Aggregate Blend Calculator

Design your perfect aggregate mix with precision. Combine 2-5 aggregates, adjust proportions, and compare results against industry specifications in real-time.

How to Use

  1. Enter sieve analysis for each aggregate using % Passing or % Retained format
  2. Adjust proportions using the sliders or input fields (must total 100%)
  3. View results in the gradation table below - calculations update automatically
  4. Compare to specs by selecting an optional target specification (KDOT, CDOT, NDOT, ODOT, or ASTM)

Blend Composition

Aggregate 1100%
Total:100%
Aggregate 1

Target Specification (Optional)

Share & Compare

Share the current calculator view as a public link, or compare up to three real gradations side-by-side.

Choose up to 3 items

Gradation Curve

Semi-log sieve opening size (mm) vs % cum. retained

Upload or enter sieve values to see the gradation curve.

Blended Gradation Results

SieveAggregate 1100%
4" [100mm]—
3" [75mm]—
2 1/2" [63mm]—
2" [50mm]—
1 1/2" [37.5mm]—
1" [25mm]—
3/4" [19mm]—
1/2" [12.5mm]—
3/8" [9.5mm]—
#4 [4.75mm]—
#8 [2.36mm]—
#10 [2.0mm]—
#16 [1.18mm]—
#30 [600μm]—
#40 [425μm]—
#50 [300μm]—
#100 [150μm]—
#200 [75μm]—

Note: Results are theoretical calculations. Actual blend performance may vary based on material properties, moisture content, and mixing methods. Always verify with laboratory testing for critical applications.

About This Calculator

This calculator uses the standard weighted average formula for aggregate blending:

Pblend = f1 × P1 + f2 × P2 + ... + fn × Pn

Where Pblend is the percent passing for each sieve, and f is the fraction (0-1) of each aggregate in the blend.

Terminology Reference

Sieve Analysis & Gradation
Sieve Analysis
A laboratory test that separates aggregate into size fractions using a stack of wire mesh screens with progressively smaller openings. The weight retained on each sieve determines the gradation.
Gradation
The distribution of particle sizes within an aggregate sample, typically expressed as percent passing or percent retained for each sieve size. Gradation directly affects workability, strength, and density.
Percent Passing
The percentage of aggregate (by weight) that passes through a given sieve opening. A value of 60% passing the #4 sieve means 60% of the material is smaller than 4.75mm.
Percent Retained
The percentage of aggregate (by weight) that is retained on (does not pass through) a given sieve. Percent Retained = 100 - Percent Passing.
Well-Graded
An aggregate with a good representation of all particle sizes, creating a dense structure with minimal voids. Ideal for base courses and concrete where density and strength are critical.
Gap-Graded
An aggregate missing one or more intermediate size fractions. Used intentionally in some applications like stone matrix asphalt (SMA) for improved drainage or texture.
Uniformly-Graded (Open-Graded)
An aggregate where most particles are approximately the same size, creating high void content. Used for drainage applications and permeable pavements.
Physical Property Tests
Los Angeles Abrasion Test (AASHTO T96)
Measures aggregate durability by tumbling it with steel balls in a rotating drum. The percent loss (material broken down to passing the #12 sieve) indicates wear resistance. Lower values mean harder, more durable aggregate. Typical spec: maximum 40-50% loss.
Aggregate Durability Index (AASHTO T210)
Measures resistance to producing detrimental clay-like fines when agitated in water. Higher values indicate more durable aggregate with less clay content. Typical spec: minimum 35-40.
Fractured Faces (ASTM D5821)
An angular, rough, or broken surface of an aggregate particle created by crushing, other artificial means, or by nature. A face must cover at least 25% of the particle's maximum cross-sectional area to qualify. Fractured faces provide better particle interlock than rounded surfaces, increasing shear strength. Specs typically require a percentage of particles to have 1 or 2+ fractured faces.
Specific Gravity
The ratio of aggregate density to water density. Used to calculate batch weights and determine if aggregate will float or sink. Typical values: 2.4-2.9 for most aggregates.
Absorption (ASTM C127/C128)
The increase in aggregate mass due to water filling pore spaces, expressed as a percentage of dry weight. Affects concrete mix water requirements and freeze-thaw durability. Typical values: granite 0.3%, limestone 0.9-1.9%, sandstone 1.8%+. Most normal-weight aggregates: 0.2-2%.
Soil Plasticity Tests
Liquid Limit (LL) - AASHTO T89
The moisture content (percent by weight) at which soil transitions from a plastic state to a liquid state. Determined using the Casagrande cup method. High LL indicates soil that holds more water and has greater potential for swelling/shrinking. Typical base spec: maximum 25-35.
Plastic Limit (PL) - AASHTO T90
The moisture content at which soil transitions from a semi-solid to a plastic state. Determined by rolling soil into 1/8" diameter threads until they crumble. The difference between LL and PL defines the plastic range.
Plasticity Index (PI)
Calculated as PI = LL - PL. Indicates the range of moisture content over which soil remains plastic. High PI means more clay content, which is problematic in base materials (swells when wet, shrinks when dry, pumps under traffic). Typical base spec: maximum 6-8.
Non-Plastic (NP)
Material that cannot be rolled into threads at any moisture content, indicating minimal clay content. Desirable for drainage and base applications.
Aggregate Classifications
Coarse Aggregate
Material predominantly retained on the #4 sieve (larger than 4.75mm). Provides the structural skeleton in concrete and asphalt mixes. Includes crushed stone, gravel, and recycled concrete.
Fine Aggregate
Material predominantly passing the #4 sieve (smaller than 4.75mm). Fills voids between coarse particles and affects workability. Includes natural sand, manufactured sand, and stone screenings.
Natural Sand
Sand produced by natural weathering and erosion, typically from river deposits or beaches. Particles are rounded, which improves workability but reduces interlock compared to manufactured sand.
Manufactured Sand (M-Sand)
Sand produced by crushing rock, creating angular particles with rough surfaces. Provides better interlock and higher strength but may reduce workability. Often blended with natural sand.
Aggregate Base Course (ABC)
A well-graded mixture of coarse and fine aggregate used as a structural layer beneath pavement. Must meet gradation, plasticity, and durability requirements for load distribution and drainage.
Recycled Concrete Aggregate (RCA)
Aggregate produced by crushing demolished concrete structures. Can substitute for virgin aggregate in many applications but may have higher absorption and variability.
Standard Sieve Sizes
US StandardMetric OpeningCommon Use
3"75 mmLarge riprap, base rock
2"50 mmLarge base aggregate
1-1/2"37.5 mmBase course top size
1"25 mmCoarse aggregate
3/4"19 mmStandard coarse aggregate
1/2"12.5 mmMedium coarse aggregate
3/8"9.5 mmPea gravel size
#44.75 mmCoarse/fine boundary
#82.36 mmCoarse sand
#102.0 mmCoarse/medium boundary
#161.18 mmMedium sand
#30600 μmMedium sand
#40425 μmMedium/fine boundary
#50300 μmFine sand
#100150 μmVery fine sand
#20075 μmSilt/clay boundary
Specification Sources
KDOT - Kansas Department of Transportation
State highway agency specifications for Kansas. Division 1100 covers aggregates for concrete, base, and other applications.
CDOT - Colorado Department of Transportation
State highway agency specifications for Colorado. Section 703 covers aggregate requirements for various applications.
NDOT - Nebraska Department of Transportation
State highway agency specifications for Nebraska. Includes unique combined aggregate specs like 47BR for concrete pavement.
ODOT - Oklahoma Department of Transportation
State highway agency specifications for Oklahoma. Section 703 covers aggregate base Types A, B, C, and D with gradation and physical property requirements.
ASTM International
American Society for Testing and Materials. Develops voluntary consensus standards for materials, products, and services. ASTM C33 is the standard specification for concrete aggregates.
AASHTO
American Association of State Highway and Transportation Officials. Develops standards, specifications, and test methods used by state DOTs. AASHTO M43 defines standard aggregate sizes.

Target specifications are provided for reference only. Always verify blend compliance with official DOT or project specifications. Contact us through the contact form for custom aggregate solutions.