Pervious concrete is a concrete with 15 to 35 % connected voids that lets water pass through the pavement into a drainable base, as ACI PRC-522-23 reports, with a compressive strength of 2.8 to 28 MPa (400 to 4,000 psi). The FHWA TechBrief FHWA-HIF-13-006 (2012) gives a drainage rate of 81.5 to 733 L/min/m² (2 to 18 gal/min/ft²) for the same material, which is why the mix is specified by its voids first and its strength second.
Permeable concrete, porous concrete and no-fines concrete are other names for pervious concrete. Its admixture system has two parts: set control by retarders or hydration-control admixtures, because the low-water paste gives a working time of only about 1 hour, and air entrainment wherever the pavement freezes and thaws. Few mixes show as plainly how the choice of concrete additives defines what a concrete can do.
The sections below follow that order: the definition and void structure, the admixture system, the mix ranges with a calculated worked mix, drainage and strength, acceptance testing to ASTM C1688, C1701 and C1754, placement, the US standards and the dated cost ranges.
The table below summarizes the core values of pervious concrete with the document that states each one.
| Attribute | Value |
|---|---|
| Other names | Permeable concrete, porous concrete, no-fines concrete |
| Void content (hardened) | 15 to 35 % (ACI PRC-522-23) |
| Pore size | 2 to 8 mm (0.08 to 0.32 in) (ACI PRC-522-23) |
| Compressive strength | 2.8 to 28 MPa (400 to 4,000 psi) (ACI PRC-522-23) |
| Water/cementitious materials ratio | 0.27 to 0.34 (FHWA-HIF-13-006, 2012, typical) |
| Drainage rate | 81.5 to 733 L/min/m² (2 to 18 gal/min/ft²) (FHWA 2012) |
| Admixture system | Set retarders and hydration stabilizers for working time; air-entraining admixtures required in freeze-thaw environments (FHWA 2012) |
| US report and specification | ACI PRC-522-23 Pervious Concrete, Report; ACI SPEC-522.1-20 Specification for Construction of Pervious Concrete Pavement |
| Acceptance tests | ASTM C1688/C1688M-26 (fresh), ASTM C1701/C1701M-17a(2023) (in place), ASTM C1754/C1754M-25 (hardened) |
Each value is traced to its source: standards and codes to their issuing body, product values to the data sheet named with them, prices to the dated source beside them (methodology and fact-checking).
What Is Pervious Concrete?#
Pervious concrete is gap-graded coarse aggregate bound by a thin film of cement paste, with little or no sand, so the voids between the particles stay connected and carry water through the slab. A conventional mix fills those voids with sand and paste; a pervious mix leaves them open on purpose.
The connected voids turn the slab itself into a drainage layer: rain passes through the pore network to a drainable base below. The thin paste film is what makes the mix sensitive to early setting and, in cold regions, to frost.
Pervious concrete counts among the placement-defined special concretes, the group that also holds self-compacting concrete, shotcrete and 3D printing concrete, because its purpose follows from how it is placed and how it drains rather than from a strength class. Its main US document is a pavement specification, ACI SPEC-522.1-20 Specification for Construction of Pervious Concrete Pavement, which places the material firmly in pavement work among the other special concretes.
Permeable, porous and no-fines concrete: one material, several names#
Permeable concrete, porous concrete and no-fines concrete are synonyms of pervious concrete and describe the same gap-graded, high-void material. The term "no-fines" points to the missing sand fraction, "porous" and "permeable" to the open pore network. The American Concrete Institute uses "pervious" in the report ACI PRC-522-23 Pervious Concrete (2023, 56 pages) and the specification ACI SPEC-522.1-20, and ASTM uses it in the titles of its three test methods for density, void content and infiltration.
Void content and pore size under ACI PRC-522-23#
ACI PRC-522-23 reports a hardened void content of 15 to 35 % and pore sizes of 2 to 8 mm (0.08 to 0.32 in). The void content is the first design number of a pervious mix: it sets the paste volume, the drainage rate and the strength the slab can reach. A specifier states it as a target with a tolerance and checks it in the fresh state and in cores.
The range of 15 to 25 % found in older literature is the range of ACI 522R-10 as cited by FHWA (2012) and PCA EB302. It still appears in older guidance, but it is not the current ACI range. The 2023 report extends the upper bound to 35 %, so a mix designed at 28 or 30 % voids falls inside the current ACI description although it lies outside the older band.
Which Admixtures Does Pervious Concrete Need?#
Two admixture functions define a pervious concrete mix: set retarders or hydration-control admixtures that stretch a working time of about 1 hour, and air-entraining admixtures that FHWA lists as required wherever the pavement freezes and thaws. FHWA TechBrief FHWA-HIF-13-006 (2012) states that "set retarders and hydration stabilizers are commonly used to help control the rapid setting" and that air-entraining admixtures are required in freeze-thaw environments, with hardened air measured by ASTM C457. Viscosity modifiers form a third, product-level option.
The table below compares the admixture types used in pervious concrete by role, standard and dose basis.
| Admixture | Role in pervious concrete | Standard | Typical basis or dose |
|---|---|---|---|
| Set-retarding admixtures | Control the rapid setting of the thin, low-water paste film (FHWA 2012); discharge time to 1.5 h or more (PCA EB302) | ASTM C494/C494M-24 Type B (retarding) or Type D (water-reducing and retarding); EN 934-2:2009+A1:2012 Table 8 set retarding | Manufacturer's recommended dosage (PCA EB302) |
| Hydration-control admixtures | Extend working and discharge time (PCA EB302) | ASTM C494/C494M-24 Type B or D as declared; EN 934-2:2009+A1:2012 Table 8 | Typical product value of MasterSet DELVO (data sheet 05/24): 261 ± 65 mL/100 kg (4 ± 1 fl oz/cwt) of cementitious materials for most mixes, about 1 to 5 h set extension |
| Air-entraining admixtures | Protect the paste in freeze-thaw exposure; required there (FHWA 2012) | ASTM C260/C260M-24; EN 934-2:2009+A1:2012 Table 5 (spacing factor 0.200 mm) | Per data sheet; hardened air checked by ASTM C457/C457M-24 |
| Viscosity-modifying admixtures (VMA) and welan and diutan gum viscosity modifiers | Paste cohesion | Product data sheet | Typical product value of KELCO-CRETE DG (diutan gum): 0.01 to 0.15 % by mass of mix water |
Doses convert to batch quantities with the admixture dosage calculator.
Extending the one-hour working time#
PCA EB302 (Tennis et al., 2004) gives pervious concrete a working time of about 1 hour from mixing to discharge, extended to 1.5 hours or more when a retarder or hydration-stabilizing admixture is used. The short window follows from the mix itself: a low water content and a thin paste film exposed in open voids lose workability fast, and a slab that sets before it is compacted cannot reach its design voids or bond between particles.
Retarders and hydration-control products are classified under the same standards on both sides of the Atlantic. In the US, ASTM C494/C494M-24 Type B (retarding) and Type D (water-reducing and retarding) are the types declared for hydration-control products such as MasterSet DELVO and GCP RECOVER. In Europe, EN 934-2:2009+A1:2012 Table 8 covers set retarding admixtures, with an initial setting time of at least control + 90 min and a final setting time of at most control + 360 min.
For the dose in a pervious mix, PCA EB302 refers to the "manufacturer's recommended dosage" and gives no fixed figure. A product value published for general mixes, such as the hydration-control dose in the table above, describes that product in conventional concrete and is not a pervious-specific dose; trial batches at the project temperature and haul time settle the figure. The chemistry, the types and the hot-weather use of set-retarding admixtures are covered on the page for set-retarding admixtures.
Air entrainment for freezing climates#
FHWA (TechBrief FHWA-HIF-13-006, 2012) states that air-entraining admixtures are required in pervious concrete exposed to freeze-thaw environments. The air protects the paste film itself; the large voids between aggregate particles drain water but do not protect the paste. Hardened air is verified by ASTM C457/C457M-24, the active standard for hardened air-void analysis by microscopy.
FHWA (2012) adds a second measure for freezing exposure: 5 to 7 % fine aggregate for freeze-thaw resistance. The void target is then set with that sand in the mix.
Air-entraining admixtures are specified in the US under ASTM C260/C260M-24, which is active and tests the admixture by ASTM C233/C233M-24. In Europe, EN 934-2:2009+A1:2012 Table 5 covers air entraining admixtures and sets a spacing factor of the test mix of at most 0.200 mm. Wood-derived and synthetic types, their dosage and their test methods are treated on the page for air-entraining admixtures.
Viscosity modifiers and other admixtures#
One named product lists pervious concrete among its uses: the typical product value of KELCO-CRETE DG (diutan gum) is 0.01 to 0.15 % by mass of mix water, listed for SCC, underwater, pervious and pigmented concrete. That range covers all listed uses together and is a product value, not a dose rule for pervious mixes.
ACI PRC-212.3-16 treats pervious concrete in its chapter 21, within its report on chemical admixtures. No verified pervious-specific rule for water reducers, supplementary cementitious materials or fibers is held in this reference, so none is stated on this page; the mix ranges in the next section come from FHWA.
How Is a Pervious Concrete Mix Proportioned?#
A pervious concrete mix uses a water/cementitious materials ratio of 0.27 to 0.34 and 267 to 415 kg/m³ (450 to 700 lb/yd³) of cementitious materials, the typical ranges of FHWA TechBrief FHWA-HIF-13-006 (2012). The same TechBrief gives 1,187 to 1,483 kg/m³ (2,000 to 2,500 lb/yd³) of coarse aggregate. These are guide ranges for a specification and a trial batch, not standard requirements and not a site recipe. General proportioning methods for conventional mixes are set out under concrete mix design with admixtures and SCMs.
The table below lists the FHWA (2012) mix ranges with their basis in metric and US units.
| Constituent | Typical range (FHWA-HIF-13-006, 2012) | US units |
|---|---|---|
| Water/cementitious materials ratio (water-cement ratio (w/c and w/cm)) | 0.27 to 0.34 | 0.27 to 0.34 |
| Cementitious materials | 267 to 415 kg/m³ | 450 to 700 lb/yd³ |
| Coarse aggregate | 1,187 to 1,483 kg/m³ | 2,000 to 2,500 lb/yd³ |
| Aggregate/cementitious ratio | 4 to 4.5:1 by mass | 4 to 4.5:1 by mass |
| Fine aggregate in freezing exposure | 5 to 7 % fine aggregate | 5 to 7 % fine aggregate |
| In-place density | 1,602 to 2,002 kg/m³ | 100 to 125 lb/ft³ |
Typical guide ranges, not standard requirements.
FHWA (2012) gives an aggregate/cementitious ratio of 4 to 4.5:1 by mass. The ratio links the two mass ranges: the cementitious content fixes the paste, and the aggregate mass at that ratio fixes how much open space is left between particles. The void target is the controlling number, so the paste volume is set to coat the aggregate without filling the voids.
A worked example, calculated from the FHWA ranges above, shows how the mass numbers fit together. Input 1: cementitious materials 340 kg/m³ (573 lb/yd³). Input 2: w/cm 0.30. Input 3: aggregate/cementitious ratio 4.2:1 by mass. The mix then needs 102 kg/m³ (172 lb/yd³) of water, and the ratio gives 1,428 kg/m³ (2,407 lb/yd³) of coarse aggregate, inside the 1,187 to 1,483 kg/m³ range. Admixture doses are then added on the cementitious mass of 340 kg/m³. The mass proportions do not by themselves show the void content: the trial batch is checked for fresh density and void content to ASTM C1688/C1688M-26, and the paste content is adjusted until the measured voids sit on the design target inside the 15 to 35 % range.
Aggregate sizes and the role of sand#
FHWA TechBrief FHWA-HIF-13-006 (2012) cites ASTM C33 size numbers 7, 8, 67 and 89 for the coarse aggregate of pervious concrete. These single-sized or narrowly graded aggregates leave the open pore structure that a well-graded aggregate would fill. Sand is the second aggregate decision: a pervious mix has little or none, and FHWA (2012) adds 5 to 7 % fine aggregate where the pavement faces freeze-thaw exposure. Every sand addition reduces the open space between the coarse particles, so the void target and the drainage rate are checked again on the trial batch once sand is in the mix.
How Fast Does Pervious Concrete Drain and How Strong Is It?#
Pervious concrete drains at 81.5 to 733 L/min/m² (2 to 18 gal/min/ft²) and reaches 3.4 to 27.6 MPa (500 to 4,000 psi) in compression, according to FHWA-HIF-13-006 (2012). ACI PRC-522-23 gives its own strength range, so both sources appear in the table below.
The table below compares the hardened properties of pervious concrete by source.
| Property | Value | Source |
|---|---|---|
| Void content (hardened) | 15 to 35 % | ACI PRC-522-23 |
| Pore size | 2 to 8 mm (0.08 to 0.32 in) | ACI PRC-522-23 |
| Drainage rate | 81.5 to 733 L/min/m² (2 to 18 gal/min/ft²); 488 to 4,379 cm/h (192 to 1,724 in/h) | FHWA-HIF-13-006 (2012) |
| Compressive strength | 2.8 to 28 MPa (400 to 4,000 psi) | ACI PRC-522-23 |
| Compressive strength | 3.4 to 27.6 MPa (500 to 4,000 psi), typical 17.2 MPa (2,500 psi) | FHWA-HIF-13-006 (2012) |
| Flexural strength | 1.0 to 3.8 MPa (150 to 550 psi) | FHWA-HIF-13-006 (2012) |
| In-place density | 1,602 to 2,002 kg/m³ (100 to 125 lb/ft³) | FHWA-HIF-13-006 (2012) |
Infiltration and drainage rates#
The FHWA (2012) drainage range of 81.5 to 733 L/min/m² (2 to 18 gal/min/ft²) equals 488 to 4,379 cm/h (192 to 1,724 in/h), a water depth passing per hour. The rate depends on the connected void content set in the mix design, which is why the void target comes before any drainage figure in a specification. On site, the rate is measured in place by ASTM C1701/C1701M-17a(2023), described in the acceptance section below. A design rate for a project comes from that project's specification; the FHWA range describes the material, not a pass value.
Compressive and flexural strength#
Pervious concrete reaches 2.8 to 28 MPa (400 to 4,000 psi) in compression (ACI PRC-522-23) and 1.0 to 3.8 MPa (150 to 550 psi) in flexure (FHWA 2012). FHWA gives 3.4 to 27.6 MPa (500 to 4,000 psi) in compression, with 17.2 MPa (2,500 psi) as the typical value. A specifier states the strength as a design value together with the void target, because a pervious mix is accepted on density, voids and infiltration in the field.
In-place density#
FHWA (2012) gives an in-place density of 1,602 to 2,002 kg/m³ (100 to 125 lb/ft³) for pervious concrete. The density reflects the void content: the more open space a slab holds, the lower its unit weight. That relation is why fresh density measured by ASTM C1688 serves as the first acceptance check.
How Is Pervious Concrete Tested and Accepted?#
Three ASTM methods accept pervious concrete: ASTM C1688/C1688M-26 for fresh density and void content, ASTM C1701/C1701M-17a(2023) for infiltration in place, and ASTM C1754/C1754M-25 for hardened density and void content. A fourth method, ASTM C1747/C1747M-13 for impact and abrasion degradation, was withdrawn in 2022 and is no longer a current reference. Slump, air content and the other fresh concrete tests serve conventional mixes; for a pervious mix the fresh acceptance check is density and void content to ASTM C1688.
The table below lists each acceptance property with its ASTM method and the typical acceptance values of PCA EB302 (2004).
| Property | ASTM method (edition, status) | What it reports | Typical acceptance (PCA EB302, 2004) |
|---|---|---|---|
| Fresh density and void content | ASTM C1688/C1688M-26, current | Density and void content of freshly mixed pervious concrete | Average unit weight within 80 kg/m³ (5 lb/ft³) of the design value |
| Infiltration in place | ASTM C1701/C1701M-17a(2023), active | Infiltration rate of in-place pervious concrete | Project specification |
| Hardened density and void content | ASTM C1754/C1754M-25, current | Density and void content of hardened pervious concrete (cores) | Cores no more than 13 mm (0.5 in) under design thickness |
| Hardened air (freezing exposure) | ASTM C457/C457M-24, active | Hardened air-void analysis | Project specification |
| Impact and abrasion | ASTM C1747/C1747M-13, withdrawn 2022 | Not a current method | Not used |
Fresh density and void content to ASTM C1688#
ASTM C1688/C1688M-26 measures the density and void content of freshly mixed pervious concrete. The fresh unit weight is compared with the design value of the approved mix, and PCA EB302 (2004) gives a typical acceptance requirement of an average unit weight within 80 kg/m³ (5 lb/ft³) of the design value. A load outside the tolerance signals a change in paste content, water or compaction before the concrete is placed, while it can still be rejected.
Infiltration in place to ASTM C1701#
ASTM C1701/C1701M-17a(2023), active and last updated on 2023-10-06, measures the infiltration rate of in-place pervious concrete. The test is run on the finished slab rather than on a laboratory specimen. The pass value is set in the project specification. Permeable unit pavers have their own method, ASTM C1781, and C1701 is not used for them.
Hardened voids and hardened air#
ASTM C1754/C1754M-25 measures the density and void content of hardened pervious concrete on cores. PCA EB302 (2004) gives a typical thickness requirement of cores no more than 13 mm (0.5 in) under the design thickness. In freezing exposure, hardened air is checked by ASTM C457/C457M-24, the method FHWA (2012) names for the air-entrained paste of pervious mixes.
How Is Pervious Concrete Placed?#
Pervious concrete is placed on a drainable base within about 1 hour of mixing, or 1.5 hours or more with a retarder or hydration-control admixture, and kept free of traffic for 7 days (PCA EB302). The admixture choice therefore sets the haul distance and the size of each placement.
Drainable base thickness#
PCA EB302 calls for a drainable base of at least 152 mm (6 in) under pervious concrete, and 305 to 457 mm (12 to 18 in) is common. The base receives the water that passes through the slab, so its depth is a design decision of the drainage engineer, not of the mix designer. Its thickness also enters the price, as the cost section shows.
Discharge time, placement and protection#
Discharge time follows from the admixture system: about 1 hour from mixing without set control, and 1.5 hours or more when a retarder or hydration-stabilizing admixture is in the mix (PCA EB302). A producer who knows the haul time can choose between a plain mix, a retarded mix and a hydration-control product before the first load leaves the plant. PCA EB302 calls for plastic sheeting immediately after placement and kept for at least 7 days; curing methods and curing products are outside this page. The same guide keeps traffic off the slab for 7 days.
Which Standards and Guides Govern Pervious Concrete?#
In the US, pervious concrete is specified under ACI SPEC-522.1-20, described in ACI PRC-522-23 and tested to ASTM C1688/C1688M-26, C1701/C1701M-17a(2023) and C1754/C1754M-25. Its admixtures are classified by ASTM C494/C494M-24 and ASTM C260/C260M-24, with EN 934-2:2009+A1:2012 as the European admixture standard. ACI SPEC-522.1-20 supersedes ACI SPEC-522.1-13 and is published by the American Concrete Institute.
The table below lists each document by region, edition and role.
| Region | Document (edition, status) | Role |
|---|---|---|
| US | ACI PRC-522-23 Pervious Concrete, Report (2023, 56 pages), current | Report: void content, pore size, strength |
| US | ACI SPEC-522.1-20, current; supersedes ACI SPEC-522.1-13 | Specification for Construction of Pervious Concrete Pavement |
| US | ASTM C1688/C1688M-26; ASTM C1701/C1701M-17a(2023); ASTM C1754/C1754M-25 | Fresh density and voids; infiltration in place; hardened density and voids |
| US | ASTM C494 chemical admixtures types: ASTM C494/C494M-24, Types B and D, active | Retarding and water-reducing retarding admixtures |
| US | ASTM C260 air-entraining admixtures: ASTM C260/C260M-24, active | Air-entraining admixtures |
| US | ACI 212.3R-16 report on chemical admixtures (ACI PRC-212.3-16), chapter 21 | Guide: pervious concrete chapter |
| EU | EN 934-2 admixture requirements: EN 934-2:2009+A1:2012, Tables 5 and 8 | Air entraining and set retarding admixtures |
| EU and India | Pervious concrete standard | None in this reference |
How to specify pervious concrete#
A pervious concrete specification states six items that the acceptance tests can check, listed below.
- State the hardened void target inside the 15 to 35 % range of ACI PRC-522-23.
- Set the w/cm (0.27 to 0.34) and the cementitious content (267 to 415 kg/m³ or 450 to 700 lb/yd³) of the approved trial mix, using the FHWA (2012) ranges as the guide.
- Name the set-control admixture by ASTM C494/C494M-24 Type B or D (or EN 934-2:2009+A1:2012 Table 8) and the maximum discharge time.
- Require air entrainment in freeze-thaw exposure, with hardened air verified by ASTM C457/C457M-24.
- Accept each load by ASTM C1688/C1688M-26 unit weight against the design value, and the slab by core thickness to ASTM C1754/C1754M-25.
- Check infiltration in place by ASTM C1701/C1701M-17a(2023) against the rate set in the project documents.
What Does Pervious Concrete Cost?#
Pervious concrete costs 15 to 25 % more than conventional concrete according to FHWA (2012), and installed permeable pavement ranged from USD 75 to 161 per m² (USD 7 to 15 per ft²) in Chesapeake Bay Trust's March 2022 guidance. The Chesapeake Bay Trust (March 2022) adds that permeable pavement may cost 50 % more than conventional pavement. HomeAdvisor (June 2026) gives USD 65 to 161 per m² (USD 6 to 15 per ft²) installed in the US, but for permeable concrete and asphalt combined, not for concrete alone. No dated range per cubic meter of pervious concrete is available here, so a quote rests on its basis: the pavement area, the slab thickness, the drainable base depth of at least 152 mm (6 in), the set-control admixture and, in freezing climates, the air-entraining admixture.
The table below lists the dated cost ranges with region, date and source.
| Measure | Range | Region | Date | Source |
|---|---|---|---|---|
| Premium over conventional concrete | 15 to 25 % | US | 2012 | FHWA-HIF-13-006 (2012) |
| Installed permeable pavement | USD 75 to 161 per m² (USD 7 to 15 per ft²), may be 50 % more than conventional pavement (2022) | US | March 2022 | Chesapeake Bay Trust (2022) |
| Installed permeable pavement, concrete and asphalt combined, not concrete alone | USD 65 to 161 per m² (USD 6 to 15 per ft²) (2026) | US | June 2026 | HomeAdvisor (2026) |
Where Does Pervious Concrete Sit Among Special Concretes?#
Pervious concrete belongs to the special concretes defined by how they are placed, next to self-compacting concrete, shotcrete and 3D printing concrete, rather than by strength or density. Four related special concretes are listed below.
- Self-compacting concrete: placement-defined, flows and consolidates under its own weight.
- Shotcrete mixes: placement-defined, projected pneumatically from a nozzle.
- 3D printing concrete: placement-defined, extruded layer by layer.
- Cellular concrete: density-defined, the contrast case of a special concrete set by its unit weight.
Admixtures for conventional paving mixes, such as slipform and fast-track paving, are covered under admixtures for concrete pavements. Porous asphalt is an asphalt material, not a concrete, and is outside this page.
Pervious concrete FAQs#
Is pervious concrete the same as permeable pavers?#
No: pervious concrete is cast in place and tested by ASTM C1701, while permeable unit pavers have their own method, ASTM C1781. Both let water through the surface, but one is a monolithic slab and the other a system of units with open joints.
What are the disadvantages of pervious concrete?#
Pervious concrete has four documented drawbacks against a conventional mix, listed below.
- Strength traded for drainage: 2.8 to 28 MPa (400 to 4,000 psi) compressive strength (ACI PRC-522-23), and a higher void target lowers the strength the slab reaches.
- Working time: about 1 hour from mixing to discharge without a retarder (PCA EB302).
- Cost: 15 to 25 % above conventional concrete (FHWA 2012).
- Frost: air entrainment required in freeze-thaw exposure, with 5 to 7 % fine aggregate added for freeze-thaw resistance (FHWA 2012).
Can pervious concrete be colored?#
Yes, integral pigments are dosed in pervious concrete as in any concrete; no pervious-specific pigment dose is set by the documents cited here.
Iron oxide and other pigments, their dosage basis and their standards are covered under concrete pigments and integral color.
Does pervious concrete work in freezing climates?#
Yes, with air entrainment, which FHWA (2012) lists as required for pervious concrete in freeze-thaw environments.
FHWA (2012) also adds 5 to 7 % fine aggregate for freeze-thaw resistance, and hardened air is checked by ASTM C457/C457M-24.
The mechanism behind the air rule, from air voids to spacing factor, is explained under freeze-thaw damage and salt scaling.