Fresh concrete tests check a mix between discharge and setting, and ten test groups, from sampling under ASTM C172/C172M-25 to temperature, consistence, air content and self-compacting flow, decide whether a load and the admixtures in it are accepted. Which sample, which method and which value apply?
The work is also called fresh concrete testing, tests on fresh concrete or concrete field testing; European documents say "consistence" and "spot sample". A fresh test is the acceptance step for every product in concrete additives.
A sample is at least 0.03 m³ (1 ft³), with slump and air started within 5 minutes (AASHTO R 60-23). ACI SPEC-301-20 caps delivered concrete at 35 °C (95 °F), and ASTM C494 and EN 934-2 judge admixtures against a control mix.
What Are Fresh Concrete Tests?#
Fresh concrete tests are standardized methods run on plastic concrete, from a representative sample taken as delivered, to measure temperature, consistence, air content, density and, for self-compacting mixes, flow, passing ability and segregation. ASTM C172/C172M-25 defines how that sample is taken from stationary, paving and truck mixers, agitating and non-agitating equipment and continuous mixers.
Hardened tests, such as strength and chloride penetration, run on cured specimens instead. The EN 12350 series covers the fresh family in twelve parts, from part 1 (sampling) to part 12 (J-ring), and the fresh behavior these tests measure is explained under the properties of fresh concrete.
Why admixture acceptance depends on fresh tests#
An admixture is accepted against a control concrete, and both ASTM C494/C494M-24 and EN 934-2:2009+A1:2012 measure that comparison with fresh tests. ASTM C494/C494M-24 tests at three levels: Level 1 initial approval, Level 2 limited retesting and Level 3 lot acceptance when the purchaser specifies it. EN 934-2:2009+A1:2012 lists EN 12350-2, -5 and -7, EN 12390-3 and EN 480-1, -2, -4, -5 and -11 as normative test methods.
ASTM C494/C494M-17 and -19e1 Table 1 hold water content at most 95 % of the control for Types A, D and E and 88 % for Types F and G. EN 934-2:2009+A1:2012 Table 5 requires air-entrained test mixes at least 2.5 % by volume above the control, total air 4 to 6 %.
How Is Fresh Concrete Sampled Under ASTM C172, AASHTO R 60 and EN 12350-1?#
Fresh concrete is sampled under ASTM C172/C172M-25 in the US (active since 2025-10-10, superseding C172/C172M-17), under AASHTO R 60-23 on DOT work and under EN 12350-1 in Europe. Every test result is only as representative as that sample.
Table 2 lists the sampling rules with the document that sets each one.
| Rule | Value | Document |
|---|---|---|
| Sampling window | increments from the middle of the batch, not before 10 % or after 90 % of the batch is discharged | AASHTO R 60-23 (WAQTC field operating procedure, October 2024) |
| Composite | all increments combined into one composite sample within 15 minutes | AASHTO R 60-23 |
| Test start | temperature finished and slump and air started within 5 minutes; strength specimens molded within 15 minutes | AASHTO R 60-23 |
| Sample size | at least 1.5 times the test volume, not less than 0.03 m³ (1 ft³); routine slump and air sample after 1/5 m³ (1/4 yd³) discharged | AASHTO R 60-23 |
| Continuous mixers | after at least 140 L (5 ft³) discharged; wait 2 to 5 minutes before testing | AASHTO R 60-23 |
| Wet sieving | sieving area at least 0.19 m² (2 ft²); not allowed for density (AASHTO T 121) samples | AASHTO R 60-23 |
| UK spot sample | six scoopfuls from the next 0.3 m³ (0.39 yd³) after the first concrete | BRMCA, July 2020 |
| UK test volumes | slump and slump flow 8.5 L; flow table 6.5 L; air 10 L; 100 mm cube 1.5 L; 150 mm cube 6 L | BRMCA, July 2020 |
When and where the sample is taken from a truck mixer#
AASHTO R 60-23 takes the increments from the middle of the batch, never before 10 % or after 90 % of the batch is discharged, and combines them into one composite sample within 15 minutes. The first and last tenth of the discharge are therefore never sampled.
Temperature is then finished and slump and air started within 5 minutes, and strength specimens molded within 15 minutes. Paving adds a placement effect: 1 to 2 % air is commonly lost in pumping and consolidation, and Kansas and Indiana sample behind the paver (FHWA-HIF-17-009).
Sample size, continuous mixers and wet sieving#
The sample is at least 1.5 times the volume the tests need and never less than 0.03 m³ (1 ft³), and a routine slump and air sample may be taken once 1/5 m³ (1/4 yd³) has been discharged. Continuous mixers wait for 140 L (5 ft³) of discharge, and wet sieving is not allowed for density samples. The worked example below combines UK test volumes with the AASHTO R 60 rule.
- Tests: slump 8.5 L, air 10 L, three 150 mm cubes 3 × 6 L.
- Total: 36.5 L (1.29 ft³).
- Sample: 1.5 × 36.5 = 54.8 L (1.93 ft³), above 0.03 m³ (1 ft³).
Spot samples in UK ready-mix practice#
UK ready-mix practice (BRMCA, July 2020) lets the first concrete go and takes six scoopfuls from the next 0.3 m³ (0.39 yd³), or six scoopfuls after the first 0.3 m³. The guide sets 8.5 L (0.30 ft³) for slump, 10 L (0.35 ft³) for air and 6 L (0.21 ft³) per 150 mm (5.9 in) cube.
How Is Fresh Concrete Temperature Measured (ASTM C1064)?#
Fresh concrete temperature is measured under ASTM C1064/C1064M-23 (active since 2023-12-21) and the DOT method AASHTO T 309-22, with the sensor under at least 75 mm (3 in) of concrete and the reading finished within 5 minutes. ASTM C1064/C1064M-23 notes that concrete with aggregate above 75 mm (3 in) may need up to 20 minutes for heat transfer.
Thermometer, cover and timing rules#
The AASHTO T 309-22 procedure fixes five rules for the device and the reading, listed below.
- Range and readability: -18 to 50 °C (0 to 120 °F), readable to ±0.5 °C (±1 °F).
- Cover: at least 75 mm (3 in) of concrete and at least 3 times the nominal maximum aggregate size.
- Time in the concrete: at least 2 minutes, with the reading finished within 5 minutes.
- Record: to the nearest 0.5 °C (1 °F).
- Verification: each year at two temperatures at least 15 °C (27 °F) apart.
UK practice (BRMCA, July 2020) inserts a thermometer accurate to 1 °C (1.8 °F) 50 mm (2 in) and reads it after 30 to 60 seconds.
Concrete temperature limits at delivery#
ACI SPEC-301-20 4.2.2.5(b) sets 35 °C (95 °F) as the maximum concrete temperature as delivered, while ASTM C94 sets no hot-weather limit on fresh concrete as delivered (NRMCA). Higher values are permitted where proven locally or by preconstruction testing, and mass concrete is excluded. ACI SPEC-301-20 4.2.2.5(a) sets cold minimums by section: 13 °C (55 °F) below 305 mm (12 in), 10 °C (50 °F) to 914 mm (36 in), 7 °C (45 °F) to 1,829 mm (72 in) and 5 °C (40 °F) above.
BRMCA (July 2020) sets at least 5 °C (41 °F) at delivery, a default maximum of 35 °C (95 °F) and 30 °C (86 °F) for air-entrained concrete. The standard temperature therefore comes from the specification, not the test method.
Fresh Test Methods by Property: ASTM, AASHTO and EN Side by Side#
Table 1 sets the fresh concrete test methods side by side in seven rows, from sampling to setting and bleeding, with the edition where it is stated.
| Property | What it shows | ASTM (edition) | AASHTO | EN |
|---|---|---|---|---|
| Sampling | representative composite | C172/C172M-25 | R 60-23 | EN 12350-1 |
| Temperature | delivery limits, set and strength gain | C1064/C1064M-23 | T 309-22 | no EN 12350 part |
| Consistence | workability, water reducer effect | C143/C143M-26b | T 119-23 | EN 12350-2:2019; Vebe -3, compactability -4, flow table -5 |
| Air | entrained air, air-entraining admixture effect | C231/C231M-26, C173/C173M-26 | T 152-24, T 196, T 395-22 (SAM) | EN 12350-7 |
| Density and yield | unit weight, gravimetric air | C138/C138M-24a | T 121 | EN 12350-6 |
| SCC filling, passing, segregation | flow, blocking, stability | C1611/C1611M-21, C1621/C1621M-17(2023), C1610/C1610M-24 | none listed | EN 12350-8 to -12 |
| Setting and bleeding | retarder and accelerator effect; bleed water | C403/C403M-23, C232/C232M-26 | none listed | EN 480-2:2006, EN 480-4:2005 (admixture tests) |
EN parts without a year: edition not stated here.
Consistence and its validity limits#
The slump of ASTM C143/C143M-26b suits coarse aggregate up to 37.5 mm (1-1/2 in): below 15 mm (1/2 in) concrete may not be adequately plastic, above about 230 mm (9 in) not adequately cohesive. EN 12350-2:2019 is sensitive between 10 and 210 mm (0.39 and 8.3 in), is unsuitable when Dmax exceeds 40 mm (1.57 in) and reports true slump to the nearest 10 mm.
AASHTO T 119-23 is the DOT counterpart.
Air: pressure, volumetric, gravimetric and sequential pressure methods#
ASTM C231/C231M-26 measures air by pressure in concrete with dense aggregate only, ASTM C173/C173M-26 measures it by volume in any aggregate including lightweight, and ASTM C138/C138M-24a gives it by gravimetric calculation. For dense aggregates all three give substantially the same results (ASTM C231/C231M-26).
AASHTO uses T 152-24 (Type B, read to 0.1 %), T 196 and T 121, and T 395-22 adds the sequential pressure method: AASHTO PP84-19 sets a SAM number of at most 0.20 with more than 4 % air for mixture design and at most 0.30 in the field. Fresh and hardened air contents usually agree within 1 % (FHWA-HRT-04-150).
Self-compacting mixes: filling, passing and segregation#
Self-compacting concrete is accepted on three fresh properties instead of slump: filling ability by ASTM C1611/C1611M-21 slump flow, passing ability by the ASTM C1621/C1621M-17(2023) J-ring, and static segregation by the ASTM C1610/C1610M-24 column. ASTM C1611/C1611M-21 covers coarse aggregate up to 25 mm (1 in); ASTM C1610/C1610M-24 does not apply to lightweight-aggregate SCC.
EN 206-1:2026 cites EN 12350-8 to -12 (slump flow, V-funnel, L-box, sieve segregation, J-ring). The slump-flow classes are SF1 550 to 650 mm (21.7 to 25.6 in), SF2 660 to 750 mm (26.0 to 29.5 in) and SF3 760 to 850 mm (29.9 to 33.5 in) (EN 206-9:2010 Table 1).
Density, setting time, bleeding and chloride penetration#
Four more methods complete the family: density by ASTM C138/C138M-24a, setting time by ASTM C403/C403M-23, bleeding by ASTM C232/C232M-26 and, as the one hardened test grouped here, chloride penetration by ASTM C1202-25. ASTM C403/C403M-23 measures penetration resistance on mortar sieved from the concrete: initial set at 3.5 MPa (500 psi), final set at 27.6 MPa (4,000 psi).
ASTM C1202-25 indicates resistance to chloride ion penetration and is not a permeability test; AASHTO T 277 is its counterpart.
Which Admixtures Change Fresh Test Results?#
Each admixture family shows its effect first in one test: water reducers in slump or water content, air-entraining admixtures in air content, retarders and accelerators in setting time, and ionic admixtures in the charge passed of ASTM C1202. Table 3 gives the value for each.
| Admixture family | Test that shows it first | Value and the document that sets it |
|---|---|---|
| water-reducing admixtures | slump at equal water, water content at equal slump | water content at most 95 % of the control for Types A, D, E and at most 88 % for Types F, G (ASTM C494/C494M-17 and -19e1 Table 1) |
| air-entraining admixtures | air content | test-mix air at least 2.5 % by volume above the control, total air 4 to 6 % (EN 934-2:2009+A1:2012 Table 5) |
| set-retarding admixtures | time of setting | initial set at 3.5 MPa (500 psi), final at 27.6 MPa (4,000 psi) penetration resistance (ASTM C403/C403M-23) |
| accelerating admixtures | time of setting | same ASTM C403/C403M-23 thresholds; EN 480-2:2006 for EN conformity |
| supplementary cementitious materials | air content | finely divided materials may reduce entrained air, so air is checked by test and the air-entraining dose raised (ASTM C618-26 Note 1) |
| corrosion-inhibiting admixtures | charge passed (hardened) | calcium nitrite, calcium nitrate, calcium chloride and sodium thiocyanate raise ASTM C1202 coulombs without changing permeability |
Air is rechecked when the water reducer changes, because some polycarboxylate water reducers give large, widely spaced bubbles (FHWA-HIF-17-009).
Which Tests Does Each Application Need?#
The application decides which fresh tests carry acceptance: ready-mix is specified under ASTM C94/C94M-26c, paving can add air checks behind the paver and the SAM number, and self-compacting, hot-weather, cold-weather and pervious work each add one governing test. Table 4 lists them; the admixture systems of these special concretes have their own hub.
| Application | Governing fresh test or limit |
|---|---|
| ready-mix concrete admixtures | ASTM C94/C94M-26c delivery; purchaser-stated time limit since C94/C94M-21 |
| admixtures for concrete pavements | air sampled behind the paver by Kansas and Indiana (1 to 2 % lost in pumping and consolidation); SAM 0.20 design, 0.30 field (AASHTO PP84-19) |
| self-compacting concrete | slump flow: SF1 550 to 650 mm (21.7 to 25.6 in), SF2 660 to 750 mm (26.0 to 29.5 in), SF3 760 to 850 mm (29.9 to 33.5 in) (EN 206-9:2010 Table 1) |
| hot-weather concreting | temperature: 35 °C (95 °F) maximum as delivered (ACI SPEC-301-20 4.2.2.5(b)) |
| cold-weather concreting | temperature: 13 °C (55 °F) minimum as delivered for sections below 305 mm (12 in) (ACI SPEC-301-20 4.2.2.5(a)) |
| freeze-thaw damage and air voids | air: ACI CODE-318-25 Table 19.3.3.1 targets (Table 4a) |
| pervious concrete | density and void content of freshly mixed pervious concrete (ASTM C1688/C1688M-26) |
| admixtures for precast concrete | SCC spot checks in NPCA practice (2023): slump flow, J-ring, column segregation, rapid static segregation, VSI, slump-flow life |
Table 4a gives the ACI CODE-318-25 Table 19.3.3.1 air targets (NRMCA 2PE004-26) by aggregate size.
| Aggregate size | F1 target air | F2 target air |
|---|---|---|
| 9.5 mm (3/8 in) | 6.0 % | 7.5 % |
| 12.5 mm (1/2 in) | 5.5 % | 7.0 % |
| 19 mm (3/4 in) | 5.0 % | 6.0 % |
| 25 mm (1 in) | 4.5 % | 6.0 % |
| 37.5 mm (1-1/2 in) | 4.5 % | 5.5 % |
| 50 mm (2 in) | 4.0 % | 5.0 % |
| 75 mm (3 in) | 3.5 % | 4.5 % |
1.0 point lower at a specified f'c equal to or exceeding 5,000 psi, as worded by NRMCA.
Which Standards Govern Fresh Concrete Testing?#
Three layers of documents govern fresh concrete testing: test methods (ASTM and AASHTO methods, the EN 12350 series), specifications that set acceptance values (ASTM C94/C94M-26c, EN 206-1:2026) and admixture standards that test against a control mix. Table 5 sets the layers by region.
| Role | US (edition, status) | EU | India |
|---|---|---|---|
| Test methods | C172/C172M-25, C1064/C1064M-23, C143/C143M-26b, C231/C231M-26, C173/C173M-26, C138/C138M-24a, C1611/C1611M-21, C1621/C1621M-17(2023), C1610/C1610M-24, C403/C403M-23, C232/C232M-26 (all active) | EN 12350-1 to -12 (EN 12350-2:2019 stated) | IS 1199 series (edition not stated) |
| DOT methods | AASHTO R 60-23, T 309-22, T 119-23, T 152-24, T 395-22 | none | none |
| Ready-mix specification | ASTM C94/C94M-26c (active since 2026-08-12) | EN 206 (EN 206-1:2026, CEN approval 2026-01-19, dated March 2026) | none |
| Admixture conformity | ASTM C494 (C494/C494M-24, Levels 1 to 3) | EN 934-2 (EN 934-2:2009+A1:2012; normative EN 12350-2, -5, -7) | IS 9103 (IS 9103:1999, active, reaffirmed 2018) |
EN 206-1:2026 supersedes EN 206:2013+A2:2021. India appears through IS 9103:1999, the Indian specification for concrete admixtures (five types); every admixture document is classified under concrete admixture standards.
How a specification turns test results into acceptance#
A specification turns a test into an acceptance rule by naming the target, the tolerance and the time window, and ACI CODE-318-25 Table 19.3.3.1 shows the pattern for air. Its target is 6.0 % for F1 and 7.5 % for F2 with 9.5 mm (3/8 in) aggregate.
Since ASTM C94/C94M-21 the purchaser states the time limit from the start of mixing to the end of discharge; otherwise the producer sets it before delivery. C94 tolerances are not reproduced: the current text is unchecked.
Complete List of Fresh Concrete Tests#
The fresh concrete test family has ten test groups, from sampling and temperature to chloride penetration, and Table 6 lists each with its ASTM and EN method and the page that covers it in depth.
| # | Test group | ASTM | EN | Covered on |
|---|---|---|---|---|
| 1 | Sampling | C172/C172M-25 | EN 12350-1 | this page |
| 2 | Temperature | C1064/C1064M-23 | none | this page |
| 3 | Slump | C143/C143M-26b | EN 12350-2:2019 | concrete slump test |
| 4 | Air content | C231/C231M-26, C173/C173M-26 | EN 12350-7 | air content tests |
| 5 | Density (unit weight) | C138/C138M-24a | EN 12350-6 | air content tests page |
| 6 | SCC flow, passing, segregation | C1611/C1611M-21, C1621/C1621M-17(2023), C1610/C1610M-24 | EN 12350-8 to -12 | SCC fresh tests (slump flow, J-ring, L-box, V-funnel) |
| 7 | Setting time | C403/C403M-23 | EN 480-2:2006 | setting time of concrete |
| 8 | Bleeding | C232/C232M-26 | EN 480-4:2005 | bleeding and segregation in concrete |
| 9 | Vebe, compactability, flow table | none | EN 12350-3, -4, -5 | concrete workability |
| 10 | Chloride penetration (hardened) | C1202-25 | EN 12390-18:2021 (migration) | rapid chloride permeability test |
A testing program combines these groups, from a trial batch to field acceptance.
Fresh Tests and Hardened Concrete: What the Results Do Not Show#
Fresh tests accept a load at discharge, but they do not measure strength, chloride resistance or freeze-thaw durability, which hardened tests settle weeks later. The former 1.5 h (90 min) default discharge time of ASTM C94 gave way in 2021 to the purchaser-stated limit.
Curing compounds and sealers are not covered here. How admixtures and SCMs prevent deterioration is covered under concrete durability.
What tests are done on fresh concrete?#
Ten test groups: sampling, temperature, slump, air, density, SCC flow tests, setting time, bleeding, Vebe and flow-table consistence, and chloride penetration as the hardened add-on. Table 6 gives the ASTM and EN method for each.
Is there a code for fresh concrete testing?#
Yes: test methods are ASTM, AASHTO and EN standards, and specifications set the acceptance values, such as ASTM C94/C94M-26c for US ready-mix and EN 206-1:2026. EN 206-1:2026 cites EN 12350-8 to -12 for self-compacting concrete, and ACI CODE-318-25 Table 19.3.3.1 sets the air targets for freeze-thaw exposure.
How much does it cost to have concrete tested?#
One dated public fee schedule (ENGEO, effective February 2024, California) prices an ASTM C192 laboratory trial batch including cylinders at USD 1,000, or USD 2,000 for same-day service. Per-test field fees are not reproduced here: no dated public range has been checked.
Do fresh test results predict compressive strength?#
Not reliably: in the laboratory slump generally rises with water content and is inversely related to strength, but in the field the relation is not clear or consistent (ASTM C143/C143M-26b). Strength acceptance therefore runs on hardened specimens molded from the same sample within 15 minutes (AASHTO R 60-23).