❄️ Frost Resistance of Concrete — Ordinary Method

Construction PN-88/B-06250

Overview

STATUS (as of 06.11.2026). PN-B-06250:1988 “Beton zwykły” (Ordinary concrete; in accreditation scopes usually in the old notation PN-88/B-06250) — Polish version, published 14.11.1988, WITHDRAWN on 28.01.2004 and replaced by PN-EN 206-1:2003. The frost resistance method of this standard (cited in PCA accreditation scopes as 6.5 or 6.5.1, the “ordinary method”) was taken over by the national supplementary standard PN-B-06265 — in accreditation scopes as Annex N of the 2018-10 and 2022-08 editions. PN-B-06265:2022-08 (Polish version, published 08.08.2022), together with amendment Az1:2025-08, was withdrawn on 15.09.2026; it was replaced by PN-EN 206-1:2026-09 (English version, published 15.09.2026, implements EN 206-1:2026).

WHAT THIS ENTRY COVERS. The entry describes only the ordinary method — the one that laboratories cite with PN-88/B-06250 in accreditation scopes (copy of the scope database of 06.11.2026: “Odporność na działanie mrozu” (resistance to frost), some entries with the note “Metoda: zwykła” (method: ordinary)). The same old standard is also cited in scopes for water absorption (6.4) and water permeability (6.6) — this entry does not describe those tests. The assessment of surface scaling of concrete according to specification CEN/TS 12390-9 is described in a separate Knowledge Base entry “Freeze-Thaw Resistance of Concrete” (PN-88/B-06250 and PKN-CEN/TS 12390-9).

BACKGROUND. According to a document by a cement producer, standard PN-EN 206 does not define a method for testing frost resistance or criteria for assessing it — the method and criteria were given by the national supplementary standard PN-B-06265. The ordinary method assesses both internal damage of the concrete (through the strength of the specimens) and external damage (visually and through mass loss).

ORDINARY METHOD (PN-88/B-06250 6.5.1, later PN-B-06265 Annex N — according to a document by a cement producer; we do not have the text of the standards). The designed frost resistance grade F is verified — after the number of cycles contained in its symbol (F25, F50, F75, F100, F150, F200, F300). From one batch of concrete, 12 specimens are tested — cubes or cylinders as for compressive strength testing, or regular specimens cut from a structure or product, with a side or diameter of at least 100 mm — stored at (18 ± 2) °C and a relative humidity above 90 %. All specimens are saturated with water for at least 7 days. Six specimens remain in water at (18 ± 2) °C throughout the test; the other six, after wiping off the water, are weighed to an accuracy of 0.2 %, frozen in air at (−18 ± 2) °C for at least 4 h and thawed in water at (18 ± 2) °C for 2–4 h; a full cycle lasts at least 6 h. After the last cycle the specimens are weighed and their compressive strength is tested. The grade is achieved if the specimens show no cracks, the total mass loss (broken corners, edges, spalls) does not exceed 5 % of the mass before the first freezing, and the compressive strength is lower than that of the unfrozen specimens by not more than 20 %. Mass loss ΔG = (G1 − G2) / G1 · 100 %, strength decrease ΔR = (R1 − R2) / R1 · 100 % (G1, G2 — mean masses of saturated specimens before the first freezing and after the last thawing; R1 — mean strength of the unfrozen specimens, R2 — of the tested specimens).

WHAT WE DO NOT GIVE HERE. We do not have the text of PN-B-06250:1988 or Annex N of PN-B-06265 — the ordinary method is described according to a document by a cement producer; nor do we know the content of PN-EN 206-1:2026 and whether it takes over the ordinary method. We do not give other variants of the test from this standard or the frost resistance grade required for particular structures — the required grade F follows from the design and application documents, not from the test method.

Method principle

Six water-saturated concrete specimens are frozen in air at (−18 ± 2) °C for at least 4 h and thawed in water at (18 ± 2) °C for 2–4 h (cycle of at least 6 h), while six reference specimens remain in water during that time. After the number of cycles in the symbol of grade F (for example 150 cycles for F150), the frozen specimens are weighed and tested in compression together with the reference specimens.

Grade F is achieved when the specimens show no cracks, the mass loss ΔG does not exceed 5 % and the decrease in compressive strength ΔR relative to unfrozen specimens does not exceed 20 % (according to a document by a cement producer).

Applications

• Verification of the designed frost resistance grade F of concrete (F25–F300) — cited in PCA accreditation scopes as PN-88/B-06250 (6.5 or 6.5.1) or PN-B-06265 Annex N
• Testing of concrete specimens from one batch — cubes or cylinders as for compressive strength testing
• Testing of regular specimens cut from a structure or a concrete product (side or diameter at least 100 mm)

Key parameters

Standard

Standard number

PN-88/B-06250 (PN-B-06250:1988)

Title (PL)

Beton zwykły

Title (EN)

Ordinary concrete

Step-by-step procedure

1. Specimens

   From one batch of concrete prepare 12 cubic or cylindrical specimens (as for compressive strength testing) or regular specimens cut from a structure or product, with a side or diameter of at least 100 mm; store at (18 ± 2) °C and a relative humidity above 90 %.

2. Saturation and division

   Saturate all specimens with water for at least 7 days. Leave six reference specimens in water at (18 ± 2) °C until the end of the test; weigh the other six, after wiping off the water, to an accuracy of 0.2 %.

3. Freeze–thaw cycles

   Freeze in air at (−18 ± 2) °C for at least 4 h and thaw in water at (18 ± 2) °C for 2–4 h; full cycle of at least 6 h. Number of cycles according to the symbol of grade F (e.g. 150 for F150).

   🌡 Temperature: −18 ± 2 °C / 18 ± 2 °C

4. Weighing and compression

   After the last cycle weigh the tested specimens and test the compressive strength of the tested and reference specimens.

5. Assessment

   Calculate ΔG = (G1 − G2) / G1 · 100 % and ΔR = (R1 − R2) / R1 · 100 %. Grade F achieved: no cracks, ΔG ≤ 5 %, ΔR ≤ 20 %.

Required equipment and apparatus

Reagents, media and consumables

Health and safety (OHS)

• The available sources contain no safety requirements — the rules for working with the freezing chamber, heavy specimens and the compression testing machine are set by the laboratory on the basis of a risk assessment

Frequently asked questions