ACI · PRELIMINARY TRIAL WORKSPACE
An ACI absolute-volume trial worksheet: cylinder strength in psi, dry-rodded coarse aggregate, moisture corrections and quantities in lb or kg.
01 / STRENGTH REQUIREMENT
Declared strength test age: 28 days. f′c is the specified cylinder strength. Selecting psi does not derive a safe water ratio or predict the strength of this trial.
1 yd³ designed volume · measured yield still requires testing
03 / YOUR BATCH
These are illustrative trial quantities. Sand and stone use measured total moisture; mixer water accounts for aggregate absorption and water in admixture. Neither the chosen strength nor standards conformity has been demonstrated.
Prefilled numbers are demonstration assumptions. Current ACI lookup tables and a strength-qualified ratio are not selected automatically.
UNDERSTAND YOUR RESULTS
This US concrete mix design calculator makes trial proportioning visible in pounds per cubic yard or kilograms per cubic metre. It uses the ACI absolute-volume method family with water, air and aggregate inputs supplied by the user.
No. A specified cylinder strength such as 3,000, 4,000 or 5,000 psi is a performance requirement, not a cement:sand:stone recipe. The strength button records that requirement. It does not establish a water ratio or predict that the example materials will reach the selected strength.
NRMCA: materials, strength and water-ratio guidance →Water-cementitious ratio, w/cm, is free-water mass divided by cementitious-material mass. For an arithmetic example, 300 lb of free water and 600 lb of cementitious material give w/cm = 0.50. The permitted materials and limiting ratio come from the project specification and material evidence; this example is not a recommended mixture.
NRMCA: guide to ready-mixed concrete specifications →The selected coarse-aggregate bulk-volume fraction and its measured oven-dry, dry-rodded bulk density determine the coarse aggregate mass. Bulk volume includes spaces between stones. Particle specific gravity is used separately in the absolute-volume calculation, so entering particle density in the bulk-density field changes the method.
FHWA: mixture proportioning and aggregate measurements →One cubic yard is about 0.7646 m³. Switching display units preserves the physical batch; it does not turn 1 yd³ into 1 m³. Review the selected air content, wet aggregate weights and mixer water, then export the trial worksheet. Current ACI selection tables and complete project conformity checks are not automated here.
Review the ACI method and worksheet limits →A VISUAL GUIDE TO THE MIX
Start with the ingredients, then see why wet aggregate changes the batch. These concepts support every regional worksheet.
Four main ingredients, each with a different role.
Some mixes also use supplementary cementitious materials and chemical admixtures. Air occupies volume too. Their amounts depend on the specification, materials and trials.
The surface and the pores tell different stories.
Air-dry aggregate lies between oven dry and SSD. Measure absorption and total moisture; appearance alone cannot determine the correction.
Illustrative example, separate from your mix: 100 kg of oven-dry sand, 2% absorption and 5% total moisture. Both percentages use oven-dry mass.
The reference mass
100 + 2 absorbed water
100 + 5 total water
105 − 102 = 3
Batch 105 kg of wet sand to supply 102 kg on an SSD basis. Deduct 3 kg from the water otherwise added at the mixer. Account separately for moisture in other aggregates and water in liquid admixtures.
Learn more: NRMCA · aggregate moisture and ACI · batch water adjustments.
From SSD to wet batch weights: follow a complete moisture correction →
METHOD & SOURCE BOUNDARIES
Water and a qualified water/cementitious ratio establish cementitious demand. The selected coarse bulk fraction and measured dry-rodded density establish coarse aggregate mass. SSD volume accounting determines the remaining sand, and measured moisture determines the wet batch and mixer water.
The method family is ACI PRC-211.1-22. Current ACI water, air and aggregate selection tables are not automatically applied. ACI 318 requirements depend on the project-adopted edition. The worksheet does not certify ASTM material conformity, strength, durability or acceptance.
Normal-density concrete only. Special concrete, structural design and complete conformity assessment are outside this worksheet. Keep the specimen type and test age consistent. A grade change is not evidence of achieved strength.
Read the methodology and privacy details · Open this regional worksheet directly
Preliminary calculations. Not project approval or a strength prediction.
| Concrete Ratio — preliminary regional trial worksheet | ||
| Region | United States | |
| National reference context | No additional national reference selected | |
| Method | ACI absolute-volume / dry-rodded coarse aggregate worksheet | |
| Engine | 1.1.0 | |
| Status | Arithmetic only; strength, durability and conformity are not certified | |
| Project governing specification | Not supplied | |
| Exposure / project conditions | Not supplied | |
| Cement identity | Illustrative cement product — replace with measured properties | |
| Input / trial evidence | Not supplied; illustrative inputs | |
| Specified strength | 27.579029172673444 | MPa |
| Strength specimen | cylinder | |
| Declared strength test age | 28 | days |
| Required average strength · user supplied, unverified | Not supplied | MPa |
| Batch volume input | 0.764554857984 | m³ |
| Total free water | 180 | kg/m³ |
| Selected water/cementitious ratio | 0.45 | mass / mass |
| Total air | 6 | % volume |
| Cement particle specific gravity | 3.15 | |
| Fine aggregate SSD specific gravity | 2.65 | |
| Coarse aggregate SSD specific gravity | 2.7 | |
| Sand absorption | 1 | % oven-dry mass |
| Sand total moisture | 4 | % oven-dry mass |
| Stone absorption | 1 | % oven-dry mass |
| Stone total moisture | 2 | % oven-dry mass |
| Dry-rodded coarse aggregate bulk fraction | 0.62 | m³/m³ |
| Dry-rodded coarse aggregate density · oven dry | 1600 | kg/m³ |
| Fly ash share of cementitious mass | 0 | % |
| Slag share of cementitious mass | 0 | % |
| Admixture product dose | 0 | % cementitious mass |
| Project maximum water ratio | Not supplied | |
| Project minimum cementitious content | Not supplied | kg/m³ |
| Project maximum cementitious content | Not supplied | kg/m³ |
| Project minimum air | Not supplied | % volume |
| Material | per yd³ · lb | batch · lb |
| Cement | 674.2219742223618 | 674.2219742223618 |
| Sand — as batched | 1204.739848075127 | 1204.739848075127 |
| Coarse aggregate — as batched | 1705.5119059928863 | 1705.5119059928863 |
| Water to add at mixer | 251.92707243718112 | 251.92707243718112 |
| Batch volume | 1 | yd³ |
| Total batch weight | 3836.400800727556 | lb |
| Actual water ratio | 0.45 | |
| Free water kg/m3 | 180 | |
| Mixer water kg/m3 | 149.46239195348107 | |
| Constituent | Absolute m3 per m3 | Mass kg/m3 on stated basis |
| Cement | 0.12698412698412698 | 400 |
| Sand · SSD | 0.2619343915343916 | 694.1261375661376 |
| Stone · SSD | 0.37108148148148146 | 1001.92 |
| Free water outside admixture | 0.18 | 180 |
| Air | 0.06 | 0 |
| Outstanding check | No strength or complete code conformity assessment | |
| Water and cementitious content | B = max(W / r, supplied minimum) | 180.000 / 0.450 → 400.000 kg/m³; actual W/B = 0.450. Water demand and the strength-qualified ratio are inputs, not inferred from the grade. |
| Account for paste, liquid admixture and air | Vagg = 1 − Σ(Bj / 1000 Gj) − (W − D·u)/1000 − D/(1000 GD) − air | Admixture carries 0.000 kg/m³ water. Residual aggregate absolute volume = 0.633 m³/m³. Water density reference: 1000 kg/m³. |
| Coarse aggregate from dry-rodded bulk volume | CAOD = bulk fraction × dry-rodded density; CASSD = CAOD × (1 + absorption) | 0.620 × 1600.000 = 992.000 kg OD/m³. At 1.000% absorption → 1001.920 kg SSD/m³. Bulk volume includes particle voids; absolute volume does not. |
| Close the one-cubic-metre balance | VF = Vagg − CASSD / (1000 GCA); FASSD = VF × 1000 GFA | Sand 694.126 kg SSD/m³; coarse aggregate 1001.920 kg SSD/m³. The constituent absolute volumes, including air, sum to 1 m³. |
| Correct the aggregate moisture | OD = SSD / (1 + A); wet = OD × (1 + T); surface water = OD × (T − A) | Sand contributes 20.618 kg/m³ and stone 9.920 kg/m³ free surface water. Negative values represent absorption deficits. A and T are fractions of oven-dry mass in the equation. |
| Prepare the batch and test it | Mixer water = W − admixture water − sand surface water − stone surface water | 180.000 − 0.000 − 20.618 − 9.920 = 149.462 kg/m³. Multiply each ingredient by 0.765 m³. Measure workability, air, density/yield and strength; revise the trial. |
| Reference | ACI PRC-211.1-22 · proportioning guide | https://www.concrete.org/store/productdetail.aspx?ItemID=211122&Language=English |
| Reference | ACI 318 · structural requirements; project-adopted edition | https://www.concrete.org/publications/typesofpublications/standards%28codesandspecs%29/suiteofcodes.aspx |
| Reference | FHWA · absolute-volume and dry-rodded aggregate method | https://www.fhwa.dot.gov/pavement/pubs/013683.pdf |
| Reference | ASTM C39/C39M · cylinder strength testing | https://store.astm.org/c0039_c0039m-26.html |