⛏️ Proctor Test — Optimum Water Content and Density of Mixtures
In short
Determination of the relationship between water content and dry density of unbound and hydraulically bound aggregate mixtures after compaction with a rammer in a cylindrical mould by the Proctor test or the modified Proctor test. The test is performed according to PN-EN 13286-2:2010 + AC:2014-07; Range of mixtures: upper sieve size D up to 63 mm, oversize up to 25 % by mass. The procedure comprises 6 steps; it is used for: Unbound and hydraulically bound mixtures used in road construction and civil engineering (clause 1) — not soils for earthworks, Reference density for assessing the compaction of a placed layer of the mixture (clause 1), Comparing mixtures before use and establishing the water content at which a mixture can be compacted to a given density (clause 1).
At a glance
- Standard: PN-EN 13286-2:2010 + AC:2014-07
- Category: Construction
- Procedure steps: 6
- Range of mixtures: upper sieve size D up to 63 mm, oversize up to 25 % by mass
- Moulds (diameter × height): A 100 × 120 mm, B 150 × 120 mm, C 250 × 200 mm (± 1.0 mm); diameter at least 4D
- Rammers: A 2.50 kg / 305 mm, B 4.50 kg / 457 mm (base 50 mm), C 15.00 kg / 600 mm (base 125 mm)
Overview
STATUS (as of 06.11.2026). PN-EN 13286-2:2010 “Mieszanki niezwiązane i związane hydraulicznie — Część 2: Metody badań laboratoryjnych gęstości na sucho i zawartości wody — Zagęszczanie metodą Proktora” (Unbound and hydraulically bound mixtures — Part 2: Test methods for laboratory reference density and water content — Proctor compaction) — English version, published 17.11.2010, implements EN 13286-2:2010 [IDT]; it replaced PN-EN 13286-2:2007 (Polish version). A corrigendum PN-EN 13286-2:2010/AC:2014-07 (English version, implements EN 13286-2:2010/AC:2012) has been issued — it corrects equation (B.4) in B.5.4 of Annex B (density correction in the one point test). The card has no withdrawal note — the standard is current. EN 13286-2:2010 replaced EN 13286-2:2004.
SCOPE (clause 1). The standard specifies test methods for the relationship between water content and dry density of unbound and hydraulically bound mixtures after Proctor compaction. It allows an estimate of the density achievable on site and provides a reference for assessing the density of the compacted layer. It applies only to aggregate mixtures used in road construction and civil engineering; it is not applicable to soils for earthworks. The test is suitable for mixtures with an upper sieve size D of up to 63 mm and an oversize of up to 25 % by mass.
PRINCIPLE (clauses 3–4). The standard describes six similar tests that differ in mould size, rammer mass and the number of layers and blows, chosen according to the grading of the mixture. The Proctor test uses a 2.5 kg rammer (energy of about 0.6 MJ/m³ — “Proctor density”), the modified Proctor test a 4.5 kg or 15 kg rammer and thinner layers (energy of about 2.7 MJ/m³). If more than 25 % of the material is retained on a 63 mm sieve, the method is not suitable.
APPARATUS (clause 5). Cylindrical moulds with an extension at least 50 mm high and a steel base plate: Proctor mould A — diameter (100.0 ± 1.0) mm, height (120.0 ± 1.0) mm; large mould B — (150.0 ± 1.0) × (120.0 ± 1.0) mm; extra large mould C — (250.0 ± 1.0) × (200.0 ± 1.0) mm; the mould diameter at least four times D of the mixture. Rammers: A — (2.50 ± 0.02) kg, base 50 mm, height of fall (305 ± 3) mm; B — (4.50 ± 0.04) kg, 50 mm, (457 ± 3) mm; C — (15.00 ± 0.04) kg, 125 mm, (600 ± 3) mm. Automatic compactors meeting these requirements and giving the same results are permitted. In addition: sieves according to EN 933-2, balance readable to 0.1 % of the compacted sample mass, mixing tray with sides about 80 mm deep, steel straightedge at least 200 mm, apparatus for water content according to EN 1097-5, depth gauge readable to 0.02 mm, mixer of at least 0.01 m³ and a concrete block of at least 50 kg as support for manual compaction.
SAMPLE AND TYPE OF TEST (clause 6, Tables 4 and 5). The sample mass and mould are chosen according to grading: a mixture totally passing the 16 mm sieve — 15 kg (mould A) or 40 kg (mould B); 75–100 % passing the 31.5 mm sieve — 40 kg (mould B); with a larger oversize on the 31.5 mm sieve and 75–100 % passing the 63 mm sieve — 200 kg (mould C). Proctor test: mould A — 3 layers of 25 blows, mould B — 3 layers of 56 blows (2.5 kg rammer, 305 mm), mould C — 3 layers of 22 blows (15 kg rammer, 600 mm). Modified Proctor test: mould A — 5 layers of 25 blows, mould B — 5 layers of 56 blows (4.5 kg rammer, 457 mm), mould C — 3 layers of 98 blows (15 kg rammer). Larger moulds have the same compaction effort per unit volume, but wall friction can give different densities — for a series of tests on one mixture, one mould size should be used. For routine control of pavement layers, the one point Proctor test of Annex B may be used.
PROCEDURE AND CALCULATIONS (clauses 7–8 — outside the available text of the standard; according to a laboratory instruction of Lublin University of Technology for PN-EN 13286-2). A sample with a water content lower than the expected optimum is compacted in layers in the mould with extension; after removing the extension the excess is trimmed level with the mould rim, the mould with the mixture is weighed and material is taken for the determination of water content by drying. The test is repeated for further portions with increased water content until the dry density starts to decrease. The bulk density ρ is the mass of the compacted mixture divided by the mould volume, and the dry density ρd = ρ / (1 + w/100), where w is the water content in percent. The maximum dry density and the corresponding optimum water content are read from the plot of ρd against w.
WHAT WE DO NOT GIVE HERE. Details of clause 7 (preparation and wetting of portions, required number of points on the curve), clause 8 (plotting the curve), Annexes B–D (one point test, correction for oversize, self-draining mixtures) — they are outside the available preview. We do not give required degrees of compaction or “typical” densities — they are not part of the test standard.
Method principle
An aggregate mixture of known water content is compacted in layers in a cylindrical mould by a rammer falling from a specified height — in the Proctor test or in the modified Proctor test, with a heavier rammer and thinner layers. The mould, the number of layers and blows depend on the grading of the mixture (moulds A 100 mm, B 150 mm, C 250 mm).
Compaction energy: about 0.6 MJ/m³ in the Proctor test (2.5 kg rammer) and about 2.7 MJ/m³ in the modified test (4.5 kg or 15 kg rammer). The test is repeated for several water contents; for each point the dry density ρd = ρ / (1 + w/100) is calculated. The maximum of the ρd(w) curve gives the maximum dry density and the optimum water content.
Applications
- Unbound and hydraulically bound mixtures used in road construction and civil engineering (clause 1) — not soils for earthworks
- Reference density for assessing the compaction of a placed layer of the mixture (clause 1)
- Comparing mixtures before use and establishing the water content at which a mixture can be compacted to a given density (clause 1)
- Routine control of pavement layers by the one point Proctor test (Annex B)
Key parameters
| Parameter | Value |
|---|---|
| Range of mixtures | upper sieve size D up to 63 mm, oversize up to 25 % by mass |
| Moulds (diameter × height) | A 100 × 120 mm, B 150 × 120 mm, C 250 × 200 mm (± 1.0 mm); diameter at least 4D |
| Rammers | A 2.50 kg / 305 mm, B 4.50 kg / 457 mm (base 50 mm), C 15.00 kg / 600 mm (base 125 mm) |
| Proctor test | A: 3 × 25, B: 3 × 56, C: 3 × 22 (layers × blows); energy about 0.6 MJ/m³ |
| Modified Proctor test | A: 5 × 25, B: 5 × 56, C: 3 × 98; energy about 2.7 MJ/m³ |
| Sample mass | 15 kg (mould A), 40 kg (mould B), 200 kg (mould C) — according to grading (Table 4) |
| Balance | readable to 0.1 % of the compacted sample mass |
Standard
- Standard number
- PN-EN 13286-2:2010 + AC:2014-07
- Title (PL)
- Mieszanki niezwiązane i związane hydraulicznie — Część 2: Metody badań laboratoryjnych gęstości na sucho i zawartości wody — Zagęszczanie metodą Proktora
- Title (EN)
- Unbound and hydraulically bound mixtures — Part 2: Test methods for laboratory reference density and water content — Proctor compaction
Step-by-step procedure
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Choice of mould and sample mass
From sieving through the 16 mm, 31.5 mm and 63 mm sieves, choose the mould and the sample mass according to Table 4 of the standard (15 kg, 40 kg or 200 kg); with an oversize on the 63 mm sieve of more than 25 % the method is not applicable.
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Choice of test type
Proctor test or modified Proctor test; number of layers and blows according to Table 5 (e.g. mould A: 3 × 25 with the 2.5 kg rammer or 5 × 25 with the 4.5 kg rammer). Use one mould for a series of tests on one mixture.
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Compaction
According to the Lublin University of Technology instruction: compact the mixture, with a water content lower than the expected optimum, in layers in the mould with extension, remove the extension, trim the excess level with the mould rim and weigh the mould with the mixture.
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Water content
Take material for the determination of water content and determine it according to EN 1097-5 (drying in a ventilated oven).
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Further points
Repeat the test for portions with increased water content until the dry density starts to decrease (according to the Lublin University of Technology instruction).
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Calculations and result
For each point ρ = mass of mixture / mould volume and ρd = ρ / (1 + w/100); read the maximum dry density and optimum water content from the ρd(w) curve.
Required equipment and apparatus
| Equipment | Example | Indicative price |
|---|---|---|
| Cylindrical moulds A, B, C | with an extension at least 50 mm high and a steel base plate; dimensions according to Table 1 of the standard (5.1) | — |
| Rammer A, B or C | mass, base diameter and height of fall according to Table 2; with adjustment of the height of fall; automatic compactors giving the same results permitted (5.2) | — |
| Steel plate | for finishing the compaction of the last layer, dimensions according to Table 3 (5.3) | — |
| Sieves and balance | sieves according to EN 933-2; balance readable to 0.1 % of the compacted sample mass (5.4–5.5) | — |
| Tray, trowel, straightedge, depth gauge | corrosion-resistant tray with sides about 80 mm deep, steel straightedge at least 200 mm, depth gauge readable to 0.02 mm (5.6–5.10) | — |
| Apparatus for determining water content | according to EN 1097-5 — drying in a ventilated oven (5.9) | — |
| Mixer and concrete block | mixer of at least 0.01 m³; concrete block of at least 50 kg as support for manual compaction (5.11–5.12) | — |
Reagents, media and consumables
| Reagent | CAS | Details |
|---|---|---|
| Water | — | for wetting successive portions of the mixture |
Health and safety (OHS)
- The available text of the standard contains no safety requirements — the rules for working with heavy rammers (up to 15 kg), large samples and the oven are set by the laboratory on the basis of a risk assessment
Frequently asked questions
Which standard describes this test?
The test is performed according to PN-EN 13286-2:2010 + AC:2014-07 — “Unbound and hydraulically bound mixtures — Part 2: Test methods for laboratory reference density and water content — Proctor compaction”.
How does this method work?
An aggregate mixture of known water content is compacted in layers in a cylindrical mould by a rammer falling from a specified height — in the Proctor test or in the modified Proctor test, with a heavier rammer and thinner layers. The mould, the number of layers and blows depend on the grading of the mixture (moulds A 100 mm, B 150 mm, C 250 mm).
What is the measuring range and accuracy?
Range of mixtures: upper sieve size D up to 63 mm, oversize up to 25 % by mass; Moulds (diameter × height): A 100 × 120 mm, B 150 × 120 mm, C 250 × 200 mm (± 1.0 mm); diameter at least 4D; Rammers: A 2.50 kg / 305 mm, B 4.50 kg / 457 mm (base 50 mm), C 15.00 kg / 600 mm (base 125 mm); Proctor test: A: 3 × 25, B: 3 × 56, C: 3 × 22 (layers × blows); energy about 0.6 MJ/m³.
How long does the test take?
The procedure comprises 6 steps. The standard does not give a duration for every stage — the laboratory's own procedure decides.
What equipment is required?
Cylindrical moulds A, B, C, Rammer A, B or C, Steel plate, Sieves and balance, Tray, trowel, straightedge, depth gauge, Apparatus for determining water content, Mixer and concrete block.
Where is this test used?
Unbound and hydraulically bound mixtures used in road construction and civil engineering (clause 1) — not soils for earthworks; Reference density for assessing the compaction of a placed layer of the mixture (clause 1); Comparing mixtures before use and establishing the water content at which a mixture can be compacted to a given density (clause 1); Routine control of pavement layers by the one point Proctor test (Annex B).
What safety precautions apply?
The available text of the standard contains no safety requirements — the rules for working with heavy rammers (up to 15 kg), large samples and the oven are set by the laboratory on the basis of a risk assessment.
Which laboratory can perform this test?
The test is performed by laboratories accredited to ISO/IEC 17025. On LabCoda you can find them by the standard number PN-EN 13286-2.