Article 1 — Description
Furnish and install a carbon fiber reinforced polymer (CFRP) system for protecting or strengthening concrete members .
Article 2 — Materials
Provide unidirectional high- strength carbon fiber fabric, fully saturated with compatible epoxy resin in conformance with manufacturer’s recommendations, to form a CFRP system unless otherwise shown on the plans. Use carbon fibers in the CFRP system that a re in accordance with DMS -4700 , “Externally Bonded Fiber Reinforced Polymer (FRP) System for Repairing and Strengthening Concrete Structure Members,” and are pre- approved for use unless otherwise shown on the plans. Pre- approved CFRP systems are listed on the Department ’s MPL for Fiber -Reinforced Polymer and shown on the plans. Provide appearance coating recommended by CFRP system manufacturer to protect the CFRP from ultraviolet radiation. Match color of protective appearance coating to adjacent concrete. Submit a schedule of repair materials to be used including detailed application instructions. Provide manuf acturer’s product data sheets that include mechanical, physical, and chemical properties for the proposed primer, putty, resin, saturant, carbon fiber, and protective appearance coating. Provide manufacturer’s Safety Data Sheets for all materials to be used onsite and certification that the materials are in conform ance with local, state, and federal environmental and worker’s safety laws and regulations. Provide all CFRP components (excluding fabric) in original factory -sealed, unopened packaging clearly marked with the manufacturer’s name, product identification (including brand, system identification number, and batch number), and expiration date or shelf life. Store and handle the products in conformance with the manufacturer’s instructions. Ensure outdat ed components are not used.
Article 3 — Work Methods
Obtain approval for all materials, qualifications, and methods of application at least 10 days before beginning application. Provide a technical representative from a CFRP manufacturer for concrete member strengthening during the initial installation of the strengthening materials to provide onsite project support and to verify adequacy of surface preparation.
3.1 Qualifications. Provide documentation from the CFRP manufacturer showing project personnel have completed training on the CFRP system selected. Ensure trained personnel always remain at the worksite at all times to install and direct the CFRP field installation work. Provide documentation for concrete member
strengthening work to demonstrate previous CFRP field installation, including successful completion of at least three CFRP field installation projects similar in scope and magnitude to the work. Additionally, the Engineer may request the presence of the manufacturer’s representative for additional training if work personnel do not adequately follow manufacturer’s installation directions. CFRP work will be delayed until personnel are trained and have demonstrated proper installation on approved mock location at the Contractor’s expense.
3.2 Working Drawings . Workin g drawings are not required for CFRP application to confine or protect concrete
members, unless otherwise shown on the plans. Provide working drawings and calculations signed and sealed by a licensed professional engineer for concrete member strengthening. Include in working drawings: repair locations; relevant dimensions of the system; details of the number, thickness, and orientation of 1019 carbon fiber layers; locations of splices and corresponding lap lengths; number, size, and location of CFRP anchors; and construction procedures specifying the individual steps in the installation process. Identify the environmental and substrate conditions that may affect the application and curing of the CFRP system. Calculations must show the proposed system provides the required strengthening as shown on the plans.
3.3 Concrete Structure Repair . Perform concrete structure repair in accordance with Item 429, “Concrete
Structure Repair ,” as shown on the plans. Allow enough time for concrete repair material to cure in conformance with CFRP manufacturer’s specifications before placing CFRP. Repairing surface defects to ensure required contact surface condition is not considered concrete structure repair and is required work for this Item.
3.4 Surface Preparation . Prepare concrete substrate surfaces to promote continuous intimate contact between
the CFRP and the concrete by providing a clean, smooth, and flat or convex surface. Grind away all irregularities, unevenness, and sharp protrusions to provide less than 1/32- in. surface profil e deviation. Fill all voids or depressions of diameters larger than 1/2 in. or depths greater than 1/8 in. with approved material. Provide surface roughness requirements for strengthening as shown on the plans . Round or chamfer all inside and outside corners and sharp edges to a minimum radius of 1/2 in. Remove all laitance, dust, dirt, oil, foreign particles, disintegrated materials, and any other matter that could interfere with the bond of the CFRP to the concrete using abrasive blasting. Drill holes in concrete using a rotary impact drill when CFRP anchors are shown on the plans. Ensure existing reinforcing steel is not cut when drilling holes. Thoroughly clean holes by using a wire hole- brush and oil -free compressed air to remove all drill powder from i nterior surfaces of hole.
3.5 Installation . Monitor environmental conditions before and during installation of the CFRP system in
conformance with the C ontract requirements and manufacturer’s recommendations. Ensure CFRP components are not installed if the substrate surface is moist or wet, or if ambient or concrete surface temperatures are outside the 50– 95°F range. Apply CFRP only when relative humidity is below 85% and the surface temperature is at least 5°F above the dew point temperature. Apply system usin g the wet lay -up method unless otherwise approved. Install the CFRP system in conformance with Contract requirements and the manufacturer’s recommendations and shown on the plans . Release or roll out entrapped air beneath each layer before the resin sets. Obtain approval before implementing any change to the approved installation procedure. Place CFRP anchors between layers of the applied system when shown on the plans.
3.6 Testing . Perform the following tests after the initial resin has cured for at least 24 hr. and in conformance
with manufacturer’s specifications: a visual inspection of the entire CFRP surface, an acoustic tap test of any areas suspected to contain air pockets, and at least two direct pull -off tests for each member strengthened in accordance with ASTM D4541 to verify the tensile bond between the concrete and the CFRP system. The Engineer will select areas to perform the direct pull -off test. Perform some or all direct pull -off tests on CFRP test samples prepared at locations of similar substrate near the CFRP installation area at the discretion of the Engineer. Prepare the test samples using identical application procedures at the same time the project CFRP is installed. The required minimum pull -off stress is 200 psi, or failure in the concrete substrate, unless otherwise shown on the plans. Repair the damaged CFRP and concrete at test areas after testing is completed with thickened resin or putty.
3.7 Remediation . Epoxy -inject behind CFRP layers where small voids and bubbles that have a nominal size of
3 in. or less are located. Analyze defect areas larger than 3 in., and perform repair work as directed, which may include removal and replacing portions or all of the applied CFRP. Perform required remediation for pull - off test results failin g to meet the required minimum as directed. 1020 3.8. Protective Appearance Coat. Clean and paint CFRP system in conformance with manufacturer’s specifications.
Article 4 — Measurement
This Item will be measured by the square foot of concrete area covered with CFRP system. This is a plans quantity measurement Item. The quantity to be paid is the quantity shown in the proposal, unless modified by Article 9.2., “Plans Quantity Measurement.” Additional measurements or calculations will be made if adjustments of quantities are required.
Article 5 — Payment
The work performed and materials furnished in accordance with this Item and measured as provided under “Measurement” will be paid for at the unit price bid for “Carbon Fiber Reinforced Polymer Protection” and “Carbon Fiber Reinforced Polymer Strengthening.” This price is full compensation for all materials, labor, equipment, pull -off testing (including repair of test sites), manufacturer’s supervision, and related work necessary to prepare the surface of the concrete, to install the CFRP system as shown on the plans , and to apply the protective appearance coat. Payment will be under this Item unless otherwise stated.