FIGURE 1.
FIGURE 2.
FIGURE 3.
FIGURE 4.
FIGURE 5.
FIGURE 6.
FIGURE 7.
FIGURE 8.
Physical properties of crumb rubber
| Property | Value |
|---|---|
| Methylene blue value [g⸱l−1] | 0.67 |
| Relative compaction [%] | 68.81 |
| Porosity [%] | 31.19 |
| Absolute density [g⸱cm−3] | 0.533 |
| Apparent density [g⸱cm−3] | 0.367 |
Composition of dune sand concrete with crumb rubber (SCCR) [kg⸱m−3]
| Composition | Concrete variant | |||||
|---|---|---|---|---|---|---|
| SCCR 0% | SCCR 1% | SCC 2% | SCCR 3% | SCCR 4% | SCCR 5% | |
| Cement | 350.00 | 350.00 | 350.00 | 350.00 | 350.00 | 350.00 |
| Medaflow SR20 | 5.25 | 5.25 | 5.25 | 5.25 | 5.25 | 5.25 |
| Dune sand | 1,541.70 | 1,526.28 | 1,510.86 | 1,495.44 | 1,480.02 | 1,464.60 |
| Crumb rubber | 0 | 15.42 | 30.84 | 46.26 | 61.68 | 77.01 |
| Water | 241.50 | 241.50 | 241.50 | 241.50 | 241.50 | 241.50 |
Physical characteristics of natural sand (NS) and dune sand (DS)
| Physical characteristics | NS | DS | Gravel (3/8) | Gravel (8/15) |
|---|---|---|---|---|
| Fineness modulus | 3.08 | 1.04 | – | – |
| Visual sand equivalent [%] | 89.49 | 91.52 | – | – |
| Methylene blue value [g⸱l−1] | 0.63 | 0.50 | – | – |
| Friability [%] | 39.20 | 21.00 | – | – |
| Apparent density [g⸱cm−3] | 1,452.00 | 1,870.00 | 1.31 | 1.42 |
| Absolute density [g⸱cm−3] | 2.50 | 2.56 | 2.50 | 2.50 |
| Porosity [%] | 43.37 | 27.07 | 47.60 | 43.36 |
| Compactness [%] | 56.63 | 72.93 | 52.40 | 56.64 |
| Los-Angeles degradation of wear [%] | – | – | 34.89 | 21.73 |
| Micro-Deval coefficient [%] | – | – | 38.40 | 18.20 |
| Flattening coefficient [%] | – | – | 26.00 | 8.58 |
Composition of ordinary concrete with crumb rubber (OCCR) [kg⸱m−3]
| Composition | Concrete variant | |||||
|---|---|---|---|---|---|---|
| OCCR 0% | OCCR 1% | OCCR 2% | OCCR 3% | OCCR 4% | OCCR 5% | |
| Cement | 350.00 | 350.00 | 350.00 | 350.00 | 350.00 | 350.00 |
| Medaflow SR20 | 5.25 | 5.25 | 5.25 | 5.25 | 5.25 | 5.25 |
| Natural sand | 535.04 | 529.69 | 524.34 | 518.98 | 513.64 | 508.29 |
| Crumb rubber | 0 | 5.35 | 10.70 | 16.05 | 21.40 | 26.75 |
| Gravel (3/8) | 164.00 | 164.00 | 164.00 | 164.00 | 164.00 | 164.00 |
| Gravel (8/15) | 1,086.50 | 1,086.50 | 1,086.50 | 1,086.50 | 1,086.50 | 1,086.50 |
| Water | 180.45 | 180.45 | 180.45 | 180.45 | 180.45 | 180.45 |
Chemical composition of cement
| Constituent | CaO | SiO2 | Al2O3 | Fe2O3 | SO3 | K2O | Na2O | MgO | CaO free |
|---|---|---|---|---|---|---|---|---|---|
| % | 65 | 20.71 | 4 | 7 | 2.72 | 0.41 | 0.13 | 1 | 1.20 |
Comparison between the different parameters studied
| CR | Apparent density [kg⸱m−3] | Compressive strength [MPa] | Flexural strength [MPa] | |||
|---|---|---|---|---|---|---|
| OCCR | SCCR | OCCR | SCCR | OCCR | SCCR | |
| 0 | 2,453 | 2,190 | 42.50 | 22.60 | 4.97 | 1.56 |
| 1 | 2,443 | 1,415 | 38.70 | 16.00 | 4.22 | 1.11 |
| 2 | 2,438 | 1,340 | 34.54 | 13.20 | 3.38 | 1.00 |
| 3 | 2,432 | 1,280 | 27.00 | 10.00 | 2.98 | 0.92 |
| 4 | 2,425 | 1,205 | 19.50 | 8.15 | 1.77 | 0.85 |
| 5 | 2,419 | 1,180 | 15.80 | 7.65 | 1.56 | 0.80 |