5-162 practice conforms to the manufacturer's product data sheet. Di scard concrete that becomes unworkable. Do not use water or water-base d products to aid in finishing fr esh concrete. After the concrete has been placed and finished and before the forms are covered, remove all concrete from projecting reinforcing steel.
534.14 Acceptance and Quality Control Testing of Concrete Ref er to Section 712.061.
534.15 Manufacture of Precast Units The units shall be free of fractures. The ends of the
units shall be normal to the walls and centerline of the unit, within the limits of variation provided, except where beveled ends are specified. The surfaces of the units shall be a smooth steel form or troweled surface finish, unless a form lin er is specified. The ends and interior of the assembled structure shall make a continuous lin e of units with a smooth interior surface. Defects which may cause rejection of precast units include, but are not limited to, the following:
A.Any discontinuity (crack, rock pocket, etc.) of the concrete which could allow moisture to reach the reinforcing steel.
B.Rock pockets or honeycomb over 6 square inches in area or ov er 1 inch deep.
C.Edge or corner breakage exceeding 12 inches in length or 1 i nch in depth.
D.Any other defect that clearly and substantially impacts the quality, durability, or maintainability of the structure, as determined by the Fabricat ion Engineer. The manufacturer of the units shall sequentially number and sho p fit each adjacent unit to ensure that they fit togeth er in the field. This fit up sha ll be witnessed by the QAI. Any non-fitting units shall be corrected or replaced at no cost to the Department. The manufacturer of the units shall keep accurate records of a ggregate gradations, concrete batching, testing, curing, and inspection activities t o verify that forms, reinforcing and unit dimensions conform to t hese requirements. Copies of r eports shall be furnished to the Resident when requested.
534.16 Tolerances Dimensional tolerances shall be in conforma nce with the
following:
A.The internal dimensions shall not vary by more than 1 percen t from the design dimensions or 1-½ inches, whichever is less, with the exception of the cross diagonal dimension which shall not vary by more than one-half inch from the design dimension.
B.The haunch dimensions shall not vary by more than three-quar ters inch from the design dimension. 5-163
C.The dimension of the legs shall not vary by more than one-qu arter inch from the dimension shown on the reviewed Working Drawings.
D.The slab and wall thickness shall not be less than the desig n thickness by more than one-quarter inch. A thickness gr eater than the design thicknes s shall not be cause for rejection.
E.Variations in laying lengths of two opposite surfaces shall not be more than five- eights inch in any unit, except where beveled ends for laying o f curves are specified.
F.The under-run in length of any unit shall not be more than o ne-half inch.
534.17 Finishing Concrete Products shall be finished to meet t he ordinary finish
requirements of Standard Specification Section 502. Units, or portions of units, that will be exposed to view in their final location shall receive a rubbed finish, per Section 502. The Contractor may use alternative methods of achieving an acceptab le finish on exposed units if approved by the Fabrication Engineer. Marking: The date of manufact ure, the production lot number, and the type of unit shall be clearly and indelibly scribed on a rear, unexposed por tion of each unit.
534.18 Repairing Defects Defects requiring repair will be cons idered either non-
structural or structural. Non-Structural Defects: Exposed surfaces shall be of uniform a ppearance; only minor repairs to remove and blend fins, patch minor spalls and to rep air small, entrapped air pockets, shall be permitted. Repair honeycombing, ragged or ir regular edges and other non- structural or cosmetic defects using a patching material from t he Department Qualified Products List (QPL). The repai r, including preparation of the repair area, mixing and application and curing of the patching material, shall be in ac cordance with the manufacturer's product data sheet. Corners not exposed in the final product may be ground smooth with no further repair n ecessary, if the depth of the de fect does not exceed one-half inch. Remove form ties and other hardware to a depth of not le ss than one inch from the face of the concrete and patch the holes using a patching mater ial from the Department QPL. Structural Defects: Repair stru ctural defects only with the ap proval of the Fabrication Engineer. Submit a nonconformance report (NCR) to the Fabricat ion Engineer with a proposed repair procedure. Do not perform structural repairs w ithout an NCR that has been reviewed by the Fabrication Engineer. Structural defects inclu de, but are not be limited to, exposed reinforcing steel, cracks in bearing areas, through cra cks and cracks 0.013 inch in width that extend more than 12 inches in length in any directio n. Give the QAI adequate notice prior to beginning any structural repairs.
534.19 Handling, Storage and Transportation Handle, store and transport units in a
manner as to eliminate the danger of chipping, cracks, fracture , and excessive bending stresses. Any units found damaged upon delivery, or damaged af ter delivery, shall be subject to rejection.
Source: Maine Standard Specifications for Road and Bridge Construction, 2020 Edition. Pages 454–455 of 817.