Cement compressive and flexural strength on 40 × 40 × 160 mm mortar prisms per EN 196-1 — prism prep (mixer, jolting, cure) then flexure at 50 ± 10 N/s and compression at 2400 ± 200 N/s on a calibrated cement test press.

ISO

EN 196-1

Revision: 2016

Cement testing

Methods of testing cement — Part 1: Determination of strength

Cement compressive and flexural strength on 40 × 40 × 160 mm mortar prisms per EN 196-1 — prism prep (mixer, jolting, cure) then flexure at 50 ± 10 N/s and compression at 2400 ± 200 N/s on a calibrated cement test press.

Test method

Three-point flexure (100 mm span, wet specimen); compression on prism halves with 40 × 40 mm platens; force rates and Fmax per press method; six compressive results with ±10 % outlier rule.

Specimen requirements

Per 3-prism set: 450 ± 2 g cement, 1350 ± 5 g CEN sand, 225 ± 1 g water; mould 160.0 × 40.0 × 40.1 mm; press platens ≥600 HV, loading rates as specified.

Compatible equipment

EN 196-1: Methods of testing cement — Part 1

Determination of strength

National examples: BS EN 196-1, TS EN 196-1 — technical requirements align with EN 196-1:2016. The international basis is ISO 679 (mortar strength — same apparatus set and tolerances).

Legal notice

The information on this page is a summary prepared by Vector Scientific Testing Devices based on a review of the applicable standard; it does not replace the official standard. For the authoritative, complete text, obtain the standard from the relevant standards body (e.g. your national standards institute, ASTM International, CEN) through official channels. Vector accepts no liability for direct or indirect loss arising from reliance on this summary.

1. Principle and mortar proportions

Principle: Prepare plastic mortar and cast 40 mm × 40 mm × 160 mm prisms. Test flexural strength first, break the prism into two halves, then determine compressive strength on each half.

Mortar composition (by mass):

  • 1 part cement
  • 3 parts standard sand (CEN reference sand)
  • 0.5 parts water (w/c = 0.50)

Batch for one triple mould set:

| Component | Mass | |-----------|------| | Cement | 450 ± 2 g | | Standard sand | 1350 ± 5 g | | Water (distilled/deionized for reference tests) | 225 ± 1 g |

2. Laboratory climate and recording

Temperature and humidity strongly affect strength development — control and log them:

| Zone | Temperature | Relative humidity | Recording | |------|-------------|-------------------|-----------| | Mixing and moulding room | 20 ± 2 °C | ≥ 50 % | Room T and RH ≥ once per day | | Mould storage (first 24 h) | 20 ± 1 °C | ≥ 90 % | Cabinet T and RH every 4 h | | Water curing tank | 20 ± 1 °C | — | Tank temperature monitored |

All materials and apparatus shall be at room temperature before use.

3. Apparatus

3.1 Mortar mixer

  • Stainless ~5 L bowl with planetary blade motion; blade and bowl are a matched set.
  • Blade–bowl clearance checked monthly: 3 ± 1 mm.

| Speed stage | Blade spin (rpm) | Planetary orbit (rpm) | |-------------|------------------|------------------------| | Low | 140 ± 5 | 62 ± 5 | | High | 285 ± 10 | 125 ± 10 |

The Vector cement mortar mixer (VTR-1017) supports timed low / high speed programmes and bowl–blade clearance checks for EN 196-1 batching.

3.2 Triple prism moulds

  • Steel, wall thickness ≥ 10 mm; inner faces ≥ 200 HV (recommended ≥ 400 HV).
  • Internal dimensions: length 160.0 ± 0.8 mm, width 40.0 ± 0.2 mm, depth 40.1 ± 0.1 mm.
  • Joints sealed; thin mould oil on inner faces.

3.3 Jolting (shock) table

  • Mass of table, arms, empty mould, hopper, and clamps: 20.0 ± 0.5 kg.
  • Table lift by eccentric cam: 15.0 ± 0.3 mm, then free drop.
  • 1 drop per second; control unit delivers 60 jolts in one run (per layer).

The Vector jolting table (VTR-1024) delivers controlled stroke, 60-jolt runs per layer, and mould clamping for prism compaction.

3.4 Curing cabinet (mould storage)

  • 20 ± 1 °C and ≥ 90 % RH for the first 24 h after moulding (see §5).
  • Log temperature and humidity every 4 h during mould storage.

The Vector curing cabinet (VTR-1025S single-door or VTR-1025D dual-door) is factory-programmed for EN and ASTM mortar/concrete cure profiles.

4. Mixing procedure (timing ± 1 s)

| Time (s) | Action | |----------|--------| | 0–30 | Pour water, add cement, start low speed | | 30–60 | Continue low speed; add all sand in 30 s with steady flow | | 60–90 | Switch to high speed for 30 s | | 90–180 | Stop mixer; scrape bowl walls to centre in first 15 s; rest remaining 75 s | | 180–240 | High speed again for 60 s |

5. Moulding and curing

  1. Fill the clamped mould on the jolting table in two layers; 60 jolts per layer (120 total).
  2. Strike off excess with a metal straightedge.
  3. Store in the ≥ 90 % RH cabinet for 24 h (extend to 48 h only if demoulding is impossible — report on the test record).
  4. Demould carefully; cure prisms horizontally in the water tank until the test age — no contact between specimens or with the tank floor.

6. Strength tests (cement test press)

A typical EN 196-1 bay runs mixer → jolting table → curing cabinet → test press on one climate programme. See the EN 196-1 equipment summary above for prep links; flexure and compression below use the press.

Flexural and compressive tests are performed on a calibrated cement compression/flexure machine with closed-loop force control. The Vector cement test press (VTR-1026S single-chamber or VTR-1026D dual-chamber) is configured for EN 196-1 prism workflows: flexure fixture with 100 mm support span, 40 × 40 mm compression platens, and programmed loading rates.

6.1 Flexural strength

  • Test wet immediately after removal from the tank.
  • Three-point bending, support span 100 mm, load roller at mid-span.
  • Loading rate 50 ± 10 N/s until break — verify on the press before each test series.

6.2 Compressive strength

  • Test both halves without delay after flexure.
  • Place each half so the smooth top faces from moulding contact the 40 × 40 mm platens (mould side faces are the loaded surfaces).
  • Platen blocks: 40.0 ± 0.1 mm square, length ≥ 10 mm, hardness ≥ 600 HV.
  • Loading rate 2400 ± 200 N/s; record maximum force Fmax (digital indicator or software).

6.3 Press setup checklist

  • Annual (or accredited-interval) force calibration and rate verification at flexure and compression setpoints.
  • Confirm flexure span and roller alignment; platens parallel and clean.
  • Dual-chamber layouts (VTR-1026D) allow one chamber for flexure and one for compression when throughput is critical — still follow wet-test timing from the standard.

7. Calculation and acceptance

Compressive strength Rc (MPa):

Rc = Fc / 1600

(Platen area 40 mm × 40 mm = 1600 mm²; Fc in N.)

Evaluation:

  1. Mean of two compressive values per prism.
  2. Six values per set (three prisms).
  3. Compute the mean of six. If any single value deviates by more than ± 10 % from that mean, discard it and average the remaining five.
  4. If more than one value lies outside ± 10 %, void the entire test and repeat from mortar preparation.

Report flexural and compressive results per your specification and EN 197-1 conformity rules where applicable.

8. Practical notes

  1. Cement test press: Most conformity decisions hinge on flexure + compression results — treat press calibration, fixture wear, and loading-rate checks as mandatory, not optional.
  2. Traceability: Sand, water, mixer speed, jolt count, and cure temperature logs support the strength data; weak prep cannot be corrected at the press.
  3. Specimen prep: Mortar mixer, jolting table, and curing cabinet feed the press — keep all three on the same climate programme.
  4. EN 196-3: Vicat tests per EN 196-3 share the mixing room with EN 196-1 prep.
  5. ISO 679: Global reference for the same mixer–jolt–cure–press line — see ISO 679 summary for procurement wording and the equipment-set table.

This document is a comprehensive summary of EN 196-1:2016 (national titles such as BS EN 196-1 or TS EN 196-1 may apply). For official use, refer to the standard issued by your national standards body.