Features
The calculations behind every result
One shared, tested calculation library powers the free tools today. Here is exactly what it covers, grouped by test.
Concrete
- Compressive strengthASTM C39
- Average of two diameters measured at right angles, cross-sectional area, and strength from maximum load, reported to the nearest 10 psi.
- Length-to-diameter correctionASTM C39
- Interpolated correction factor for specimens with L/D of 1.75 or less. Below 1.00 the result is flagged as outside the correction range.
- Cylinder sets4 × 8 and 6 × 12 in
- Several cylinders at once, each with its own strength, plus the set average.
- ACI 318 acceptanceACI 318
- Strength-test averages, running averages of three consecutive tests, and the single-test limit for your f′c, with a plain-English explanation.
| Cyl. | D avg, in | Area, in² | L/D | Factor | Strength, psi |
|---|---|---|---|---|---|
| A | 6.010 | 28.37 | 2.00 | 1.000 | 4,230 |
| B | 6.005 | 28.32 | 2.00 | 1.000 | 4,350 |
| C | 4.000 | 12.57 | 1.50 | 0.960 | 3,820 |
Average of A and B (6 × 12 in)4,290 psi
Cylinder A: 120,000 lbf ÷ 28.37 in² = 4,230 psi
- Test 14,125 psiPass
- Test 23,650 psiPass
- Test 34,275 psiavg of 3: 4,017Pass
- Test 44,120 psiavg of 3: 4,015Pass
Single-test limit3,500 psi
OverallAccepted
Soils
- Proctor pointsASTM D698 / D1557
- Wet density from mold mass and volume, or entered directly, then dry density from moisture content.
- Curve fit, MDD and OMCLeast squares
- A 2nd-order fit for three points and 3rd-order for four or more. The peak gives maximum dry density and optimum moisture.
- Zero air voidsGs default 2.70
- ZAV line from specific gravity, with a warning when a point lands above it or the peak sits at the edge of the data.
- Sand coneASTM D1556
- Sand in the hole, hole volume, wet and dry density, and percent compaction when you supply the maximum dry density.
MDD
113.7 pcf
OMC
11.7%
Fit
3rd order
Field density
- Nuclear gauge resultsASTM D6938
- Dry density from wet density and moisture, percent compaction against MDD, and pass or fail against your required percentage.
- Moisture windowOptional
- Flag each point as dry, wet or within range of optimum moisture when the project sets a window.
- Standard count checkEditable limits
- Today's density and moisture standard counts compared with the average of the previous four, with the percent difference shown.
| Test | Wet, pcf | w, % | Dry, pcf | Comp. | Result |
|---|---|---|---|---|---|
| 1 Sta. 2+40, lift 3 | 125.0 | 10.0 | 113.6 | 96.3% | Pass |
| 2 Sta. 3+10, lift 3 | 121.4 | 11.6 | 108.8 | 92.2% | Fail |
| 3 Sta. 3+85, lift 3 | 126.3 | 10.8 | 114.0 | 96.6% | Pass |
Density std. count
0.9% Within 1%
Moisture std. count
0.1% Within 2%
Aggregates and gradation
- Sieve analysisPresets
- Fine aggregate, coarse aggregate and soil sieve sets, all editable. Percent retained, cumulative retained and percent passing.
- Fineness modulusStandard series
- Calculated automatically when the sieve set includes the sieves the definition requires.
Rounding you can defend
Full precision is stored. Results are rounded the way they are reported, and pass or fail is decided on that rounded value.