375 Top surfaces of prestressed members shall be screeded or rough floated to bring mortar to the surface and cover a ll aggregate. The top surface of members that will receive cast -in-place concrete on the project site shall be finished as noted on the project plans, or if no finish is noted, they shall have either a raked or stiff broom finish. Aggregate shall not be loosened when roughening the surface. The fascia surfaces of bridge members shall be finished with a PCI Grade A Formed Finish. All other members shall be finished with a PCI Standard Grade Formed Finish. Concrete on exposed reinforcing steel and loose laitance on concrete surfaces to be in contact with cast-in-place concrete shall be removed from all members. Fabrication holes, except box beam vent holes, in the bottom of all beams, shall be filled with nonshrink mortar and made flush with the surround ing surface. No patching is required for small holes and irregularities on the sides of adjacent box beams that are to be sandblasted prior to shipment. Care shall be taken in final cutting the ends of strands to avoid damaging the concrete surface.
603.10 Workmanship :
603.10.1 General: Holes and voids in the surface of concrete resulting from bolts, ties, or
large air pockets shall be wetted and filled with mortar having the same proportion of fine aggregate and cement as in the concrete, after which exposed mortar surfaces shall be finished smooth and even with a wood float. Surfaces to be repaired and finished shall be kept wet for at least one hour before hydraulic cement mort ar is applied. Immediately following patching work, repaired areas shall be wet cured for at least 48 hours. The wet cure may be accomplished by the use of steam, wet burlap or continuous spray wetting. A liquid membrane -curing compound may be used on non - composite surfaces. Beams or girders having honeycomb of such extent to affect their strength or resistance to deterioration will not be accepted.
603.10.2 Defects and Breakage: Defective or damaged members which cannot be
satisfactorily repaired, o r which are not acceptable to the Engineer will not be incorporated into the work. All other members that sustain damage during fabrication, handling, storage or transportation shall be evaluated in accordance with Chapter three of PCI Journal Vol. 30, # 3 entitled “Fabrication and Shipment Cracks in Precast or Prestressed Beams and Columns”, hereinafter referred to as “specification”. This specification is to be used to determine the severity of cracks. All cracks with a width of 4 mils or less may be repa ired by silane treatment if the repair section of the specification allows repairs. All cracks over 4 mils to and including 16 mils shall be repaired by epoxy injection if allowed by the specification. Members with cracks over 16 mils shall not be incorpor ated into the work unless approved by the Engineer.
603.10.2 1 -Epoxy Injection of Cracks: The work shall consist of repairing cracks
with a width greater than 4 mils and up to and including 16 mils on prestressed concrete bridge beams.
603.10.2 1.1 -Materials: The epoxy material used for epoxy injection crack repair shall
meet the requirements specified for epoxy resin adhesives in ASTM C881, Type IV, Grade 1, and Classes B or C. For the epoxy paste or material used to bond and cover the injection ports to the substrate, use the epoxy resin manufacturer’s recommendation. 376 603.10.2.1.2 -Equipment: The equipment to be used to inject the epoxy shall meet the recommendations of the epoxy injection material manufacturer and/or the following requirements:
1.Use equipment that has the ability to automatically proportion the material components within the mix ratio tolerances set by the epoxy materials manufacturer.
2.Use equipment that has the ability to automatically mix the epoxy component materials within the pump and injection apparatus.
603.10.2 1.3 -Crack Surface Preparation and Cleaning Requirements: After the
concrete beam has achieved 28 day shipping stren gth, clean the concrete surface along the crack of all deteriorated concrete, efflorescence and other contaminants which would be detrimental to the adhesion of the surface sealing epoxy compound. The substrate must be sound, dry on the surface, and free from oil and grease. Blow out the crack with oil free and dry compressed air.
603.10.2 1.4 -Epoxy Injection: Place the base of the injection ports directly over the
crack and bond to the substrate with an epoxy paste or the recommended product by the epoxy resin manufacturer. The injection ports should be spaced over the length of the crack at a spacing that will allow the epoxy resin to seal the entire crack traveling from one port to another. The ports spacing is dependent upon the viscosity of the resin. Use an epoxy adhesive to seal over the surface ports and exposed cracks. The entire exposed crack is to be covered with the epoxy adhesive leaving only the port holes uncovered. The cure time for the epoxy will be based upon concrete temperatu re. The temperature requirements of the concrete for the injected resin must be satisfied before the process can begin. Begin injecting at the lowest port on the beam and continue until the epoxy resin begins to “ooze” out of the port above it. The “ooz e” out of the port above it is a sign that the crack has been filled to that level. Plug the first port with a cap and move up to the next port, repeating this procedure until the entire crack has been filled with epoxy. Use slow, constant pressure to in ject the epoxy into the crack which will reduce the possibility of leaks or blow -outs and allow time for the repair material to fully penetrate the crack.
603.10.2 1.5 -Post Epoxy Injection: After a minimum of 24 hours, the injection ports
can be removed from the beam. Clean the concrete surface areas of excess epoxy injection work. Clean so as to not damage the concrete by scraping, light sand blasting, grinding, use of solvents, or any other appropriate method approved by the engineer. Clean the excess materials so that no epoxy material or injection ports extend beyond the plane surface of the concrete.
603.11 Dimensional Tolerances :
All tolerances shall be applied with respect to the theoretical positions and dimensions shown in the plans. The tolerances listed in this article represent the total allowable tolerance that will be accepted in the finished product. The limits of tolerance do not necessarily represent fully acceptable construction; they are the limits at which construction becomes unacceptable. In general, workmanship shall be at a level of quality that wil l be well within the tolerance limits. Out of tolerance dimensions shall be handled in accordance with MP 603.10.40 .
Source: West Virginia Standard Specifications for Road and Bridge Construction, 2023 Edition. Pages 395–396 of 1,006.