oSIST prEN 196-16:2026

oSIST prEN 196-16:2026 is the Slovenian version of draft European Standard prEN 196-16 from CEN, published by SIST. It specifies a mortar prism test for evaluating the sulfate resistance of cements under controlled sulfate exposure. The method is aimed at cast test specimens, especially CEM III/A cements and other binders with pozzolanic main constituents.

What does oSIST prEN 196-16:2026 specify?

oSIST prEN 196-16:2026 specifies a laboratory method for checking how mortar prisms change when they are exposed to a defined sulfate solution. The purpose is to assess the sulfate resistance characteristic so users can judge whether a cement is suitable for concrete exposed to sulfate attack.

The document is organized into clauses 1 to 12. It covers scope, normative references, the method description, apparatus and solution, cements, specimen preparation, conditioning, testing, measurements, analysis and the test report. It also notes that the method is adapted from CUR Recommendation 48 and is listed in EAD 150004-00-0301, Annex B.

What are the key requirements of oSIST prEN 196-16:2026?

Clause 4 defines the core test logic: cure mortar prisms in water for 28 days, then expose them either to distilled water or to sulfate solution and follow their length change up to 52 weeks. In practice, the result is a time history of expansion plus a visual check for cracking, exudations and deposits.

Specimens and materials

Clauses 5, 6 and 7 require mortar specimens prepared according to EN 196-1, using standard sand and distilled water or water of equal purity. The test set uses six prisms of (20 x 20 x 160) mm with two stainless steel studs. This fixes the specimen geometry so length changes can be compared consistently.

Exposure conditions

Clause 5.3 requires a sulfate solution with a concentration of 16 ± 0.5 g SO4/l, made from Na2SO4 or Na2SO4·10H2O of analytical purity. Clause 5.2 requires containers that are non-reactive, light-proof and sized to keep the specimens under the stated solution depth. In practice, this keeps the chemical exposure stable and repeatable.

Conditioning and storage

Clause 8 places the prisms in distilled water after demoulding, three per container, with spacing and clearance around each specimen. Clause 9 then moves three prisms to distilled water and three to sulfate solution at (20 ± 2) °C, and the sulfate solution is replaced every 28 days. This separates the reference condition from the sulfate exposure and keeps the test environment controlled.

Measurement and reporting

Clauses 9 to 12 require an initial length measurement at 28 days, calibration with a reference bar, repeated length measurements after 4, 8, 12, 16, 20, 26, 29, 40 and 52 weeks, and photographic records of visible changes. The report also has to state the cement identification, specimen details, curing and conditioning history, individual and mean results, mass and specific weight changes, deviations, and the statement that the test followed this document.

What terms does oSIST prEN 196-16:2026 define?

Sulfate resistance (SR) is the characteristic being assessed, meaning suitability for concrete exposed to sulfate attack.

Square-based prism method (SQPM) is the test approach used here: mortar prisms are exposed and their length change is tracked over time.

CEM III/A is a cement type identified as particularly suitable for this test method.

EN 196-1 is the referenced cement testing standard used for mortar preparation, curing and related specimen handling.

Na2SO4 is sodium sulfate, one of the chemicals used to prepare the sulfate exposure solution.

Who uses oSIST prEN 196-16:2026?

oSIST prEN 196-16:2026 is used by cement producers, testing laboratories, and quality or technical staff who need to assess sulfate resistance in a controlled way. It is also relevant to engineers and assessors working with cements for concrete exposed to sulfate attack, especially when comparing CEM III/A and pozzolanic binders. In practice, it supports product evaluation, suitability testing, and technical documentation.

Which standards are used with oSIST prEN 196-16:2026?

EN 196-1 supplies the mortar testing framework that this method depends on for specimen preparation and curing.

EN 197-1 is the cement framework mentioned in the introduction, where this sulfate-resistance characteristic sits in the context of common cements.

EAD 150004-00-0301 lists this test method in Annex B, which makes it relevant for European assessment work.

CUR Recommendation 48 is the source method from which this square prism procedure is adapted.

What does the oSIST prEN 196-16:2026 document contain?

The document sets out the apparatus and sulfate solution requirements, then gives the specimen preparation, conditioning, test procedure, measurement schedule and analysis method. It also describes how to check the prisms visually and how to calculate and present length change over time.

The reporting clause asks for both numerical results and photographic evidence. That makes the document useful not only for testing, but also for traceable records in qualification and assessment work.