❄️ Freeze-thaw resistance of concrete in the presence of de-icing salt — surface scaling, slab test with 3 % NaCl or water; PKN-CEN/TS 12390-9

Construction PKN-CEN/TS 12390-9

Overview

WHAT THE DOCUMENT COVERS. A technical specification (not a European Standard) of the EN 12390 series "Testing hardened concrete", part 9. Introduction: freezing and thawing damage concrete in two ways — by surface scaling and by internal structural damage; this part covers ONLY scaling, and internal damage is described in CEN/TR 15177. The "Scope" field of the PKN card of PKN-CEN/TS 12390-9:2017-07, in full (our translation): "This Technical Specification describes the testing of the resistance of concrete to scaling resulting from freezing and thawing both in water and in sodium chloride solution. The test can be used either to compare new constituents or new concrete compositions against a constituent or composition that is known to ensure adequate performance in the local environment, or to assess test results against some absolute numerical values based on local experience. Extrapolation of test results to assess different concretes, i.e. new constituents or new concrete compositions, requires an expert evaluation. NOTE In some cases the test methods may not be suitable for testing special concretes, e.g.: high-strength concrete or permeable concrete. In such cases the result should be treated with caution. Also, the test methods included in this document may not identify aggregates that cause occasional spalling. There is no established correlation between the results obtained by these three test methods. All tests will clearly identify poor and good behaviour, but they differ in the assessment of extreme behaviour. The application of different acceptance limits for test results enables assessment for different degrees of exposure severity. In the case of justified modifications of the test parameters, precautions should be taken. Some alternative applications are described in Annex A." Two places in the Polish text of the card are worth reading together with the English scope of the final draft: "occasional spalling" (sporadycznie odpryski) is "occasional ‘pop-outs’", and "extreme behaviour" (zachowania skrajne) is "marginal behaviour", i.e. borderline behaviour — between clearly poor and clearly good concrete. The sentence on modifications reads differently in the draft: a change of parameters of the procedure may cause artefacts, some of which are explained in Annex A.

THREE METHODS — AND NO RELATIONSHIP BETWEEN THEM. Clause 5 — slab test, the reference method; clause 6 — cube test, alternative; clause 7 — CF/CDF test, alternative. For routine testing any of them may be used by agreement of the parties; in case of doubt and lack of agreement the reference method is used. According to the scope there is no established correlation between the results of the three methods: all clearly distinguish poor concrete from good, but assess borderline behaviour differently. Limiting values require linking laboratory results with field experience — according to local conditions, in national application documents.

SLAB TEST — WHAT THE TEXT READ STATES (final draft FprCEN/TS 12390-9 of December 2015, clauses 4–5.3). Concrete specimens are prepared according to EN 12390-2; concrete requiring vibration is compacted on a vibrating table; the maximum aggregate size (upper D) not greater than one third of the mould length. Principle: slabs cut from concrete cubes are subjected to freezing and thawing under a 3 mm layer of de-ionized water or 3 % NaCl solution; the resistance is assessed by the mass of material scaled from the test surface after 56 cycles. Preparation: four specimens, one from each of four 150 mm cubes; first day in the moulds under foil at 20 ± 2 °C; after 24 ± 2 h the cubes into tap water at 20 ± 2 °C; at the age of 7 days into a climate chamber (20 ± 2 °C, relative humidity 65 ± 5 %, evaporation 45 ± 15 g/(m²·h), CO2 concentration measured and kept as a daily mean of 300–1000 ppmv); at the age of 21 ± 1 days a slab 50 ± 2 mm thick is cut from each cube perpendicular to the top surface so that the cut producing the test surface passes through the centre of the cube (spread of the mean thickness up to 2 mm); after washing the dimensions are measured to ± 0.5 mm; at the age of 25 ± 1 days rubber 3 ± 0.5 mm thick is glued to all surfaces except the test surface (projecting 20 ± 1 mm above the test surface; purpose — one-directional moisture exchange); at the age of 28 days about 3 mm of de-ionized water is poured on and saturation takes place for 72 ± 2 h at 20 ± 2 °C (for a surface of 150 × 150 mm about 67 ml); before testing all surfaces except the test surface are thermally insulated with polystyrene 20 ± 1 mm thick. The test starts at the age of 31 days: not earlier than 15 min before placing in the freezer the water is replaced by 3 mm of the freezing medium (20 ± 2 °C). Medium: 97 % by mass of tap water and 3 % NaCl (test with salt) or de-ionized water only (without salt). Equipment includes: diamond saw, time- and temperature-controlled freezing chamber, capable of maintaining the cycle of Figure 4 at every point of the specimen, horizontal shelves (deviation up to 3 mm per metre), temperature sensors on the test surface accurate to ± 0.5 K, a vessel for scaled material resistant to NaCl and to 120 °C, a brush with semi-soft polyamide bristles (Annex B), a sprayer with tap water, an oven at 110 ± 10 °C, a balance accurate to ± 0.05 g, a calliper ± 0.1 mm, a CO2 meter.

CHANGES FROM THE 2006 EDITION (foreword of the draft). Normative references updated; in all three methods measurement of the CO2 concentration in the storage room introduced; alternative applications strictly specified (Annex A); a specification of the brush introduced (Annex B).

STATUS (state of the PKN cards on 10.10.2026). The card of PKN-CEN/TS 12390-9:2017-07 (English version) carries no withdrawal label: title "Badania betonu -- Część 9: Oznaczanie odporności na zamrażanie i rozmrażanie w obecności soli odladzających -- Złuszczanie" (Testing concrete — Part 9: Determination of freeze-thaw resistance in the presence of de-icing salts — Scaling; our translation), publication 04-07-2017, 34 pages, Sector of Construction and Building Structures, KT 196 Cement and Lime, "Introduces: CEN/TS 12390-9:2016 [IDT]", ICS 91.100.30, without the fields "Replaces" and "Replaced by". The card of PKN-CEN/TS 12390-9:2007 (English version, title "Testing hardened concrete -- Part 9: Freeze-thaw resistance -- Scaling", publication 19-06-2007, 24 pages, introduced CEN/TS 12390-9:2006): withdrawn on 08-06-2017. PKN search engine, query "12390-9" (10.10.2026): only these two cards — the document has no Polish language version; only the title and the "Scope" field of the card are in Polish. In the iTeh catalogue (read on 10.10.2026) CEN/TS 12390-9:2016 has the status "Published" (publication 07.12.2016). The text read is the FINAL DRAFT (FprCEN/TS 12390-9:2015, submitted to the vote), made available by iTeh as a sample of the Slovenian SIST-TS CEN/TS 12390-9:2017 — the final text of the published specification may differ.

HOW MANY LABORATORIES AND IN WHAT FORM (copy of the accreditation scope database of 10.10.2026 and current PCA documents read on 10.10.2026). The number 12390-9 appears in 9 records at 8 laboratories: AB 535, AB 619, AB 1251, AB 1354 (2 records), AB 1414, AB 1486, AB 1641 and AB 1689; the document is present in all 8 current PCA documents, no entry is suspended. Forms: "PKN-CEN/TS 12390-9:2017-07" at all of them; three laboratories also give the earlier edition "PKN-CEN/TS 12390-9:2007" (AB 535, AB 1414, AB 1641). The "Laboratories" tab ("PKN-CEN/TS 12390-9") shows all 8 laboratories.

WHAT THE LABORATORIES TEST (copy and PCA documents). Subject: concrete. All laboratories that state the method state the slab test: "slab test" (AB 1251, AB 1354, AB 1641, AB 1689), "reference method (slab test)" (AB 535, AB 1486 — excluding clauses 6 and 7, i.e. the cube and CF/CDF methods), "clause 5" (AB 1414); AB 619 does not state the method. Three laboratories also cite PN-B-06265, Annex O, in the same entry: AB 535 (editions 2018-10 and 2022-08), AB 1251 (2022-08) and AB 619 (2022-08 with amendment Az1:2025-08).

WHERE A SEEMINGLY CORRECT RESULT IS EASY TO GET. First — three methods, three different numbers: the result of the cube or CF/CDF method must not be compared with a limiting value established for the slab test (no correlation according to the scope of the document); the method has to be stated in the report. Second — water instead of salt: the same test set-up with de-ionized water measures freeze-thaw resistance without salt — when assessing freeze-thaw resistance with de-icing salt the medium must contain 3 % NaCl. Third — specimen history: cutting on day 21, gluing the rubber on day 25, saturation from day 28 and start on day 31, as well as the chamber conditions (evaporation, CO2), affect the microstructure of the surface; a note to the method says that if the cutting date is shifted, the following steps (7 days of conditioning and 3 days of saturation) shall be strictly kept. Fourth — two editions in one scope entry (2007 and 2017): the 2017 edition introduced, among other things, CO2 control and the brush specification, so with a reference that does not distinguish them it is not known according to which edition the test was carried out (PKN withdrew the 2007 edition on 08-06-2017).

WHAT WE DO NOT GIVE. We read the final draft up to Figure 3 (5.3). We do not give the temperature cycle (Figure 4), the way of collecting and weighing the scaled material during the cycles, the formulae and units of the result, the cube and CF/CDF methods, precision data or limiting values (the document leaves these to national application documents).

Method principle

Slabs 50 mm thick cut from the centre of four 150 mm concrete cubes, after curing in water and conditioning in a climate chamber, insulated with rubber and polystyrene except for the test surface, are subjected to freeze-thaw cycles under a 3 mm layer of de-ionized water or 3 % NaCl solution; the measure of resistance is the mass of material scaled from the test surface after 56 cycles (slab test — reference method; draft FprCEN/TS 12390-9:2015, clause 5). The cube and CF/CDF methods are alternatives and are not correlated with the slab test.

Applications

• Concrete exposed to freezing and thawing, also in the presence of de-icing agents (e.g. pavements, road structures); mixes, products, precast units, elements and concrete in structures (introduction)
• Comparison of new constituents or concrete compositions with concrete of known good performance in local conditions, or assessment against limiting values from national documents
• In the accreditation scopes: 8 laboratories, all that state the method — slab test

Key parameters

Standard

Standard number

PKN-CEN/TS 12390-9:2017-07 (wersja angielska; wprowadza CEN/TS 12390-9:2016 [IDT])

Title (PL)

Badania betonu — Część 9: Oznaczanie odporności na zamrażanie i rozmrażanie w obecności soli odladzających — Złuszczanie

Title (EN)

Testing hardened concrete — Part 9: Freeze-thaw resistance with de-icing salts — Scaling

Step-by-step procedure

1. Making and curing the cubes

   150 mm cubes according to EN 12390-2; 1st day in the moulds under foil (20 ± 2 °C); after 24 ± 2 h into water at 20 ± 2 °C; on day 7 into the climate chamber.

2. Cutting the slabs

   At the age of 21 ± 1 days cut from each cube a 50 ± 2 mm slab perpendicular to the top surface, test surface in the centre of the cube; wash, measure (± 0.5 mm), return to the chamber.

3. Sealing

   At the age of 25 ± 1 days glue rubber to all surfaces except the test surface (edge 20 ± 1 mm above the surface), seal the joint with adhesive or silicone.

4. Saturation and insulation

   At the age of 28 days a layer of about 3 mm of de-ionized water for 72 ± 2 h (20 ± 2 °C); then thermal insulation of all surfaces except the test surface with 20 mm of polystyrene.

   ⏱ Time: 72 ± 2 h

5. Freezing and thawing

   At the age of 31 days replace the water with 3 mm of the medium (3 % NaCl or de-ionized water) not earlier than 15 min before placing in the chamber; 56 cycles according to Figure 4 (we DO NOT GIVE the cycle).

6. Scaled material and result

   Collect the material scaled from the test surface, dry (110 ± 10 °C) and weigh (± 0.05 g); we DO NOT GIVE the details of collection, the formula or units. In the report state the method (slab/cube/CF/CDF) and the medium. PKN-CEN/TS 12390-9:2017-07 current, 2007 edition withdrawn on 08-06-2017 (state of the PKN cards on 10.10.2026).

Required equipment and apparatus

Reagents, media and consumables

Health and safety (OHS)

• Cutting with a diamond saw — eye and hearing protection, water cooling
• Working at low temperatures at the freezing chamber — gloves
• NOTE ON SUBSTANCE: the results of the slab, cube and CF/CDF methods cannot be converted into one another

Frequently asked questions