POST-TENSIONIN G
462-1 Description.
1.Furnish, test, transport, store, handle, and install all components of Post -Tensioning (PT) systems, in accordance with the requirements of this Section and the component manufacturer’s recommendations. Constituent components of PT systems include, but are not limited to, anchorage assemblies, filler containment assemblies, filler material, and related steel reinforcement. Use the most stringent requirements, as determined by the Engineer, of those specified in this Section or the component manufacturer’s recommendations for protecting components from damage due to environmental exposure, improper handling, or improper installation.
2.With the exception of mild reinforcing and prestressing steel, furnish all PT system components from a single supplier (vendor).
3.Submit PT system shop drawings in accordance with Section 5. Perform PT system testing in accordance with Section 960. Include in the PT system testing all possi ble combinations of components to be incorporated into the structure.
4.Use only PT systems meeting the requirements of Section 960 and approved by the Engineer in accordance with Section 5 .
a.Use only PT systems of appropriate type and size required to construct tendons shown in the Contract Documents.
b.Use only the exact manufacturer and/or model of major components, as defined in 960-2, that were used in system testing and as listed on the approved PT system shop drawings.
c.With the exceptio n of local zone reinforcement, do not substitute, modify, or delete any major components , as defined in 960 -2, of a PT system approved by the Engineer for use on the project .
5.Provide a mockup test in accordance with this Section. PT system acceptance testing may be performed concurrent with mockup testing if performed prior to installation of any PT system hardware .
6.Just prior to PT tendon installation, blow oil -free dry compressed air meeting ASTM D4285 through the duct . Provide visual confirmatio n that the duct is free of water and moisture.
7.Install the PT tendon (e.g., strands, wires, or bars) in duct. Stress the PT tendon to a predetermined load, anchor ends directly against hardened concrete and install permanent anchorage caps.
8.Just prior to wax filler injection, blow oil -free dry compressed air meeting ASTM D4285 through the duct. Provide visual confirmation that the duct and tendon are free of water and moisture.
9.Inject ducts with filler to completely fill voids and install prot ection at anchorages.
10.Submit all required documents in accordance with this Section and Section 5 to the Engineer for review and written approval.
11.Arches, cable supported and extradosed bridges are not covered by this Specification.
12.Install duct filler. Provide fully filled duct and anchorage assemblies free from leaks, blockages, and voids. Submit test data to the Engineer to verify that the work meets the requirements of this Section. Perform filler injection operations in accordanc e with 462 -7.4. FY 2023-24 Return to Table of Contents
462-2 Materials.
462-2.1 General:
Approval of any material by the Engineer will not preclude subsequent rejection if material is damaged or otherwise found to not meet the requirements of this Section or Section 960.
462-2.2 Steel Reinf orcing:
462-2.2 1 Mild Steel:
1.Provide reinforcing steel per Section 931.
2.Final design and details of local zone reinforcement are system specific and are the responsibility of PT system supplier (vendor). Design system specific local zone reinforcement for the number of strands or wires a particular PT system can accommodate at maximum allowable strand or wire force; do not design project specific local zone reinforcement for a reduced system capacity.
3.Submit signed and sealed project specific local zone reinforcement details to the Engineer for review and written approval.
462-2.2 2 Prestressing:
462-2.2 2.1 Strand:
1.Provide prestressing strands per Section 960.
2.Strand couplers are not permitted.
462-2.2 2.2 Bar:
1.Provide prestressing bars per Section 960.
2.For permanent applications, use and location of bar couplers is subject to written approval by the Engineer.
462-2.2 2.3 Parallel Wire :
1.Provide prestressing parallel wire assemblies per Sec tion 960.
2.Wire couplers are not permitted.
462-2.3 Duct Filler: Use only grout and flexible filler meeting the requirements of
Section 938 and are listed on the Department’s Approved Product List (APL).
462-2.3 1 Grout:
1.Select grout for us e in PT system by application: repair, horizontal, or vertical.
2.Mix grout per manufacturer’s instructions with potable water meeting requirements of Section 923.
3.Do not combine different grout products.
462-2.3 2 Flexible Filler: Prepare flexible filler for installation in accordance
with the manufacturer’s instructions. Do not combine different flexible filler products.
462-2.4 Other Material References:
Meet the requirements of this Section, as well as the following: Class 5 Applied Coating* ................................ ...............Section 975 Elastomeric Coating System* ................................ .........Section 975 Epoxy Compound* ................................ ......................... Section 926 Magnesium Ammonium Phosphate Concrete* ..............Section 930 Methacrylate* ................................ ................................ .Section 413 Water ................................ ................................ ...............Section 923 *Use products listed on the Department’s Approved Product List ( APL).
462-2.5 Component Samples:
FY 2023-24 Return to Table of Contents
462-2.5 1 Prestressing Steel:
1.Furnish samples per Section 933 from each manufacturer of prestressing strand, wire, and bar to be used on project.
2.The Engineer will collect sample materials from prestressing steel used for PT operations on the Project.
3.Samples, properly identified and tagged per 462 -6, will be stored by the Engineer.
462-2.5 2 Grout:
1.The Engineer may sample grout packages at random, not to exceed a total quantity of one bag per L OT or shipment. A LOT is defined as a quantity of material from a single production batch or shipment
2.Grout sample may be virgin package mix, liquefied state, or solid state; Engineer will determine at what frequency, interval, sample phase (powder, liquid or solid) and location those samples will be recovered from the project.
3.Sample, properly identified and tagged per 462 -6, will be stored by the Engineer.
4.Submit the following samples from each manufacturer per each production LOT of gro ut to be used on the project. These samples will be used by the State Materials Office for product testing.
a.Submit three 2” x2” x2” hardened grout cube samples from a trial batch using the same water source and grout to be used for production grouti ng.
b.One bag of grout. Submit samples a minimum of four weeks prior to initial production grouting. Do not commence grouting operations until grout test results are available and approved by the Engineer. Mock -up testing per section 462 -7.4.1.1 (5) m ay proceed prior to grout approval.
462-2.5 3 Flexible Filler:
1.The Engineer may sample flexible filler at random, not to exceed a total quantity of one gallon per LOT. A LOT is defined as a quantity of material from a single production batch or shipment not to exceed 1,000 gallons.
2.Sample may be virgin product in liquefied state or solid state. The Engineer will determine at what frequency, interval, sample phase (liquid or solid) and location those samples will be recovered from the projec t.
3.Sample, properly identified and tagged per 462 -6, will be stored by the Engineer.
462-3 Alternate PT System Designs.
Designs using a PT scheme different from that shown in the Contract Documents may be submitted for the Engineer’s approval provid ed proposed scheme fulfills the design requirements, and the Contractor demonstrates compliance with these requirements:
1.PT system type and size meets all requirements of this Section.
2.Net compressive stress in the concrete after all prestress lo sses is equivalent to or greater than that provided by the PT scheme shown in original Contract Documents.
3.Distribution of individual tendons at each cross section generally conform to the distribution shown in original Contract Documents.
4.Propos ed PT scheme meets the ultimate strength requirements of the American Association of State Highway and Transportation Officials Load and Resistance Factor Design, FY 2023-24 Return to Table of Contents AASHTO LRFD Bridge Design Specifications Section 5, and is equivalent to or greater than service and strength limit states provided in original Contract Documents.
5.Stresses in concrete and PT steel at all sections and at all stages of construction meet requirements of the Design Criteria shown in original Contract Documents.
6.All Design C riteria provisions noted in original Contract Documents are satisfied.
7.Show complete design and detail of all elements for proposed locations of alternate PT scheme.
8.Submit the following for the Engineer’s approval:
a.design calculations incl uding short and long term prestress losses
b.complete shop drawings including PT scheme and system, reinforcing steel, and concrete cover
9.Any alternate PT system approved by the Engineer resulting in a change in quantity from that shown in the Co ntract Documents is paid based on comparison of the following:
a.quantity actually used and accepted or original plan quantity, whichever is less, and
b.unit bid price. If approved alternate PT scheme or system is under a Cost Savings Initiative Proposal (CSIP), method of payment will be in compliance with CSIP agreement.
10.Submit alternate PT scheme signed and sealed by the Contractor’s Engineer of Record.
462-4 Qualifications.
Provide all project personnel and crew foreman in accordance wi th Section 105.
462-5 Submittals.
1.Submit to the Engineer all necessary information, Plans, shop and working drawings, and manuals in accordance with this Section and Section 5. Submit to the Engineer signed and sealed PT related shop drawings designed by the Contractor’s Engineer of Record.
2.Prepare shop drawings addressing all requirements stated in the Contract Documents and requirements of this Section. Show details of PT hardware components, tendon geometry and locations complying with the Cont ract Documents and limitations of selected PT system. Include all inlets, outlets, high point inspection port details, anchorage inspection details, permanent anchorage caps, protection system materials, and application limits. If applicable, include detai ls of the duct dehumidification system.
462-6 Transport, Handling and Storage.
462-6.1 General:
Store all materials in a weatherproof building, shed, covering, or container until time of use.
462-6.2 LOT Identification:
1.Assign an individual LOT number and tag items shipped to project in a manner that allows each LOT to be clearly identified at project site for all PT system components, filler, bars of each size from each mill heat of steel, and all strands from each manufactured re el.
2.Submit records to the Engineer identifying assigned LOT numbers with heat or reel of material represented if applicable. FY 2023-24 Return to Table of Contents
3.All unidentified prestressing components, strands, wires, bars, or filler received at the site will be rejected.
4.Loss of positive identification of these items at any time will be cause for rejection.
5.Submit filler Quality Control Data Sheets from the manufacturer, to the Engineer for each LOT of filler on the project.
462-6.3 Prestressing Steel:
1.Protect all prestressing steel against physical damage and corrosion at all times.
a.Package prestressing steel in containers for protection against physical damage and corrosion during shipping and storage.
b.Place a corrosion inhibitor, which prevents rust, in package or incorporate it into a corrosion inhibitor carrier type packaging material.
c.Corrosion inhibitor must have no deleterious effect on steel, filler, concrete, or bond strength of steel to concrete.
d.Inhibitor carrier type packaging mat erial must conform to provisions of Federal Specification MIL -P-3420.
e.Immediately replace or restore damaged packaging to original condition.
f.Clearly mark shipping package with a statement that package contains high-strength prestressing steel, care to be used in handling, include type, kind, and amount of corrosion inhibitor used, date when placed, safety orders, and instructions for use.
2.The Engineer will reject prestressing steel that has sustained physical damage.
3.Remove and discar d lengths of strand found to contain broken wires.
4.Wire must be bright and uniformly colored, with no foreign matter or pitting on its surface.
462-6.4 Filler:
1.Maintain filler in environmental exposure conditions (e.g., temperature, humidity) in strict conformance with manufacturer’s recommendations at all times from manufacture to installation.
2.Storage in the open must be on a raised platform with adequate waterproof covering to protect the filler.
3.On site storage of grout filler on a raised and covered platform is limited to a maximum period of one week. The allowable on site storage time may be extended by the Engineer if the grout filler is in a climate -controlled structure. Grout filler material with a total time from manufacturer i n excess of six months must be removed from the jobsite and replaced with new material.
4.Flexible filler may be stored on site on a raised and covered platform up to the manufacturer’s expiration date. Do not use flexible filler that has exceeded the m anufacturer’s recommended usage date. Remove all such filler from the jobsite and replace with new material .
462-6.5 Duct and Pipe:
1.Protect ducts against ultraviolet degradation, crushing, excessive bending, dirt contamination, corrosive elements, or any other damage or contamination during transport, storage, and handling.
2.Furnish ducts with end caps to prevent contamination inside duct. Do not remove duct end caps until duct is incorporated into the bridge component.
3.Ship capped duct in bu ndles that are covered during transport and storage. FY 2023-24 Return to Table of Contents
4.Store on a raised platform and completely covered to prevent contamination.
5.If contamination is discovered, immediately flush duct with potable water per
462-7.2 4 before use.
462-7 Construction.
462-7.1 General:
1.Prior to installing any PT system hardware:
a.Submit to the Engineer a list of all PT systems chosen for the project.
b.For each PT system, s ubmit a package to the Engineer meeting the requirement s of Section 960-3.6.
c.For each PT system, submit to the Engineer written certification that all major components, as defined in 960 -2, furnished to the project and shown on the approved PT system shop drawings exactly match the major components used in PT system te sting.
2.Use methods to place and consolidate concrete that will not displace or damage any PT ducts, anchorage assemblies, splices and connections, reinforcement, or other embedded items.
3.Conduct all stressing and filler injection operations in th e presence of the Engineer.
462-7.2 System Installation:
Accurately and securely fasten all PT anchorages, ducts, inlet and outlet pipes, miscellaneous hardware, reinforcing bars, and other embedded items at locations shown in the Contract Documents or on approved shop or working drawings or as otherwise approved by the Engineer in writing.
462-7.2 1 Ducts:
1.Construct tendon ducts using the minimum number of splices as practical.
2.Accurately position and align ducts at locations shown in the Contract Documents, or according to approved shop or working drawings, or as approved in writing by the Engineer.
3.Securely fasten all internal ducts at regular intervals not exceeding 30 inches for steel pipes, 24 inches for round plastic ducts, and 12 inches for flat ducts to prevent movement, displacement, or damage from concrete placement and consolidation operations.
4.Show method and spacing of duct supports on appropriate shop drawings.
5.Ensure external tendon ducts are straight between connections to internal ducts at anchorages, diaphragms, and deviation saddles and are supported at intermediate locations according to the Contract Documents including approved shop drawings.
6.Ensure all alignments, including curves and straight por tions, are smooth and continuous with no lips, kinks, or dents. This also applies to curves in pre -bent steel pipe.
7.Check and repair all ducts in accordance with 462 -7.5 as necessary before placing any concrete.
8.Ensure ducts at end connections to anchorages, splices, inlets, outlets, drains, and all other duct openings are sealed at all times after installing ducts and until tendon installation is complete.
9.Provide an absolute seal of anchorage and duct termination locations per the approv ed system drawings. FY 2023-24 Return to Table of Contents
10.Use of tape , caulking, epoxy or other sealants is not permitted to make connections or sealing for any reason.
11.Use heat welding techniques, in accordance with duct manufacturer’s instructions, to make splices between secti ons of smooth plastic duct or make connection with electrofusion duct coupler as shown on the approved PT system shop drawings.
12.When connecting steel pipe to plastic pipe with a boot, use a 3/8 inches wide power seated band and clamps in accordance with 960-2.2 on each end of a duct boot to seal against filler leakage. Install band per manufacturer’s instructions.
13.Ducts for prestressing used exclusively for temporary erection where PT will be removed from structure are not required to be coupl ed across segment joints.
14.Briefly open low point drains to allow for drainage of any water that may be present within the duct.
462-7.2 1.1 Installation Tolerances:
1.Ensure final position of PT ducts is within the tolerances in the following table: Table 462-1 Duct Installation Tolerances Type Vertical Position (inches) Horizontal Position (inches) Horizontal tendons in slabs or in slab regions of larger members ±1/4 ±1/2 Longitudinal draped superstructure tendons in webs: Tendon over supports or in middle third of span ±1/4 ±1/4 Tendon in middle half of web depth ±1/2 ±1/4 Longitudinal, generally horizontal, superstructure tendons usually in top or bottom of member ±1/4 ±1/4 Horizontal tendons in substructures and foundations ±1/2 ±1/2 Vertical tendons in web Longitudinal Position ±1 Transverse Position ±1/4 Vertical tendons in pier shafts ±1/2 ±1/4 All other cases ±1/4 ±1/4
2.Ensure entrance and exit angles of tendon paths at anchorages, duct joints, and/or at faces of concrete are within plus or minus 3 degrees of desired angle measured in any direction.
3.Accomplish any deviations in alignm ent with smooth unkinked transitions.
4.Locate anchorages within plus or minus 1/4 inch of desired position laterally and plus or minus 1 inch along tendon except that minimum cover requirements must be maintained.
5.Position local zone anchorage confinement reinforcement in the form of spirals, multiple U -shaped bars, or links centered around duct and anchorage (±1/4 inch tolerance) and starting within 1/2 inch of the back of the main anchorage plate. FY 2023-24 Return to Table of Contents
6.If conflicts exist between reinforceme nt and a PT duct/anchorage and other non -local zone reinforcement, the position of duct prevails. Adjust the non-local zone reinforcement with the Engineer’s written approval.
462-7.2 2 Splices and Joints:
1.All splices, joints, couplings, connection s (inlet and outlet), and valves are part of approved PT system.
2.Fabricate all duct splices to prevent duct kinks during concrete placement.
3.Use mandrels as needed to maintain duct alignment and shape.
462-7.2 3 Inlets, Outlets, Drains and Ports :
1.Place filler inlets, outlets, drains and ports at locations shown in the Contract Documents including approved shop drawings.
2.Equip all filler inlets, outlets, drains and ports with approved positive shut-off devices (e.g., valves).
3.At a minimum, place filler inlets, outlets or ports in the following positions and those shown in Standard Plans, Index 462-001:
a.Top of tendon anchorage;
b.Top and bottom of anchorage cap;
c.At high points of duct profile when verti cal distance between highest and lowest point is more than 2 feet;
d.At major change in duct cross section; and,
e.At other locations required by the Engineer.
4.For all tendons other than grouted top slab transverse tendons in box girders, p lace drains at the geometric low points of all duct profiles, or as close as is practical to the geometric low points of all duct profiles, except where an inlet, outlet or anchorage that can serve as a drain is located at a low point. Locate drains, and i nlets and outlets serving as drains, at the bottom of the duct cross section. Do not locate drains within the limits of diabolos.
5.Extend filler and drain tubes a sufficient distance out of concrete member to allow for proper closing of valves.
6.Direct inlets, outlets , drains and ports exiting on vertical or predominantly vertical surfaces of box and I -girders toward the inside face of exterior I -girders or toward the interior of box girders.
462-7.2 4 Tendons:
1.Store the PT tendon in such a way that it remains completely dry and free of moisture prior to installation within the duct.
2.Do not exceed 14 calendar days between first installation of PT strand within duct and completion of the stressing and filler injection operation.
3.Do not exceed 21 calendar days between the first installation of PT bars within duct and completion of the stressing and filler injection operations.
4.With written appr oval of the Engineer , the maximum number of calendars days allowed between the first installation of the PT tendon within the duct and completion of the stressing and filler injection operations is 30 for PT strand and 45 for PT bars by monitoring and cont inuously maintaining the relative humidity of air within the duct below 40%. Use a closed dehumidification system or other means approved by the Engineer. The dehumidification system must be in stalled and operational within 24 hours of first installation o f the PT tendon within the duct and remain operational until just prior to filler injection . FY 2023-24 Return to Table of Contents
5.The use of temporary corrosion inhibitor powder is not permitted as a method to increase the allowed number of calendar days between the first installation o f the PT tendon within the duct and completion of the stressing and filler injection operations .
6.Any light surface corrosion forming during the period of time described in (1), (2), (3) or (4) of this Article will not be cause for rejection of the PT tendon.
7.Failure to inject filler into duct within the number of calendar days specified, will result in stoppage of work, except when waived by the Engineer in writing.
8.Just prior to PT tendon installation, briefly open low point drains to allow for drainage of any water that may be present within the duct. Close all low point drains and ports except the inlet and outlet ports at the anchorage caps. Blow oil-free dry compressed air meeting ASTM D4285 through one of the anchorage cap ports until the relative humidity measured at the inlet and outlet ends are less than 40% and continuing blowing for an additional 30 minutes. Stop blowing, wait a minimum of 15 minutes, and take humidity measurements at the inlet and outlet ends of blowing . Further blowing is not required if both humidity readings are less than 40%. If the humidity readings are 40% or greater, then repeat the process of blowing and waiting for 15 minutes until the humidity measurements at the inlet and outlet end of blowing are less than 40% . Take humidity measurements of air within the duct at the inlet end and outlet end of blowing using separate humidity meters. Use humidity meter s approved by the Engineer.
9.Provide visual confirmation that the duct is free of water, mois ture, and debris at the anchorages and low points of the tendon profile before installing the PT tendon within the duct.
10.Flushing of filler is not permitted without written approval of the Engineer and is only permitted as defined in this Article.
11.For grouted operations, v acuum injection is required to repair all voids and blockages as subject to provisions of 462-8.3.2. For flexible filler operations, use the repair procedure described in the approved Wax Injection Operations Plan.
12.For tendon ducts subjected to contamination with chlorides (e.g., uncapped ducts that have been subjected to salt spray), flush duct with potable water containing slack lime (i.e., calcium hydroxide) or quicklime (i.e., calcium oxide) in the amount of 0.17 pounds per gallon.
a.Test for presence of chlorides and oils in discharged water before placing tendon.
b.If chloride levels in flush water outflow exceed 300 ppm, continue to flush duct until chloride level in flush water outflow is below 250 ppm.
c.After the chloride level of flush water is below 250 ppm, open low point drains to allow for drainage of flush water within the duct. Perform the blowing process described in (8) of this Article . Provide visual confirmation that the duct is free of water and moisture for its entire length before installing the PT tendon within the duct .
13.Push or pull strands and wires through d ucts to make up a tendon using methods that will not snag on any lips or joints in ducts.
14.Round off end of strands and wires that are pushed or fit advancing end with smooth protective cap.
15.Do not intentionally rotate strands or wires by any mechanical means during installation of PT strand into duct. FY 2023-24 Return to Table of Contents
16.For superstructure tendons, provide sufficient strand and wire length beyond dead end anchorages to allow for second end stressing as needed for reconciliation of jacking force versus meas ured elongation.
17.Alternatively, tendons may be pulled through duct using a special steel wire sock or other device attached to advancing end. Strands may be brazed together for pulling as long as one foot of strand from the brazed end is removed by cutting after installation. Do not electric arc weld strand ends together for this purpose.
18.Cut tendons in accordance with 462 -7.3.2.7.
19.Strand installation aids (i.e. wire/nylon ties around strand bundle, strand spacers, etc.) must be removed prior to stressing
20.Do not install permanent tendons before completion of testing as required by this Section or the Contract Documents. The only two exceptions are:
a.Tendon to be tested by “Theoretical Elongation Verification” may be installe d for test; and,
b.Transverse tendons may be pre -installed in precast segmental boxes prior to concrete casting such that they meet 462 -8.3.1.
462-7.3 Post-Tensioning Operations:
1.Do not apply PT forces until concrete has attained compressive str ength specified in the Contract Documents.
2.Conduct all stressing operations in presence of the Engineer.
3.With the written approval of the Engineer, revise PT operations so final tendon force is in agreement with the Contract Documents.
462-7.3 1 Stressing Equipment:
Only use equipment furnished by supplier of PT system.
462-7.3 1.1 Jacks and Gauges:
Equip each jack with pressure gauge for determining jacking pressure that has a minimum dial diameter of six inches.
462-7.3 1.2 Calibration:
1.Calibrate each jack and its gauges as a unit.
2.Calibration must consist of three test cycles with cylinder extension of jack in various positions (e.g., two -inch, four -inch, eight -inch stroke).
3.At each pressure increment, average forces from each test cycle to obtain an average force.
4.Perform calibration with equipment (e.g., jack, pump, hoses, etc.) setup in same configuration intended for use on Project.
5.Jack and gauge calibration is to be initially perform ed by PT supplier or an independent laboratory.
6.Use load cells calibrated within the past 12 months to calibrate stressing equipment.
7.Supply documentation denoting the load cells calibration date and tractability to National Institute of Stan dards and Technology (NIST) along with jack/gauge calibration.
8.Submit to the Engineer certified calibration charts and curves for each jack and gauge unit used on the project prior to start of work and every six months thereafter or as requested by the Engineer. FY 2023-24 Return to Table of Contents
9.Calibrations subsequent to initial calibration with a load cell may be accomplished with use of a master gauge. Supply master gauge to the Engineer in a protective waterproof container capable of protecting calibration of gauge during shipment to a laboratory. Provide a quick -attach hydraulic manifold to enable quick and easy installation of master gauge to verify permanent readings. Master gauge will remain in the possession of the Engineer for duration of project and will be returned to the Contractor after final acceptance of project by the Engineer.
10.Any jack repair, such as replacing seals or changing length of hydraulic lines, requires recalibration using a load cell.
11.No extra compensation will be allowed for initial or any subsequent calibrations or use of master gauge required by the Engineer.
462-7.3 2 Stressing Tendons:
1.Tension all PT steel so PT force is not less than that required by the Contract Docum ents or as otherwise approved by the Engineer in writing.
2.Do not use monostrand jacks to stress straight tendons with five or more strands or wires , or for curved tendons with two or more strands or wires.
3.4-strand curved top slab transverse te ndons in box girders are permitted to use a monostrand jack.
4.Use of curved stressing noses or chairs is not permitted.
462-7.3 2.1 Jacking Maximum Stress:
Maximum temporary stress (i.e., jacking stress) in PT steel must not exceed 80% and 75% of Guaranteed Ultimate Tensile Strength (GUTS) for PT strands and bars, respectively. The maximum temporary jacking stress must not exceed 50% of GUTS for PT bars that will be reused.
462-7.3 2.2 Initial and Permanent Stresses:
1.PT steel must be anchored at initial stresses resulting in long term retention of permanent stresses or forces of no less than those shown in the Contract Documents.
2.Unless otherwise approved by the Engineer in writing, initial stress after anchor set must not excee d 70% of GUTS at anchorages and 74% of GUTS at all other locations between anchorages.
3.Permanent stress and permanent force are stress and force remaining in PT steel after all losses, including long term creep and shrinkage of concrete, elastic shortening of concrete, relaxation of steel, losses in PT steel from sequence of stressing, friction, and unintended wobble of ducts, anchor set, friction in anchorages, and all other losses particular to the specific PT system.
462-7.3 2.3 Stressing Seque nce:
1.Permanent PT tendons must be stressed from both ends, except as noted in the Contract Documents.
2.Required force may be applied at one end and subsequently at other end or simultaneously at both ends.
462-7.3 2.4 Elongation:
1.Ensure forces being applied to tendon and resulting elongation of tendon can be measured at all times.
2.Measure elongations to nearest 1/16 inch. FY 2023-24 Return to Table of Contents
3.For required tendon force, observed elongation must agree within 7% of theoretical elongation or ent ire operation must be halted, checked, and source of error determined and remedied to satisfaction of the Engineer before proceeding.
4.Do not overstress tendon to achieve theoretical elongation.
5.If agreement between observed and theoretical el ongations at the required force falls outside acceptable tolerances, additional tests may be required, at the Engineer’s discretion and without additional compensation to the Contractor, for Tendon Modulus of Elasticity and/or In Place Wobble and Friction Test, or Lift -Off Test.
462-7.3 2.5 Friction:
1.Provide actual expected friction and wobble coefficients and anchor set in the shop drawings; submit calculations and show a typical tendon force diagram on shop drawings based upon expected actual co efficients and values for the PT system to be used.
2.Graphite may be used as a lubricant when friction must be reduced, subject to written approval of the Engineer.
462-7.3 2.6 Tendon Wire Failure:
1.Multi-strand PT tendons with wires which f ail by breaking or slipping during stressing may be accepted provided these conditions are met:
a.Completed structure has a final PT force of at least 98% of original total design PT force;
b.PT force across a mating joint is at least 98% of PT force required by the Contract Documents for that mating joint for that stage of construction for precast or cast -in-place segmental construction. This 98% minimum PT force requirement applies to segmental construction, or any similar construction, that h as members post -tensioned together across a common joint face at any stage of construction; and,
c.Any single tendon must have no more than a 5% reduction in cross -sectional area of PT steel due to wire failure.
2.When conditions permit the Contractor to propose acceptable alternative means of restoring PT force lost due to wire failure, any of the above conditions may be waived at discretion of and with approval of the Engineer in writing.
462-7.3 2.7 Cutting of PT Steel:
1.Cut PT st eel using an abrasive saw or plasma torch within 3/4 inches to 1 -1/2 inches away from the anchorage.
2.Flame cutting of PT steel is not permitted.
3.Do not cut tendon to final length prior to acceptance.
462-7.3 2.8 Post -Tensioning Operations Record:
1.Keep a record of these PT operations for each tendon installed:
a.Project name, Financial Project ID (FPID);
b.Contractor and/or subcontractor;
c.Tendon location, size, and type;
d.Date tendon was first installed in d uct;
e.Reel number for strands and wires and heat number for bars;
f.Tendon cross -sectional area;
g.Modulus of elasticity;
h.Date stressed;
i.Jack and Gauge numbers per tendon end; FY 2023-24 Return to Table of Contents
j.Required jacking force;
k.Gauge pressures at the pump and at the inlet;
l.Elongations (theoretical and actual);
m.Anchor sets (anticipated and actual);
n.Stressing sequence (i.e., sequential order of tendon stressing by number);
o.Stressing mode (single -end, dual-end, simultaneous);
p.Witnesses to stressing operations (Contractor and Inspector);
q.Any other relevant information.
2.Submit to the Engineer a complete set of stressing operation records within five days of completed tendon installation .
462-7.3 3 System Protection:
462-7.3 3.1 Tendon:
1.Seal all other duct openings other than installing anchorage caps within four hours after tendon stressing.
2.Install anchorage caps after tendon has been accepted. If acceptance of tendon will be delayed more than four hours after stressing, immediately provide temporary weatherproofing of tendons at open ends of anchorages. If tendons and anchorages are temporarily weatherproofed, install anchorage caps within 1 day of tendon being accept ed.
3.If tendon contamination occurs and if directed by the Engineer, remove tendon, flush duct with potable water per 462 -7.2.4, and replace with new tendon.
462-7.3 3.2 Anchorage:
1.Provide the following at anchorages as shown on Standard Plans, Index 462-002:
a.Temporary drain holes at the bottom of open top blockouts.
b.Temporary weatherproof plugs for upwardly oriented access or vent holes.
2.Cap all filler inl ets/outlets with plugs meeting the requirements of Section 960.
3.Construct anchorage pour -backs and place elastomeric coatings at anchorages as indicated in the Contract Documents and as shown on Standard Plans, Index 462-002 within seven days of com pleting filler injection operations (see 462 -7.4 for filler injection operations). For anchorages which require acrylic aliphatic polyurethane top coating, apply the acrylic aliphatic polyurethane top coating after the elastomeric coating has fully cured. See Standard Plans Index 462 -002 and the Contract Documents for details on anchorages which require acrylic aliphatic polyurethane top coating. Construct anchorage pour -backs using reinforced concrete, magnesium ammonium phosphate concrete, or a Type Q epoxy grout meeting the requirements of Section 926.
a.Remove all laitance, grease, curing compounds, surface treatments, coatings, and oils by grit blasting or water blasting. Flush surface with water and blow dry. Surfaces must be clean, sound, and wi thout any standing water. Test substrate at all pour-back locations using ACI 503 and develop a minimum of 175 psi tension (e.g., pull -off value). Testing frequency may be reduced, as determined by the Engineer, after the Contractor FY 2023-24 Return to Table of Contents has demonstrated an abi lity to prepare substrate surfaces for bonding as indicated by the result of the ACI 503 test.
b.Mix and apply epoxy grout and magnesium ammonium phosphate concrete in accordance with the manufacturer’s current standard technical guidelines. Construct all pour-backs in leak proof forms creating neat lines. Epoxy grout may require pumping for proper installation. Construct forms to maintain a liquid head to ensure intimate contact with concrete surface. Use vents as needed to provide for escape of air to ensure complete filling of forms.
4.Coat exposed surfaces of pour -backs and anchorage caps as shown on Standard Plans, Index 462-002 with an elastomeric coating system meeting the requirements of Section 975 and having a thickness of 30 mils to 45 mils. Apply the acrylic aliphatic polyurethane top coating to a dry film thickness of 5 to 6 mils. Ensure concrete, anchorage caps, or other substrates are structurally sound, clean, and dry. Concrete must be a minimum of 28 days old. Remove all laitance, grease, curing compounds, surface treatments, coatings, and oils by grit blasting or water blasting using a minimum 3,000 psi nozzle pressure. Blow surface with compressed air to remove dust or water. Apply the elastomeric coating within 90 days of filler injection. Apply the acrylic aliphatic polyurethane top coat and the manufacturer’s approved primer over the elastomeric coating before applying Class 5 coating, if required.
5.Prior to application of elastomeric coating, construct a 2 foot x 4 foot concrete test block with a similar surface texture to surfaces to be coated. Coat a vertical face with chosen elastomeric coating system. Determine number of coats required to achieve the specified thickness without runs and drips. Mix and apply elastomeric coating as per manufacturer’s current standard technical specifications. Spray application is preferred; roller application is permitted. Have coating manufacturer representative on site to supervise and comment on application of elastomeric coating onto test block. Apply coating using approved and experienced personnel with a minimum of three years experience applying similar polyurethane systems. Submit credentials of these persons to the Engineer for review and consideration for approval.
462-7.4 Filler Injection Operations:
462-7.4 1 Grouting Operations: Conduct all grouting operations in the presence
of the Engineer.
462-7.4 1.1 Grout Injection Operations Plan:
1.Submit a Grouting Operations Plan to the Engineer for approval at least six weeks in advance of any scheduled grouting operation.
2.Written approval of Grouting Operations Plan by the Engineer is required before any grouting of permanent structure takes place.
3.At minimum, Grouting Operations Plan will address and provide:
a.Names and proof of training for grouting crew and crew supervisor in conformance with this Specification;
b.Type, quantity, and brand of materials to be used in grouting, including all required certifications;
c.Type of equipment to be used, including capacity in relation to demand and working conditions, as well as, standby equipment and spare parts;
d.General grouting procedure; FY 2023-24 Return to Table of Contents
f.If applicable, p rocedures for monitoring and continuously maintaining less than 40% relative humidity of air within the duct;
g.Method to be used to control rate of flow within ducts;
h.Theoretical grout volume calculations;
i.Mixing and pumping procedures in accordance with the manufacturer’s reco mmendations;
j.Direction of grouting accounting for grade and/or slope of tendon;
k.Sequence of inlet and outlet pipes use;
l.Procedures for handling blockages;
m.Procedures for possible post grouting repair.
4.Conduct a joint meeting of the Contractor, grouting crew, and the Engineer before grouting operations begin. Discuss Grouting Operations Plan, required testing, corrective procedures, and any other relevant issues at the meeting.
5.Prior to production grouting, d emonstrate to the Engineer’s satisfaction successful grout injection by injecting full -scale mockups that are constructed with all associated PT system components using the mockup tendon profiles shown in the Plans and the proposed Grouting Operations Plan. Uti lize smooth duct and associated couplers and fittings meeting the requirements of Section 960 for all mockups. Utilize smooth duct for the mockups which has an inside diameter required for a given mockup tendon size. If the mockup is also being used to perform PT system acceptance testing, use the duct type appropriate for the PT system location. Place the mockup tendons specified in the Plans inside the ducts to simulate the in -place PT tendons. Stress mockup tendons to the minimum values shown in the Plan s by using jacks or other methods approved by the Engineer . Perform pressure tests on the mockups in accordance with 462-8.2.1 prior to grout injection. Fo r the grout injection operations, utilize the same grout material and types and sizes of grout injection equipment that will be used on the project including but not limited to mixers, pumps, hoses, valves and pressure gauges. Inject grout into the mockups using the proposed Grouting Operations Plan. Allow the grout to harden a minimum of 24 hours after i njection before inspecting the mockup. Inspect the mockup in accordance with the requirements of 462 -8.3.2.1 and then carefully cut open the duct at all high points and other locations as directed by the Engineer to check for voids. Prepare a report documenting the findings and submit it to the Engineer. If voids are found, determine the cause and revise the proposed Grouting Operations Plan accordingly. If directed by the Engineer, construct additional mockups and repeat the grout injection operation using the revised Grouting Operations Plan as many times as are required until the results are acceptable.
462-7.4 1.2 Inlets and Outlets:
1.Ensure connections from grout pump hose to inlets are free of dirt and are air -tight.
2.Inspect valves to e nsure they can open and close properly.
462-7.4 1.3 Supplies:
Provide an adequate supply of water and compressed air for clearing and testing ducts, as well as, mixing and pumping grout before grouting operations start.
462-7.4 1.4 Equipment:
1.Provide grouting equipment consisting of measuring devices for water, a high -speed shear colloidal mixer, a storage hopper (e.g., holding reservoir) and pump with all necessary connecting hoses, valves, and pressure gauge. FY 2023-24 Return to Table of Contents
2.Provide pumping equipm ent with sufficient capacity to ensure PT ducts can be filled and vented in not more than 30 minutes without interruption.
3.Provide an air compressor and hoses with sufficient output to perform required functions.
4.Have vacuum grouting equipmen t (i.e., volumetric measuring type) and experienced operators available to meet the timeframe requirements of 462 -8.3.2.1-6.
462-7.4 1.4.1 Mixer and Storage Hopper:
1.Provide colloidal grout machinery with a charging tank for blending and a holding tank. Blending tank must be equipped with a high speed shear colloidal mixer capable of continuous mechanical mixing producing a homogeneous and stable grout free of lumps and un-dispersed cement. Holding tank must be kept agitated and at least 10% full at all times during pumping operations to prevent air from being drawn into duct.
2.Add water during primary mixing phase in the colloidal mixer by use of a flow meter or calibrated water reservoir with measuring accuracy equal to 1% of total water volume.
462-7.4 1.4.2 Pumps:
1.Provide pumping equipment capable of:
a.continuous operation which includes a system for circulating and agitating grout when ac tual grouting is not in progress,
b.maintaining pressure on grouted ducts,
c.fitted with a valve that can be closed off without loss of pressure in duct.
2.Grout pumps will:
a.be positive displacement type,
b.provide a continuo us grout flow
c.be able to maintain a discharge pressure of at least 145 psi.
3.Use pumps constructed with seals to prevent oil, air, or other foreign substances from contaminating grout and prevent loss of grout or water.
4.Specify pump ca pacity adequate to maintain the specified grouting rate.
5.Place pressure gauges with full scale reading of no more than 300 psi at the pump and at the duct inlet.
6.Grout hoses to be compatible with pump output (diameter and pressure rating).
462-7.4 1.4.3 Vacuum Grouting: Provide vacuum grouting
equipment meeting these minimum requirements:
1.Volumeter for measurement of void volume;
2.Vacuum pump with a minimum capacity of ten cubic feet per minute and equipped with a flow -meter, graduated hopper, or other acceptable means approved by the Engineer capable of measuring the amount of grout being injected.
3.Manual colloidal mixers, manual high speed shear mixers, or other mixing methods recommended and approved by the grout manufacturer, in writing, for the specific project covered by this Section for voids less than 5.5 gallons in volume. However, mix a minimum of one full bag of grout regardless of the size void to be grouted. FY 2023-24 Return to Table of Contents
4.Standard colloidal mixers for voids 5.5 gallons and greater in volume.
462-7.4 1.4.4 Standby Equipment: Provide a standby colloidal
grout mixer and pump during grouting operations.
462-7.4 1.5 Grouting:
1.Maintain grout fluidity in strict compliance with grout manufacturer’s recomme ndations.
2.In the presence of the Engineer, perform a test to confirm accuracy of grouting equipment volume -measuring components each day of use before performing any grouting operations. Testing in a warehouse or similar condition is acceptable. Use either water or grout for testing using standard testing devices with volumes of 0.5 gallon and 6.5 gallon and an accuracy of equal to or less than four ounces. Perform one test with each device. Results must verify accuracy of grouting equipment void vol ume-measuring component within 5% of test device volume and must verify accuracy of grouting equipment grout volume component within 10% of test device volume for the 0.5 gallon test device. When testing the 6.5 gallon device, ensure an accuracy of 3% (tes t device volume) and 6% (grout volume).
3.Do not use grout that tests outside allowable flow rates.
4.Perform grouting in accordance with procedures set forth in approved Grouting Operations Plan.
5.Grout all ducts.
462-7.4 1.5.1 Tempera ture:
1.At inlet end of grout hose, the maximum limit for grout temperature is 90°F for normal grouting procedures and 85°F when performing repair operations with vacuum grouting.
2.Condition grout material to maintain mixed grout temperature b elow maximum limit.
3.Grouting operations are not permitted when ambient temperature is below 40°F or is expected to fall below 40°F within one day subsequent to grouting.
4.Postpone grouting operations if freezing temperatures are forecasted w ithin two days subsequent to grouting.
462-7.4 1.5.2 Mixing and Pumping:
1.Mix grout with a metered amount of water.
2.Mix materials to produce a homogeneous grout.
3.Continuously agitate grout until grouting operations are complete.
4.Reject bags of grout containing clumps.
462-7.4 1.5.3 Production Test:
1.Test grout fluidity to verify it is within limits established by grout manufacturer during grouting operations. Target fluidity rate is established by manufacturer’s representative based on ambient weather conditions.
2.Determine grout fluidity in accordance with Section 938.
a.Perform a fluidity test using flow cone on grout discharged from anchorage cap outlet immediately after uncontaminated uniform co nsistency discharge begins for each tendon greater than 50 feet in length. For tendons 50 feet or less, perform a fluidity test on a per batch basis. For fluidity tests done on a per batch basis, perform FY 2023-24 Return to Table of Contents test after new batch has been transferred from mixin g tank to holding tank and thoroughly mixed with remains of the previous batch to produce a new homogenous mixture. During mixing process, continually re -circulate grout from hose into holding tank. Ensure measured grout efflux time is not less than efflux time measured at injection end of grout hose.
b.Additionally , check grout fluidity using Wet Density method contained in Section 938. Density at discharge outlet must not be less than grout density at inlet. Continuously discharge grout until densi ty requirements are met. Discard grout used for testing fluidity.
3.Perform fluidity test for each tendon to be grouted without modifying water -cement ratio.
4.Check temperature of grout at inlet end of grout hose hourly to verify conformance t o this Section.
5.Obtain a sample from first production batch of grout and perform a wick induced bleed test on this sample in accordance with Section 938 at beginning of each day’s grouting operation. Begin grouting operations after sample is obtained.
6.Once grouting has begun, if zero bleed requirement is found to not have been achieved in the wick induced bleed test at any time during required test time period, complete grouting of any partially grouted tendons currently being grouted but do not begin grouting any new or additional tendons. Immediately inform the Engineer when grouting operations have ceased due to non -compliance of the wick induced bleed test.
7.Do not re -start grouting operations until such time that testing sho ws grout meets specified requirements.
462-7.4 1.5.4 Grout Injection Operations:
1.Briefly open low point drains to allow for drainage of any water that may be present within the duct. If water is present:
a.Capture and measure the water r emoved from the duct and retain for further testing as directed by the Engineer ; blow the duct with oil free dry compressed air meeting the ASTM D4285 with the end vent port open.
b.Obtain written authorization from the Engineer to proceed with grou ting injection operations.
2.Open all grout outlets before starting grouting operation.
3.Inject grout into duct in accordance with approved Grouting Operations Plan.
4.Pump grout at the lowest possible pressure practical.
5.Conduct normal grouting operations at a pressure range of 10 psi to 50 psi measured at grout inlet.
6.Do not exceed a pumping pressure of 145 psi anywhere within the system. Do not exceed a pumping pressure of 75 psi at the grout inlet for flat ducts.
7.Use grout pumping methods that ensure complete filling of ducts and complete encasement of steel.
8.Grout must flow from first and subsequent outlets until any residual water or entrapped air has been removed prior to closing outlet.
9.Pump grout through duct and continuously discharge it at anchorage and anchorage cap outlets until all free water and air are discharged and consistency of grout is equivalent to that of grout being pumped into inlet. Close anchorage outlet and FY 2023-24 Return to Table of Contents discharge a mini mum of two gallons of grout from anchorage cap into a clean receptacle. Close anchorage cap outlet.
10.Elevate grout pressure to the equivalent realized pumping pressure while grouting the duct, seal inlet valve, and wait two minutes to determine if any leaks exist after all outlets have been bled and sealed. If leaks are present repair all identified leaks using methods pre -approved by the Engineer and repeat steps until no leaks are present. Bleed pressure to 5 psi and wait a minimum of ten minutes for any entrapped air to flow to high points if no leaks are present. Increase pumping pressure not to exceed actual realized pumping pressure of duct and discharge grout at each high point outlet to eliminate any entrapped air or water after specified ten minute period has expired. Complete process by locking a pressure of 30 psi into tendon duct.
11.If actual grouting pressure exceeds maximum allowed, close inlet and pump grout at next outlet which has just been closed or is ready to be closed as long as a one -way flow is maintained. Do not pump grout into a succeeding outlet from which grout has no t yet flowed. Fit outlet/inlet to be used for pumping with a positive shut -off valve as shown in the approved system drawings and pressure gauge if this procedure is used.
12.Stop grouting operation if complete grouting of tendon cannot be achieved b y the steps stated and in compliance with the approved Grouting Operations Plan. After waiting 48 hours, vacuum grout duct in accordance with this Section.
462-7.4 1.5.5 Vertical Grouting:
1.Provide a reservoir, equivalent to a minimum of 2% of the total anticipated grout volume used on a particular tendon, at upper end of tendon to store bleed water and grout; maintain grout level above level of prestressing plate and anchorage for all vertical tendons. Design and size this device to maintain lev el grout at an elevation that ensures potential bleed will not drop below the highest point of upper anchorage device. Design reservoir to allow all bleed water, if any, to rise into reservoir.
2.Discharge grout and check grout fluidity as described in this Section. Immediately add grout if level of grout begins to drop, potentially allowing bleed water into the upper anchorage device and tendon duct. Remove reservoir after grout has hardened. Visually inspect for voids using a borescope or probe in p resence of the Engineer. Fill all voids found in duct using volumetric measuring vacuum grouting process in accordance with this Section.
3.Allow grout to flow from each outlet until all air and water have been purged prior to using a higher elevatio n outlet for pumping. Pump grout at increasingly higher outlets which have been or are ready to be closed, as long as one -way grout flow is maintained for vertical tendons within allowable grouting pressures.
462-7.4 1.5.6 Grouting Operations Report:
1.Submit grouting report signed by the grouting Contractor within five days of each grouting operation for review by the Engineer.
2.Record theoretical quantity of grout anticipated as compared to actual quantity of grout used to fill duct. Noti fy the Engineer immediately of shortages or overages.
3.Information to be noted in this report must include at a minimum, but not necessarily be limited to:
a.identification of tendon;
b.date grouted; FY 2023-24 Return to Table of Contents
c.number of days from tendo n installation to grouting;
d.type of grout;
e.injection end;
f.verification that water or moisture is not present within the duct;
g.daily duct humidity readings if applicable ;
h.Pressure gauge readings at the pump and at the inlet;
i.Ratio of actual to theoretical grout quantity;
j.Number of grout bags mixed;
k.Total quantity of water used to mix grout;
l.Summary of any problems encountered; and,
m.corrective action taken,
n.description and results of the post grouting operations and inspection.
462-7.4 2 Flexible Filler Operations:
1.Inject flexible filler with or without using vacuum assistance for tendons with vertical or predo minately vertical profiles as shown on Standard Plans, Index 462- 001.
2.Inject flexible filler using vacuum assistance for all other tendon profiles shown on Standard Plans, Index 462-001.
462-7.4 2.1 Microcrystalline Wax: Conduct all wax injection operations,
repairs, and inspections in the presence of the Filler Injection Foreman, Filler Injection QC Inspector and the Engineer.
462-7.4 2.1.1 Wax Injection Operations Plan:
1.Prepare a Wax Injection Operations Plan in cooperation with the P T system vendor and the PT wax manufacturer.
2.Submit the Wax Injection Operations Plan to the Engineer for approval at least six weeks in advance of any scheduled injection operation.
3.Written approval of the Wax Injection Operations Plan by the Engineer is required before any injection of permanent structure can begin.
4.At a minimum, the Wax Injection Operations Plan will address and provide the following:
a.Names and qualifications for wax injection crew and crew supervisor in conformance with this Specification;
b.Type, quantity, and brand of materials to be used in wax injection including all required certifications;
c.Type of equipment to be used, including capacity in relation to demand and working conditions, as well as, standby equipment and spare parts;
d.Personal Protective Equipment (PPE);
e.Communication equipment to be used during injection;
f.Location and sequence of ducts to be injected;
g.Calculation of temporary elongation of tendons due to wax injection temperature; FY 2023-24 Return to Table of Contents
h.Procedures for checking the presence of water or moisture in the duct , blowing oil -free dry compressed air, and measuring humidity of air within the duct;
i.If applicable, p rocedures for monitoring and continuously maintaining less than 40% humidity of air within the duct;
j.General wax injection procedure for all duct geometries and types;
k.Duct pressure test and repair procedures;
l.Method to be used to control rate of flow within ducts and anchorage assembly;
m.Theoretical wax volume calculations;
n.Injection rate;
o.Maximum injection pressure during injection and locking pressure;
p.Vacuum (gauge) pres sure requirements, vacuum tests and repair procedures;
q.Heating, mixing and pumping procedures in accordance with the manufacturer’s recommendations;
r.Direction of wax injection accounting for grade and/or slope of tendon;
s.Location of all high points and all low points accounting for grade and/or slope of tendon;
t.Sequence of valve operations at PT system inlets and outlets, including minimum wax discharge quantities;
u.Procedures for handling blockages;
v.Procedure for sealing duct after wax injection;
w.Procedure for inspecting the PT system after wax injection, filling voids created by inspection procedures, and sealing duct after PT system inspection;
x.Procedures for possible post injection re pair;
y.Method(s) and material(s) that will be used to protect concrete surfaces from wax spills, leaks, etc. during wax injection, post injection inspection and post injection repair;
z.Safety and clean -up procedures;
5.Conduct a joint meeting of the Contractor, wax injection crew, and the Engineer before wax injection operations begin. Discuss Wax Injection Operations Plan, required testing, corrective procedures, and any other relevant issues at the meeting.
6.Prior to production wax injection, d emonstrate to the Engineer’s satisfaction successful wax injection by injecting full -scale mockups that are constructed with all associated PT system components using the mockup tendon profiles shown in the Plans and the proposed Wax Injection Operations Plan. Utilize smooth duct and associated couplers and fittings meeting the requirements of Section 960 for all mockups. Utilize smooth duct for the mockups which has an inside diameter required for a given mockup tendon size. If the mockup is also being used to perform PT system acceptance testing, use the duct type appropriate for the PT system location. Place the mockup tendons specified in the Plans inside the ducts to simulate the in -place PT tendons. Stress mockup tendons to the minimum values shown in the Plans by using jacks or other methods approved by the Engineer . Perform pressure FY 2023-24 Return to Table of Contents tests on the mockups in accordance with 462 -8.2.1 prior to wax injection. If vacuum assisted wax injection is required to be used, perform vacuu m tests on the mockups in accordance with 462 - 8.2.1 prior to wax injection. For the wax injection operations, utilize the same wax material and types and sizes of wax inject ion equipment that will be used on the project including but not limited to heaters , pumps, hoses, valves and pressure gauges. Inject wax into the mockups using the proposed Wax Injection Operations Plan. Allow the wax to cool a minimum of 24 hours after injection before inspecting the mockup. Inspect the mockup in accordance with the re quirements of 462-8.3.2.2.1 and then carefully cut open the duct at all high points and other locations as directed by the Engineer to check for voids. Prepare a report documenting the findings and submit it to the Engineer. If voids are found, determine t he cause and revise the proposed Wax Injection Operations Plan accordingly. If directed by the Engineer, construct additional mockups and repeat the wax injection operation using the revised Wax Injection Operations Plan as many times as are required until the results are acceptable.
462-7.4 2.1.2 Inlets and Outlets:
1.Ensure connections from wax pump hose to inlets are free of dirt and are air -tight.
2.Inspect valves to ensure they can open and close properly.
3.Provide clear hose and connections to outlet valves compatible with heated wax injection for discharging excess wax. Kinks and clogs in the vent hoses are not permitted during pumping operations.
462-7.4 2.1.3 Supplies:
1.Provide an adequate supply of compressed air f or clearing and testing ducts before wax injection operations start.
2.Provide clean receptacles for collecting excess wax at outlet locations.
3.Provide supplies for stopping wax leaks including rags and buckets of cold water.
462-7.4 2.1.4 Equipment:
1.Provide equipment consisting of measuring devices for wax, wax melting unit(s), wax mixer for maintaining uniform temperature, a storage holding reservoir, pump, and volumetric flow rate and displacement volumetric meters with all nece ssary connecting hoses, valves, pressure gauges, timer, and temperature gauge.
2.Provide pumping equipment with sufficient capacity to ensure PT ducts can be filled and vented in not more than time specified by the wax manufacturer and this Specifica tion.
3.Provide an air compressor and hoses with sufficient output to perform required functions.
4.For filling of air voids in an incomplete wax injection, have the required equipment and personnel as stated in the approved Wax Injection Operations plan available to meet the timeframe requirements of 462 -8.3.2.2.1-6.
5.For vacuum assisted injection, provide vacuum pump equipment able to measure and have sufficient capacity to ensure a minimum of 90% vacuum in the PT system prior to filler injection. Provide a continuously running vacuum pump or vacuum reservoir capable of maintaining vacuum during the wax injection process. FY 2023-24 Return to Table of Contents
6.Ensure that all injection and inspection equipment is maintained in accordance with equipment manufacturer’s instructions and is calibrated and in good working condition.
7.Provide equipment for dislodging congealed wax blockages.
8.Provide standby pumping and vacuum equipment on the project site during injection operations.
462-7.4 2.1.4.1 Storage Reservoir and Mixing:
1.Provide heated holding tanks for wax injection.
a.Holding tanks must be equipped with a heating system capable of producing a melted wax free of lumps within the temperature limits specified by the manufacturer.
b.Holding tanks must be kept at least 10% full at all times during pumping operations to prevent clogs and air from being drawn into duct
c.Holding tanks must have at time of injection a quantity of heated wax required to inj ect the PT system. The quantity of heated wax required to inject the PT system is calculated as 25% more than the total quantity to fill the duct and anchorages, to discharge wax at outlets, to fill pumping equipment and hoses, and to maintain the minimum amount of wax in the holding tanks during pumping operations.
2.Provide equipment to ensure uniform temperature of heated wax, either by mixing or other methods.
462-7.4 2.1.4.2 Pumps:
1.Provide pumping equipment capable of the following :
a.continuous operation which includes a system for heating pump components when wax injection is not in progress;
b.maintaining pressure on wax injected ducts;
c.fitted with a valve that can be closed off without loss of pressure in duct.
2.Wax pumps will:
a.be positive displacement type;
b.provide a continuous wax flow;
c.be able to maintain a discharge pressure of at least 75 psi;
d.provide an injection of filler into duct in a velocity rang e of 40-70 ft/min.
3.Use pumps constructed with seals to prevent oil, air, or other foreign substances from contaminating wax and prevent loss of wax.
4.Pumps with hoppers are not permitted.
5.Specify pump capacity adequate to maintain the wax injection rate.
6.Place pressure gauge with full scale reading of no more than 300 psi at pump and duct inlets.
7.Wax injection hoses to be compatible with pump output (diameter, pressure rating and temperature). FY 2023-24 Return to Table of Contents
462-7.4 2.1.4.3 Vacuum Wax Injection:
1.If vacuum wax injection is to be used f or filling voids in incomplete wax filling operations, provide vacuum wax injection equipment meeting these minimum requirements:
a.Volumeter for measurement of void volume;
b.Vacuum pump with a minimum capacity of ten cubic feet of air per minute and equipped with a flow -meter, graduated reservoir, or other acceptable means approved by the Engineer capable of measuring the amount of wax being injected.
c.Mixers and heaters, or other mixing and heating methods recommended and approved by the wax manufacturer, in writing, for the specific project covered by this Section.
2.For vacuum assisted injection, provide vacuum wax injection equipment meeting these minimum requirements:
a.Vacuum pump with a minimum capacity of ten cubic feet of air per minute (free air) with the capability of removing 90% of standard atmospheric pressure within the PT system and eq uipped with a vacuum pressure gauge;
b.Hoses, vacuum reservoirs, and connections required for attachment to the PT system.
462-7.4 2.1.4.4 Heaters: Use a heater and temperature
monitoring system capable of liquefying the entire mass of PT wax to be used for a given injection operation within the temperature limits specified by the PT wax manufacturer. The heater systems must apply a uniform heat to the PT wax and avoid locally high temperatures that may damage the PT wax or container. Use a hea ter and temperature monitoring system which complies with the recommendations of the PT wax manufacturer.
462-7.4 2.1.5 Wax Injection:
1.Maintain wax temperature in strict compliance with the wax manufacturer’s published product data sheet and w ithin the limits of this Section.
2.Perform wax injection in accordance with procedures set forth in approved Wax Injection Operations Plan.
3.Inject hot wax into specified duct inlet.
462-7.4 2.1.5.1 Temperature:
1.Condition wax to maintain its temperature during injection between 212°F and 240°F.
2.Wax injection operations are not permitted when ambient temperature is below minimum temperatures specified by the wax manufacturer.
462-7.4 2.1.5.2 Production Test:
1.Check wax temperature to verify it is within established limits during operations.
2.Do not start operations until such time that testing shows wax meets specified requirements.
462-7.4 2.1.5.3 Wax Injection Operations:
1.Briefly open low point drains to allow for drainage of any water that may be present within the duct. If water is present: FY 2023-24 Return to Table of Contents
a.Capture and measure the water removed from the duct and retain for further testing as directed by the Engineer ;
b.Obtain written authorization from the Engineer to proceed with blowing of compressed air.
2.Just prior to wax injection, c lose all low point drains and ports except the inlet and outle t ports at the anchorage caps. Blow oil-free dry compressed air meeting ASTM D4285 through one of the anchorage cap ports until the humidity measured at the inlet and outlet ends are less than 40% and continuing blowing for an additional 30 minutes. Stop blowing, wait a minimum of 15 minutes, and take humidity measurements at the inlet and outlet ends of blowing . Further blowing is not required if both humidity readings are less than 40%. If the humidity readings are 40% or greater, then repeat the process of blowing and waiting for 15 minutes until the humidity measurements at the inlet and outlet end of blowing are less than 40% . Take humidity measurements of air within the duct at the inlet end and outlet end of blowing using separate humidity meters. Use humidity meter s approved by the Engineer.
4.Provide visual confirmation that the duct and tendon are free of water, moisture and debris at the anchorages and low points of the tendon profile.
5.Protect concrete surfaces from wax spills, lea ks, etc.
6.Inject wax in accordance with approved Wax Injection Operations Plan.
7.Use pumping methods that ensure complete filling of ducts and anchorage assembly with wax.
8.Ensure the entire mass of wax is fully liquefied prior to and throughout injection operations. Establish a non -turbulent, laminar system circulation by continuously recirculating the wax between the pump and the storage container prior to injecting the wax into the duct. Pump components must be at wax injection te mperature prior to wax injection into duct. Do not allow wax to free fall during recirculation or injection operations. Maintain a positive head of liquid wax above all withdrawal and recirculation ports and do not allow air intrusion into the pumping syst em. Do not pour liquid wax into an open pump or hopper.
9.Inject PT wax at a continuous and steady rate in accordance with the approved Wax Injection Operations Plan at a flow rate through duct at a velocity between 40 and 70 feet per minute and pre ssure limited to 75 psi at the duct inlet and 145 psi at the pump.
10.For tendons in which vacuum assisted injection is used, provide a minimum of 90% vacuum in the duct prior to injection. Connect both the anchorage outlet and the cap outlet to th e vacuum system. After the vacuum is established, lock off the air supply to the duct and monitor the vacuum for 1 minute. If the loss of vacuum after 1 minute exceeds 10%, repair leaks as directed by the Engineer and retest the duct. If the results are acceptable, reestablish and maintain a minimum 90% vacuum using the outlet s at the higher end anchorage shown on Standard Plans, Index 462-001 while injecting wax using the inlet at the lower end anchorage shown on the same Standard. Close all outlets, inlet s, and ports other than at injection and vacuum locations during injection procedure. Pump wax into inlet and continuously vacuum air at the outlet. After the duct is fully injected with wax and the wax FY 2023-24 Return to Table of Contents reaches the vacuum end, close the outlet valve, turn off the vacuum pump and continue the injection pump. Bleed all outlets starting at the anchorage cap at the injection end and proceed to bleed every valve thereafter from injection end to vacuum end, ending with the anchorage cap at the vacuum end. When bl eeding each valve, collect a minimum of two gallons of continuously flowing wax free from air before closing the valve. After all outlet valves are closed, c lose inlet valve with locking pressure between 30 psi and 45 psi. Do not reuse discharged wax.
11.For tendons in which vacuum assisted injection is not used, inject wax under pressure at locations shown on Standard Plans, Index 462-001. Allow wax to flow from duct and anchorage discharge points until a steady flow of wax free from air is continu ously discharged. Collect a minimum of two gallons of continuously flowing wax free from air at discharge point before closing outlet valve. Do not reuse discharged wax. After all outlets are closed, close the inlet valve at locking pressure between 30 and 45 psi.
12.Record the total volume of wax injected into the system.
13.Upon completion of wax injection, seal the duct in accordance with the approved PT system drawings. Remove all excess wax from exposed surfaces.
462-7.4 2.1.5.4 Wax Injection Operations Report:
1.Submit the wax injection report signed by the wax injection Contractor within five days of each wax injection operation for review by the Engineer.
2.Record theoretical quantity of wax antici pated as compared to actual quantity of wax used to fill duct. Notify the Engineer immediately of shortages or overages.
3.Information to be noted in this report must include at a minimum, but not necessarily be limited to:
a.Identification of duct;
b.Date of duct pressure test;
c.Date wax injected;
d.Number of days from tendon installation to wax injection;
e.Wax product identification;
f.Daily duct humidity readings if applicable;
g.Humidity readings from blowing compressed air through duct ; h. Verification that water or moisture is not present within the duct prior to wax injection ;
i.Pressure gauge readings at the pump and at the inlet;
j.Final locking pressure of wax in PT system;
k.Reservoir temperature at time of initiation of wax injection;
l.Theoretical volume of wax required to completely fill the duct;
m.Volume of wax injected into duct; FY 2023-24 Return to Table of Contents
n.Volume of wax collected at discharge points;
o.Injection rate including timing of duct inlet opening and closing;
p.Ambient temperature;
q.Summary of any problems encountered and any deviations from the Wax Injection Operations Plan;
r.Corrective action taken;
s.Description and results of the post wax injection operations and inspection;
t.Vacuum gauge pressure and percent vacuum in duct prior to injection;
4.Maintain daily wax injection operations reports at the job site for review by the Enginee r. Submit all daily reports to the Engineer on a weekly basis or as directed by the Engineer.
462-7.4 2.1.6 Manufacturer’s Installation Technician:
Provide for a PT system vendor installation technician, certified by the vendor as having sufficient kno wledge and expertise to oversee the wax injection personnel. The vendor’s technician shall be under the direct employ of the vendor and shall be present for all wax injection activities for a minimum of the first two days of wax injection for each of the Contractor’s wax injection crews. The vendor’s technician shall submit written certification to the Engineer that the Contractor’s installation process is in conformance with the approved Wax Injection Operations Plan.
462-7.5 Repair: Perform no remedial or repair work without the Engineer’s approval in
writing.
462-7.5 1 Lifting and Access Holes:
1.Repair all holes with magnesium ammonium phosphate concrete meeting requirements of Section 930 or Type Q epoxy grout meeting requirements of Section 926. Immediately before casting concrete (i.e., within 24 hours), mechanically clean and roughen the mating concrete surfaces to remove any laitance and expose small aggregate. Use grit blasting or water blasting using a minimum 10,000 psi nozzle pre ssure. Flush surface with water and blow dry. Form, mix, place, and cure material in strict compliance with manufacturer’s recommendations.
2.Upon completion of deck grooving, c oat repaired holes, block -outs, and an area extending six inches outside pe rimeter of repair with a high molecular weight methacrylate (HMWM) meeting the requirements of Section 413. Prepare surface to be coated and apply HMWM in accordance with Section 413. Friction (skid) tests per Section 413 are not required.
462-7.5 2 Inle ts, Outlets, Drains and Ports :
1.Place threaded plastic plugs in all inlet , outlet, drain and port locations required in the Contract Documents.
2.Fill inlet , outlet, drain and port recesses as shown in the Contract Documents using a Type Q epoxy compound, Type E epoxy compound, or Type F-1 epoxy compound meeting requirements of Section 926.
3.Prepare surface to receive epoxy compounds in compliance with manufacturer’s recommenda tions. FY 2023-24 Return to Table of Contents
462-7.5 3 Duct:
1.Repair the following ducts using heat -shrink wrap material designed for duct repair:
a.Smooth plastic ducts that will be encased in concrete;
b.Corrugated plastic ducts;
c.External smooth plastic ducts after th e flexible filler injection procedure has been completed. Install heat -shrink wrap in accordance with manufacturer’s instructions.
2.Repair external smooth plastic ducts before the flexible filler injection procedure has been completed using elasto mer sleeves and stainless steel band clamps.
462-8 Acceptance and Testing.
462-8.1 Contractor Material Testing:
1.The following tests are not required on post -tensioned, precast flat slab bridges, and double -tee bridges, but are required on all other PT applications.
2.Include cost for Contractor Tendon Modulus of Elasticity Test and In -Place Wobble and Friction Test in price of PT system.
462-8.1 1 Tendon Modulus of Elasticity Test:
Perform a tendon modulus of elasticity test in accordance wit h the following procedure if required in the Contract Documents or ordered by the Engineer.
1.Bench test two samples of each size tendon prior to stressing tendons to determine modulus of elasticity for purpose of accurately determining tendon elongations while stressing.
2.Bench length between anchorages must be at least 40 feet and tendon duct at least two inches clear of tendon all around for purpose of this test.
3.Test procedure must consist of stressing tendon at an anchorage assembly w ith a load cell at dead end.
4.Tension test specimen 80% of GUTS in ten increments and then detention from 80% of GUTS to zero in ten decrements.
5.Record gauge pressure, elongations, and load cell forces for each increment and decrement.
6.Note elongations of tendon for both ends and the central 30 feet, measured to an accuracy of plus or minus 1/32 inches.
7.Correct elongations for actual anchor set of dead end.
8.Calculate modulus of elasticity as follows: E = PL/Adl where, P = force in tendon L = distance between pulling wedges and dead end wedges or exact length in the center 30 feet of tendon A = cross sectional area of tendon dl = tendon elongation within length, L, for load, P
9.Submit rev isions to theoretical elongations to the Engineer for approval if bench test varies from modulus of elasticity used for shop or working drawings by more than 1%. FY 2023-24 Return to Table of Contents
10.Additional Tendon Modulus of Elasticity Tests may be required when observed tendon elo ngations in erected structure fall outside acceptable tolerances or to otherwise settle disputes to the satisfaction of the Engineer.
11.Additional test series of substantiation from previous projects, not to exceed two per source, will be required if source of prestressing steel changes during project.
12.Apparatus and methods used to perform the test must be submitted to the Engineer for approval in writing.
13.Tests must be conducted in the Engineer’s presence.
462-8.1 2 In-Place Wobble and Friction Test:
1.Test in -place a minimum of one tendon per tendon group performing the same function for tendons in excess of 100 feet long.
2.Functional tendon groups are cantilever tendons, continuity tendons, draped external tendons, or cont inuous profiled tendons passing through one or more spans.
3.Selected tendon will represent the size and length of tendon group being tested.
4.In-place test is not required on projects with straight tendons used in flat slabs or precast voided sla bs.
5.Test procedure consists of stressing tendon at an anchorage assembly with a load cell or a second certified jack at dead end.
6.Stress test specimen to 80% of GUTS in eight equal increments.
7.For each increment, record gauge pressure, el ongations, and load cell force (if a load cell is used).
8.Take into account any wedge seating in both live end (i.e., back of jack) and dead end (i.e., back of load cell) and any friction within anchorages, wedge plates, and jack as a result of slight deviations of strands or wires through these assemblies.
9.Keep an accurate account of elongation at jacking end allowing for intermediate wedge seating and slip of the jack’s wedges for long tendons requiring multiple jack pulls with intermediate tem porary anchoring.
10.If elongations fall outside the plus or minus 7% range compared to anticipated elongations, investigate reason and make detailed calculations confirming final tendon forces are in agreement with requirements of the approved Contrac t Documents.
11.Do not vary value of expected friction and wobble coefficients by more than plus or minus 10% in reconciling theoretical and actual elongations.
12.Submit for written approval by the Engineer a plan to correct or compensate for elon gation discrepancies if necessary.
13.The Engineer will require one successful test for each tendon group for the project.
14.The Engineer may require additional in -place tests if there are irreconcilable differences between forces and elongations or other difficulties during the course of routine stressing operations.
15.Submit apparatus and methods used to perform test to the Engineer for approval in writing.
16.Conduct all in -place tests in the Engineer’s presence.
462-8.1 3 Required Reports:
FY 2023-24 Return to Table of Contents
1.Submit the test report for “Tendon Modulus of Elasticity Test” to the Engineer at least 30 days before installing tendon.
2.Submit the test report for “In -Place Wobble and Friction Test” to the Engineer within two weeks after su ccessful installation of tested tendon.
462-8.1 4 Test Results Application:
1.Reevaluate theoretical elongations shown on PT shop or working drawings using results of “Tendon Modulus of Elasticity Test” and “In -Place Wobble and Friction Test,” as app ropriate, and correct calculations as necessary.
2.Submit revisions to theoretical elongations to the Engineer for approval in writing.
462-8.2 Contractor Field Tests:
462-8.2 1 Prior to Concrete Placement:
462-8.2 1.1 All Tendons Except as Noted :
1.Test all PT system components utilized on the project, except those used for internal longitudinal tendons in precast box -girder segments in the casting cell (e.g., cantilever tendons).
2.In the formwork, pressure test each duct with all asse mblies used in a single structural component (e.g. segment, beam, etc.).
3.Test assemblies in their final position just prior to concrete placement by sealing them at their anchorages or construction joint termini and then applying compressed air in a ccordance with this Section to determine if assembly connections are pressure tight.
4.In presence of the Engineer, pressurize duct to 7.5 psi and lock - off outside air source. Record pressure loss for one minute. If pressure loss exceeds 0.75 psi, or 10%, find and repair leaks in duct assembly using repair methods approved by the Engineer and retest.
462-8.2 1.2 Tendons for Which Vacuum Assisted Filler Injection Will
Be Used:
1.Test all PT system components utilized on the project except those used for internal longitudinal tendons in box -girder segments.
2.In the formwork, perform a vacuum test for each duct with all assemblies used in a single structural component (e.g. segment, beam, etc.).
3.Test assemblies in their final position just prior to concrete placement by sealing them at their anchorages or construction joint termini and then applying a vacuum in accordance with this Section to determine if assembly connections are pressure tight.
4.In presence of the Engineer, apply a 90% vacuum and lock -off outside air source. Record vacuum loss for five minutes. If vacuum loss exceeds 10%, find and repair leaks in duct assembly using repair methods approved by the Engineer and retest.
462-8.2 2 Post Concrete Placement:
1.After stressing and before injecting filler into duct, install all anchorage caps, inlets and outlets and test the duct with compressed air in accordance with this Section to determine if duct connections require repair.
2.In the presence of the Engineer, pressurize duct to 50 psi and lock -off outside air source. Record pressure loss for one minute. A pressure loss less than 25 psi, or 50%, is acceptable for ducts with a length of equal to or less than 150 feet and a pressure loss less than 15 psi is accept able for ducts longer than 150 feet. FY 2023-24 Return to Table of Contents
3.If the pressure loss exceeds allowable, repair leaking connections using methods approved by the Engineer and retest.
462-8.3 Contractor Inspections:
462-8.3 1 Post Concrete Placement/Prior to Filler Injection Operations:
1.Upon completion of concrete placement and except as otherwise described, prove PT ducts are free and clear of any obstructions or damage and are able to accept intended PT tendons by passing a torpedo through ducts.
2.Use a torpedo ha ving same cross -sectional shape as duct that is 1/4 inches smaller all around than clear, nominal inside dimensions of duct. Make no deductions to torpedo section dimensions for tolerances allowed in manufacture or fixing of ducts. For straight ducts, use a torpedo at least two feet long. For curved ducts, determine length so that when both ends touch outermost wall of duct, torpedo is 1/4 inches clear of innermost wall. The Engineer will reject member if torpedo will not travel completely through duct and workable repair cannot be made to clear duct. Torpedo must pass through duct easily when pushed through by hand, without resorting to excessive effort or mechanical assistance.
3.Alternatively, four strand tendons in flat ducts used for transverse PT o f segmental box -girders may be preplaced prior to concrete casting. Prove PT ducts are free and clear of any obstructions or damage by moving the group of strands back and forth in duct for a minimum distance of one foot in each direction. Move strands eas ily, by hand, without resorting to excessive effort or mechanical assistance.
462-8.3 2 Post Filler Injection Operations:
462-8.3 2.1 Post Grouting Operations:
1.Inspect all tendons. Complete the inspection of a given tendon within 96 hours after grouting of that tendon.
2.Do not open or remove inlets , outlets, drains or ports until grout has cured for a minimum of 24 hours.
3.Perform inspections within one hour after removal of all inlets and outlets and drains located at anchorages and points along the tendon.
4.Drill into grout ports at all high points along tendon as well as inlets or outlets located at anchorages for inspection. Drill through hardened grout to penetrate full-length of grout port access piping to to p of trumpet or duct. If drilling of inlets or outlets is not feasible with conventional equipment, propose an alternative method of tendon inspection for approval by the Engineer in writing. Use drilling equipment that will automatically shut -off when steel is encountered. Do not drill into anchorage cap unless anchorage caps are determined to have voids by sounding.
5.Perform all inspections using borescopes or probes and in presence of the Engineer.
6.Fill voids using volumetric measuring vacuu m grouting process within 4 days from grouting.
7.Seal and repair all anchorage and inlet/outlet voids that are produced by drilling for inspection purposes as specified within four hours of completion of inspections if no additional voids are detecte d in tendon ducts or anchorages.
8.Remove inlet/outlet to a minimum depth of two inches below face of concrete and seal the surface as specified within 4 hours of inlet/outlet removal. Use an injection tube to extend to bottom of holes for backfilling with epoxy grout. FY 2023-24 Return to Table of Contents
9.Drill into duct and explore voided areas with a borescope if grouting operations were prematurely terminated prior to completely filling duct. Probing is not allowed. Determine location and extent of all voided areas. Fill voids u sing volumetric measuring vacuum grouting equipment in accordance with this Section.
462-8.3 2.2 Post Flexible Filler Injection Operations:
462-8.3 2.2.1 Microcrystalline Wax:
1.Inspect all tendons . Complete the inspection of a given tendon wi thin 96 hours after injecting that tendon with wax.
2.Do not open or remove inlets, outlets, drains or ports until wax has cooled for a minimum of 24 hours.
3.Perform inspections within one hour after removal of all inlets/outlets located at an chorages and high points along the tendon.
4.Visually inspect existing ports at all high and low points along tendon as well as all ports located at anchorages. Repair wax leaks according to the Wax Injection Operations Plan.
5.Between 24 and 4 8 hours following wax injection, perform the following inspection operations for each tendon:
a.Sound external ducts with a rubber mallet to ensure the system is free from voids,
b.Remove all inspection port caps and visually inspect to ensur e the system is free from voids,
c.If a void is detected and the void is deeper than 1/2 inch or if the strands are exposed and uncoated, address the void using this section and methods described in the approved Wax Injection Operations Plan;
d.Fill voids created by inspection procedures and replace all inspection port caps and seal in accordance with the approved Wax Injection Operations Plan.
6.Fill voids using the methods described in the approved Wax Injection Operations Plan within 4 days from filler injection.
7.Seal and repair all anchorage and inlet, outlet and port voids that are produced for inspection purposes as described in the approved Wax Injection Operations Plan within four hours of completion of inspections if no a dditional voids are detected in tendon ducts or anchorages.
8.Inspect duct and explore voided areas with a borescope if wax injection operation was prematurely terminated prior to completely filling duct. Determine location and extent of all voided a reas. Fill voids using gravity feed or injection, do not use vacuum repair injection unless proven by a mockup and approved by the Engineer.
462-9 Method of Measurement.
1.Quantity of PT tendons to be paid for under this Section will be computed weight, in pounds, of permanent PT steel tendons installed in the completed structure and accepted.
2.Quantity is determined by theoretical plan length measured from anchorage to anchorage (measured from front face of bearing plate) with no allowance made for wa ste or extension past bearing faces.
3.No measurement will be made for temporary PT which is considered incidental to Pay Item 462-2, Post Tensioning Tendons.
4.Use these unit weights for quantity determination: FY 2023-24 Return to Table of Contents Table 462-2 PT Strand and Bar Weight per Unit Length Prestressing System Weight per Unit Length, Lb/Ft 1/2 inch diameter 7 -wire strand 0.52 0.6 inch diameter 7 -wire strand 0.74 5/8 inch high strength deformed bar 0.98 3/4 inch high strength deformed bar 1.49 1 inch high strength deformed bar 3.01 1-1/4 inch high strength deformed bar 4.39 1-3/8 inch high strength deformed bar 5.56 1-3/4 inch high strength deformed bar 9.10 2-1/2 inch high strength deformed bar 18.20 3 inch high strength deformed bar 24.09 Note: Weight per unit length of high strength deformed bars is based on values given in ASTM A722.
462-10 Basis of Payment.
462-10.1 General:
1.PT tendons will be paid for at the Contract unit price per pound of steel tendon, completed and accepted.
2.Payment will be full compensation for furnishing, installing, stressing, and filler injection of all temporary and permanent, internal and external ducts. Payment also includes anchorage assemblies and associated supplemental reinforcing steel required by supplier, PT system hardware not embedded in concrete, ducts, grout and grouting operations, flexible filler and filler injection operations, all testing, including construction of and filler injection into mockup s, Tendon Modulus of Elasticity Test and In -Place Wobble and Friction Test, protection of PT anchorages, inlets, outlets, drains, and all labor, materials, tools, equipment, and incidentals necessary for completing the work in accordance with the Contract Documents. This payment also includes lubricants in tendon ducts for friction control and flushing lubricants or contaminants from ducts.
3.Anchorage components, ducts, and similar items of PT system hardware embedded within precast components or cast -in-place concrete will be deemed to be included in cost of precast component or cast -in-place concrete in which it is embedded.
4.Payment is based on unit price bid extended by either quantities shown in the Contract Documents or actual quantities used a nd accepted, whichever is less, if the Contractor constructs structure with an accepted alternate not detailed in the Contract Documents.
5.Permanent PT strand, wire, or bar tendons which are an integral part of individual precast concrete segments or u nits will be measured and paid for under this item and will not be considered incidental to cost of those precast concrete segments or units.
6.Payment for PT will be made following successful placement, stressing, filler injection, inspection, repair, protection, and written approval by the Engineer.
7.Full payment for PT tendons within precast segmental concrete structure units may occur prior to erection of segments into final position when ducts have been injected and anchorage protection system a pplied and the segmental unit otherwise approved in writing for placement by the Engineer.
462-10.2 Pay Items:
FY 2023-24 Return to Table of Contents Payment will be made under: Item No. 462 - 2- Post-Tensioning Tendons - per pound. FY 2023-24 Return to Table of Contents SECTION 470 TIMBER STRUCTURES
470-1 Description.
Furnish and erect treated timber into various structures.
470-2 Materials.
Meet the following requirements: Timber ................................ ................................ .Section 952 Preservative ................................ ......................... Section 955 Use timber as specified in the Plans.
470-3 Timber Handling.
Handle treated timber with rope slings, without sudden dropping, breaking of outer fibers, bruising, or penetration of the surface with tools. Do not use cant dogs, hooks, or pike poles.
470-4 Cutting and Framing.
Before treatment, cut and frame all timbers which are shown by the Plans to be furnished in special lengths or framed to detailed dimensions. Limit the cutting of treated timber to minor fitting which might be necessary and that is authorized by the Engineer. For all places where the surface is broken, by cutting or otherwise, thoroughly coat with the preservatives and by the methods specified in AWPA M4.
470-5 Bolt Holes.
The Contractor may drill holes in the field. For timbers originally treated with pentachlorophenol, creosote, creosote solutions, or waterborne preservatives, field treat all cuts, abrasions, bolt holes, and recesses that occur after treatment with two liberal applications of a compatible preservative in accord ance with the requirements specified in AWPA Standard M4, Standard for the Care of Pressure -Treated Wood Products.
470-6 Pile Caps.
Ensure that pile caps have full even bearing on all piles in the bent, and secure them to each pile by a 3/4 inch diameter drift bolt extending at least 9 inches into the pile. Where so shown in the Plans, cover the tops and ends of pile caps with 10 ounce, minimum weight, copper sheet meeting the requirements of ASTM B370.
470-7 Floors.
Attach the planks to each joist or nai ling strip with at least two 8 inch nails for 3 inch planks, or two 10 inch nails for 4 inch planks. Use nails that are at least 1/4 inch in diameter. For treated timber floors where a bituminous wearing surface is to be applied, lay the planks with the best side up and with adjacent edges in contact. Grade the planks as to thickness before laying, and lay the planks so that no two adjacent planks vary in thickness more than 1/8 inch. Cut the floor to straight lines along the side of the roadway and walkway . FY 2023-24 Return to Table of Contents
Source: Florida Standard Specifications for Road and Bridge Construction, 2024 Edition. Pages 672–705 of 1,299.