product literature and suitable samples of the OCB, anchors , and filter fabric to the Engineer for approval before the delivery of any material to the work site. Submit the OCB revetment system and manufacturer’s certification that the revetment system and components meet the requirements of the Contract. Foundation Preparation.
a.General. Construct areas on which filter fabric and cellular concrete blocks will be placed to the required lines and grades. Protect all native materials from over compaction and properly compact the subbase materials.
b.G rading. Grade the application area to a smooth plane surface to ensure that intimate contact is achieved between the slope face and the geotextile (filter fabric) and between the geotextile and the entire bottom surface of the cellular concrete blocks. Regrade or remove all slope deformities, roots, grade stakes, and stones that project normal to the local slope face. Do not allow any holes, pockmarks, slope board teeth marks, footprints, or other voids greater than 1.0 in. in depth normal to the local slope face. Do not allow any grooves or depressions greater than 0.5 in. in depth normal to the local slope face with a dimension exceeding 1.0 ft in any direction. As necessary, raise any surfaces to
Part 700 — Drainage and Selected Utility Accessories August 2025
SECTION 716 — OPEN CELL CONCRETE BLOCK 700-43 grade by placing compacted homogeneous material. Ensure that the slope and slope face are uniformly compacted and that the depth of layers, homogeneity of soil, and amount of compaction are as required. Perform the excavation and preparation for anchor trenches, side trenches, and toe trenches or aprons according to the required lines, grades, and dimensions. Uniformly grade the anchor trench hinge-point at the top of the slope so that no dips or bumps greater than 0.5 in. over or under the local grade occur. Uniformly grade the width of the anchor trench hinge point to ensure intimate contact between all concrete blocks and the underlying grade at the hinge point.
c.Inspection. The Engineer, Design Engineer , and manufacturer ’s representative will inspect the prepared subgrade area before placement of the open cell concrete blocks and filter fabric if required. Provide a minimum of 72 hours notice before the placement of the concrete blocks. Do not place anything until the areas have been approved by each of the parties. Placement of Geotextile Filter Fabric.
a.General. Place filter fabric or filtration geotextile, when specified, below all OCB within the required limits.
b.P lacement . Place filter fabric directly on the prepared surface in intimate contact with the subgrade and free of folds or wrinkles. Do not walk on or disturb t he filter fabric if this results in a loss of intimate contact between the open cell concrete block and the fabric or between the fabric and the subgrade. Place the filter fabric so that the upstream strip of fabric overlaps the downstream strip. Overlap the longitudinal and transverse joints at least 2 ft and at least 1 ft beyond the top and bottom revetment termination points or as required by the manufacturer. Placement of Concrete Blocks.
a.Placement. Place the OCB on the filter fabric , if required, to produce a smooth plane surface in complete contact. Do not allow any individual block within the plane of placed cellular concrete blocks to protrude more than ½ in. To ensure that the cellular concrete blocks are flush and develop complete contact with the subgrade, seat the blocks with a roller or other means as approved by the Engineer. Place the OCB side by side and/or end to end or as described by the manufacturer. Where distinct changes in grade that result in a discontinuous revetment surface in the direction of flow occur, install a seam per the manufacturer at the grade change location to produce a continuous surface. Backfill anchor trenches and side trenches and compact flush with the top of the blocks. Ensure that the integrity of a soil trench backfill is maintained to ensure a surface that is flush with the top surface of the concrete blocks for its entire service life. Complete the backfilling and compaction of trenches in a timely fashion.
Part 700 — Drainage and Selected Utility Accessories August 2025
700-44 SECTION 716 — OPEN CELL CONCRETE BLOCK
b.Finishing. Backfill the cells or openings in the concrete blocks following the placement of the OCB. Spread the backfill material over the surface of the OCB to ensure that there are no voids and that th e backfill material extends from the filter fabric to the surface of the concrete blocks.
716.04 Method of Measurement.
Open Cell Concrete Block will be measured by the number of square yards installed.
716.05 Basis of Payment.
The Department will pay for the completed and accepted quantities as follows. Pay Item Pay Unit Open Cell Concrete Block SY The price constitutes full compensation for all labor, materials, and equipment necessary to install the open cell concrete block , including providing, preparing, placing, and grading the subbase; placing and installing filter fabric; and all other incidentals required to finish the work , complete and accepted.
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Source: Standard Specifications for Road and Bridge Construction (Blue Book), 2022 (Aug 2025 compilation) Edition. Pages 366–369 of 951. View official source ↗