ASTM D6690

ASTM D6690, Standard Specification for Joint and Crack Sealants, Hot Applied, for Concrete and Asphalt Pavements, is the primary performance specification for hot-poured rubberized-asphalt sealants used on portland cement concrete (PCC) pavement joints, asphalt pavement cracks, and the longitudinal joints between PCC and asphalt. It consolidates and replaces the older AASHTO M 301 family of specifications and is the standard most state DOT pavement specifications now reference.

D6690 covers four product types (Type I through Type IV), each tied to a different climate or service-durability scenario. Selecting the right type is a function of pavement service temperature range, joint movement, and exposure to water. Fuel-spillage areas are excluded from D6690's scope entirely; see ASTM D7116 for those. The standard sets minimum requirements for resilience, cone penetration, flow, bond, and ductility, and prescribes the laboratory test methods used to qualify a sealant for each type.

The legacy designation AASHTO M 324 (formerly the parallel AASHTO spec) is still cited in older state spec books and contract documents. AASHTO M 324 has been harmonized with ASTM D6690, so a sealant qualified to one is generally accepted under the other; project specifications should be read carefully when both are referenced. The FHWA Pavement Preservation Compendium treats hot-applied D6690 sealants as a core preservation tool for both PCC joint resealing and asphalt crack sealing.

D6690 applies to single-component sealants that are heated in a jacketed melter and poured into a prepared joint or routed crack. The standard does not cover cold-applied sealants, preformed compression seals, or chemically curing materials. Within the hot-applied family it defines four types, distinguished primarily by climate severity and durability screening.

Type designations are not strictly hierarchical. Type III qualifies the same low-temperature bond as Type II and adds water-immersed bond and oven-aged resilience screening, so it is generally acceptable wherever Type II is specified. Type IV is the high-extension class for very cold climates: it passes the bond test at 200% extension rather than 50%, with a softer allowable consistency to match. D6690 has no fuel-resistant type; the standard's scope excludes pavement areas subject to fuel spillage, which are covered by ASTM D7116 instead.

D6690 sets minimum thresholds for five core properties, each measured by a referenced ASTM test method. Manufacturer technical data sheets typically list the as-tested values alongside the specification minimum so a specifier can confirm conformance.

Hot-applied sealants are heated in a jacketed, agitated, oil-bath melter and dispensed through a heated wand or pour pot. Two temperatures govern the work: the manufacturer's Safe Heating Temperature (SHT) and Pour Temperature (PT). Operating outside the published window damages the sealant before it reaches the joint.

Application also requires clean, dry, frost-free joint walls. Most spec books require sandblasting or hot-air-lance preparation for resealing work, and prohibit application onto damp substrates. Traffic opening temperatures are product-specific; many D6690 sealants can accept traffic once the surface temperature drops below 90°F (32°C), but the manufacturer's data sheet governs.

Sample specification paragraphs that appear in state DOT and federal contract documents. Adapt the type designation and reference standard to the project's climate and surface use.

Older agency specifications may reference AASHTO M 324, AASHTO M 301, Federal Specification SS-S-1401C, or ASTM D3405 in lieu of D6690. These legacy callouts are generally satisfied by D6690-qualified products of the equivalent type, but the specifier should confirm the current cross-reference language used by the contracting agency.

Choosing between Type I, II, III, and IV is primarily a climate and surface-use decision. The table below summarizes the conventional selection logic used in pavement preservation programs and in the FHWA Pavement Preservation Compendium guidance for hot-applied sealants.

FAA Item P-605, Joint Sealants for Pavements, published in Advisory Circular 150/5370-10H, names ASTM D6690 as one of three acceptable joint sealant materials for airport pavement, alongside cold-applied silicone qualified to ASTM D5893 and jet-fuel-resistant ASTM D7116. P-605 leaves both the material choice and the D6690 type to the project engineer, so the climate-based selection logic above applies on airfield work the same way it does on highways. See our FAA Item P-605 reference page for the full material acceptance rules, joint preparation requirements, and submittal checklist.

On projects funded through the Airport Improvement Program, use of the advisory circular, and with it P-605, is mandatory under the FAA grant assurances. The same AIP grant also triggers the FAA Buy American preference (49 USC 50101) for steel and manufactured goods, so airfield sealant submittals typically pair material certifications with Buy American documentation. See the Buy America Compliance Guide for the domestic-content side.

US Made Supply is building out a brand-neutral catalog of D6690-qualified hot-applied joint and crack sealants. If you are sourcing Type I, II, III, or IV material for a state DOT, FAA, military, or municipal pavement project and need pricing, Buy America documentation, or Qualified Products List confirmation, reach our sourcing team at partnerships@usmadesupply.com. Specify the type, the climate zone or agency QPL the project requires, estimated quantity in pounds or boxes, and the application equipment available so we can match a product family that fits the work.