The Guide Specifications in this catalog may be used as models for either office master specifications or specifications for particular projects. In either case, the Guide Specifications must be edited to fit the conditions of use. Material is included that will not be suitable for every purpose and should be deleted as necessary; other material will have to be added for specific projects. Blanks have been provided where appropriate requirements should be added.

Structural Precast Concrete

(Section 03410)

PART 2 ­ PRODUCTS

⇒ part 1 | part 3

2.01 MATERIALS

Delete or add materials to the following list as required for the particular job.
  1. PORTLAND CEMENT:
    1. ASTM C150 ­ Type I or III.
  2. ADMIXTURES:
    1. Air-entraining admixtures: ASTM C260.
    2. Water reducing, retarding, accelerating admixtures: ASTM C494.
  3. AGGREGATES:
    1. ASTM C33 or C330.
  4. WATER:
    1. Potable and free from amounts of foreign materials harmful to concrete and embedded steel.
  5. REINFORCING STEEL:
    1. Bars:
      1. deformed billet steel: ASTM A615
      2. where bar welding is required, bars shall conform to AWS D1.4
    2. Wire:
      1. cold drawn steel: ASTM A82
    3. Wire fabric:
      1. welded steel: ASTM A185
      2. welded deformed steel: ASTM A497
  6. PRESTRESSING STRAND:
    1. Uncoated seven-wire, stress-relieved: ASTM A416, Grade 270K.
  7. ANCHORS AND INSERTS:
    1. Materials:
      1. structural steel ASTM A36
      2. malleable iron (usually specified by type and manufacturer)
      3. stainless steel: ASTM A666
    2. Finish:
      1. shop primer: manufacturer’s standards
      2. hot dipped galvanized: ASTM A153
      3. zinc-rich coating: MIL-P-2135, self-curing, one component, sacrificial
      4. cadmium coating
  8. GROUT:
    1. Cement grout: Portland cement, sand, and water sufficient for placement and hydration.
    2. on-shrink grout: premixed, packaged, ferrous and non-ferrous aggregate shrink-resistant grout.
    3. Epoxy-resin grout: two-component, mineral-filled epoxy-polysulfide, Fed. Spec. MMM-G-560, Type_______, Grade C.  (Check with local suppliers to determine availability and types of epoxy-resin grouts)
    4. Minimum 28-day compressive strength:_______ psi. (Check with local suppliers to determine compressive strength)
  9. BEARING PADS:
    1. Elastomeric: conform to Division 2, Section 25 of AASHTO Standard Specifications for Highway Bridges.
      2. The pads specified have a strength of 2500 psi. For many applications, commercial grade pads are adequate and are more economical, but strengths vary and should be determined in advance by the specifier. Bearing strips of hard plastic or pressed, nonstaining hardboard are acceptable for Hollowcore or solid slabs and are more economical than elastomeric bearing pads.
    2. Tetraflouroethylene (TFE) reinforced with glass fibers and applied to stainless or structural steel plates.
    3. ________________________________. (Manufacturer and type to be specified)
  10. WELDED STUDS:
    1. Comply with AWS D1.1.

2.02 CONCRETE MIXES

  1. COMPRESSIVE STRENGTH:
    1. Minimum release strength:______psi. (Normally 5000 psi. Verify with local manufacturer.)
  2. RELEASE STRENGTH:
    1. Minimum release strength:______ psi. ( Normally 3500 psi. Verify with local manufacturer.)
  3. USE OF SALTS:
    1. Use of calcium chloride, chloride ions, or other salts is not permitted.

2.03 MANUFACTURE

  1. STANDARDS:
    1. Comply with referenced standards (see 1.02.D above).
     
  2. FORMING AND FINISHING:
    1. Concealed surfaces:
      1. remove fins and large protrusions; fill large holes and rock pockets
      2. formwork surface texture, air bubble holes, form joint marks, and minor chips, spalls, and color variations are acceptable
    2. Surfaces to receive concrete topping:
      1. roughen for mechanical bond
    3. Exposed vertical ends:
      1. recess strand ends, fill recesses with non-shrink material, and finish to match other adjacent exposed surfaces
    4. All other surfaces:
      1. remove fins and large projections
      2. fill large holes and rock pockets
      3. grind smooth form off-sets over 1/8 inch
      4. remove any ragged edges
    5. Exposed sandblasted surfaces:
      1. blast concrete where indicated with coarse, sharp aggregate to remove matrix approximately 1/16 inch in a depth in accordance with approved sample
      2. small, unobjectionable imperfections will be accepted
      3. mix patching, where allowed, as dry as possible; match color of adjacent hardened concrete, ad determined by approved trial patch
    6. Exposed surfaces to receive plaster:
      1. leave surfaces straight and clean, to the satisfaction of the plastering contractor
    7. Exposed surfaces not cast against formwork:
      1. match adjacent exposed surfaces
    8. All other exposed surfaces:
      1. fill holes larger than 1˛4 inch with sand-cement paste
      2. coat exposed surfaces with neat cement paste; after the paste has dried, rub surface vigorously with burlap to remove loose particles (finishing costs can be reduced by deleting this process)
  3. MANUFACTURING TOLERANCES:
    1. Standard tolerances:
      1. length ±3/4 inch, or ±1/8 inch per 10 feet of length, whichever is greater
      2. cross sectional dimensions:
        1. less than 24 inches: ±3/8 inch
        2. 24 to 36 inches:±1/2 inch
        3. over 36 inches: ±5/8 inch
      3. flange thickness (thin sections): ±1/4 inch
      4. position of anchors and inserts:±1 inch from center line location shown on drawings
      5. horizontal alignment (sweep):1/2 inch, or 1/8 inch per 10 feet of length, whichever is greater; maximum of 1 inch gap between two adjacent members due to sweep
      6. end squareness: 1˛2 inch maximum
      7. blockouts:±1 inch from center line location shown on drawings
      8. midspan camber deviation from design:±3/16 inch per 10 feet of length, ±3/4 inch maximum
      9. midspan camber differential between adjacent members after installation: 1˛4 inch per 10 feet of length, 3˛4 inch maximum
      10. position of reinforcement designed primarily for connections: between +1/2 inch and ­ 1˛4 inch (minus represents a reduction in cover)
    2. Special tolerances specified below involve additional expense to the manufacturer and will result in higher costs for the project. If special tolerances are required for some or all of the products, special notes should be made on the drawings or in the specifications noting which pieces or dimensions require special tolerances. Tolerances tighter than the special tolerances indicated can only be obtained through the use of nonstandard special forms and will involve considerable additional cost. Please consult the manufacturer before specifying such tolerances.
      1. length:±1/8 inch per 10 feet, ± 1˛4 inch maximum
      2. cross sectional dimensions:
        1. less than 24 inches: ±1˛4 inch
        2. 24 to 36 inches: ±3/8 inch
        3. over 36 inches: ±1˛2 inch
      3. thickness: + 1˛4 inch
      4. position of anchors and inserts: ±1/2 inch from center line location shown on drawings
      5. horizontal alignment (sweep): 1˛4 inch, or 1/8 inch per 10 feet of length, whichever is greater; maximum of 1˛2 inch gap between two adjacent members due to sweep
      6. end squareness: 3/8 inch maximum
      7. blockouts: + 1˛2 inch from center line location shown on drawings
      8. out of square: 1/8 inch per 6 feet diagonal measurement
      9. warpage, after installation: 1/8 inch per 6 feet of length, or 3/ 8 inch, whichever is greater
  4. OPENINGS:
    1. 100 square inch or larger and shown on drawings: cast in plant following approved shop drawings.
    2. Smaller than 100 square inches or not shown on drawings: field cut or core drill neatly, without chipping, by the trade requiring the opening. (This requires other trades to field cut or drill holes needed for their work, and such trades should be alerted to these requirements through proper notation in their sections of the specifications. Some manufactures prefer to install openings smaller than 10 inches square; this is acceptable if the locations are properly identified on the drawings.)
    3. Do not cut reinforcement.
  5. INSERTS:
    1. Cast in structural inserts, bolts, and plates, as shown on drawings.
  6. DETENSIONING:
    1. Prevent shock, overloading, or unbalanced loading.

⇒ Section 03410 part 1 | part 3