Asphalt core patch and density retest record before pay-factor closeout

Direct answer

Before pay-factor dispute closeout, an asphalt core location patch and density retest photo record should identify the project, item, mix, lift, lot, sublot, station, offset, lane, joint or mat category, original random location, adjusted location and reason, core diameter, core ID, coring date and time, traffic control status, photos before coring, photos during coring, core condition, chain of custody, lab density method, Gmm or target density basis, original density result, disputed result, retest request, referee or dispute lab, replacement result if allowed, pay-factor recalculation, core-hole patch material, tack, compaction, final patch photo, exceptions, witnesses, and closeout decision.

The record should not argue density with a loose collection of screenshots. It should show exactly where the core came from, whether the location was allowed, how the core was handled, how the core hole was restored, which result controls the pay calculation, and what area the dispute actually closes.

Use this field note as documentation guidance only. The contract specifications, DOT procedure, engineer, inspector, testing agency, project lab, contractor QC plan, traffic control plan, mix design, approved dispute procedure, safety rules, and agency pay-factor rules control the actual sampling, coring, testing, retesting, patching, acceptance, payment, and dispute resolution.

Why density disputes get messy

Asphalt density disputes often start with one number and end with a stack of loose documents. The contractor says the core was in a bad location. The inspector says the location was random. The lab report does not show the station. The core-hole patch is missing. The pay factor was recalculated from a spreadsheet no one can trace. By the time the dispute closes, the pavement is under traffic and the physical evidence is gone.

The weak record says retest complete and pay factor updated. The strong record shows the lot, sublot, random selection, location adjustment, photos, core labels, chain of custody, lab method, density result, retest basis, core-hole repair, and final payment calculation.

Caltrans construction guidance, FHWA density demonstration material, NYSDOT coring procedures, Iowa specifications, MnDOT coring guidance, and other agency documents all show the same pattern: density acceptance is a formal lot and sublot process, and the record must preserve the location and test chain that supports the pay decision.

Start with the contract rule

The first page of the packet should name the contract specification, special provision, density acceptance method, lot size, sublot definition, random-location procedure, joint-density rule, dispute procedure, retest rule, lab method, pay equation, and who has authority to select or adjust core locations.

Do not mix rules from different agencies. Caltrans pay-factor characteristics, Iowa random core location language, NYSDOT MP 404 procedures, and Illinois dispute-resolution language are useful examples, but the project contract decides the actual process.

If the specification says dispute cores must be taken at the same time as the original core, do not build a record around later cores unless the engineer accepted that procedure in writing. If the specification says referee results replace original results, the record should show which original results were replaced and why.

Map the lot and sublot before retesting

Create a map that shows the paving date, mix type, lift, lane, station range, offset range, mat width, shoulder or mainline category, longitudinal joint category, tonnage or area represented, lot boundaries, sublot boundaries, original core locations, disputed core locations, and any adjusted locations.

NYSDOT and MnDOT guidance illustrate how core location selection depends on lot, sublot, offset, lane geometry, and category. Iowa specifications similarly describe random core locations by lot and sublot and allow new random locations in certain impractical cases. The packet should make the map visible, not buried in notes.

If the dispute is about a joint core, a mat core, a shoulder core, or an edge-adjacent location, label it that way. Do not let a mat density result silently stand in for a joint density issue.

Photograph the location before the core is cut

Before drilling, photograph the station mark, offset mark, lane or shoulder reference, core circle, pavement condition, joint or edge reference, nearby traffic control, and any reason a location was moved. Include a wide photo and a readable close-up.

This matters because location disputes are common. Was the core too close to an unsupported edge? Was it in a taper, bridge approach, utility patch, joint, construction stop, or contaminated area? Was the offset measured from the correct reference line? The photo record answers those questions before the pavement is cut.

If the engineer adjusts a random location for safety, impracticality, or specification language, capture the original mark, adjusted mark, reason, and authorizing person.

Core ID and custody are part of density

Every core should have a durable ID that ties to the lot, sublot, station, offset, lane, date, mix, lift, and whether it is original, companion, dispute, verification, or referee. The label on the core, bag, lab sheet, and photo should match.

SCDOT's asphalt pavement compaction procedure addresses sampling, transporting, trimming, weighing, calculations, and dispute handling. NYSDOT's MP 404 procedure includes pavement and joint core sample handling and documentation elements. The field record should preserve the chain from pavement to lab.

Do not let unlabeled photos or unlabeled cores enter a pay-factor dispute. If the core label, bag label, and lab report do not match, hold the dispute closeout until the testing agency and engineer resolve the chain of custody.

Lab density method and target basis

Record how density was calculated. Include the core bulk specific gravity or density method, the maximum specific gravity or target density basis, daily Gmm or project target density where applicable, percent of theoretical maximum density, rounding rule, and whether the result is for mat, joint, or another acceptance category.

ASTM D2726 covers bulk specific gravity and density of compacted asphalt mixtures. WSDOT's field operating procedure for AASHTO T 166 covers bulk specific gravity of compacted asphalt mixtures. ASTM D2950 covers in-place asphalt density by nuclear method and notes its use as a rapid nondestructive technique with proper calibration and confirmation testing.

The packet should not mix nuclear gauge readings, core densities, Gmm values, and pay-factor percentages without explaining the relationship. If gauge readings were used for process control and cores were used for acceptance, say that.

Retest and dispute rules must be explicit

Record who requested the dispute, when the request was made, which lot or sublots were contested, which original results are disputed, what specification clause allows the retest, who selects the retest locations, which lab performs the retest, and whether the retest result replaces or only verifies the original result.

Illinois pay-for-performance language reviewed for this package describes dispute-resolution timing and replacement of original quality assurance test results in specified circumstances. SCDOT procedure describes taking cores to a central laboratory for dispute resolution. The AASHTO SHRP2 draft compaction specification describes contractor-requested evaluation of disputed lots by randomly located drilled cores in a defined workflow.

Do not close a pay-factor dispute with a retest number alone. The packet needs the procedural basis that makes the retest controlling.

Patch the core hole as a quality item

The core-hole repair is part of the closeout, not an afterthought. Photograph the open hole, dry condition, cleaned hole, tack application where required, patch material, lift placement, compaction, surface flushness, and final traffic-ready condition.

MnDOT guidance states core holes must be filled within a specified time after cutting. ODOT laboratory guidance says core holes should be filled as soon as possible and gives a dry-and-tack approach as a guideline. Texas Asphalt Pavement Association municipal dense-graded asphalt guidance also calls for drying core holes, tacking sides and bottom, filling with the same type of mixture, and compacting the patch.

If the core hole remains open, is patched with the wrong material, is low, high, loose, wet, or missing tack where required, do not call the dispute physically closed.

Pay-factor recalculation belongs in the packet

After the retest or dispute result is accepted, include the pay-factor worksheet or calculation page. Show the original result, replacement result if applicable, PWL or density pay-factor inputs where used, lot quantity, unit price where the contract requires it, and final incentive, disincentive, remove-and-replace, or acceptance decision.

FHWA density demonstration material explains how percent within limits density specifications are affected by average lot density, density standard deviation, and specification limits. Caltrans guidance describes core density as one of the pay-factor quality characteristics and discusses lot evaluation. Those concepts are why the dispute record needs the calculation, not just the conclusion.

If the dispute changes only one sublot, say that. If it recalculates the entire lot, say that. If it affects joint density separately from mat density, keep those payment paths separate.

Use a compact dispute table

Use the agency form, lab report, dispute form, or pay-factor worksheet first. Add a field table where those documents do not clearly connect the core location, retest result, core-hole patch, and closeout decision.

Build the photo packet

A strong photo packet includes the lot map, random-location sheet, station and offset marks, core circle before drilling, coring setup, extracted core beside label, core thickness or lift condition where recorded, bag label, chain-of-custody form, open core hole, cleaned and dried hole, tack, patch material, compaction, finished patch, lab result, retest request, and pay-factor worksheet.

Name files with project, lot, sublot, core ID, station, offset, and date. A photo named Lot4-Sublot3-CoreD4-214+80-8R-before-cut is more useful than a camera roll number.

If a location was moved or a core was rejected, keep those photos. The dispute record should show why a sample did not control rather than pretending it never happened.

Before pay-factor dispute closeout checklist

Run this check before accepting a density retest, pay-factor recalculation, or dispute closeout.

• Confirm the governing specification, special provision, density acceptance method, lot and sublot definitions, random-location rule, retest rule, referee lab rule, and pay-factor calculation.
• Map the disputed lot: mix, lift, paving date, station range, offset range, lane, shoulder, joint category, lot quantity, sublots, original cores, and retest cores.
• Verify every core location photo: station, offset, reference line, original random location, adjusted location where used, joint or mat category, and reason for any move.
• Verify core labels: lot, sublot, core ID, date, mix, lift, companion or dispute status, bag label, lab sample number, and chain of custody.
• Attach original density reports, Gmm or target density basis, calculation method, rounding rule, and original pay-factor effect.
• Attach retest request, disputed result list, specification clause, retest authorization, referee lab or dispute lab identity, and replacement-result rule.
• Attach retest result and show whether it replaces, verifies, or does not affect the original result.
• Patch every core hole and photograph dry condition, cleaning, tack where required, patch material, compaction, flushness, and final traffic-ready surface.
• Recalculate the pay factor or payment adjustment with original and replacement values clearly identified.
• Log exceptions: wrong location, missing photo, damaged core, unlabeled sample, open hole, wrong patch material, late dispute, missing lab report, or unresolved calculation.
• State the closeout decision: pay factor accepted, pay factor recalculated, deduction upheld, incentive changed, remove-and-replace required, claim held, or engineer exception.

Weak and strong records

Weak note: Density dispute retested. Core holes patched. Pay factor final.

That note does not identify the lot, sublot, core location, retest authority, lab method, replacement result, patch condition, or final calculation.

Stronger note: Density dispute closeout completed on 2026-06-09 for Lot 7, Surface Mix 12.5 mm, Lift 2, eastbound mainline Sta. 214+00 to 226+50. Dispute covers Sublots 2 and 3 only. Original random locations were marked by the engineer at 218+20 7.5R and 222+60 8.0R from lane line reference. Photos show station marks, offset tape, core circles, and traffic control before coring. Location 222+60 was moved to 222+64 8.0R because the original point landed on a visible utility patch; engineer authorization is attached.

Cores D7-2 and D7-3 were cut, labeled, bagged, and delivered to the regional lab with chain-of-custody form COC-17. Original core densities were 91.8 percent and 91.5 percent of Gmm. Dispute retest results from the referee lab were 92.6 percent and 92.4 percent. Specification clause 403.18 allows accepted dispute results to replace the original results for the contested sublots. Pay worksheet PF-7 revision 2 recalculates the Lot 7 density pay factor from 0.96 to 0.99.

Core holes were dried, cleaned, tacked, filled with approved surface mix, compacted, and photographed flush with surrounding pavement before traffic release. Release closes the density pay-factor dispute for Sublots 2 and 3 only. Joint-density results and Surface Mix Lot 8 remain outside this closeout.

The stronger note works because it ties the location, retest authority, sample custody, lab result, patch repair, recalculation, and closeout boundary together.

Common mistakes

The first mistake is arguing density without a lot and sublot map.

The second mistake is photographing the core after extraction but not the station and offset before drilling.

The third mistake is losing the connection between core label, bag label, lab report, and pay worksheet.

The fourth mistake is patching the core hole casually and leaving no photo proof that it was cleaned, tacked where required, compacted, and flush.

The fifth mistake is using a retest result without proving the specification allows that retest to replace the original result.

The sixth mistake is mixing mat density, joint density, nuclear gauge data, and core density in one calculation without explaining which value controls.

The seventh mistake is closing the dispute for more pavement than the tested and recalculated lot actually represents.

When to hold closeout

Hold closeout if the core location is not tied to a station, offset, lot, sublot, and reference line. Hold it if the location was adjusted but the reason and authorization are missing.

Hold closeout if the core label, bag label, lab ID, or chain-of-custody record does not match. A density number without sample identity should not control payment.

Hold closeout if the core hole is open, poorly patched, low, high, loose, wet, un-tacked where required, or missing final traffic-ready photos.

Hold closeout if the pay-factor worksheet does not show which result controls, which sublot changed, what quantity is affected, and whether the retest replaces or verifies the original result.

Owner and agency handoff

The final handoff should include the dispute request, specification clause, random-location sheet, lot map, photos, chain of custody, original report, retest report, lab method, Gmm or target basis, core-hole patch photos, pay worksheet, and final closeout decision.

If the pavement later shows distress at a core-hole patch or disputed sublot, the owner needs the map, photo, and calculation record. The dispute closeout should not live only in one inspector's email thread.

For agency work, keep the packet in the same document control path as the pay estimate or change record. For private work, attach it to the paving closeout and owner acceptance file.

Questions that come up

Can a contractor choose the retest location? Follow the specification. Many procedures assign location selection to the engineer or agency, sometimes with random-location rules and safety adjustments.

Does a nuclear gauge reading replace a core? Not unless the accepted procedure says so. Nuclear density can support process control or acceptance in some systems, but core, gauge, correlation, and referee rules are project-specific.

Should the core hole be patched the same day? Follow the contract. Several agency examples require prompt repair or set time limits, and the photo record should show the final patched condition.

What if the retest result is higher but the dispute request was late? The specification controls whether a late result matters. Record the request date and acceptance of the dispute procedure.

What if the core broke or was damaged? Record the condition, photos, lab note, and engineer decision. Do not quietly substitute a new value without the accepted procedure.

Does the pay factor close the quality issue? Not always. A payment adjustment may close the contract dispute, but remove-and-replace, monitoring, warranty, or maintenance requirements can remain if the specification or owner requires them.

Compliance and safety limits

This field note is not a DOT specification, sampling plan, random-location procedure, density test method, pay-factor equation, traffic control plan, dispute ruling, laboratory instruction, core-hole repair specification, claim decision, or engineer approval. The contract documents, DOT procedures, approved special provisions, engineer, testing agency, contractor QC plan, traffic control plan, lab accreditation rules, and site safety plan control the work.

Do not use this checklist to bypass traffic control, lane closure rules, qualified-worker requirements, hot-work or saw-cutting controls, PPE, silica controls, water handling, nuclear gauge controls, core drilling safety, lab procedures, chain-of-custody requirements, patching specifications, payment rules, or engineer approval. The packet preserves asphalt core location, patch, density retest, and pay-factor evidence. It does not authorize unsafe work or payment closeout.

Sources checked

• Caltrans Construction Manual, Section 39 Asphalt ConcreteUsed for pay-factor quality characteristic context, including core density and PWL lot evaluation.
• FHWA, Density Demonstration Projects and Related SpecificationsUsed for density specification and percent-within-limits pay-factor context.
• NYSDOT, MP 404-02 Asphalt Pavement Density ProcedureUsed for pavement and joint core sample selection, density gauge monitoring, random core location, and documentation context.
• Iowa DOT, Section 2303 Hot Mix Asphalt MixturesUsed for random core location and sublot context in a current DOT specification.
• MnDOT, Compaction and Coring GuidanceUsed for core stationing, offset, lot, companion core, longitudinal joint, and core-hole fill timing examples.
• SCDOT, SC-T-87 Asphalt Pavement Compaction ProcedureUsed for core sampling, transport, trimming, weighing, calculations, and dispute-resolution lab context.
• Illinois DOT, Hot-Mix Asphalt Pay for Performance Using Percent Within LimitsUsed for dispute resolution timing, density core retest, replacement-result, and pay-factor recalculation context.
• AASHTO SHRP2, Asphalt Full Coverage Compaction Specification DraftUsed for disputed lot evaluation by randomly located drilled cores and core compaction evaluation context.
• ASTM, D2726/D2726M Bulk Specific Gravity and Density of Compacted Asphalt MixturesUsed for compacted asphalt mixture bulk specific gravity and density test context.
• ASTM, D2950/D2950M Density of Asphalt Mixtures in Place by Nuclear MethodsUsed for nuclear density method context and its role as a rapid density technique with calibration and confirmation testing.
• WSDOT, FOP for AASHTO T 166Used for bulk specific gravity of compacted asphalt mixtures by saturated surface-dry specimens.
• ODOT, OHD L-14 Density of Compacted Asphalt SpecimensUsed for roadway density importance, random core location, companion core spacing, and core-hole filling guidance.
• Texas Asphalt Pavement Association, Item 341M Dense-Graded Asphalt MixturesUsed for core-hole repair context: drying, tacking, filling with the same mixture type, compacting, and approved alternate repair methods.

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