🏗️ Concrete paving blocks — tensile splitting strength, abrasion resistance, water absorption and freeze/thaw resistance with salt

Construction PN-EN 1338

Overview

THE KEY NOTATION (measurement and cross-check of 23.09.2026). The key "PN-EN 1338" matches on the beginning of the notation and shows 28 laboratories / 91 entries, of which 17 entries concern other standards: PN-EN 13383 (stone for hydraulic engineering works, 12 entries at 2 laboratories) and PN-EN 13381 (fire protection, 5 entries at 1 laboratory). Only ONE of these three laboratories is on the list solely because of another standard; the other two also have records of PN-EN 1338. A colon after the number ("PN-EN 1338:") would cut off the other standards together with that one laboratory, but it would also take away THREE laboratories whose record is correct, only without the colon ("PN-EN 1338", "PN-EN 1338 zał. D", "PN-EN 1338, załącznik F") — the list would shrink to 24 laboratories / 57 entries. That would trade one laboratory that does not belong on the list for three that do, so the key stays broader. FIXING AN EXCESS PRODUCES A SHORTFALL when the cut-off character is chosen from a single example instead of from the list of forms.

**The kind of standard.** This is a product standard, not a method standard: it lays down the requirements for concrete paving blocks and at the same time contains its own normative annexes with the methods of checking them — C for linear dimensions, D for freeze/thaw resistance with de-icing salt, E for total water absorption, F for tensile splitting strength, G for abrasion resistance by the wide wheel, H for abrasion resistance by the Böhme method and I for slip resistance. The tests described below come precisely from these annexes, and with each one it is stated which annex it comes from.

The standard lays down the requirements and test methods for concrete paving blocks. It replaced the national system of assessment based on the technical approvals of the Road and Bridge Research Institute (IBDiM), changing not only the criteria but also the test procedures themselves.

The most serious change concerns strength. Previously, for a technical approval to be granted, the determination of the compressive strength was required, tested with rectangular bearing plates of areas depending on the nominal thickness of the blocks, with two classes: "50" at a strength of not less than 50 MPa and "35" at 35 MPa. The test required as many punches as there were thicknesses produced, and the compressed surfaces had to be flat and parallel, which usually forced grinding. The standard assesses a different parameter: the tensile splitting strength. Concrete has its highest resistance to compression, and bending and tensile loads destroy it at lower forces, so it is they which are decisive.

The resistance to weathering is determined by a freeze/thaw test with de-icing salt or by a water absorption test, together with the conformity criteria of clause 6 of the standard. The requirements of the table concerning freeze/thaw resistance are applied where special conditions occur, for example frequent contact of the surface with de-icing salts in frost.

The assessment of appearance is also different from before. The former procedures covered the whole block: the face, the walls and the side edges, with a list of limiting parameters and a division into grade 1 and grade 2. The standard assesses the face and the condition of the arrises adjoining it. Efflorescence is not considered significant and has no harmful effect on the performance characteristics.

A note on editions: the Polish edition PN-EN 1338:2005 implements EN 1338:2003 and superseded the earlier PN-EN 1338:2004 in the English version. The description below is based on the preview of EN 1338:2003, on the corrigendum EN 1338:2003/AC:2006 and on a Polish paper describing the introduction of this standard.

CORRIGENDUM AC:2006 — one sheet of paper which changes the sense of a requirement. To EN 1338:2003 the corrigendum EN 1338:2003/AC:2006 was issued and it has to be known, because it is not a collection of misprints. The most important change concerns Table 4.1: "In the second row, delete »as a mean«". The 2003 edition required for class 2 (marking B) a water absorption of "≤ 6 as a MEAN value"; after those two words have been deleted, the requirement of ≤ 6 % by mass applies to EVERY individual result. The figure has remained the same, its character has changed — and that is the difference between acceptance and rejection of a consignment of product: a series whose mean lies within the limit while an individual result exceeds it meets the requirement as it stood before the corrigendum and does not meet the requirement after it. Polish papers of 2004–2005 describing the introduction of the standard still give the form from before the corrigendum („Wartość średnia ≤ 6" [Mean value ≤ 6]) and must not be copied out on this point. The corrigendum further changes: the title of clause 6 (the word "criteria" deleted), clause 6.3.8.1 (a new paragraph at the end of sub-point B: if the sample and the corresponding production have not been accepted, 6.3.7 applies), point E.4.1 in the annex on water absorption (in the second line "2 000" replaced by "0.2" — we do not have the content of the point itself, the preview of the standard breaks off before it) and the title of Annex F, which after the corrigendum reads "Measurement of tensile splitting strength" instead of "Measurement of strength". It also updates three normative references to the ISO editions of 2005 and corrects minor errors in Tables 1, 3 and B.1, in Figure C.2 and in points C.5.2 and F.2.

Method principle

The block is tested in several independent determinations, each according to its own normative annex. The characteristic tensile splitting strength T is determined by a test according to Annex F (after the corrigendum AC:2006 entitled "Measurement of tensile splitting strength", in the 2003 edition — "Measurement of strength"), with the conformity criteria of clause 6: T not less than 3.6 MPa, no individual result less than 2.9 MPa, and a failure load not less than 250 N per millimetre of the splitting length. Abrasion resistance is determined by the wide wheel abrasion test according to Annex G, which is the reference test, or alternatively by the Böhme test according to Annex H; no individual result may exceed the value required. Freeze/thaw resistance with de-icing salt is tested according to Annex D, and total water absorption according to Annex E. The resistance to slipping and skidding is regarded as adequate provided the whole upper surface has not been ground or polished to a very smooth finish; where exceptionally a numerical value is required, the method of Annex I is used and a minimum value is declared. As regards reaction to fire, concrete paving blocks are classified as class A1 without testing.

Applications

• Acceptance testing of concrete paving blocks at the producer’s works and on site
• Factory production control and declaration of the performance characteristics of the product
• Assessment of blocks intended for surfaces exposed to de-icing salt in frost
• Qualification of blocks to an abrasion class and to traffic conditions
• Settling disputes about the quality of a pavement of concrete blocks

Key parameters

Standard

Standard number

PN-EN 1338:2005 + AC (EN 1338:2003/AC:2006)

Title (PL)

Betonowe kostki brukowe — Wymagania i metody badań

Title (EN)

Concrete paving blocks — Requirements and test methods

Step-by-step procedure

1. Taking and preparing the sample

   Take a series of blocks representative of the consignment of product. With two-layer blocks check whether the wearing layer is at least 4 mm over the whole surface declared by the producer as visible; individual aggregate particles entering that layer are not taken into account.

2. Checking for delamination

   Check each block separately for delamination before the units are laid out for the assessment of appearance.

3. Assessment of appearance

   Lay the units under test together so that they form an approximately square piece of trial pavement, and view them from a distance of about 2 m from each side of the square, recording every block with cracks or chips. What is assessed is the face and the condition of the arrises adjoining it; efflorescence is not considered significant. With a surface of special texture, check its uniformity against the producer’s description.

4. Linear dimensions

   Check the dimensions and the permissible deviations in accordance with the procedures of Annex C of the standard; features affecting use, such as a chamfer, grooves and distance profiles, should be declared and dimensioned by the producer; „wpusty" [grooves] are recesses in the face of the block and are not to be confused with the distance profiles — the list comes from the Polish paper (Łój 2004) and not from a quotation of Annex C.

5. Tensile splitting strength

   Carry out the test according to Annex F and assess the result against the conformity criteria: characteristic strength T not less than 3.6 MPa, no individual result less than 2.9 MPa, failure load not less than 250 N per millimetre of the splitting length.

6. Abrasion resistance

   Carry out the wide wheel abrasion test according to Annex G as the reference test, or alternatively the Böhme test according to Annex H. No individual result may exceed the value required for the class declared. With the wide wheel the result is the width of the groove measured at its centre to an accuracy of 0.1 mm, with the Böhme test — the loss of volume referred to 5000 mm² of the surface tested.

7. Resistance to weathering

   Determine the freeze/thaw resistance with de-icing salt according to Annex D or the water absorption according to Annex E, together with the conformity criteria of clause 6. The requirements concerning freeze/thaw resistance are applied where frequent contact of the surface with de-icing salts in frost occurs.

8. Slip, fire and test report

   Regard the slip resistance as adequate provided the surface has not been ground or polished to a very smooth finish; where a value is required, carry out the test according to Annex I and declare a minimum value. Take the reaction to fire as class A1 without testing. In the test report give the results of all the determinations together with the classes and the letter markings.

Required equipment and apparatus

Reagents, media and consumables

Health and safety (OHS)

• Splitting a block under the press throws out fragments of concrete — a guard around the working zone and protective goggles
• Silica dust from abrading and cutting concrete is harmful to the lungs — extraction or wet working, a dust mask
• Units of several kilograms laid out in the plane of a trial pavement — gloves, care when lifting
• Freezing chamber and salt solution — thermal gloves, protection against cold burns
• The moving abrasion wheel and the pendulum — guards and interlocks, do not reach into the zone of movement while the apparatus is working

Frequently asked questions