Nine provincial specifications. Three design philosophies. A national picture that is more fragmented — and more interesting — than most practitioners realize.
Canada has no national asphalt mix design standard. Each of the ten provinces maintains its own specification framework, and while shared reference standards — AASHTO M323 (American Association of State Highway and Transportation Officials), the Asphalt Institute's MS-2, and the Superpave volumetric method — provide a common vocabulary, the way those standards are interpreted, combined, and supplemented varies considerably from one jurisdiction to the next.
This article reviews the mix design requirements across nine provinces, drawing on the most current publicly available specification documents from 2024 to 2026. Quebec is not included in this edition; its specification is published in French and requires additional review before we can present it with confidence. It will be added in a follow-up update.
The goal here is to establish a baseline reference for the national landscape before subsequent articles explore individual provinces in more depth. What emerges is a picture in transition: some provinces completed their shift to Superpave a decade ago, others retain Marshall design for part or all of their work, at least one province still specifies penetration-graded binder as its primary standard, and Nova Scotia is actively introducing performance-based testing requirements in 2025 while running Marshall and Superpave methods simultaneously.
The most fundamental difference across Canadian provincial specifications is the mix design methodology itself. A review of current specifications reveals three distinct approaches in active use: Superpave volumetric design using the Superpave Gyratory Compactor (SGC), Marshall design using the impact hammer, and dual-system approaches that maintain both methods for different road classes or traffic levels.
Alberta, New Brunswick, and Ontario have fully transitioned to Superpave volumetric design. In each case, the SGC is the compaction device, design traffic is expressed in terms of equivalent single-axle loads (ESALs), and the number of design gyrations (Ndes) is selected from a traffic-tiered table. The three provinces differ, however, in how they structure those tiers and what Ndes values they assign.
Alberta uses two traffic tiers: Ndes = 75 for projects below 3 million ESALs and Ndes = 100 for 3 million and above. New Brunswick similarly uses 75 or 100 gyrations depending on traffic level and mix type. Ontario takes a more granular approach, defining five traffic categories (A through E) with Ndes = 96% Gmm as the density target across all categories, but varying Nini thresholds between categories to reflect differences in mix tenderness risk.
Manitoba also runs Superpave as its primary method but maintains Marshall design for its Bit B mix type, which is used on lower-volume roads. Manitoba's Superpave tier table is the most detailed of any province reviewed, defining four ESAL ranges from below 0.3 million up to 30 million and above, with Ndes values of 50, 75, 100, and 125 respectively.
Newfoundland and Labrador and Saskatchewan retain Marshall design as their sole mix design method. Both reference the Asphalt Institute MS-2 and specify 75 blows per face. There are, however, meaningful differences between the two provinces in how the Marshall method is applied.
In Newfoundland and Labrador, the specification dates to 2013 with subsequent amendments. The physical requirements for the mix are consistent with conventional Marshall practice: stability thresholds vary by highway classification (ranging from 5,400 N for lower-volume roads to 8,000 N for arterials), flow is specified between 2.5 and 4.25 mm, and voids in the mineral aggregate (VMA) minimums of 14% (base and levelling) and 15% (surface) apply. Design air voids are set based on highway classification rather than a fixed target.
Saskatchewan's Marshall specification is notable for a different reason: it is the only province in this review that does not specify a Performance Grade (PG) asphalt binder. Saskatchewan's standard binder grade is 150-200A, a penetration-graded cement, with grade selection based on a viscosity-penetration chart rather than the PG grading system. This represents the most conservative approach to binder specification in the country, predating the SHRP research that produced the PG system in the early 1990s.
British Columbia and Nova Scotia each maintain both methods in parallel, with the applicable approach determined by project type, traffic level, or road class.
British Columbia specifies both Marshall design (for Class 1 and Class 2 pavements) and Superpave design (for higher-traffic projects with design ESALs in the 10–30 million range). The Marshall specification uses 75 blows per face with acceptance criteria drawn from AI MS-2. The Superpave specification uses Ndes = 100 gyrations. Which method applies to a given project is determined by the Special Provisions.
Nova Scotia runs two specification frameworks in parallel. The method specification (Division 4, Section 4) governs lower-volume work and uses 75-blow Marshall design. A separate Superpave End Product Specification (EPS), revised in November 2024, governs higher-traffic projects. Nova Scotia is also the most advanced province in this review with respect to performance-based testing: starting in 2025, high-traffic contracts include a Balanced Mix Design (BMD) special provision requiring IDEAL-RT, IDEAL-CT, and Hamburg Wheel Track testing alongside the standard volumetric design. The results are collected for informational purposes and do not currently trigger bonus or penalty adjustments — a deliberate shadow-testing approach intended to build capacity and establish local baseline data before performance criteria are formally specified.
Prince Edward Island completed its transition to Superpave in the 2026 specification. The finalized Section 603 states plainly: "The asphalt mix design shall follow the Superpave method of mix design based on 75 Gyrations." Table 603-5 in the 2026 edition no longer includes Marshall stability or flow criteria — it lists only air voids, VMA, and VFA. Reclaimed Asphalt Pavement (RAP) is now formally permitted at up to 15% by mass (Section 603.02.08), and WMA technologies are recognized subject to Engineer approval (Section 603.02.07). PEI's transition is complete rather than ongoing, making it a straightforward Superpave province for the 2026 construction season and beyond.
Despite the diversity in design methods, the volumetric criteria that define an acceptable mix are broadly consistent across provinces. Air void targets cluster around 4% at the design compactive effort for most mix types. Voids in the mineral aggregate (VMA) minimums range from 12% to 16% depending on nominal maximum aggregate size (NMAS) and mix type, tracking the AASHTO guidance that smaller NMAS mixes require higher VMA to maintain adequate film thickness. voids filled with asphalt (VFA) ranges are typically in the 65–78% band for standard traffic levels, widening slightly for lower-volume or fine mixes.
The most notable departures from the national consensus involve PEI's traffic-tiered air void targets, which vary from 2.5% (SADT below 1,000) to 3.5% (SADT above 10,000), and Ontario's use of Stone Mastic Asphalt mixes, which carry their own distinct volumetric framework including VMA ≥17%, air voids of 4%, and a coarse aggregate skeleton verified against the dry-rodded void content.
| Province | Spec Edition | Design Method | Ndes / Blows | Air Voids (%) | VMA min (%) | VFA (%) | Dust/Binder | TSR min |
|---|---|---|---|---|---|---|---|---|
| AB | 2019 | SP | 75 / 100 | 4.0 | 13–15 (by NMAS) | 65–78 | 0.8–1.5 | 60% |
| BC | 2016 | SP M | 100 (SP) / 75 blows (M) | 2.5–4.5 (M); 95–97% Gmm (SP) | 14–15 (M); ≥14 (SP) | 65–75 (SP) | 0.6–1.2 | 80% (SP); 85% (M) |
| MB | 2025 | SP M | 50 / 75 / 100 / 125 (SP); 75 blows (Bit B) | 4.0 (design) | 13–16 (by NMAS) | 65–80 (traffic-tiered) | 0.6–1.2 | 70% |
| NB | 2019 | SP | 75 or 100 | 3.0–5.0 | 13.5–15.5 (by type) | 70–77 (by type) | 0.6–1.2 | 80% |
| NL | 2013 | M | 75 blows | 2.5–5.0 (by class) | 14–15 (by course) | — | — | 80% |
| NS | 2025 | SP M | 75 blows (method spec) | 3–5 | 12–15 (by type) | 65–80 (by type/AADT) | — | 73% |
| ON | 2021 | SP (incl. SMA) | Cat. A–E (tiered) | 4.0 (design) | 11–16 (by NMAS); ≥17 (SMA) | 65–80 (by cat.) | 0.6–2.0 (by type) | 80% |
| PEI | 2026 | SP | 75 gyrations | 2.5–4.5 (most types); SADT-tiered target | 13–16 (by type) | 68–85 (by type) | — | 80% |
| SK | 2024 | M | 75 blows | Plotted (not fixed target) | Plotted | Plotted | — | — |
RAP allowances vary substantially across the nine provinces, from no stated provision to percentage-based limits to Ontario's binder replacement method, which arguably provides the most technically rigorous framework of any province reviewed.
Alberta allows up to 30% RAP by mass relative to virgin aggregate. Below 10% RAP, no rheological testing of the reclaimed binder is required. Between 10% and 30%, the contractor must either adjust the virgin binder grade or conduct blending calculations per AASHTO M323 Appendix X1. This tiered approach reflects the industry consensus that low RAP contents have minimal effect on blend stiffness while higher contents require explicit accounting for the aged binder contribution.
New Brunswick takes a different approach, specifying fixed RAP percentages tied to mix type rather than leaving the upper limit open to the designer. Base mixes are required to contain 30% ± 5% RAP, and surface mixes 15% ± 5% — making RAP incorporation mandatory on applicable projects rather than optional. This is the only province in the review where RAP content is prescribed as a target, not a maximum.
Ontario uses a binder replacement calculation to determine the maximum allowable RAP content rather than specifying a percentage directly. The formula divides the asphalt cement contributed by the RAP by the total design binder content, and limits the resulting percentage based on traffic category and layer position. Surface courses are limited to 0% binder replacement across all traffic categories, meaning RAP is not permitted in wearing surfaces. For binder courses, limits range from 20% (within 150 mm of the pavement surface, Cat. C/D) to 40% (deep binder courses). When binder replacement exceeds 20%, the high and low PG grades of the virgin binder must each be reduced by 6°C. Ontario's approach is more defensible than percentage limits alone because it explicitly tracks the aged binder contribution regardless of RAP asphalt content variability.
Newfoundland and Labrador restricts RAP to levelling and base courses at a maximum of 20%, explicitly prohibiting its use in surface courses. The RAP must be fractionated into at least three size ranges before incorporation. Nova Scotia's method spec section does not address RAP directly; RAP provisions for Superpave EPS work are covered in a separate section not reproduced here. Saskatchewan permits RAP but governs the allowable percentage through an equation rather than a fixed limit. Manitoba permits only department-supplied RAP — RAP from outside the department's own sources is explicitly prohibited, a policy that reflects quality control concerns about unknown RAP composition.
| Province | Max RAP (surface) | Max RAP (base/binder) | Method | Grade adjustment | Rheology required |
|---|---|---|---|---|---|
| AB | 30% ratio | 30% ratio | % of virgin aggregate | Yes (>10%) | Optional (>10%) |
| BC | Special Provisions | Special Provisions | Per project | Per project | Per project |
| MB | Dept. RAP only | Dept. RAP only | % of mix | Not stated | Not stated |
| NB | 15% ± 5% (required) | 30% ± 5% (required) | Fixed target | Implied | Not stated |
| NL | Not permitted | ≤20% | % of mix | Yes (if needed) | Yes |
| NS | See EPS section | See EPS section | — | — | — |
| ON | 0% | 0–40% binder replacement | Binder replacement % | Yes (>20% BR) | Yes |
| PEI | ≤15% (no bridge decks) | ≤15% | % of total mix | Not specified | Not stated |
| SK | Formula-based | Formula-based | Equation | Yes | Yes |
Warm mix asphalt (WMA) provisions appear explicitly in four of the nine specifications reviewed: Alberta, Manitoba, New Brunswick, and Ontario. Three treat WMA as a permissible production method subject to conditions. New Brunswick is the exception: it is the only province in Canada to have fully mandated WMA on all capital paving projects.
Alberta requires that WMA products be selected from the department's approved products list and that the contractor notify the consultant at least two weeks before use. No additional payment is made for WMA, and all existing specification requirements continue to apply. The department explicitly permits WMA as a compaction aid for late-season and cold-weather paving.
Manitoba's WMA provision is the most operationally consequential among the permissive frameworks: it directly lowers the minimum ambient temperature thresholds for paving. Standard top-lift paving requires air temperature of at least 6°C and rising; with an approved WMA additive, this drops to 0°C. This is a meaningful extension of the paving season in a province where short construction windows are a practical constraint.
New Brunswick's WMA framework reflects a trajectory that culminated in full mandate in 2020. The province began trialling WMA on low-volume local roads in 2008, expanded to nine additional trial projects in 2009, and incorporated WMA into regular paving practice by 2010. By 2020, WMA was 100% mandated on capital paving projects — the first and, as of this review, only such mandate in Canada. All 22 asphalt and batch plants in the province are capable of producing WMA. The specification defines dedicated WMA mix types (WMA-B, WMA-C, WMA-D) corresponding to the standard Superpave types and maintains an approved technology list covering both chemical additives and foaming systems. Critically, WMA in New Brunswick is not a permissive option: loads of asphalt produced above the permitted temperature range are subject to rejection.
Ontario requires Hamburg Wheel Track testing for WMA mixes when the combined aggregate contains more than 75% quartzite and dolomitic sandstone, reflecting concerns about moisture susceptibility in WMA mixes using these aggregate types.
No WMA provisions appear in the Newfoundland, Nova Scotia (method spec), or Saskatchewan specifications. This does not necessarily mean WMA cannot be used in these provinces — special provisions or separate guidelines may exist — but it is not embedded in the base specification framework as reviewed.
Across the nine specifications reviewed, the moisture susceptibility test — AASHTO T283 Tensile Strength Ratio (TSR) — is the only performance test universally present. TSR requirements range from 60% (Alberta, treated mix) to 80% (most provinces), with PEI also specifying a minimum absolute tensile strength of 400 kPa in addition to the ratio requirement.
Beyond T283, performance testing requirements are sparse. Ontario conditionally requires the Hamburg Wheel Track test for WMA mixes with susceptible aggregate types, but it is not a standard design requirement for all mixes. No province in this review currently requires the IDEAL-CT, IDEAL-RT, Dynamic Modulus, Disk-Shaped Compact Tension (DCT), or Illinois Flexibility Index Test (I-FIT) as a condition of mix design approval.
Nova Scotia is the clear exception — not in its base specification, but in the special provisions being applied to high-traffic contracts beginning in 2025. The Balanced Mix Design language introduces IDEAL-RT (RTindex) and IDEAL-CT (CTindex) testing at the volumetric optimum binder content and at two additional binder contents within ±0.3–0.5%, alongside Hamburg Wheel Track testing for rutting and moisture performance verification. The testing protocol follows the National Asphalt Pavement Association (NAPA)'s Approach B: Volumetric Design with Performance Optimization. Crucially, the results are currently informational only — they do not affect the acceptance decision or bonus-penalty calculations. The stated goals are to build laboratory capacity in the consulting community, familiarize contractors with the testing, and accumulate local data to support future specification criteria development.
This approach — introducing performance testing as a data-gathering exercise before attaching consequences to the results — mirrors the transition path taken in several U.S. states and represents a considered way of managing the practical risks of implementing new test methods without the supporting data needed to set defensible acceptance criteria.
The BMD language described above was shared by a Nova Scotia DOT representative in correspondence from July 2025. It represents one of the most substantive steps toward performance-based mix design specification currently underway in Atlantic Canada. A separate article on the NS DOT's full specification history and BMD transition is in preparation by this journal.
Aggregate quality requirements across the nine specifications are broadly consistent in the tests they require, though threshold values and the specificity of traffic-tiering vary considerably. Los Angeles Abrasion loss limits of 30–35% are universal. Sodium or magnesium sulfate soundness limits of 12–15% appear in all specifications that address soundness. Crushed particle requirements are present in all Superpave and most Marshall specifications.
Several provinces use aggregate quality requirements that go beyond the standard suite. Nova Scotia and New Brunswick both rely on the Petrographic Number (PN), a Nova Scotia Department of Transportation-developed test that assesses aggregate mineralogy and its susceptibility to polishing. This test is not referenced in any other provincial specification in the dataset, reflecting a distinctly Atlantic Canadian approach to aggregate quality control for high-friction surfaces. Nova Scotia's PN limits are tiered by mix type and traffic level, ranging from 135 (high-friction and arterial mixes) to 180 (lower-volume applications).
The Micro-Deval abrasion test appears in Alberta, British Columbia, New Brunswick, Nova Scotia, Ontario, and PEI — notably absent from Newfoundland and Saskatchewan. Where it is specified, limits range from 17% to 22% for fine aggregate depending on traffic level and province.
British Columbia specifies that Superpave aggregate must include sufficient manufactured fines to achieve fine aggregate angularity, and sets a minimum uncompacted void content of 45% (AASHTO T304, Method A) — consistent with AASHTO practice but more explicitly stated than in most other provincial documents. Ontario mandates hydrated lime or an approved aggregate anti-stripping treatment for all mixes where quartzite and dolomitic sandstone exceed 75% of the combined aggregate, irrespective of TSR test results — a prescriptive requirement based on known stripping susceptibility of these rock types.
The variation documented here raises questions that are worth examining in subsequent provincial deep-dives. The coexistence of Marshall and Superpave design within individual provincial specifications — in British Columbia, Manitoba, and Nova Scotia — reflects a pragmatic reality: different road classes and traffic levels may not justify the same level of design rigor, and maintaining a simpler method for lower-volume work can be defensible on cost and capacity grounds. What is less clear is whether the volumetric criteria in the Marshall portions of these dual-system specifications have been updated to reflect current understanding, or whether they represent legacy requirements carried forward without critical review.
Saskatchewan's continued use of penetration-graded binder and Marshall design deserves attention not as a criticism but as a data point. Saskatchewan has a distinct climate and traffic environment, and the province may have made a considered judgment that the marginal benefit of transitioning to PG grading does not justify the infrastructure investment required — particularly for provincial roads that carry relatively low traffic volumes. Understanding the reasoning behind that decision would be more informative than simply noting the departure from national practice.
The Nova Scotia BMD initiative is the most forward-looking development in the dataset. The methodological choice to introduce performance testing in an informational-only mode before attaching consequences to the results is sound practice — perhaps the only responsible way to introduce new acceptance criteria without the local calibration data needed to set meaningful thresholds. The specific tests chosen (IDEAL-RT, IDEAL-CT, Hamburg) reflect a balanced mix design framework oriented toward both rutting and cracking resistance, consistent with the NAPA Approach B methodology. Whether the data collected in 2025 and beyond leads to enforceable performance thresholds will depend on the quality and volume of data gathered, the willingness of contractors and consultants to invest in the testing capacity, and the department's internal bandwidth to interpret results and develop calibrated criteria.
Ontario's trajectory toward BMD deserves particular attention. The Ontario Ministry of Transportation (MTO)–Ontario Asphalt Pavement Council (OAPC) Hot Mix Asphalt Subcommittee has been tracking Mix Performance Testing since 2019, and the April 2025 meeting notes document meaningful forward movement: the Ontario Mix Asphalt Program (O-MAP) Round 3 study — conducted by OAPC in collaboration with Carleton University — produced positive results, with an SP12.5 FC2 (PG70-28) mix meeting or exceeding MTO's preliminary Mix Performance Testing (MPT) threshold values through gradation and binder content adjustments consistent with the BMD process. MTO has indicated it is considering moving to a BMD trial with a similar mix and updating the MPT specification to integrate BMD acceptance criteria and quality assurance (QA) MPT testing on an informational basis — a staging approach broadly consistent with what Nova Scotia has already put into formal practice. From 2026, the Canadian Council of Independent Laboratories (CCIL) is planned to begin laboratory certification for the Illinois Flexibility Index Test (IFIT), DCT, Hamburg Wheel Track (HWT), and Interlayer Shear Strength (ISS) testing, establishing the proficiency infrastructure that any enforceable BMD specification will require. The picture that emerges is of a province that has done substantial groundwork and is approaching a decision point on whether to commit to a formal BMD trial framework.
A full review of this landscape across all ten provinces — including Quebec — and with a focus on how specifications are evolving rather than simply what they currently require, will be the subject of ongoing coverage on this site. The provincial deep-dives that follow this overview will provide more detailed examination of individual specification frameworks, their historical development, and the technical rationale behind key provisions.
Alberta Transportation, Standard Specifications for Highway Construction Edition 16, Specification 3.53 (2019) · BC Ministry of Transportation, Section 502 Asphalt Pavement Construction EPS (2016) · Manitoba Infrastructure, Construction Specification for Bituminous Pavement No. 801 (April 2025) · New Brunswick Department of Transportation and Infrastructure (DTI), Standard Specifications Item 261 Asphalt Concrete ERS (January 2019) · Government of Newfoundland and Labrador, Section 330 Hot Mix Asphalt Concrete (March 2013 with amendments) · Nova Scotia Department of Public Works, Division 4 Pavements Section 4 (January 2025) and Performance Graded Asphalt Binder (PGAB) Section 2 (January 2025) · Ontario Provincial Standard Specifications (OPSS) OPSS.PROV 313 and 1151 (April 2021) · Prince Edward Island Department of Transportation and Infrastructure, General Provisions and Contract Specifications Section 603 (2026) · Saskatchewan Highways, Division 4 Section 04010 Asphalt Mix (February 2024) · NS DOT representative correspondence on Balanced Mix Design special provisions (July 2025) · MTO-OAPC Hot Mix Asphalt Subcommittee Meeting Notes (April 24, 2025) · Sweezie, M., New Brunswick Department of Transportation and Infrastructure — "New Brunswick's Experience with Warm Mix Asphalt," keynote presentation, OAPC Virtual Fall Asphalt Seminar (December 2020), as reported in Daily Commercial News, ConstructConnect Canada (December 9, 2020)