Figure 1:
Test configurations and details of the tested beams (above) beam BS_0; (bottom) beams with SF
Table 1:
Details of beam specimens tested
| No. | Specimen designation* | Steel Fiber Type** | Vf [%] | Shear Reinforcement [Stirrups] | Average Measured fcu [MPa] |
|---|---|---|---|---|---|
| 1 | B_0 | --- | 0 | --- | 43.0 |
| 2 | BS_0 | --- | 0 | See Fig. 1 | 44.8 |
| 3 | BH_0.7 | H | 0.7 | --- | 46.0 |
| 4 | BH_1.05 | H | 1.05 | --- | 51.0 |
| 5 | BH_1.4 | H | 1.4 | --- | 50.5 |
| 6 | BC_0.7 | C | 0.7 | --- | 48.5 |
| 7 | BC_1.05 | C | 1.05 | --- | 52.0 |
| 8 | BC_1.4 | C | 1.4 | --- | 50.0 |
| 9 | BM_0.7 | M | 0.7 | --- | 46.5 |
| 10 | BM_1.05 | M | 1.05 | --- | 49.0 |
| 11 | BM_1.4 | M | 1.4 | --- | 48.0 |
Table 2:
Properties of the Materials Used
| Material | Property | Value | |
|---|---|---|---|
| Steel | Yield strength [MPa] | 520 | |
| Ultimate strength [MPa] | 690 | ||
| Elongation [%] | 12 | ||
| Conplast SP2000 | 1.22 at 25°C | Specific gravity | |
| Brown liquid | Appearance | ||
| Steel Fibers | Type | Hooked-ends | Crimped |
| Length [mm] | 50 | 50 | |
| Diameter [mm] | 1 | 1 | |
| Aspect Ratio | 50 | 50 | |
| Tensile Strength [MPa] | 1000 | 1100 | |
Figure 2:
Reinforcement cages and beams formwork
Table 3:
Concrete Mix Proportions
| Proportion by Weight [Kg/m3] | ||||||
|---|---|---|---|---|---|---|
| Mix Type | Cement | Fine Aggregate | Coarse Aggregate | Water | Steel Fiber (SF) | Conplast SP2000 |
| Mix without SF | 400 | 775 | 1030 | 176 | 0 | 5.2 |
| Mix with SF | 400 | 775 | 1030 | 176 | 49, 73.5 or 98 | 5.2 |
Figure 3:
Types of the steel fibers used and casting of specimens
Table 4:
Experimental Results of the Tested Beams
| No. | Specimen | Pu [kN] | Pu [%] Compared to B_0 | Pu [%] Compared to BS_0 | Max Deflection [mm] | Mode of Failure |
|---|---|---|---|---|---|---|
| 1 | B_0 | 76.0 | 100 | −33 | 4.2 | Shear failure |
| 2 | BS_0 | 114.0 | 150 | 100 | 6.86 | Shear failure |
| 3 | BH_0.7 | 126.0 | 165 | 110.5 | 7.92 | Shear failure |
| 4 | BH_1.05 | 143.2 | 188 | 125.4 | 13.68 | Shear-Flexure failure |
| 5 | BH_1.4 | 151.0 | 199 | 132.4 | 11.7 | Flexure failure |
| 6 | BC_0.7 | 119.6 | 157 | 105 | 9.88 | Shear failure |
| 7 | BC_1.05 | 134.0 | 176 | 117.5 | 10.58 | Shear-Flexure failure |
| 8 | BC_1.4 | 142.0 | 187 | 124.5 | 11.46 | Flexure failure |
| 9 | BM_0.7 | 152.0 | 200 | 133.3 | 15.65 | Shear-Flexure failure |
| 10 | BM_1.05 | 160.0 | 211 | 140.3 | 18.36 | Flexure failure |
| 11 | BM_1.4 | 155.0 | 204 | 136 | 15.02 | Flexure failure |
Figure 4:
Load - Midspan deflection for beams reinforced with hooked-ends steel fibers
Figure 5:
Load - Midspan deflection for beams reinforced with crimped steel fibers
Figure 6:
Load - Midspan deflection for beams reinforced with mixed steel fibers
Figure 7:
Load - Midspan deflection for beams reinforced with 0.7% steel fibers
Figure 8:
Load - Midspan deflection for beams reinforced with 1.05% steel fibers
Figure 9:
Load - Midspan deflection for beams reinforced with 1.4% steel fibers
Figure 10:
Effect of volume fraction of steel fiber on shear strength
Figure 11:
Modes of failures and cracks patterns of some tested beams