+---
+title: Pavement Rehabilitation and Sealcoating
+category: Sitework
+toc_depth: 3
+description: >
+ When to use: planning, specifying, and executing preservation and rehabilitation
+ of existing asphalt surfaces on roadways, parking lots, driveways, and service
+ areas - cold milling, hot-mix asphalt mill-and-overlay, thin overlays, crack
+ cleaning/routing and sealing/filling, asphalt-emulsion or coal-tar sealcoating,
+ slurry seal, microsurfacing, chip seal, and fog seal - including pre-treatment
+ condition assessment (PCI per ASTM D6433), surface preparation, weather limits,
+ and acceptance testing.
+ Not intended for: new asphalt placement on prepared subgrade (sync/asphalt-paving);
+ new portland cement concrete pavement (sync/concrete-paving); aggregate base course
+ (sync/aggregate-base-course); subgrade/base stabilization (sync/soil-stabilization);
+ pavement marking removal and re-striping (sync/pavement-markings); site grading and
+ subgrade preparation (sync/site-rough-grading); full-depth reclamation, which is a
+ new-pavement scope (sync/asphalt-paving or sync/soil-stabilization); and rigid
+ (concrete) pavement joint sealing and spall repair.
+---
+
+# Scope {toc}
+
+## This standard governs the preservation and rehabilitation of existing flexible (asphalt) pavement surfaces, including condition assessment, strategy selection, material specification, surface preparation, and the execution and acceptance of the selected treatment. {note}
+
+## The treatments covered span the full preservation-to-rehabilitation continuum: cold milling (partial- and full-depth), hot-mix asphalt (HMA) mill-and-overlay, thin and ultra-thin overlays, crack cleaning and routing, hot-applied crack sealing and cold-applied crack filling, asphalt-emulsion and coal-tar sealcoating, slurry seal, microsurfacing, single- and double-application chip seal, and fog seal. {note}
+
+## The selected treatment shall be matched to the measured pavement condition and the governing distress type, not chosen by default or by lowest first cost alone.
+
+## A pre-bid pavement condition assessment shall be performed and made a contract document before any mill-and-overlay or surface-treatment scope is bid.
+
+## The following work is outside this standard and is governed elsewhere. {note}
+
+- New asphalt pavement placement on prepared subgrade - see [[sync/asphalt-paving]].
+- New portland cement concrete pavement - see [[sync/concrete-paving]].
+- Aggregate base course construction and stabilization beneath the pavement - see [[sync/aggregate-base-course]] and [[sync/soil-stabilization]].
+- Site grading and subgrade preparation prior to any pavement work - see [[sync/site-rough-grading]].
+- Pavement marking removal, re-striping, and thermoplastic application after rehabilitation - see [[sync/pavement-markings]].
+- Full-depth reclamation (FDR), where the entire pavement section is pulverized and re-stabilized - this is a new-pavement scope under [[sync/asphalt-paving]] or [[sync/soil-stabilization]].
+- Joint sealing and spall repair on rigid (concrete) pavements - this standard addresses flexible (asphalt) surfaces only.
+
+## Full-depth structural patching of failed base or subgrade areas is a separate scope that shall be completed before surface rehabilitation begins; that patching is performed under [[sync/asphalt-paving]] and is not part of the surface treatment bid. {note}
+
+# Referenced Standards {toc}
+
+## Materials, design, and workmanship shall comply with the latest adopted edition of each of the following unless a specific edition is cited.
+
+## Where referenced standards conflict, the more stringent requirement shall govern unless the Engineer of Record directs otherwise in writing.
+
+| Standard | Title |
+|----------|-------|
+| ASTM D6433-20 | Standard Practice for Roads and Parking Lots Pavement Condition Index Surveys |
+| ASTM D6690-21 | Standard Specification for Joint and Crack Sealants, Hot Applied, for Concrete and Asphalt Pavements |
+| ASTM D3405 | Standard Specification for Joint Sealants, Hot-Applied, for Concrete and Asphalt Pavements |
+| ASTM D6372-23 | Standard Practice for Design, Testing, and Construction of Microsurfacing |
+| ASTM D3910-24 | Standard Practices for Design, Testing, and Construction of Slurry Seal |
+| ASTM D5360/D5360M-23 | Standard Practice for Design and Construction of Asphalt Surface Treatments |
+| ASTM D5167-13(2024) | Standard Practice for Melting of Hot-Applied Joint and Crack Sealant and Filler for Evaluation |
+| ASTM D3381/D3381M-18(2024) | Standard Specification for Viscosity-Graded Asphalt Binder for Use in Pavement Construction |
+| ASTM D4695-03(2025) | Standard Guide for General Pavement Deflection Measurements |
+| ASTM D5727 | Standard Specification for Emulsified Refined Coal Tar (Concentrate) |
+| ASTM D3320 | Standard Specification for Emulsified Coal-Tar Pitch |
+| ASTM D4552/D4552M-20(2025) | Standard Classification for Hot-Mix Recycling Agents |
+| AASHTO R 10 | Standard Recommended Practice for Definition of Terms Related to Pavement Distress |
+| AASHTO M 156 | Requirements for Mixing Plants for Hot-Mixed, Hot-Laid Bituminous Paving Mixtures |
+| UFGS 32 01 16.71 | Cold Milling Asphalt Paving (Unified Facilities Guide Specification) |
+
+## Slurry seal and microsurfacing submittals commonly reference the ISSA design manuals A105 (slurry seal) and A143 (microsurfacing) alongside the ASTM practices above; where the contractor's mix design cites an ISSA manual, the ASTM practice still governs acceptance unless the project specification states otherwise. {note}
+
+# Pavement Condition Assessment and Strategy Selection {toc}
+
+## Treatment selection is the single highest-leverage decision in a rehabilitation project, and it is driven by measured condition, not assumption. A pavement in good condition (high PCI) is over-served and money is wasted by an overlay; a structurally failed pavement (low PCI) is under-served and the treatment fails early when a surface seal is applied over a base problem. The condition survey exists to place the pavement on this continuum objectively. {note}
+
+## A Pavement Condition Index (PCI) survey shall be performed in accordance with ASTM D6433-20 over the project area before the rehabilitation strategy is finalized.
+
+## The PCI survey, including the distress map and the computed PCI value per management section, shall be included in the contract documents so that bidders price against a common, measured baseline.
+
+## Distress types shall be classified and reported using the terminology of AASHTO R 10 so that the survey, the bid documents, and field RFIs share one vocabulary.
+
+## The PCI ranges below are the industry-standard strategy bands (consistent with ASTM D6433-20 and FHWA pavement preservation guidance); they are a starting point, and the governing distress type may move the selection within an adjacent band. {note}
+
+- PCI 70 to 100 - preventive preservation (fog seal, sealcoat, crack seal).
+- PCI 55 to 70 - surface treatment (microsurfacing, slurry seal, chip seal).
+- PCI 40 to 55 - thin overlay (with or without partial-depth milling).
+- PCI 25 to 40 - mill-and-overlay.
+- PCI below 25 - reconstruction (outside this standard; see [[sync/asphalt-paving]]).
+
+## A surface treatment shall not be applied where the survey identifies the controlling distress as load-related (alligator/fatigue cracking, rutting from base failure), because a surface seal bridges the symptom without arresting the structural cause.
+
+## Crack sealing shall not be specified as a stand-alone remedy where the survey attributes the cracking to inadequate drainage or base failure; the underlying cause shall be addressed in a separate scope before or instead of sealing.
+
+## Where structural capacity is in question prior to an overlay design, deflection testing (falling weight deflectometer or Benkelman beam) should be performed per ASTM D4695 to confirm the existing section can carry the design traffic. {note}
+
+## Select the governing rehabilitation strategy. {note}
+
+```datasheet
+label: Rehabilitation strategy
+type: select
+options:
+ - Crack seal only (preservation)
+ - Sealcoat only (preservation)
+ - Fog seal (preservation)
+ - Microsurfacing (surface treatment)
+ - Slurry seal (surface treatment)
+ - Chip seal (surface treatment)
+ - Thin overlay, no milling
+ - Mill-and-overlay
+default: Mill-and-overlay
+```
+
+```datasheet
+label: Measured PCI of project area (pre-treatment)
+type: range
+unit: PCI
+min: 0
+max: 100
+step: 1
+drawing_ref: "condition survey report"
+default: deferred
+```
+
+## State whether a pre-bid PCI survey is furnished by the Owner or performed by the Contractor. {note}
+
+```datasheet
+label: PCI survey responsibility
+type: radio
+options:
+ - Owner-furnished survey (contract document)
+ - Contractor-performed survey, Owner-reviewed
+default: Owner-furnished survey (contract document)
+```
+
+# Submittals {toc}
+
+## Action Submittals {toc}
+
+### The Contractor shall submit the following action submittals for review and acceptance before mobilizing the corresponding work:
+
+- HMA mix design(s) for each overlay course, including PG binder grade, gradation, and recycled-asphalt (RAP) content.
+- Material technical data sheets (TDS) for crack sealant/filler, tack coat, sealcoat, and any emulsion treatment.
+- Mix design for slurry seal (ASTM D3910) or microsurfacing (ASTM D6372), where those treatments are specified.
+- Chip seal design (binder type and rate, aggregate gradation and application rate, embedment target) per ASTM D5360, where specified.
+- Milling plan showing depths, limits, cross-slope correction, and edge/joint treatment details.
+- Traffic control and phasing plan for each stage of the work.
+
+```datasheet
+label: Action submittals required
+type: checkbox
+options:
+ - HMA mix design (binder grade, gradation, RAP %)
+ - Material TDS (sealant, tack, sealcoat, emulsion)
+ - Slurry/microsurfacing mix design
+ - Chip seal design
+ - Milling plan (depths, limits, edge treatment)
+ - Traffic control and phasing plan
+default:
+ - HMA mix design (binder grade, gradation, RAP %)
+ - Material TDS (sealant, tack, sealcoat, emulsion)
+ - Milling plan (depths, limits, edge treatment)
+ - Traffic control and phasing plan
+```
+
+## Informational Submittals {toc}
+
+### The Contractor shall submit the following informational submittals:
+
+- Pavement condition (PCI) survey report per ASTM D6433, where the survey is Contractor-performed.
+- Plant certification for the HMA supplier per AASHTO M 156.
+- Equipment list with milling drum widths, paver/screed type, and compaction equipment.
+- Manufacturer application instructions for sealcoat, including coverage rate and weather window.
+
+```datasheet
+label: Informational submittals required
+type: checkbox
+options:
+ - PCI survey report (ASTM D6433)
+ - HMA plant certification (AASHTO M 156)
+ - Equipment list
+ - Sealcoat manufacturer application instructions
+default:
+ - HMA plant certification (AASHTO M 156)
+ - Equipment list
+ - Sealcoat manufacturer application instructions
+```
+
+## Closeout Submittals {toc}
+
+### The Contractor shall submit the following closeout submittals before final acceptance:
+
+- Field density (core) test reports for each HMA overlay course.
+- Material delivery tickets correlating tonnage and application rates to the placed area.
+- As-built distress map confirming all surveyed defects were addressed or noting any deferred areas.
+- Warranty documentation for the placed treatment.
+
+```datasheet
+label: Closeout submittals required
+type: checkbox
+options:
+ - HMA field density (core) reports
+ - Material delivery tickets
+ - As-built distress map
+ - Warranty documentation
+default:
+ - HMA field density (core) reports
+ - Material delivery tickets
+ - Warranty documentation
+```
+
+# Quality Assurance {toc}
+
+## Quality assurance for pavement rehabilitation rests on three legs: the materials meet their referenced specification, the application rates match the design, and the finished surface meets the geometric and density tolerances. Each treatment carries its own acceptance basis, so the QA program shall be written to the treatment actually selected rather than applied generically. {note}
+
+## The HMA plant supplying overlay mixture shall be certified to AASHTO M 156.
+
+## The Contractor shall verify and document material application rates (tack coat, sealcoat, emulsion, binder) against the accepted design at the start of each work shift and whenever the source lot changes.
+
+## A test section shall be placed for slurry seal, microsurfacing, and chip seal at the start of the work to confirm rates, appearance, and cure before full production proceeds.
+
+## Hot-applied crack sealant lots shall be verified by the lab melting protocol of ASTM D5167 when required by the project specification or when field performance is in question.
+
+## All work shall be protected from traffic until the treatment has cured to the manufacturer's or referenced standard's minimum trafficking time.
+
+# Environmental and Service Conditions {toc}
+
+## Weather is a hard constraint on every treatment in this standard, not a preference. Emulsions and sealcoats are water-based and will not break, cure, or bond in cold, damp, or threatening conditions; hot-applied materials lose bond if placed on a cold or wet substrate. The application window is therefore a contract requirement, and a treatment placed outside it commonly fails within the first season. {note}
+
+## Sealcoat and emulsion treatments shall not be applied when the ambient or surface temperature is below 50 °F, when temperatures are falling, or when precipitation is forecast within 24 hours before or after application.
+
+## Hot-applied crack sealant shall be installed on a clean, dry crack face; sealing shall not proceed when the pavement is wet or frozen.
+
+## In northern climates (IECC Climate Zones 5 and 6), the practical sealcoating and emulsion-treatment season is approximately May through September, and this seasonal window shall be reflected as a schedule constraint in the project plan. {note}
+
+## Newly placed HMA shall be allowed to cure a minimum of 6 to 12 months before sealcoating; sealcoating fresh asphalt traps volatiles and softens the surface.
+
+## Confirm the project climate zone so the binder grade and seasonal constraints can be set. {note}
+
+```datasheet
+label: Project climate zone (IECC)
+type: select
+options:
+ - Zone 1-2 (hot)
+ - Zone 3 (warm)
+ - Zone 4 (mixed)
+ - Zone 5 (cool)
+ - Zone 6 (cold)
+ - Zone 7 (very cold)
+default: Zone 4 (mixed)
+```
+
+```datasheet
+label: Minimum ambient temperature for emulsion/sealcoat application
+type: range
+unit: °F
+min: 45
+max: 60
+step: 1
+default: 50
+```
+
+# Cold Milling {toc}
+
+## Milling removes the existing surface to a controlled depth and profile so the overlay can correct cross-slope, restore drainage, and re-establish curb reveal. On commercial and institutional projects an overlay-only approach is rarely acceptable because the new mat simply follows the old ruts and bird-baths; milling is what lets the rehabilitation actually fix geometry. {note}
+
+## Milling depth is selected to the purpose: partial-depth (roughly 1 to 1.5 in.) for surface correction, full surface-course removal (roughly 1.5 to 3 in.), or structural milling (roughly 3 to 6 in.) where a deeper section is replaced. The most common parking-lot and commercial case is 1.5 to 2 in. partial-depth. {note}
+
+## Cold milling shall be performed with a drum milling machine sized to the work, producing a uniform, dense textured surface suitable to receive tack coat and overlay.
+
+## The milled surface shall be swept and cleaned of all loose millings and dust before tack coat is applied.
+
+## Milling depth shall be controlled to correct cross-slope and re-establish positive drainage to inlets and channels, not merely to mill a constant thickness off the existing profile.
+
+## Edge and joint transitions at curb ramps, utility frames, drainage structures, and building entry aprons shall match the adjacent finished grade so that the grade change from milling does not create a trip hazard or an out-of-tolerance accessible route.
+
+## After milling and overlay, accessible routes, curb ramps, and accessible parking stalls shall not exceed a 2.0% cross-slope, verified against the civil drawings at every ramp and stall.
+
+## Finish grade at accessible routes, curb ramps, and accessible parking stalls shall be coordinated with the civil scope under [[sync/site-rough-grading]].
+
+## Select milling depth and edge treatment. {note}
+
+```datasheet
+label: Milling depth
+type: range
+unit: in
+min: 0.5
+max: 6
+step: 0.25
+default: 1.5
+```
+
+```datasheet
+label: Milled joint edge treatment
+type: radio
+options:
+ - Feathered taper
+ - Saw-cut vertical edge
+default: Saw-cut vertical edge
+```
+
+```datasheet
+label: Cross-slope correction by milling
+type: radio
+options:
+ - Constant-depth milling (no correction)
+ - Variable-depth milling to correct cross-slope and drainage
+default: Variable-depth milling to correct cross-slope and drainage
+```
+
+# Hot-Mix Asphalt Overlay {toc}
+
+## The overlay is the structural and ride-quality heart of a mill-and-overlay. Mix type and binder grade are chosen to the traffic and climate, and overlay thickness is governed by both the mix nominal aggregate size and the depth that was milled. The critical ratio is overlay thickness to mill depth: a thin overlay over a deep mill reflective-cracks within one freeze-thaw season. {note}
+
+## A tack (bond) coat shall be applied to the milled surface before the overlay; the tack coat shall be allowed to break and cure before paving, and shall not be tracked off the surface.
+
+## Tack coat omission or under-application on a milled surface causes delamination of the overlay; the tack coat type and application rate shall be specified and verified, not left to the paving crew's discretion. {note}
+
+## The overlay-to-mill-depth ratio shall be a minimum of 3:1 to control longitudinal and reflective cracking; a thin overlay shall not be placed over a deep mill.
+
+## The minimum compacted overlay thickness shall be 1.5 in. for an SP 9.5 (3/8 in. nominal) mix and 2 in. for an SP 12.5 (1/2 in. nominal) mix.
+
+## Each overlay course shall be compacted to between 92% and 96% of maximum theoretical density (ASTM D2041), with field cores acceptance typically set at 91% minimum density.
+
+## Longitudinal joints and lane tie-ins shall be placed and compacted to form a tight, sealed joint; cold-joint construction shall follow the same density requirement as the mat.
+
+## The PG binder grade shall be selected to the project climate and traffic: PG 64-22 for most Climate Zones 3 to 5, PG 70-22 for high-traffic or heavily loaded commercial sites, and PG 58-28 or PG 52-34 for the colder Climate Zones 6 to 7.
+
+## Where recycled asphalt pavement (RAP) is incorporated, the RAP content of a surface course shall be limited to the range the local plant can reliably produce (commonly 15% to 30%), and any recycling agent shall be classified per ASTM D4552. {note}
+
+## Select the overlay mix, thickness, and binder grade. {note}
+
+```datasheet
+label: Overlay mix type
+type: select
+options:
+ - Dense-graded SP 9.5 (3/8 in. nominal)
+ - Dense-graded SP 12.5 (1/2 in. nominal)
+ - Stone Matrix Asphalt (SMA)
+ - Open-Graded Friction Course (OGFC)
+default: Dense-graded SP 9.5 (3/8 in. nominal)
+```
+
+```datasheet
+label: Compacted overlay thickness
+type: range
+unit: in
+min: 1
+max: 3
+step: 0.25
+default: 1.5
+```
+
+```datasheet
+label: PG binder grade
+type: select
+options:
+ - PG 52-34
+ - PG 58-28
+ - PG 64-22
+ - PG 70-22
+ - PG 76-22
+default: PG 64-22
+```
+
+```datasheet
+label: Tack coat material
+type: select
+options:
+ - SS-1h emulsion
+ - CSS-1h emulsion
+default: SS-1h emulsion
+```
+
+```datasheet
+label: Tack coat application rate
+type: range
+unit: gal/sq yd
+min: 0.04
+max: 0.10
+step: 0.01
+default: 0.06
+```
+
+```datasheet
+label: RAP content in surface course
+type: range
+unit: "%"
+min: 0
+max: 30
+step: 5
+default: 20
+```
+
+# Crack Cleaning, Routing, and Sealing {toc}
+
+## Crack treatment arrests water intrusion into the base and slows the propagation of working cracks; it is a preservation measure, not a structural repair. The value depends entirely on preparing the crack - cleaning and, where specified, routing to a clean aggregate face - because sealant placed in a dirty or damp reservoir does not bond and the treatment is wasted. {note}
+
+## The distinction between sealing and filling matters: hot-applied sealing is for working (thermally active) cracks and uses a flexible, resilient material in a prepared reservoir; cold-applied filling is for narrow, non-working cracks and uses a pourable asphalt-based filler. They are not interchangeable. {note}
+
+## Working cracks designated for sealing shall be routed to a clean reservoir, typically 3/8 to 3/4 in. wide and 1/2 to 3/4 in. deep, exposing a clean aggregate face.
+
+## All cracks shall be cleaned of vegetation, dirt, and moisture (compressed air, hot air lance, or wire wheel as appropriate) immediately before sealant is placed.
+
+## Hot-applied crack sealant shall be heated and applied within the manufacturer's kettle temperature range (typically 300 to 400 °F).
+
+## Hot-applied crack sealant shall conform to the type required by ASTM D6690-21, or to ASTM D3405 where the project specifies the stricter low-temperature requirements.
+
+## Sealant shall be finished recessed approximately 1/8 in. below the pavement surface (flush to a maximum of 1/4 in. below); overbanding shall not be used where the pavement is scheduled for future milling.
+
+## Cold-applied crack filler (pourable, asphalt-based) shall be used only for non-working cracks narrower than approximately 1/4 in.; it shall not be substituted for hot-applied sealant on working cracks.
+
+## Select crack treatment type and reservoir. {note}
+
+```datasheet
+label: Crack treatment method
+type: radio
+options:
+ - Hot-applied sealing (working cracks, routed reservoir)
+ - Cold-applied filling (narrow non-working cracks)
+default: Hot-applied sealing (working cracks, routed reservoir)
+```
+
+```datasheet
+label: Hot-applied sealant type (ASTM D6690-21)
+type: select
+options:
+ - Type I (high resilience, general purpose)
+ - Type II (low-modulus, flexible)
+ - Type III (fuel-resistant)
+ - Type IV (rubberized)
+default: Type II (low-modulus, flexible)
+```
+
+```datasheet
+label: Routed reservoir width
+type: range
+unit: in
+min: 0.375
+max: 0.75
+step: 0.125
+default: 0.5
+```
+
+```datasheet
+label: Sealant recess below surface
+type: range
+unit: in
+min: 0.125
+max: 0.25
+step: 0.0625
+default: 0.125
+```
+
+# Sealcoating {toc}
+
+## Sealcoat is a sacrificial protective film over an aged but sound surface; it restores the dark surface, resists oxidation and fuel/oil intrusion, and improves appearance, but it adds no structural capacity. The two decisions that drive a sealcoat specification are the base chemistry (asphalt emulsion versus coal tar) and the surface preparation, and both carry liability if specified carelessly. {note}
+
+## Coal-tar sealcoat is regulated or banned in a growing number of jurisdictions (for example Austin TX, Madison WI, the Washington DC area, and Massachusetts) because of PAH runoff concerns; the local ordinance shall be confirmed before coal-tar sealcoat is specified or bid, and asphalt-emulsion sealcoat is the safer default. {note}
+
+## The pavement surface shall be cleaned of all dirt, debris, and vegetation before sealcoat is applied; persistent vegetation in cracks shall be treated with herbicide where specified.
+
+## Petroleum-contaminated areas (oil and fuel spots) shall be cleaned and primed with an oil-spot primer before sealcoating, because sealcoat will not bond to a petroleum-contaminated surface and will peel.
+
+## A minimum of two coats shall be applied on aged or oxidized parking-lot surfaces; a single coat soaks into a porous surface and leaves no protective film and shall not be specified as a cost-reduction measure on such pavements.
+
+## Each coat shall be applied at the rate established by the manufacturer's TDS, typically 0.10 to 0.18 gal/sq yd per coat, and each coat shall cure a minimum of 24 hours before the next.
+
+## Where anti-skid surfacing is required, silica sand (40 to 60 mesh or finer) shall be broadcast or blended into the sealcoat at approximately 3 to 5 lb/sq yd, selected to the traffic speed and use.
+
+## Select sealcoat base, coats, and rates. {note}
+
+```datasheet
+label: Sealcoat base type
+type: radio
+options:
+ - Asphalt emulsion (SS-1h / CSS-1h base)
+ - Coal-tar emulsion (verify local ordinance)
+default: Asphalt emulsion (SS-1h / CSS-1h base)
+```
+
+```datasheet
+label: Number of coats
+type: select
+options:
+ - 1 coat (maintenance reapplication only)
+ - 2 coats (standard)
+ - 3 coats (heavily oxidized surface)
+default: 2 coats (standard)
+```
+
+```datasheet
+label: Application rate per coat
+type: range
+unit: gal/sq yd
+min: 0.10
+max: 0.18
+step: 0.01
+default: 0.14
+```
+
+```datasheet
+label: Anti-skid sand broadcast rate
+type: range
+unit: lb/sq yd
+min: 0
+max: 5
+step: 0.5
+default: 3
+```
+
+```datasheet
+label: Oil-spot primer required
+type: radio
+options:
+ - "Yes - prime all petroleum-contaminated areas"
+ - "No"
+default: "Yes - prime all petroleum-contaminated areas"
+```
+
+# Slurry Seal and Microsurfacing {toc}
+
+## Slurry seal and microsurfacing are aggregate-and-emulsion surface treatments that restore surface texture and seal the pavement, but they are not interchangeable. Slurry seal uses a conventional (non-modified) emulsion and needs a longer cure; microsurfacing uses a polymer-modified emulsion, can carry light traffic within one to two hours, and can be used to fill ruts. On a high-traffic site this distinction governs which one is acceptable. {note}
+
+## Microsurfacing shall be designed, tested, and placed in accordance with ASTM D6372-23, using a polymer-modified emulsion and the aggregate type matched to the application: Type II (nominal 3/8 in.) for surface sealing or Type III (nominal 1/2 in.) for rut filling.
+
+## Slurry seal shall be designed, tested, and placed in accordance with ASTM D3910-24, with aggregate gradation and a binder (emulsion residue) content typically in the range of 7.5% to 13.5% by weight of dry aggregate.
+
+## A test section shall be placed at the start of slurry seal or microsurfacing work to confirm mix rates, surface appearance, and cure time before full production.
+
+## Microsurfacing shall be specified in place of slurry seal where the surface must reopen to traffic quickly or where shallow rut filling is required.
+
+## Select the surface-treatment type and aggregate. {note}
+
+```datasheet
+label: Surface treatment type
+type: radio
+options:
+ - Slurry seal (non-modified emulsion)
+ - Microsurfacing (polymer-modified emulsion)
+default: Microsurfacing (polymer-modified emulsion)
+```
+
+```datasheet
+label: Aggregate type
+type: select
+options:
+ - Type II (nominal 3/8 in., surface sealing)
+ - Type III (nominal 1/2 in., rut filling)
+default: Type II (nominal 3/8 in., surface sealing)
+```
+
+```datasheet
+label: Number of passes
+type: select
+options:
+ - Single pass (surface seal)
+ - Two passes (scratch/rut course plus surface)
+default: Single pass (surface seal)
+```
+
+# Chip Seal and Fog Seal {toc}
+
+## Chip seal (a sprayed binder followed by an embedded cover aggregate) is the workhorse surface treatment for low-volume roads and service areas; fog seal (a diluted emulsion, no aggregate) is the lowest-cost rejuvenation for a lightly oxidized surface. Both are preservation treatments applied to a sound surface, and both depend on getting the application rate right - too little binder and the chips ravel, too much and the surface flushes. {note}
+
+## Chip seal shall be designed and constructed per ASTM D5360, with the binder (typically CRS-2 or CRS-2P) applied at approximately 0.25 to 0.35 gal/sq yd and cover aggregate (3/8 or 1/2 in.) applied at approximately 20 to 30 lb/sq yd to a target embedment of 50% to 70%.
+
+## Cover aggregate shall be rolled with a pneumatic roller while the binder is still able to wet the aggregate, and loose aggregate shall be swept after the binder has set.
+
+## A double-application chip seal shall be specified where a single course will not provide adequate surface or where additional sealing of a rougher surface is required.
+
+## Fog seal shall be applied as a diluted SS-1h or CSS-1h emulsion at approximately 0.05 to 0.10 gal/sq yd, with no cover aggregate, only on a structurally sound, lightly oxidized surface.
+
+## Select chip seal / fog seal parameters. {note}
+
+```datasheet
+label: Treatment
+type: radio
+options:
+ - Single-application chip seal
+ - Double-application chip seal
+ - Fog seal (no aggregate)
+default: Single-application chip seal
+```
+
+```datasheet
+label: Chip seal binder
+type: select
+options:
+ - CRS-2
+ - CRS-2P (polymer-modified)
+default: CRS-2P (polymer-modified)
+```
+
+```datasheet
+label: Binder application rate
+type: range
+unit: gal/sq yd
+min: 0.25
+max: 0.35
+step: 0.01
+default: 0.30
+```
+
+```datasheet
+label: Cover aggregate application rate
+type: range
+unit: lb/sq yd
+min: 20
+max: 30
+step: 1
+default: 25
+```
+
+# Installation {toc}
+
+## Pavement rehabilitation is sequence-sensitive: structural repairs must precede surface work, surface preparation must precede every treatment, and the new surface must cure before markings are placed. A schedule that collapses these into one undifferentiated scope creates ambiguity disputes and ADA RFIs. {note}
+
+## Full-depth patching of failed base or subgrade areas (a separate scope under [[sync/asphalt-paving]]) shall be completed and accepted before the surface rehabilitation scope begins.
+
+## The surface shall be prepared to the level required by the selected treatment - blow-clean, power wash, herbicide, or oil-spot prime - before that treatment is applied.
+
+## Lane tie-ins and transitions to adjacent pavement, gutters, and structures shall be placed so that the finished surface drains positively and matches the adjacent grade.
+
+## The new surface shall be allowed to cure before pavement markings are applied - typically 7 days for paint and 30 days for thermoplastic - and the markings scope shall be sequenced accordingly under [[sync/pavement-markings]].
+
+## Coordinate the pavement-marking cure window so the markings contractor is not scheduled onto a green surface. {note}
+
+```datasheet
+label: Marking cure period before re-striping
+type: select
+options:
+ - 7 days (paint)
+ - 14 days
+ - 30 days (thermoplastic)
+default: 7 days (paint)
+```
+
+# Testing {toc}
+
+## Acceptance testing confirms the placed work meets the design, and the test method follows the treatment. For an overlay, density and thickness govern; for emulsion and sealcoat treatments, application rate and coverage govern; for surface treatments, the test section and post-cure inspection govern. {note}
+
+## Field cores shall be taken from each HMA overlay course to verify compacted density against the acceptance threshold (typically 91% minimum of maximum theoretical density).
+
+## Overlay thickness shall be verified by core measurement against the specified compacted thickness for each course.
+
+## Sealcoat, emulsion, and surface-treatment application rates shall be verified by correlating material delivery tickets to the placed area against the design rate.
+
+## Hot-applied crack sealant shall be verified by the ASTM D5167 lab melting protocol where required by the specification or where field bond performance is in question.
+
+## Finished cross-slope at accessible routes, curb ramps, and accessible parking stalls shall be field-verified to not exceed 2.0% after the overlay.
+
+```datasheet
+label: Acceptance core density (HMA overlay)
+type: range
+unit: "%"
+min: 90
+max: 96
+step: 0.5
+default: 91
+```
+
+# Warranty {toc}
+
+## The Contractor shall warrant the placed treatment against material and workmanship defects for the period stated below, including raveling, delamination, premature reflective cracking attributable to workmanship, and sealcoat peeling.
+
+## The warranty shall not cover distress arising from underlying base or subgrade failure that was outside the surface rehabilitation scope and identified in the condition survey.
+
+```datasheet
+label: Warranty period
+type: select
+options:
+ - 1 year
+ - 2 years
+ - 3 years
+default: 2 years
+```
+
+# Spare Materials {toc}
+
+## Where the Owner requires touch-up capability, the Contractor shall furnish a stated quantity of the placed crack sealant and/or sealcoat material, in the manufacturer's sealed packaging, labeled with the product and color for future maintenance.
+
+```datasheet
+label: Spare crack sealant furnished
+type: select
+options:
+ - None
+ - One 30 lb block
+ - Two 30 lb blocks
+default: None
+```
+
+```datasheet
+label: Spare sealcoat furnished
+type: select
+options:
+ - None
+ - 5 gal
+ - 55 gal drum
+default: None
+```