🏗️ Resistance of aggregates to freezing and thawing in the presence of salt (1 % NaCl, 10 cycles) — PN-EN 1367-6

Construction PN-EN 1367-6

Overview

SCOPE (PKN card and clause 1 of EN 1367-6:2008): a method for assessing the resistance of aggregate subjected to cyclic freezing and thawing in a 1 % solution of NaCl in deionised or distilled water. The results are used to assess the resistance of the aggregate where frequent freeze-thaw cycles go hand in hand with sea spray or large amounts of de-icing agents — and where the results of the test according to EN 1367-1 (in water) do not correctly describe the behaviour of the aggregate under extreme conditions. LIMITS OF APPLICATION: coarse aggregates or coarse fractions of continuously graded aggregates. The method is NOT suitable for lightweight aggregates covered by EN 13055 or for aggregates that cannot be dried at 110 °C. Thawing can be carried out by immersion in water or by air circulation in the freezer — the standard gives a choice, provided that the temperature at the reference point follows the curve of Figure 1.

PROCEDURE (clauses 4, 7 and 8 — text of the standard): • recommended fraction 8–16 mm (d–D); when the product is finer than 8 mm — fraction 4–8 mm; THREE separate test portions with a mass of 2000 g (8–16 mm) or 1000 g (4–8 mm), ±5 %; • the test portions are washed on an 8 mm (or 4 mm) sieve, dried to constant mass at (110 ± 5) °C and weighed (M1) to the nearest 0.1 g; • saturation: (24 ± 1) h in cans at (20 ± 3) °C under a layer of 1 % NaCl solution reaching at least 10 mm above the test portion; • each of the 10 cycles: lowering the temperature from (20 ± 3) °C to (-1.0 ± 0.5) °C in (150 ± 30) min and holding until (360 ± 30) min from the beginning of the cycle; then to (-17.5 ± 2.5) °C in (540 ± 30) min from the beginning of the cycle and holding for at least 240 min; thawing to (20 ± 3) °C and holding from 1 h to 10 h; the whole cycle in 24 h; • the air temperature in the freezer never below -22 °C; cans at least 50 mm from the walls and not touching one another; • an interruption (e.g. a weekend with manual control) only in the frozen state, at (-17.5 ± 2.5) °C, for not more than 72 h in total; • after the 10th cycle the contents of the can are wet-sieved by hand on a sieve with an aperture equal to half the lower size of the fraction (for 8–16 mm — a 4 mm sieve), and the residue is dried to constant mass at (110 ± 5) °C and weighed (M2). RESULT (clause 4): the proportion of aggregate that passed through the d/2 sieve, calculated separately for each of the three test portions and given as a mean percentage by mass. SOLUTION: 20.0 g of analytical-grade NaCl and 1980 g of deionised or distilled water — together 2000 g of solution (5.7). The temperature reference point is the centre of a covered can with a test portion and solution, placed in the middle of the cooled space (definition 3.3).

WHERE AN ERROR HIDES BEHIND A SEEMINGLY CORRECT RESULT: controlling the freezer according to the AIR temperature instead of the temperature in the reference can. The cycles then look correct on the controller printout, but the test portion does not follow the specified curve — the standard requires control according to the reference point (8.2) and permits several such points at different heights.

STATUS (state of the PKN cards on 25.09.2026). PN-EN 1367-6:2008 — English-language version, publication 22-09-2008, 10 pages, KT 108 Aggregates and Building Stone, ICS 91.100.15; it implements EN 1367-6:2008 [IDT]; the card has no "Withdrawn" header. The catalogue has no Polish-language version. The base standard of this series, PN-EN 1367-1:2007 (resistance to freezing and thawing in water, a separate entry in this database), is also current.

HOW ACCREDITATION SCOPES CITE THE STANDARD. Measurement of 25.09.2026 on the database of PL accreditation scopes (1310 laboratories with entries): 20 entries at 19 laboratories — notations "PN-EN 1367-6:2008" (17) and "PN-EN 1367-6" without a year (3). Object: aggregates; methodology: "Mrozoodporność w obecności soli" [resistance to freezing and thawing in the presence of salt] (14), "Mrozoodporność w soli" [freeze-thaw resistance in salt] (3). Two entries combine in one row the test in water and in salt ("PN-EN 1367-6 ; PN-EN 1367-1", "PN-EN 1367-1:2007 ; PN-EN 1367-6:2008") under the common methodology "Mrozoodporność" [freeze-thaw resistance] — such a notation does not show which of the two results concerns which test. One entry declares fractions "(4 - 63) mm" — the standard provides for fractions 8–16 mm and 4–8 mm.

THE KEY OF THE "LABORATORIES" TAB: "PN-EN 1367-6" — 19 laboratories and 20 entries, without any foreign entries and without omitted laboratories.

HOW FAR THE TEXT EXTENDS: the extract of EN 1367-6:2008 made available by the publisher covers clauses 1–8 with Figure 1 (temperature curve). We do not have clause 9 "Calculation and expression of results" or clause 10 on the report — we describe the result in the words of the principle of clause 4, without a formula.

Method principle

Three test portions of aggregate of one fraction are saturated with a 1 % NaCl solution and then, in covered cans under a layer of this solution, subjected to 10 daily cycles: freezing to -17.5 °C following the specified temperature curve in the reference can and thawing to 20 °C (in water or by air circulation). After the cycles the aggregate is sieved on a sieve with an aperture of d/2; the loss of mass of each test portion in per cent and their mean are the measure of resistance to freezing and thawing in the presence of salt.

Applications

• Aggregates for pavements exposed to de-icing agents
• Aggregates for marine and coastal structures (salt spray)
• Assessment of aggregates for which the test in water according to PN-EN 1367-1 does not reflect the behaviour under extreme conditions
• Coarse aggregates and coarse fractions of continuously graded aggregates — not lightweight aggregates (EN 13055)

Key parameters

Standard

Standard number

PN-EN 1367-6:2008 (wersja angielska; wprowadza EN 1367-6:2008 [IDT])

Title (PL)

Badania właściwości cieplnych i odporności kruszyw na działanie czynników atmosferycznych — Część 6: Mrozoodporność w obecności soli

Title (EN)

Tests for thermal and weathering properties of aggregates — Part 6: Determination of resistance to freezing and thawing in the presence of salt (NaCl)

Step-by-step procedure

1. Test portions

   Sampling according to EN 932-1, reduction according to EN 932-2; three test portions of the 8–16 mm fraction (2000 g) or 4–8 mm (1000 g); remove grains retained on sieve D and passing through d.

2. Washing, drying, weighing

   Wash on an 8 mm (or 4 mm) sieve according to EN 933-1, dry to constant mass at (110 ± 5) °C, cool and weigh (M1) to the nearest 0.1 g.

3. Saturation

   In cans, (24 ± 1) h at (20 ± 3) °C, 1 % NaCl at least 10 mm above the test portion.

4. Placing in the freezer

   Check the level of the solution (≥ 10 mm), cover the cans; distance from the walls ≥ 50 mm, cans not touching; control according to the reference can.

5. 10 freeze-thaw cycles

   According to the curve of Figure 1: -1.0 °C, then -17.5 °C (≥ 240 min), thawing to 20 °C (1–10 h); air not colder than -22 °C; each cycle in 24 h.

6. Sieving and weighing

   Wet-sieve the contents of the can by hand on the d/2 sieve, dry the residue at (110 ± 5) °C to constant mass, cool and weigh (M2).

7. Result

   For each test portion, the proportion of the mass that passed through the d/2 sieve; final result — the mean of the three test portions in per cent by mass.

Required equipment and apparatus

Reagents, media and consumables

Health and safety (OHS)

• Work with a freezer at -22 °C and frozen cans — gloves protecting against cold
• Heavy cans with aggregate and solution (about 2 kg of aggregate + solution) — lifting ergonomics
• Drying oven at 110 °C — hot trays and cans

Frequently asked questions