313SECTION 249—FLOW ABLE BACKFILL
249.01 Description
These specifications cover materials, design criteria, and mixing and testing procedures for flowable backfill used in applications where modified liquid or plastic concrete is required for backfilling pipe installations and plugging abandoned pipe lines, culverts, and conduits.
249.02 Materials
a.Hydraulic Cement shall conform to Section 214.
b.Fly Ash shall conform to Section 241.02(a).
c.Water shall conform to Section 216, except that wash water as described in Section 216.02 may comprise the total mix water.
d.Aggregates shall conform to Sections 202 and 203 with a combined gradation as determined by the Contractor.
e.Admixtures shall conform to Section 215.
f.Granulated Iron Blast Furnace Slag shall conform to Section 215.
249.03 Mix Design
The Contractor shall provide the appropriate mix design for the flowable backfill application. Flowable backfill shall have a design compressive strength of 30 to 200 pounds per square inch when used as back - fill material in pipe installations or in other uses at locations as designated on the plans. Flowable backfill shall have a design compressive strength of 30 to 1200 pounds per square inch when used as backfill material for plugging pipes and culverts designated for abandonment as shown on the plans. The design compressive strength requirement shall be at 28 days when tested in accordance with ASTM D 4832. Mix design shall result in a fluid product having no less than an 8-inch slump at the time of placement. The Contractor shall submit a mix design verifying compliance with 28 day compressive strength requirements supported by laboratory test data to the Engineer for review. The Contractor must have the Engineer’ s acceptance of the Contractor’ s mix design and test data prior to placement of the flowable backfill. SECTION 250 - CARBON FIBER MESH
250.01 Description
These specifications cover carbon fiber mesh used along with EP-7 epoxy to seal joints in between box beam bridges and other bridge joints.250.01 314250.02—Materials
a.Carbon Fiber Mesh Materials shall conform to the following: The carbon fiber mesh is comprised of high tensile strength carbon fiber strips 4 inches in width. The mesh is not impregnated, wets out with the epoxy, and cured in place in epoxy resin overlay. General Information Constituent Materials: 6K Carbon Fiber unidirectional tows Primary Fiber Directions Closed knit 0° X 90° Color Black Carbon Material Properties Requirement Test Method Nominal Thickness 0.030 inch Nominal Tensile Strength per unit width 400,000 psi ASTM D3039 Nominal Tensile Modulus 33,000,000 psi ASTM D3379 Failure Strain 1.3% ASTM D3379 Grid Spacing 1/4” x 1/4” (inch) (longitudinal x transverse) SECTION 251 - GAL V ANIC ANODES
251.01 Description
These specifications cover galvanic anodes used to minimize corrosion between the interface of existing concrete and concrete repair materials.
251.02 Detail Requirements
Anodes shall come pre-manufactured and be supplied with integral tie wires for connecting to the reinforcing steel. Tie wires shall be in accordance with ASTM A82. Anodes shall contain no corrosive constituents or substances detrimental to reinforcing steel. The material covering the zinc metal shall be inert to fresh concrete and cover the entire zinc material so that the zinc material is protected from coming into direct contact with the reinforcing steel. Metallic zinc used in the anodes shall be in compliance with ASTM B418 and shall not contain more than the following impurities: Copper 0.01 % maximum Lead 0.003 % maximum Iron 0.015 % maximum Cadmium 0.003 % maximum250.02
Source: Virginia Road and Bridge Specifications, 2020 Edition. Pages 341–341 of 1,065.