SECTION 718 - PRESTRESSED CONCRETE UNITS
718-01 Prestressed Concrete Units (Structural)
SCOPE. This specification covers the material and fabrication requirements for prestressed concrete units. GENERAL. Prestressed concrete units provided under this specification shall meet all design requirements for the structure for which they are being fabricated. MATERIAL REQUIREMENTS.
A.Concrete. The concrete shall meet the requirements of '501-2, under 501, Portland Cement Concrete, General, with the following modifications:
1.Cement shall be either Type 1, Type 2 or Type 3. Only one type of cement shall be used to fabricate units for any one structure
2.Coarse aggregate gradation shall be No. 1 Size or ASTM D448, No. 67
3.Air content shall be 7 percent + 2 percent
4.The use of calcium chloride, or an admixture containing calcium chloride will not be permitted.
B.Steel.
718-01 Prestressed Concrete Units (Structural)
NEW YORK STATE DEPARTMENT OF TRANSPORTATION Section 700 STANDARD SPECIFICATIONS (USC) January 1, 2026 VOLUME 4 Bar Reinforcement 709-01 Wire Fabric 709-02 Chairs or other devices to ensure proper placement of steel items 556-2.02 Prestressing steel 709-06 Bearing plates, if required 715-01
C.Epoxy. Epoxy shall meet the requirements of '721-01, Epoxy Resin System; '721-03, Epoxy Polysulfide Grout, or '721-05, Epoxy Repair Paste.
D.Fine Aggregate. Fine aggregate shall meet the requirements of '703-03, Mortar Sand or '703- 04, Grout Sand. Fine aggregate shall be absolutely dry. DRAWINGS.
A.Contract Drawings. Drawings which accompany the contract proposal are designated as contract drawings. These drawings are not intended to be working drawings.
B.Working Drawings. Complete and accurate drawings shall be made by the Contractor, indicating how each prestressed concrete unit is to be fabricated. The Contractor shall be responsible for modifying the dimensions of units to compensate for elastic shortening, shrinkage, grade correction and other phenomena that make in-process fabricating dimensions different from those shown on the contract drawings. Approval of the working drawings by the DCES shall not relieve the Contractor from the responsibility for the correctness of all dimensions shown on these drawings. These drawings shall be made as soon as possible after the award of contract and they shall be designated as working drawings.
1.Size and Type. Working Drawings shall be neatly drawn and clearly legible to produce microfilm negatives. The drawings shall be made in ink, or reproduced from the pencil drawings by a process subject to the approval of the DCES, on tracing cloth or mylar of acceptable quality. Working drawings shall be cut to a standard size of 22 x 34 inches (nominal) and arranged to conform to the contract drawings. Failure to submit working drawings of the required size will be cause for their return without examination. The margin line shall be drawn 1/2 inch from the top, bottom, and right-hand edges and 2 inches from the left-hand edge to permit binding. A space 3 x 11 inches, and parallel to the length of the sheet shall be reserved in the lower right-hand corner for title and approval signature. Each working drawing shall have an identical (top right) corner box to the one shown on the contract drawings. The sheets shall be arranged so that, as far as possible, the notes will appear above each other near the right edge of the sheet.
2.Information Required on Working Drawings. The working drawings shall include the following information:
a.Plan layout of superstructure indicating the piece mark assigned to each prestressed unit
b.Fabricating plant production schedule
c.Description of the fabricating plant, including any backup concrete mixing facilities, original design mix and proposed method of placement. Modifications or deviations from the original mix at any time after the working drawings have been approved, shall be submitted, in writing to the DCES
718-01 Prestressed Concrete Units (Structural)
NEW YORK STATE DEPARTMENT OF TRANSPORTATION Section 700 STANDARD SPECIFICATIONS (USC) January 1, 2026 VOLUME 4
d.Proposed admixture to be added to the concrete mix
e.Quality control tests and procedures
f.Method and outline of unit and cylinder curing procedure, as required by “Curing”
g.The name of the manufacturer of the prestressing steel, including any alternate source
h.Material and manner of sealing the exposed portions of the prestressing steel
i.Transfer of prestress procedure for all unit types to be fabricated
j.Complete details, including anticipated camber, tensioning force (initial and final), concrete strength (transfer and 28 day), and type and location of lifting device for all prestressed concrete units to be fabricated.
k.Proposed method of handling and transporting prestressed concrete units to the project site
l.Working drawings shall clearly indicate any proposed deviations from the prestressed concrete unit shown on the contract drawings
m.Winter concreting procedures, if need is anticipated.
3.Submission of Working Drawings. When the working drawings, prepared by the Contractor, as specified, are completed, check prints shall be submitted to the DCES, who will indicate thereon such corrections as may be necessary to secure the completion of the contract in accordance with the requirements of the contract documents. The Contractor shall submit three sets of check prints for the DCES and two additional sets of check prints for each Railroad or other Agency involved with the contract. All sets of check prints shall be submitted to the DCES, who will make the distribution to the Railroad and other Agencies involved. One set of check prints or sepias with desired corrections indicated thereon in colored crayon or pencil, will be returned to the Contractor. When the revisions have been completed to the satisfaction of the DCES, the original drawings shall be forwarded to the DCES for written approval, after which a set of approved drawings will be returned. The original drawings shall remain the property of the State. The DCES shall be allowed two work days for the examination of each drawing in a set of working drawings, or ten work days minimum per set. A set of working drawings shall be considered to be all drawings received by the DCES from any given Contractor for a particular contract on any calendar day. If the working drawings are detained for examination for a period longer than that previously stated, such detention will be taken into account when considering application by the Contractor for an extension of time for the completion of the contract. All working drawings are time and date stamped as they are received and recorded in a log at the office of the DCES. This log shall be the basis for determining when drawings must be returned without consideration for an adjustment of the completion date as described herein. Approval of working drawings shall not constitute approval for the following information required on the working drawings 2B(3) and 2B(7). This data is required for information only. FABRICATION.
718-01 Prestressed Concrete Units (Structural)
NEW YORK STATE DEPARTMENT OF TRANSPORTATION Section 700 STANDARD SPECIFICATIONS (USC) January 1, 2026 VOLUME 4
A.Approval of Working Drawings. No fabrication shall be started until after the working drawings have been approved and the Inspector has received prints made from the original drawings.
B.Data Required with Working Drawings. Data required by the DCES prior to approval of the working drawings shall be as follows:
1.Calculations of strand elongation for each unique casting length (grip-to-grip)
2.A calibration certificate indicating the load calibration of each gage and hydraulic jack combination used for tensioning. The gage shall be calibrated from zero, throughout its entire load range. The gage shall have clearly marked divisions that are easily readable at the initial and final tensioning force. The calibration date of each combination gage and hydraulic jack shall be within the 12 month period immediately prior to the start of the work.
3.A calibration certificate attesting to the fact that the concrete cylinder testing machine to be used has been calibrated within the 12 month period immediately prior to the first date of actual use of the machine.
C.Data for Inspector. Data required to be submitted to the Inspector for approval prior to the inclusion of the respective materials in the unit, shall be as follows:
1.Prestressing Steel Certification. A certificate from the prestressing steel manufacturer stating that the prestressing steel has been manufactured in accordance with '709-06.
2.Load-Strain Curves. Typical load-strain curves made during the processing of steel from which the elongation appropriate to the required prestressing force can be determined, including the following information:
a.The breaking strength
b.The elongation at rupture
c.The load at one percent elongation
d.The test dates The aforesaid information shall be submitted to the Inspector, in triplicate, for each 25 ton lot, or fraction thereof, of prestressing steel.
3.Other Certifications. Certificates indicating acceptance of bar reinforcement, concrete materials and any other material used in the prestressed concrete unit.
D.Inspection. Fabrication of units shall be inspected by an Inspector designated by the State. The Contractor shall inform the State 72 hours prior to:
1.Commencement of work
2.Commencement of work after a work suspension of 48 hours or more
3.Unit shipping
718-01 Prestressed Concrete Units (Structural)
NEW YORK STATE DEPARTMENT OF TRANSPORTATION Section 700 STANDARD SPECIFICATIONS (USC) January 1, 2026 VOLUME 4 The Contractor shall keep the Inspector informed of the day-to-day scheduling of operations. The Inspector shall have free access throughout the fabrication plant to see that the work being done is in conformance with the contract documents. Work done while the Inspector has been refused access shall be automatically rejected. The Inspector shall be present when necessary tests are made on the prestressing steel at the place of manufacture.
E.Concrete Forms.
1.General. Forms shall be well-constructed, carefully aligned, clean, substantial and firm, securely braced and fastened together and sufficiently tight to prevent leakage of mortar. They shall be strong enough to withstand the action of mechanical vibrators. All forms for each unit shall be approved by the Inspector prior to placing concrete. All form surfaces that come in contact with the concrete shall be thoroughly treated with an approved form coating in the manner and at the rate specified by the manufacturer. Forms so treated shall be protected against damage and dirt prior to placing concrete. Any form coating material that will stick to or discolor concrete shall not be used.
2.Void-Producing Forms. Void forms shall be coated with a waterproofing material on the outside and shall have a 3/4 inch (nominal) diameter drain placed at each end of each void. When units are steam-cured, all voids shall be vented.
F.Reinforcement and Prestressing Steel. Prior to installation in the units, reinforcement and prestressing steel shall be free of frost, dirt, oil, paint, mill scale, corrosion, or any foreign material that may prevent bond between the steel and the concrete. Tack welding of bar reinforcement shall not be allowed under any circumstances. Welded wire fabric, smooth or deformed, may be substituted for the required bar reinforcement provided that:
1.The required cover is maintained
2.The design steel area of the fabric equals that of the bar reinforcement
3.Splices to the fabric are made in accordance with the requirements of the N.Y.S.D.O.T. Standard Specifications for Highway Bridges, '1.5.22D and '1.5.22E as applicable. If wire fabric is used, the details shall be indicated on the working drawings. Design computations shall also be included.
F.Tensioning of Prestressing Strands. A calibrated force of 3000 pounds shall be applied initially to each strand. Consideration will be given by the DCES to a different initial force for special cases. This force shall be the starting point for additional tensioning by elongation. For draped strands, the additional tensioning or prestressing force induced in the prestressing steel shall be measured by jacking gages and by elongation of the steel. The jacking gages shall read within 5 percent of the force theoretically calculated to be induced by elongation. For straight strands, elongation only shall determine the prestressing force. During tensioning of any one strand, the process shall be so conducted that the applied load and the elongation of the strand may be measured at all times. Two copies of recorded gage pressures and measured elongations, as required for the tensioning of prestressing strands in each unit, shall be submitted to the Inspector. The use of load cells or other tension measuring devices may be required. They shall be furnished by the Inspector and used in accordance with his/her instructions.
718-01 Prestressed Concrete Units (Structural)
NEW YORK STATE DEPARTMENT OF TRANSPORTATION Section 700 STANDARD SPECIFICATIONS (USC) January 1, 2026 VOLUME 4
G.Concrete Mix Design and Proportioning. The Contractor shall be responsible for designing a concrete mix to produce the strength and other requirements specified on the contract plans. If no strength is indicated, the required minimum strength shall be 4000 psi at transfer and 5000 psi at 28 days. Maximum cement content for any proposed mix shall be 750 lb/cy. Proposed mixes shall be submitted in accordance with the requirements of Drawings, Paragraph 2B(3). Automatic proportioning equipment will not be required. The Contractor may request permission from the DCES to incorporate a High Range Water Reducing (HRWR) admixture into the concrete mix. The DCES will grant such permission only if deemed to be in the best interests of the State and then only under such conditions as the DCES requires.
H.Placing Concrete. No concrete shall be placed without the Inspector's approval. Compliance with the precasting tolerances is a prerequisite for casting approval by the Inspector. When the atmospheric temperature is below 40OF, the fabrication of the units shall be in accordance with the winter concrete procedures as approved on the working drawings. Suitable means shall be used for placing concrete without segregation. The concrete mixture shall not be dropped from a height greater than 12 inches above the top of the forms. Special care shall be taken to deposit the concrete in its final position in each part of the form. The plastic concrete shall be consolidated in place by either external or internal vibration methods, or both, if necessary. The vibrators shall be of a type and design approved by the Inspector and the size of the vibrating head will be governed by the spacing of the prestressing steel and reinforcement. Vibrators shall be used only to consolidate the concrete after it has been properly placed. The internal vibrator shall be slowly inserted and removed from the concrete. The following quality control tests shall be performed, by the Contractor in the presence of the Inspector from the same concrete sample as that used for the Concrete Strength Requirements of this specification:
1.Slump
2.Air content
3.Temperature
4.Unit mass.
I.Finishing. To assure production of well-formed matching beams with overall pleasing appearance, all surfaces of concrete shall be true and even, free from rough, open or honeycombed areas, depressions or projections. After all the concrete has been placed and thoroughly compacted as required under Placing Concrete, the tops of units shall be magnesium-float finished , or finished as shown on the Working Drawings. If required, all exposed surfaces shall be finished by bagging. All exposed reinforcement shall be coated with neat cement paste prior to placement in the storage area.
J.Curing. The Contractor shall indicate on the working drawings, for approval, the method of cure and complete outline of the proposed procedure under each of the phases of the curing cycle. The full curing cycle consists of an Initial Curing Phase and Final Curing Phase. The Contractor may choose any one of the following acceptable curing methods, however only one curing method will be allowed for the units of a single structure.
718-01 Prestressed Concrete Units (Structural)
NEW YORK STATE DEPARTMENT OF TRANSPORTATION Section 700 STANDARD SPECIFICATIONS (USC) January 1, 2026 VOLUME 4 To ensure complete hydration of cement, and to prevent the formation of cracks, moisture must be retained within the concrete. Therefore, immediately upon the completion of concrete placement for each unit, an enclosure shall be placed over the casting bed. The Contractor shall submit all covers for inspection prior to the commencement of work.
1.Accelerated Cures. Acceptable methods for accelerated cures are by application of low pressure steam or by application of radiant heat and moisture.
a.Initial Curing Phase. The initial curing phase for each unit shall be that period beginning from the time each unit is completely covered and continuing until the final curing phase commences. The Contractor shall indicate the duration of the initial curing phase for each unit. However, the initial curing phase shall not exceed eight hours. During this phase, the enclosure temperature shall be maintained at approximately the concrete placing temperature; artificial heat shall be applied if necessary.
b.Final Curing Phase. The final curing phase for each unit shall be that period required to raise the initial curing phase temperature to the selected temperature range at a rate not exceeding 50OF per hour and continuing until the concrete has attained the minimum transfer strength as noted on the contract plans or as noted in this specification, under the paragraph Concrete Mix Design and Proportioning, whichever is applicable. The selected curing temperature range shall be as approved on the working drawings.
2.Non-Accelerated Cure. The acceptable method of non-accelerated cure is by the application of a saturated cover.
a.Initial Curing Phase. The requirements of A1 above, shall apply.
b.Final Curing Phase. The final curing phase may begin at anytime after commencement of the initial curing phase. Each unit shall be covered with heavy, water saturated burlap, or other material acceptable to the Inspector. The burlap shall be kept saturated, and the concrete surface temperature shall not drop below 68OF. These conditions shall be maintained until either of the following has occurred:
1.Seventy-two hours have passed from the time of burlap placement; or
2.Minimum transfer strength has been reached.
K.Record of Curing Time - Temperature. The Contractor shall provide one (1) automatic temperature recorder for every 100 feet of casting bed. The recorder shall continuously record curing temperatures for the initial and final curing phases. Temperature sensors shall be carefully placed within the curing enclosure to ensure that ambient temperatures are measured at the designated locations. Recorder accuracy shall be certified once every 12 months and the certificate displayed with each recorder. In addition, random temperature checks of each recorder shall be made by the Inspector. Each temperature chart shall indicate the casting bed, date of casting, time of commencing graphic plot and units represented by chart. The start of artificial heat and the transfer of prestress shall be indicated on each graphic record. After completion of the final curing phase, the charts shall be properly marked and given to the Inspector. Temperatures recorded on the charts shall be considered as verification of whether the units have been cured in accordance with the approved working drawings.
718-01 Prestressed Concrete Units (Structural)
NEW YORK STATE DEPARTMENT OF TRANSPORTATION Section 700 STANDARD SPECIFICATIONS (USC) January 1, 2026 VOLUME 4
L.Transfer of Prestress. Transfer of prestress shall be accomplished as soon as the final curing phase is complete.
M.Concrete Strength Requirements
1.Test Cylinders. The concrete strength shall be determined from concrete test cylinders made in conformance with ASTM C31, except that all cylinders shall be vibrated. All cylinders shall be tested in conformance with ASTM C39, on an approved testing machine. All cylinders shall be made and tested by the Contractor in the presence of the Inspector. The cylinders shall be made from concrete actually placed in the units. The Inspector shall be the sole judge of which cylinders are defective or damaged and are not to be included in the determination of the strength class. Test cylinders used to determine required strengths for detensioning shall be cured as specified on the working drawings. All cylinders used to test for concrete strength shall be cured in the same manner as the units they represent unless otherwise indicated on the working drawings. The Contractor shall cast a sufficient number of concrete test cylinders to fulfill the concrete strength test requirements as stated in 2 below. This testing procedure may be altered by the DCES. If an alternate procedure is to be followed, it shall be indicated on the contract drawings. The number of test cylinders to be cast for each unit shall be shown on the working drawings.
2.Testing for Concrete Strength. The strength requirements for each unit shall be certified by the Contractor, as follows, before the unit is accepted for strength:
a.Transfer Strength. Two cylinders from each unit shall be tested in immediate succession to verify prestress transfer strength. One of the two cylinders tested to determine the strength of the last unit cast in any bed shall be taken from the last batch of concrete placed in that unit. The strength of each cylinder shall be at least 95 percent of the required prestress transfer strength. The average strength of the two cylinders shall be equal to or greater than the required prestress transfer strength.
b.28 Day Strength.
1.Two cylinders from each unit shall be tested in immediate succession at 28 days of age to verify the required 28 day strength of the concrete. The average strength of the two cylinders shall be equal to or greater than the required 28 day strength. If this requirement is not met, any remaining cylinders representing the unit shall be tested at 28 days of age. The average strength of all cylinders representing the 28 day strength of any one unit shall be equal to or greater than the required 28 day strength.
2.The Contractor may elect to test two cylinders from each unit in immediate succession, prior to the 28 day age limit. If this option is exercised sufficient cylinders shall be made to ensure that at least two cylinders are available for the 28 day test. Each cylinder shall have a strength of at least 95 percent of the required 28 day strength. The average of the two cylinders must be equal to or greater than the required 28 day strength. If these requirements are met, the cylinder test at 28 days of age shall be waived.
N.Rejection of Units. Any unit not fabricated in accordance with the contact documents or displaying any of the following defects shall be subject to rejection:
1.Strength Requirement. Any unit represented by cylinders not meeting the required strengths, as specified in Concrete Strength Requirements.
718-01 Prestressed Concrete Units (Structural)
NEW YORK STATE DEPARTMENT OF TRANSPORTATION Section 700 STANDARD SPECIFICATIONS (USC) January 1, 2026 VOLUME 4
2.Exposed Prestressing Steel. Any unit that has one (1) prestress strand exposed in excess of 24 diameters, or two (2) or more exposed strands.
3.Honeycombing. Honeycombing of the unit to such an extent that chipping away from the honeycombed concrete results in the conditions described in the above paragraph 2, Exposed Prestressing Steel. All honeycombed areas in a unit must be chipped until sound concrete is detected. Sound concrete is defined as that point at which chipping causes fracture of the aggregates.
4.Stress Cracks. Any unit that has a stress crack in the area beginning 4 inches from the unit end to the center line of the unit that is greater than 1/2 inch in depth and 2.5 mils in width.
5.Injurious Materials. Materials used for the manufacture of concrete shall not contain, nor cause concentration of, chemicals, or other materials injurious to concrete. Concentrations of total chloride ions in excess of 0.05% by mass of cement are considered injurious. Other material and concentration injury potential will be determined by the D.C.E.T.S. according to Department written instructions.
O.Damaged units. The Inspector shall determine whether spalled, honeycombed, or otherwise defective concrete shall be repaired or be subject to rejection. The decision to repair a unit or reject a unit shall require the concurrence of the DCES.
P.Removal of Unsuitable Material. Prior to beginning the repair, all spalled, honeycombed or disintegrated concrete shall be removed by chipping the unsuitable material away until sound concrete is reached. Sound concrete shall be as defined under Rejection of Units, Subparagraph 3. Chipping tools shall be pneumatic. The type and size of tools and the depth at which sound concrete is reached shall be determined by the Inspector.
Q.Blast Cleaning Surfaces. All surfaces to be repaired shall be thoroughly blast-cleaned with No. 40 boiler slag grit or No. 2 sandblast sand, or as ordered by the Inspector. REPAIR. Repair shall be designated as “structural repair” or “nonstructural repair” by the Deputy Chief Engineer (Structures). Repair to a unit shall be done in accordance with the following.
A.Structural Repair. Repair, designated as “structural” by the DCES, shall be made with an epoxy grout comprised of an epoxy resin system (721-01), or an epoxy polysulfide grout (721-03), mixed with fine aggregate. The grout shall be mixed and placed in accordance with the following:
1.Mixing. No mixing shall be started until all preparations have been made to use the grout. The Contractor shall be familiar with the pot life limitations of the epoxy being used, and its operations shall be governed accordingly. Mixing shall be carried out in strict accordance with the manufacturer's instructions and the following:
a.Mixing shall be done as close as possible to the portion to be repaired.
b.All necessary equipment for mixing and placing shall be present at the site, and in good working order, prior to the start of mixing.
718-01 Prestressed Concrete Units (Structural)
NEW YORK STATE DEPARTMENT OF TRANSPORTATION Section 700 STANDARD SPECIFICATIONS (USC) January 1, 2026 VOLUME 4
c.The grout shall be proportioned by volume in the approximate ratio of two (2) parts fine aggregate to one (1) part epoxy. The exact ratio of sand to epoxy resin system shall be determined on-site to produce a dense void-free grout.
d.Dry, fine aggregate shall be placed in the mix container first. It shall be thoroughly agitated prior to the addition of the epoxy.
e.The two components of the epoxy system shall be thoroughly mixed together before being added to the fine aggregate.
f.The epoxy shall be added to the fine aggregate slowly, but mixing time shall not exceed three minutes.
g.All grout, in any individual batch, shall be used within 25 minutes after the start of mixing of the two components to create the epoxy system. All grout not used within the time limit shall be discarded.
h.The epoxy grout shall not be retempered.
2.Placing. The epoxy grout shall be placed against a clean, primed, receiving surface, in accordance with the following:
a.The receiving surface shall be cleaned of all oil, grease, or other material which may prevent effective bond, immediately prior to priming the surface with neat epoxy (epoxy without aggregate).
b.The priming of the receiving surface shall be done immediately prior to the placement of the epoxy grout.
c.The epoxy grout shall be placed quickly and continuously. It shall not be overworked.
d.The temperature of the receiving surface shall be above 50°F at the time of grout placement.
e.Grout placement shall not be permitted when ambient temperatures are 50°F or lower, unless methods of protection, acceptable to the Inspector, are employed. Methods of protection, if permitted, shall be continued for a period of 15 hours following grout placement. The 15 hour period may be shortened, at the discretion of the Inspector, but under no circumstances will it be less than 12 hours. Methods of protection, if permitted, are conveniences granted by the State. As such, they are not considered extra work, and therefore they are not entitled to extra compensation.
f.Upon completion of grout placement, the new surface of the repaired area shall be flush with the adjacent surfaces, unless the design of the unit specifically requires otherwise.
g.On surfaces which will be exposed to view after installation, the repaired area shall be color matched to the adjacent surfaces by use of cement dust, or other means acceptable to the Inspector.
B.Nonstructural Repair. Repair, designated as “nonstructural” by the DCES shall be made with either of the following:
718-02 Thru 718-04 (Vacant)
NEW YORK STATE DEPARTMENT OF TRANSPORTATION Section 700 STANDARD SPECIFICATIONS (USC) January 1, 2026 VOLUME 4 • Epoxy grout composed of 721-01 Epoxy Resin System or 721-03 Epoxy Polysulfide Grout, and fine aggregate; or, • 721-05 Epoxy Repair Paste. The Contractor has the choice of materials.
1.Mixing. Epoxy grout shall be mixed in accordance with the requirements of A. Mixing as given under Structural Repair. Epoxy repair paste shall be mixed in strict accordance with the manufacturer's instructions.
2.Placing. Placing of either material shall be done in accordance with the requirements of B. Placing as given under Structural Repair. TOLERANCES. Tolerances of the Prestressed Concrete Units shall meet the requirements specified in the Contract Documents. Units which fail to meet the tolerances shall be rejected with the concurrence of the DCES. SHIPPING. Units shall not be shipped until the minimum 28 day strength has been attained, but in no case, before 72 hours' storage time has elapsed following transfer of prestress. BASIS OF ACCEPTANCE. The Inspector's stamp of approval shall constitute the basis of acceptance for shipment to the job site. The Inspector's stamp shall be placed on the unit after loading for shipment. Application of the Inspector's acceptance stamp indicates that at the time of shipment, it was the Inspector's opinion that the unit was fabricated from accepted materials, by approved processes, and was properly loaded for shipment. Such application does not imply that the material will not be rejected by the State if it is subsequently found to be defective.
718-02 Thru 718-04 (Vacant)
718-05 Prestressed Concrete Form Units
SCOPE. This specification contains the requirements for prestressed concrete form units. These units are used to form the lower portion of a structural slab. They act compositely with the cast-in-place portion of the slab and become an integral part of the structural slab. GENERAL. 718-01 Prestressed Concrete Units (Structural) shall apply except for the following modifications to the FABRICATION, REPAIR and TOLERANCES: FABRICATION. 718-01 shall apply except as follows:
A.Reinforcement and Prestressing Steel. 718-01 shall apply. In addition, devices which will be used as hold-down points for outside reinforcing steel shall be placed prior to concrete placement in the forms. Devices used to lift the units are acceptable for this purpose. The maximum spacing between hold-down devices shall be 4 feet center-to-center of device.
B.Finishing. 718-01 shall apply except the tops of units do not have to be magnesium float finished.
C.Concrete Strength Requirements. 718-01 shall apply except the testing shall be as follows:
718-05 Prestressed Concrete Form Units
NEW YORK STATE DEPARTMENT OF TRANSPORTATION Section 700 STANDARD SPECIFICATIONS (USC) January 1, 2026 VOLUME 4
1.Testing for Concrete Strength. The strength requirements for each day's production shall be certified by the Contractor before that day's production is accepted for strength. Certification shall be done in accordance with the terms of this subsection. All cylinders cast shall be cast in sets of three. One set shall be cast from the first concrete placement of the day. One set shall be cast from the last concrete placement of the day. In addition to those, there shall be a set cast for each 15 cubic yards of concrete, or major fraction thereof, placed in any one day.
a.Transfer Strength. Three cylinders from each day's production shall be tested in immediate succession to verify prestress transfer strength. One cylinder shall be taken from the first set cast; one cylinder shall be taken from the last set cast. The strength of each cylinder shall be at least 95 percent of the required prestress transfer strength. The average strength of the three cylinders shall be equal to, or greater than, the required prestress transfer strength.
b.28-Day Strength. Three (3) cylinders representing each day's production shall be tested in immediate succession at twenty-eight (28) days of age to verify the required 28-day strength. The strength of each cylinder shall be at least ninety-five (95) percent of the required 28-day strength. The average strength of the three cylinders shall be equal to, or greater than, the required 28-day strength. If these requirements are not met, any remaining cylinders representing the day's production shall also be tested at 28 days of age. The average strength of all cylinders representing the 28-day strength of any one day's production shall be equal to, or greater than, the required 28-day strength.
c.Option. The Contractor may test three (3) cylinders, representing each day's production in immediate succession, prior to the 28-day age limit. Each cylinder shall have a strength of at least ninety-five (95) percent of the required 28-day strength. The average strength of the three cylinders shall be equal to, or greater than, the required 28-day strength. If these requirements are met, the cylinder test at 28 days of age shall be waived. If this option is exercised, sufficient cylinders shall be made to ensure that at least 3 cylinders are available for the 28-day test.
D.Rejection of Units. Any unit not fabricated in accordance with the Contract Documents, or displaying any of the following defects, shall be subject to rejection:
1.Strength Requirements. Any unit represented by cylinders not meeting the required strengths, as specified in Concrete Strength Requirements, of this specification.
2.Exposed Prestressing Steel. Any unit which exhibits one or more exposed prestressing strand(s) on a top or bottom surface.
3.Honeycombing. Honeycombing of the unit to such an extent that chipping away from the honeycombed concrete results in the exposure of one, or more, prestressing strands on a top, or bottom, surface. All honeycombed areas shall be chipped until sound concrete is reached. Sound concrete is defined as that point at which chipping causes fracture of the aggregates. If chipping of the honeycombed portion results in a hole more than one-half the thickness of the unit, the unit will be rejected.
4.Cracks. Any unit which exhibits a crack that is greater than 1/2 inch in depth, and 2.5 mils in width.
718-06 High Performance Concrete for Precast and Prestressed Bridge Beams
NEW YORK STATE DEPARTMENT OF TRANSPORTATION Section 700 STANDARD SPECIFICATIONS (USC) January 1, 2026 VOLUME 4 REPAIR. Repair, if allowed by the DCES, shall be made with 721-05 Epoxy Repair Paste. Epoxy repair paste shall be mixed and placed in strict accordance with the manufacturer's instructions.
A.Form Supports Form supports for installation of the units shall be supplied as part of this work. They shall conform to the latest specification for ASTM A446, Grades A through E. Fabrication shall be in conformance with ASTM A653/A653M, Coating Class G165. The Contractor shall supply the Engineer with certification that the form supports meet the foregoing requirements. TOLERANCES. All units shall be checked for compliance with the tolerances listed below, after the units have completed the final curing phase and within three (3) days prior to shipping. The Inspector shall document to the DCES any unit with dimensions out of tolerance. Any unit which fails to meet these tolerances shall be rejected with the concurrence of the DCES. Finished Dimensions Position of Strands *Width ± 1/4 inch Vertical ± 1/4 inch Length ± 1/2 inch Horizontal ± 1/2 inch Depth ± 1/4 inch *Width is defined as the dimension measured parallel to the prestressing strands.
718-06 High Performance Concrete for Precast and Prestressed Bridge
BEAMS SCOPE. This specification covers the material requirements for high performance concrete for precast and prestressed bridge beams. MATERIAL REQUIREMENTS. The concrete shall meet the requirements of the approved Mix Design Sheet, described below, and the PCCM. The concrete mix shall contain a minimum of 5% microsilica measured as a percent of the total cementitious material. MIX DESIGN SHEETS (MDS). These sheets shall contain all the information on the mix design, materials, material sources, production facilities, quality control, curing, and preproduction testing of the mix. Once approved for production, the MDS may be used in any contract requiring high performance concrete for precast and prestressed bridge beams. The MDS will have a two-step approval process. The first step shall be a submittal containing all the information required in bullets A. through N. of the Information Required on MDS List. Complete submittals that meet the specification requirements will be examined according to Section 2.5 of the PCCM and, if found acceptable, it will be returned with the notation “APPROVED FOR TESTING.” Section 2.5.7 of the PCCM does not apply. Following required testing of the mix, the MDS shall be submitted to the DCES with the information in bullets O. through Q. added to the sheet. If the test results meet the requirements of this specification, the MDS will be returned with the notation “APPROVED.” After approval for production, no changes in materials sources, production, curing, or mix design shall be made, except those changes necessitated by a change in the fineness modulus of the aggregate. If changes are required after the approval of the MDS, revised MDS with all the required changes shall be submitted to the DCES After examining the revised MDS, the DCES will determine if repetition of any testing is required for the approval of the revised MDS. If it is determined that some or all tests shall be repeated, the revised MDS will be returned marked up, specifying the required tests to be repeated and stamped “APPROVED FOR TESTING.” The revised MDS will follow the procedure used for the initial approval of the MDS except that the tests to be performed will be limited to the tests to be repeated marked up by the DCES.
718-06 High Performance Concrete for Precast and Prestressed Bridge Beams
NEW YORK STATE DEPARTMENT OF TRANSPORTATION Section 700 STANDARD SPECIFICATIONS (USC) January 1, 2026 VOLUME 4 If it is determined that there is no need for repeating the preproduction testing and if the proposed changes are acceptable to the DCES, the revised MDS will be approved and returned. The MDS shall include the following information:
A.The source and type of cement.
B.The specific source of the coarse aggregate.
C.The specific source of the fine aggregate and the fineness modulus of the material proposed for use in the preproduction testing.
D.The brand and type of all admixtures that will be used.
E.The complete mix design including all ingredient and quantities proposed for the production concrete.
F.The water-to-total-cementitious-material ratio.
G.Description of the concrete transport equipment.
H.The method of concrete placement.
I.Description of the concrete batching and mixing facilities, including the date of the last annual inspection and date of the last scale calibration check.
J.Outline of the curing procedure to be used for the production units and test samples.
K.Quality control tests and procedures that the fabricator will perform.
L.Detailed description of the preproduction testing procedure to establish that concrete made from the proposed mix design meets the required performance criteria.
M.The name and address of the testing laboratory(s) conducting the tests.
N.A fabricator selected identifier for the mix.
O.Test results for the preproduction test mix.
P.Actual fineness modulus of the fine aggregate used in the preproduction test mix.
Q.Graph of compressive strength versus age through 56 days. TESTING. The concrete mix design shall be tested prior to making any bridge beams and shall meet the following performance criteria. TABLE 718-06-1 TESTING REQUIREMENTS FOR HP CONCRETE PROPERTY TEST METHOD ACCEPTANCE CRITERIA Compressive Strength (at 56 days) ASTM C39 > 10,000 psi (all tests)
718-06 High Performance Concrete for Precast and Prestressed Bridge Beams
NEW YORK STATE DEPARTMENT OF TRANSPORTATION Section 700 STANDARD SPECIFICATIONS (USC) January 1, 2026 VOLUME 4 Freeze/Thaw Durability (x=relative dynamic modulus of elasticity after 300 cycles) AASHTO T161 Procedure A (Note (A) x ≥ 80% Elasticity (E = modulus of elasticity) ASTM C469 (Note B) E ≥ 4.35 x 106 psi Creep (c = microstrain/pressure unit) ASTM C512(at 56 days, 40% f’c) c ≤ 414/ ksi Air Content (A = Air Content) AASHTO T 152 A = % selected by contractor, A ≥ 3% Water/Cementitious-Materials ratio (W= mass ratio) AASHTO T 318 (Note C) Supplier selects W, W < 0.33 Note A: The Freeze/Thaw Durability test will be waived when the Super Air Meter test per AASHTO T 395 has a result of not more than 0.20. Note B: Test two samples. Each sample is to be loaded at 40% of the load required to break a companion sample cast from the same mix at the same time as the test sample. Sample 1 is to be loaded when the strength of a companion sample achieves a strength of 7000 ± 430 psi. Sample 2 is to be loaded when the strength of a companion sample achieves a strength of 10,000 ± 860 psi. Note C: The AASHTO T 318 test shall be corrected for the absorbed water in the aggregate. This correction shall be made using the mass percentage of absorption shown under “ABS” in the Approved List of Sources of Fine and Coarse Aggregates (or as determined by AASHTO T 84 for fine aggregates and AASHTO T 85 for coarse aggregate) by an AASHTO accredited testing laboratory. PREPRODUCTION TESTING. The Contractor shall engage an AASHTO-Accredited testing laboratory for testing of all preproduction concrete specimens except compressive strength, air content, and water/cementitious-materials ratio. These tests shall be performed in the presence of the Quality Assurance (QA) Inspector. The DCES may approve laboratories with equivalent certification from another organization. The testing laboratory shall send a copy of the test results directly to the DCES. The Contractor shall notify the Department at least three work days prior to casting preproduction test specimens. No test specimens shall be cast unless the QA Inspector is present to witness the mixing, casting, and curing of the specimens. The test specimens shall be prepared of concrete made using materials from sources shown on the “Approved For Testing” MDS. The test mix shall be the water-to-total-cementitious-materials ratio that is proposed for production within a tolerance of 0.01. Include the total aggregate moisture, as determined according to AASHTO T 255, in the calculation of the water-to-total-cementitious-materials ratio with appropriate adjustments. (See Note B of Table 718-06-01.) Using the test mix, cast and test compressive strength cylinders at 18 hours, 3 days, 7 days, 28 days, and 56 days. Use three cylinders, 4 X 8 inches, for each testing age. Present the test results in a graph.A. ACCEPTANCE OF TEST SPECIMENS. All test specimens shall be prepared in accordance with an “Approved for Testing” MDS. The preparation, casting, and curing of the test specimens shall be done in the presence of the QA Inspector. The QA Inspector shall indicate the procedures on the MDS were followed by affixing the inspection agency stamp on the samples prior to shipping to the Independent Testing Laboratories. FABRICATION. The requirements of the PCCM shall apply with the following modifications:
A.Submitted Shop Drawings shall include approved Mix Design Sheets.
B.Strength testing shall be performed using 4 X 8 cylinders cast per ASTM C39. Three cylinders shall be tested for each age.
C.The required 56-day strength is 10,000 psi, unless shown otherwise in the Contract Documents.
718-08 Thru 718-29 (Vacant)
NEW YORK STATE DEPARTMENT OF TRANSPORTATION Section 700 STANDARD SPECIFICATIONS (USC) January 1, 2026 VOLUME 4
D.The required minimum strength for imparting prestressing force into the concrete is 7000 psi unless shown otherwise in the Contract Documents.
E.The fineness modulus of the fine aggregate shall not vary more than 0.2 from the actual fineness modulus used in the preproduction test mix.
F.Water/Cementitious-materials ratio shall be measured by the Fabricator for the first batch of concrete in a day’s placement and monitored by slump tests throughout production. If the QA Inspector has reason to believe the water/cementitious-materials ratio is changing, or if the slump increases by more than the allowed increase in the table below, additional water/cementitious- materials ratio tests may be ordered. Slump of First Batch Allowed Increase Less than 4 inches 1 inch 4 inches or more 1 1/2 inch
G.Batch tickets shall be provided to the Inspector to verify the concrete mix contents. BASIS OF ACCEPTANCE. Units will be considered for acceptance at the manufacturing location in accordance with the PCCM.
718-08 Thru 718-29 (Vacant)
718-47 for Site Manager Use
718-50 Thru 718-53 for Site Manager Use
718-61 for Site Manager Use
718-66 for Site Manager Use
718-96 for Site Manager Use
718-99 for Site Manager Use
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Source: Standard Specifications (US Customary Units), 2026 (Jan) Edition. Pages 1304–1319 of 1,489. View official source ↗