Two provinces answer the same question in opposite directions. Alberta publishes a list of concrete patching products that have passed a battery of eleven tests and earned an average rating of 6.0 or better. Manitoba publishes a list too, and then tells you that it is “only used in situations where ready-mix concrete is not available or economical.”
Both positions are defensible, and the gap between them is where most repair specifications go wrong. A bagged repair mortar is a premium material bought for a reason — early strength, overhead placement, a cold-weather window. If none of those reasons applies, the owner is paying several times the cost of concrete for a product that was engineered to solve a problem the job does not have.
This is what Alberta’s qualification actually measures, what the five patch categories commit you to, and where the boundary sits between a bag and a load.
The first question is whether you need a bagged material at all
Manitoba Transportation and Infrastructure states the position plainly: its approved patching list exists for situations where ready-mix concrete is not available or economical. The categories it publishes are written around that logic — high-early horizontal for deck potholes in warm weather when traffic has to reopen quickly, low-temperature horizontal for roughly 0 to 5 °C ambient in spring and late fall, normal horizontal for flat repairs in good summer weather where traffic or an overlay can wait three days of curing, and overhead or vertical for girder damage, pier caps and curb faces.
Read that list as a decision tree rather than a catalogue. Three of the four categories exist because of a constraint — cure time, temperature, or gravity. Remove the constraint and ordinary concrete, proportioned and placed properly, is the stronger and cheaper answer. Manitoba’s page also notes it will evaluate equivalent products case by case through a new-product submission, which is a reminder that an approved list is a convenience, not a closed universe.
Alberta reaches the same five categories from the other end, through testing rather than through advice.
Five patch types, and the one that is a mix order
B391, Alberta’s Material Testing Specification for Concrete Patching Products, sets the approval procedures and requirements for qualifying products used on bridge structures. It sorts them into five types:
| Type | What it covers |
|---|---|
| NH | Normal horizontal |
| OH-V | Overhead or vertical |
| LTH | Low-temperature horizontal, for 0–5 °C ambient |
| HEH | High-early horizontal |
| FP | Form and pour, or form and pump |
The FP category is the one worth pausing on, because its acceptance criteria are not mortar criteria at all. An FP product has to reach a slump flow of not less than 500 mm, with a Visual Stability Index no greater than 1. Those are self-consolidating concrete numbers. If your repair is deep enough and large enough to be formed and pumped, you are specifying a flowable concrete, and the right conversation is a mix design conversation — exposure class, aggregate, admixtures — not a product-selection one. Which exposure class applies is the first input, and if that is unsettled, work through the eleven CSA A23.1:24 exposure classes before anyone prices material.
The LTH and HEH categories are the opposite case: there, the constraint is real and a bag earns its price. Early-strength work in particular has its own supply route, which is what our rapid-set concrete in Calgary page covers.
What B391 actually measures
Eleven properties, each with a named test method. This is the table worth having when a supplier sends a one-page data sheet and calls it compliance.
| Property | Test method | Basis |
|---|---|---|
| Compressive strength | CAN/CSA A3004-C2 or ASTM C109 (C39 where coarse aggregate is used) | 1, 3, 7 and 28 days for NH, OH-V and FP; 3 hours plus 1, 3, 7 and 28 days for HEH and LTH |
| Tensile bond strength | ASTM C1583 | 28 days for NH, OH-V, FP; 24 hours for LTH; 3 hours for HEH |
| Absorption after immersion | B391 method — 14-day cure, oven-dry, 48-hour immersion | Rated |
| Linear shrinkage and moisture expansion | Alberta test method BT006 | Rated, with moisture expansion held against drying shrinkage at 90 days |
| Salt scaling | ASTM C672, with B391 modifications | Mass loss measured every 5 cycles to 50 cycles; visual rating of each specimen must be less than 2 |
| Freeze-thaw resistance | ASTM C666, Procedure A | Durability factor at 300 cycles not less than 80 DF |
| Chloride resistance | ASTM C1543, 90-day ponding | Maximum 0.420% at 13 mm depth; 0.150% at 25 mm depth |
| Cracking potential | ASTM C1581 | Net time to crack, average stress rate and cracking category reported |
| Yield and unit weight | ASTM C387 | Reported, including for aggregate-extended products |
| Total chloride content | ASTM C1152 | Less than 0.060% |
| Slump flow (FP only) | ASTM C1611 | Not less than 500 mm; Visual Stability Index not greater than 1 |
Two things about that list are more interesting than any individual number.
First, the durability half of it outweighs the strength half. Compressive strength is one row. Salt scaling, freeze-thaw, chloride resistance, shrinkage, moisture expansion and cracking potential are six. A patching material that reaches high early strength and then scales off in three winters has failed the specification even if the break numbers were impressive — which is the same logic that makes a low cylinder break a question rather than a verdict.
Second, shrinkage is measured against an Alberta test method, BT006, rather than a borrowed one. Repair materials fail at the bond line, and they fail there because the patch shrinks while the substrate does not. The same mechanism we describe in reading a length-change limit under ASTM C157 is the governing failure mode for a bonded patch, only with a restraint condition the concrete never had.
The rating math: why 6.0 is the number that matters
This is the part of B391 that is genuinely unusual, and the part no product data sheet will explain.
Most of the test results are not pass or fail. They are scored on rating scales from 1 to 10. The supplier arranges the testing at its own expense, through an independent laboratory certified to CSA A283 or AASHTO R18 and accredited by CCRL. The results are rated against the specification’s scales and then averaged, and products that can be extended with aggregate carry an additional compressive strength set into that average.
To qualify:
- The average rating must be 6.0 or greater
- No individual rating may be below 4.0, and only one may equal 4.0
- Ratings between specimens may differ by no more than one increment
That structure has a practical consequence for anyone reading a submittal. An approved product is not a product that excelled; it is a product that cleared a floor on every property and a mean across all of them. Two products on the same list can sit a long way apart. If your repair is governed by one property — a parkade deck ramp where scaling is the whole problem, a chloride-saturated pier cap — the list tells you the product is acceptable, not that it is the right one. The individual ratings are the information, and they are obtainable: the submission to Alberta’s Bridge Materials Engineer has to include the laboratory test report with all individual qualifying results, alongside the technical data sheet, mixing and installation instructions, aggregate size, quality control reports, packaging photographs showing the required expiry markings, and a list of Alberta suppliers.
Not every criterion is rated, though, and the unrated ones are the hard gates:
- Freeze-thaw durability factor at 300 cycles: not less than 80 DF
- Chloride content after 90-day ponding: 0.420% maximum at 13 mm, 0.150% at 25 mm
- Total chloride content: less than 0.060%
- Salt scaling visual rating after 50 cycles: less than 2 on every specimen
- FP slump flow: 500 mm minimum, Visual Stability Index 1 or lower
Those are the numbers to quote in a specification, because they do not move with an averaging exercise.
The list moves, and approvals expire
Alberta publishes the outcome as a product list giving each approved material’s type, name, manufacturer and Alberta suppliers. It is a live document, and the movement is easy to miss.
The list dated 11 May 2021 carried 15 approved products. The list dated 31 July 2025 carries 17, across the same five categories, with several entries renamed after corporate changes and former product names shown in parentheses. Two years of specifications written against a stale copy will name products that have changed names, and may omit materials that have since qualified.
Then there is the expiry. An approval is valid for five years from the date of approval, and the supplier has to retest before it lapses. B391 is blunt about whose problem that is: the Department will not notify the supplier or manufacturer of the expiry date.
For a spec writer, that converts into one habit. Do not write a product name into a specification without writing the list and its date beside it — “as listed on Alberta Transportation’s Approved Concrete Patching Materials for Bridges, current edition” — and do not accept a 2021 printout as evidence in 2026. The current B391 revision is dated 4 September 2025, and the thresholds above are unchanged from the earlier edition, which makes the product list, not the specification, the document that goes out of date.
Where this article stops
This covers how Alberta qualifies a packaged patching product and what the test suite measures. It does not scope the repair itself — depth, delamination boundaries, reinforcement treatment and surface preparation are a separate decision made before material selection. It does not cover sealers, which Alberta qualifies under a different material testing specification. It does not cover structural strengthening or crack injection, which are design decisions rather than material-selection ones. And it does not give per-category product counts from the current list: the published table marks which types each product is approved for, and that mapping has to be read off the list itself rather than summarised second-hand.
FAQ
What specification governs concrete patching materials in Alberta? B391, Alberta Transportation’s Material Testing Specification for Concrete Patching Products, current revision dated 4 September 2025. It sets the approval procedure and test requirements for products used on bridge structures, and the resulting approvals are published as the Approved Concrete Patching Materials for Bridges list.
How many products are currently approved? Seventeen, on the list dated 31 July 2025, across five patch types. The previous list, dated 11 May 2021, carried fifteen.
What rating does a product need to be approved? An average rating of 6.0 or greater across the rated properties, with no individual rating below 4.0 and only one result permitted to equal 4.0. Ratings between specimens may differ by no more than one increment.
What are the freeze-thaw and chloride limits? A durability factor of not less than 80 DF at 300 cycles under ASTM C666 Procedure A; after 90-day ponding under ASTM C1543, a maximum chloride content of 0.420% at 13 mm depth and 0.150% at 25 mm depth; and a total chloride content below 0.060%.
How long does an Alberta approval last? Five years from the date of approval. The supplier must arrange retesting before expiry, and the Department does not send a reminder.
Does ASTM C928 apply in Alberta? Alberta qualifies products against its own B391 test suite rather than against C928. Manitoba’s approved products list is the one that references ASTM C928/C928M for packaged, dry, rapid-hardening cementitious materials for concrete repairs — useful context if you are specifying across provincial lines.
When should I use concrete instead of a bagged repair material? When none of the constraints that justify a bag is present. If the repair is deep and formed, if there is no early-traffic deadline, and if the ambient temperature is in a normal placing range, a proportioned concrete is the stronger and cheaper option — and Alberta’s own FP category effectively concedes the point by testing for slump flow rather than mortar properties.
Settle the material when you settle the mix
A repair specification that names a product without naming the list, the date and the governing property is a specification that will be argued about on site. The ones that hold up are short: the category, the list and its edition, the two or three unrated limits that matter for the exposure, and a decision about whether the repair should be a bag at all.
Send us your project details — pour date, mix type, PSI, volume — and our team will get back to you within 1 business hour with a quote and delivery slot. If the repair is formed and pumped rather than trowelled, see our custom mixed concrete in Calgary and bring the exposure class with you; if it is an early-strength deadline, start with rapid-set concrete.
Sources
- Alberta Transportation — B391, Material Testing Specification for Concrete Patching Products (4 September 2025): https://www.alberta.ca/system/files/tec-B391-bridge-material-testing-specification-for-concrete-patching-products.pdf
- Alberta Transportation — Approved Concrete Patching Materials for Bridges, 31 July 2025: http://www.transportation.alberta.ca/planningtools/GMS/ProductList/ConcretePatchingMaterials.pdf
- Alberta Transportation — Approved Concrete Patching Materials for Bridges, 11 May 2021: https://www.transportation.alberta.ca/planningtools/GMS/ProductList/patchinglist.pdf
- Manitoba Transportation and Infrastructure — Approved Products List, Patching Materials: https://www.gov.mb.ca/mti/hpd/apl_wms/patching.html
