🛣️ Boiling test for “Sonnenbrand” basalt — a piece of basalt from a stockpile is sawn into two parts (sawn surface at least 0.005 m2), one is boiled for (36 ± 1) h in distilled water in a steel can with a water-cooled lid and the moistened surface is examined while drying (grey/white star-shaped spots, hairline cracks, larger cracks, disintegration); for basalt aggregate 4–32 mm (1000–4000 g) — loss in mass on a sieve of half the lower size after 36 h boiling and drying at 110 °C, and loss of strength (Los Angeles or impact according to EN 1097-2), PN-EN 1367-3

Construction PN-EN 1367-3

Overview

WHAT THE STANDARD COVERS. We read the text of the standard in the iTeh sample of SIST EN 1367-3:2002 (text of EN 1367-3:2001, English): from the title page through the contents, foreword and Clauses 1–8 up to and including the beginning of 9.1 (loss in mass — just before the formula). Outside the sample remain the formula for loss in mass, 9.2 and further (strength loss, expression of results) and Clause 10 (test report). We did not read the corrigendum AC:2004, which some laboratories cite.

ACCORDING TO THE TEXT OF EN 1367-3:2001 (foreword, Clauses 1–8, beginning of 9.1). The standard was prepared by CEN/TC 154 “Aggregates” (secretariat BSI); CEN approved it on 19.01.2001. Scope (1): methods for determining the presence of signs of “Sonnenbrand” in basalt and the disintegration of aggregate produced from basalt showing such signs; applicable to pieces of rock and graded basalt coarse aggregates. Normative references (2): EN 932-1, EN 932-2, EN 932-5, EN 933-1, EN 933-2, EN 1097-2. Definitions (3): “Sonnenbrand” — a type of rock decay that may be present in some basalts and manifests itself under the influence of atmospheric conditions; it starts with grey/white star-shaped spots, usually with hairline cracks radiating from them and interconnecting them, which reduces the strength of the mineral fabric, and the rock decays to small particles — depending on the source within months of extraction or over several decades; in exceptional cases rapid decay produces large cracks and breaking of particles; constant mass — weighings after drying at least 1 h apart, difference up to 0.1 % (usually after drying at (110 ± 5) °C). Principle (4): individual pieces of basalt rock are examined for signs of “Sonnenbrand”, and samples of graded basalt are tested for percentage loss in mass and loss of strength after boiling; strength according to EN 1097-2. Apparatus (5): general requirements of EN 932-5; forced-circulation oven (110 ± 5) °C; balance accurate to ± 0.1 % of the test portion mass; heat source capable of boiling the can and contents at 100 °C for (36 ± 1) h; steel cans with water-cooled lids; sieves according to EN 933-2; distilled or demineralised water; moist cloth; sawing machine. Sampling (6): according to EN 932-1. Test portions (7): for visual examination — one rock piece from a quarry stockpile, large enough to give a sawn surface of at least 0.005 m2 (a piece with a minimum dimension of 75 mm is usually sufficient), sawn into two marked parts, washed and brushed clean; for loss in mass — reduction according to EN 932-2, removal of oversize and undersize by dry sieving according to EN 933-1, washing, drying to constant mass at (110 ± 5) °C, mass m0; minimum test portion mass (Table 1): 4–8 mm — 1000 g, 8–16 mm — 2000 g, 16–32 mm — 4000 g; for strength loss — two test portions according to EN 1097-2:1998, 5.2 (for the impact test at least six specimens according to 6.2). Visual examination (8.1): one part is placed in the can, covered with distilled or demineralised water so that it remains covered throughout boiling, lid on; brought to the boil within 0.5 h and boiled for (36 ± 1) h, checking that the specimen remains covered; the warm specimen is removed and observed while drying; the sawn surface is lightly moistened with a moist cloth and, as it dries again, the following are recorded: a) grey/white star-shaped spots or radiating hairline cracks, b) larger cracks, c) breakage of the specimen; comparison with the unboiled part is possible, and several specimens may be boiled together. Loss in mass (8.2): the test portion in the can under water is brought to the boil within 0.5 h, boiled for (36 ± 1) h, cooled, the water decanted, dried to constant mass at (110 ± 5) °C, dry sieved on a sieve with an aperture of half the lower nominal size and the retained mass m1 weighed. Strength loss (8.3): one test portion is boiled and dried as in 8.2, both are tested according to EN 1097-2 — results LA1 (boiled) and LA0 (unboiled); for the impact test — means SZ1 and SZ0 from at least three specimens. The loss in mass (9.1) is calculated to the nearest 0.1 %.

STATUS (as of 03.10.2026). The PKN search (term “PN-EN 1367-3”, 03.10.2026) shows one item: PN-EN 1367-3:2002 (Polish version, “Tests for thermal and weathering properties of aggregates — Part 3: Boiling test for Sonnenbrand basalt”, “Introduces: EN 1367-3:2001 [IDT]”), without a withdrawal note; the corrigendum AC:2004 does not appear in the search results under this term. In the iTeh catalogue (read on 03.10.2026) EN 1367-3:2001 has the status “Published” and stage 90.60 “Closure of 2 Year Review Enquiry” (02.12.2022), with a link to Regulation (EU) No 305/2011. The flow coefficient of aggregates is described in a separate entry on PN-EN 933-6.

HOW MANY LABORATORIES AND IN WHAT FORM (copy of the accreditation scope database, load up to 17.09.2026, read on 03.10.2026). The number 1367-3 appears in 6 records at 6 laboratories: AB 442, AB 687, AB 937, AB 1107, AB 1110, AB 1344. In the current PCA documents (read on 03.10.2026, issues from 07.10.2025 to 21.07.2026) the number appears in 9 rows of the same 6 laboratories (AB 442, AB 1107 and AB 1344 2 each — the standard and a separate row with the corrigendum “PN-EN 1367-3:2002/AC:2004”, the others 1 each). The form “PN-EN 1367-3:2002” with “PN-EN 1367-3:2002/AC:2004” (AB 442, AB 1107, AB 1344), “PN-EN 1367-3:2002+AC:2004” (AB 687), “PN-EN 1367-3:2002” without the corrigendum (AB 1110), “PN-EN 1367-3” without year (AB 937, flexible scope “E”). None of these items is suspended. The “Laboratories” tab (“PN-EN 1367-3”) shows the same 6 laboratories — checked with the tab query on the production server labcoda.pl on 03.10.2026.

WHAT THE LABORATORIES TEST (items in PCA). Aggregates — “Sonnenbrand of basalt” (AB 1107, AB 1110, AB 1344, at AB 442 with “boiling method”), “Sonnenbrand” (AB 937), at AB 687 under the name of the standard part with “Boiling test for Sonnenbrand basalt”. At AB 1107 items according to PN-EN 13450 (aggregates for railway ballast) stand alongside. No item distinguishes between visual examination of a rock piece, loss in mass and strength loss.

WHERE A SEEMINGLY CORRECT RESULT IS EASY TO GET. With boiling: the specimen must remain covered with water throughout, and boiling must last (36 ± 1) h after reaching the boil within 0.5 h (8.1, 8.2) — shorter boiling may not reveal Sonnenbrand. With visual examination: spots and cracks are visible while the lightly moistened sawn surface dries (8.1) — looking at a dry or wet surface may hide them. With the specimen for examination: it must come from a stockpile and give a sawn surface of at least 0.005 m2 (7.1). With loss in mass: a sieve of half the lower fraction size, a test portion of at least 1000–4000 g depending on the fraction (7.2, 8.2). With strength: the boiled portion is compared with an unboiled portion from the same laboratory sample (7.3, 8.3). With the reference: three laboratories cite the corrigendum AC:2004 and two do not — we do not know its content.

WHAT WE DO NOT GIVE. We did not read the formulae for loss in mass and loss of strength, the expression of results or the content of the test report. Nor do we give the content of the corrigendum AC:2004 or Sonnenbrand resistance categories from aggregate product standards.

Method principle

A piece of basalt is sawn into two parts, one is boiled for (36 ± 1) h in distilled water in a steel can with a cooled lid, and while the moistened sawn surface dries it is examined for grey/white star-shaped spots, cracks, larger cracks and disintegration. Graded basalt aggregate is boiled in the same way, dried at 110 °C and sieved on a sieve of half the lower size (loss in mass), or its strength is tested according to EN 1097-2 and compared with an unboiled portion.

Applications

• Basalt — rock pieces (visual examination after boiling) and graded coarse aggregates (loss in mass, strength loss) (1)
• Detection of “Sonnenbrand” — decay of basalt manifesting itself under atmospheric conditions (3.1)
• Aggregates, including railway ballast — Sonnenbrand of basalt in the accreditation scopes of 6 laboratories in PCA

Key parameters

Standard

Standard number

PN-EN 1367-3:2002

Title (PL)

Badania właściwości cieplnych i odporności kruszyw na działanie czynników atmosferycznych — Część 3: Badanie bazaltowej zgorzeli słonecznej metodą gotowania

Title (EN)

Tests for thermal and weathering properties of aggregates — Part 3: Boiling test for “Sonnenbrand basalt”

Step-by-step procedure

1. Samples

   Sampling according to EN 932-1; stockpile piece sawn into two parts or aggregate reduced and sieved. PN-EN 1367-3:2002 without a withdrawal note (03.10.2026).

2. Boiling

   In a steel can under water: to the boil within 0.5 h, boiling for (36 ± 1) h.

3. Visual examination

   Remove the warm specimen; observe the moistened sawn surface while drying; record spots, cracks, larger cracks, breakage.

4. Loss in mass

   Cool, dry at (110 ± 5) °C, sieve on a sieve of half the lower size, weigh m1.

5. Strength loss

   Boiled and unboiled portions according to EN 1097-2; we do not give the formulae (Clause 9).

Required equipment and apparatus

Reagents, media and consumables

Health and safety (OHS)

• Boiling for 36 h and removing warm specimens — risk of scalding and burns (8.1, note)
• Sawing rock — protection of eyes, hearing and respiratory tract

Frequently asked questions