Summary
This experiment investigates concrete admixture blend optimization. Mixture simplex lattice design for supplementary cementitious material proportions.
The design varies 3 factors: fly ash (%), ranging from 0 to 100, silica fume (%), ranging from 0 to 100, and slag (%), ranging from 0 to 100. The goal is to optimize 2 responses: compressive strength 28d (MPa) (maximize) and workability (mm_slump) (maximize). Fixed conditions held constant across all runs include cement base = 350 kg/m3, water cement ratio = 0.45.
The Simplex-Lattice Mixture Design produces 6 experimental runs.
Key Findings
For compressive strength 28d, the most influential factors were silica fume (55.5%), fly ash (24.8%), slag (19.7%). The best observed value was 51.4 (at fly ash = 50, silica fume = 0, slag = 50).
For workability, the most influential factors were silica fume (50.5%), fly ash (31.5%), slag (18.0%). The best observed value was 156.2 (at fly ash = 0, silica fume = 100, slag = 0).
Recommended Next Steps
- Consider whether any fixed factors should be varied in a future study.
Experimental Setup
Factors
| Factor | Low | High | Unit |
fly_ash | 0 | 100 | % |
silica_fume | 0 | 100 | % |
slag | 0 | 100 | % |
Fixed: cement_base = 350 kg/m3, water_cement_ratio = 0.45
Responses
| Response | Direction | Unit |
compressive_strength_28d | ↑ maximize | MPa |
workability | ↑ maximize | mm_slump |
Configuration
{
"metadata": {
"name": "Concrete Admixture Blend Optimization",
"description": "Mixture simplex lattice design for supplementary cementitious material proportions"
},
"factors": [
{
"name": "fly_ash",
"levels": [
"0",
"100"
],
"type": "continuous",
"unit": "%"
},
{
"name": "silica_fume",
"levels": [
"0",
"100"
],
"type": "continuous",
"unit": "%"
},
{
"name": "slag",
"levels": [
"0",
"100"
],
"type": "continuous",
"unit": "%"
}
],
"fixed_factors": {
"cement_base": "350 kg/m3",
"water_cement_ratio": "0.45"
},
"responses": [
{
"name": "compressive_strength_28d",
"optimize": "maximize",
"unit": "MPa"
},
{
"name": "workability",
"optimize": "maximize",
"unit": "mm_slump"
}
],
"settings": {
"operation": "mixture_simplex_lattice",
"test_script": "use_cases/304_concrete_admixture_blend/sim.sh"
}
}
Experimental Matrix
The Simplex-Lattice Mixture Design produces 6 runs. Each row is one experiment with specific factor settings.
| Run | fly_ash | silica_fume | slag |
| 1 | 0 | 100 | 0 |
| 2 | 50 | 50 | 0 |
| 3 | 50 | 0 | 50 |
| 4 | 0 | 50 | 50 |
| 5 | 100 | 0 | 0 |
| 6 | 0 | 0 | 100 |
Step-by-Step Workflow
1
Preview the design
$ doe info --config use_cases/304_concrete_admixture_blend/config.json
2
Generate the runner script
$ doe generate --config use_cases/304_concrete_admixture_blend/config.json \
--output use_cases/304_concrete_admixture_blend/results/run.sh --seed 42
3
Execute the experiments
$ bash use_cases/304_concrete_admixture_blend/results/run.sh
4
Analyze results
$ doe analyze --config use_cases/304_concrete_admixture_blend/config.json
5
Get optimization recommendations
$ doe optimize --config use_cases/304_concrete_admixture_blend/config.json
6
Multi-objective optimization
With 2 competing responses, use --multi to find the best compromise via Derringer–Suich desirability.
$ doe optimize --config use_cases/304_concrete_admixture_blend/config.json --multi
7
Generate the HTML report
$ doe report --config use_cases/304_concrete_admixture_blend/config.json \
--output use_cases/304_concrete_admixture_blend/results/report.html
Features Exercised
| Feature | Value |
| Design type | mixture_simplex_lattice |
| Factor types | continuous (all 3) |
| Arg style | double-dash |
| Responses | 2 (compressive_strength_28d ↑, workability ↑) |
| Total runs | 6 |
Analysis Results
Generated from actual experiment runs using the DOE Helper Tool.
Response: compressive_strength_28d
Top factors: silica_fume (55.5%), fly_ash (24.8%), slag (19.7%).
ANOVA
| Source | DF | SS | MS | F | p-value |
| Source | DF | SS | MS | F | p-value |
| fly_ash | 2 | 16.7417 | 8.3708 | | |
| silica_fume | 2 | 120.7017 | 60.3508 | | |
| slag | 2 | 17.7417 | 8.8708 | | |
| Error | (Lenth | PSE) | 0 | 0.0000 | 0.0000 |
| Total | 5 | 148.4883 | 29.6977 | | |
Response: workability
Top factors: silica_fume (50.5%), fly_ash (31.5%), slag (18.0%).
ANOVA
| Source | DF | SS | MS | F | p-value |
| Source | DF | SS | MS | F | p-value |
| fly_ash | 2 | 1081.6433 | 540.8217 | | |
| silica_fume | 2 | 4530.8483 | 2265.4242 | | |
| slag | 2 | 642.2833 | 321.1417 | | |
| Error | (Lenth | PSE) | 0 | 0.0000 | 0.0000 |
| Total | 5 | 5482.5750 | 1096.5150 | | |
Multi-Objective Optimization
When responses compete, Derringer–Suich desirability finds the best compromise.
Each response is scaled to a 0–1 desirability, then combined via a weighted geometric mean.
Overall Desirability
D = 0.9338
Per-Response Desirability
| Response | Weight | Desirability | Predicted | Dir |
compressive_strength_28d |
2.0 |
|
67.08 1.0000 67.08 MPa |
↑ |
workability |
1.0 |
|
172.13 0.8142 172.13 mm_slump |
↑ |
Recommended Settings
| Factor | Value |
fly_ash | 0 % |
silica_fume | 0 % |
slag | 0 % |
Source: from RSM model prediction
Trade-off Summary
Sacrifice = how much worse than single-objective best.
| Response | Predicted | Best Observed | Sacrifice |
workability | 172.13 | 156.20 | -15.93 |
Top 3 Runs by Desirability
| Run | D | Factor Settings |
| #3 | 0.5254 | fly_ash=0, silica_fume=50, slag=50 |
| #6 | 0.5098 | fly_ash=50, silica_fume=50, slag=0 |
Model Quality
| Response | R² | Type |
workability | 0.1187 | linear |
Full Multi-Objective Output
============================================================
MULTI-OBJECTIVE OPTIMIZATION
Method: Derringer-Suich Desirability Function
============================================================
Overall desirability: D = 0.9338
Response Weight Desirability Predicted Direction
---------------------------------------------------------------------
compressive_strength_28d 2.0 1.0000 67.08 MPa ↑
workability 1.0 0.8142 172.13 mm_slump ↑
Recommended settings:
fly_ash = 0 %
silica_fume = 0 %
slag = 0 %
(from RSM model prediction)
Trade-off summary:
compressive_strength_28d: 67.08 (best observed: 51.40, sacrifice: -15.68)
workability: 172.13 (best observed: 156.20, sacrifice: -15.93)
Model quality:
compressive_strength_28d: R² = 0.0253 (linear)
workability: R² = 0.1187 (linear)
Top 3 observed runs by overall desirability:
1. Run #4 (D=0.5283): fly_ash=0, silica_fume=0, slag=100
2. Run #3 (D=0.5254): fly_ash=0, silica_fume=50, slag=50
3. Run #6 (D=0.5098): fly_ash=50, silica_fume=50, slag=0
Full Analysis Output
=== Main Effects: compressive_strength_28d ===
Factor Effect Std Error % Contribution
--------------------------------------------------------------
silica_fume 9.9333 2.2248 55.5%
fly_ash 4.4333 2.2248 24.8%
slag 3.5333 2.2248 19.7%
=== ANOVA Table: compressive_strength_28d ===
Source DF SS MS F p-value
-----------------------------------------------------------------------------
fly_ash 2 16.7417 8.3708
silica_fume 2 120.7017 60.3508
slag 2 17.7417 8.8708
Error (Lenth PSE) 0 0.0000 0.0000
Total 5 148.4883 29.6977
Note: Error estimated using Lenth's pseudo-standard-error (unreplicated design)
=== Summary Statistics: compressive_strength_28d ===
fly_ash:
Level N Mean Std Min Max
------------------------------------------------------------
0 3 46.2333 3.1021 43.2000 49.4000
100 1 41.8000 0.0000 41.8000 41.8000
50 2 43.9000 10.6066 36.4000 51.4000
silica_fume:
Level N Mean Std Min Max
------------------------------------------------------------
0 3 40.4667 3.5907 36.4000 43.2000
100 1 46.1000 0.0000 46.1000 46.1000
50 2 50.4000 1.4142 49.4000 51.4000
slag:
Level N Mean Std Min Max
------------------------------------------------------------
0 3 46.4333 4.8087 41.8000 51.4000
100 1 43.2000 0.0000 43.2000 43.2000
50 2 42.9000 9.1924 36.4000 49.4000
=== Main Effects: workability ===
Factor Effect Std Error % Contribution
--------------------------------------------------------------
silica_fume 60.0667 13.5186 50.5%
fly_ash 37.4667 13.5186 31.5%
slag 21.4167 13.5186 18.0%
=== ANOVA Table: workability ===
Source DF SS MS F p-value
-----------------------------------------------------------------------------
fly_ash 2 1081.6433 540.8217
silica_fume 2 4530.8483 2265.4242
slag 2 642.2833 321.1417
Error (Lenth PSE) 0 0.0000 0.0000
Total 5 5482.5750 1096.5150
Note: Error estimated using Lenth's pseudo-standard-error (unreplicated design)
=== Summary Statistics: workability ===
fly_ash:
Level N Mean Std Min Max
------------------------------------------------------------
0 3 106.9333 14.6889 95.5000 123.5000
100 1 144.4000 0.0000 144.4000 144.4000
50 2 111.6500 63.0032 67.1000 156.2000
silica_fume:
Level N Mean Std Min Max
------------------------------------------------------------
0 3 141.3667 16.5597 123.5000 156.2000
100 1 101.8000 0.0000 101.8000 101.8000
50 2 81.3000 20.0818 67.1000 95.5000
slag:
Level N Mean Std Min Max
------------------------------------------------------------
0 3 104.4333 38.7172 67.1000 144.4000
100 1 123.5000 0.0000 123.5000 123.5000
50 2 125.8500 42.9214 95.5000 156.2000
Optimization Recommendations
=== Optimization: compressive_strength_28d ===
Direction: maximize
Best observed run: #1
fly_ash = 50
silica_fume = 0
slag = 50
Value: 51.4
RSM Model (linear, R² = 0.7886, Adj R² = 0.4715):
Coefficients:
intercept +33.5375
fly_ash -11.3125
silica_fume -14.5325
slag -7.6925
Predicted optimum (from linear model, at observed points):
fly_ash = 0
silica_fume = 0
slag = 100
Predicted value: 51.6900
Surface optimum (via L-BFGS-B, linear model):
fly_ash = 0
silica_fume = 0
slag = 0
Predicted value: 67.0750
Model quality: Good fit — general trends are captured, some noise remains.
Factor importance:
1. silica_fume (effect: 11.1, contribution: 43.5%)
2. slag (effect: 8.9, contribution: 34.9%)
3. fly_ash (effect: 5.5, contribution: 21.5%)
=== Optimization: workability ===
Direction: maximize
Best observed run: #5
fly_ash = 0
silica_fume = 100
slag = 0
Value: 156.2
RSM Model (linear, R² = 0.5994, Adj R² = -0.0016):
Coefficients:
intercept +86.0625
fly_ash -24.6075
silica_fume -12.9475
slag -48.5075
Predicted optimum (from linear model, at observed points):
fly_ash = 0
silica_fume = 100
slag = 0
Predicted value: 146.2300
Surface optimum (via L-BFGS-B, linear model):
fly_ash = 0
silica_fume = 0
slag = 0
Predicted value: 172.1250
Model quality: Moderate fit — use predictions directionally, not precisely.
Factor importance:
1. slag (effect: 56.9, contribution: 35.6%)
2. silica_fume (effect: 53.9, contribution: 33.7%)
3. fly_ash (effect: 49.1, contribution: 30.7%)