Figure 1.
Side view and cross-section of tested beams
Table 1.
Dimensions, material grades and longitudinal reinforcement of tested beams
| Type of beam | |||||
|---|---|---|---|---|---|
| T70 | R70 | T90 | T140 | ||
| Total length L [m] | 11.96 | 14.36 | 19.00 | 24.67 | |
| Heigh (at midspan) h [m] | 0.70 | 0.70 | 0.90 | 1.40 | |
| Concrete grade (prefabricated girder) | C40/50 | C40/50 | C50/60 | C50/60 | |
| Dramix fibre volume [kg/m3] | 20 | 20 | 30 | 20 | |
| Longitudnial reinforcement | Bottom | 2φ16 + 2×3Fp93-1860 | 3×4Fp93-1860 | 6×2Fp93-1860 | 4×4Fp93-1860 |
| Top | 2φ16 + 2×Fp52-1860 | 4×Fp52-1860 | 4×Fp52-1860 | 2×Fp52-1860 | |
| Design load pd [kN/m] | 25.34 | 38.28 | 18.9 | 32.92 | |
Figure 2.
Shear loading arrangement of beam T90 and picture of the T90 beam on the test stand
Figure 3.
Measured and numerically calculated shear force – displacement diagrams
Table 2.
Values of centric tensile strength in case of the tested beams
| Beam type | Concrete grade | Fibre volume fraction [kg/m3] | Performance class (L2) [N/mm2] | Centric tensile strengh [N/mm2] | |
|---|---|---|---|---|---|
| C25/30 | Actual concrete | ||||
| T70 | C40/50 | 20 | 0.488 | 0.631 | 0.233 |
| R70 | C40/50 | 20 | 0.488 | 0.631 | 0.233 |
| T90 | C50/60 | 30 | 1.007 | 1.564 | 0.579 |
| T140 | C50/60 | 20 | 0.488 | 0.736 | 0.272 |
Figure 4.
Shear strength utilization of beam T70 in case of different fibre contents
Figure 5.
Shear force – deflection and shear crack width diagrams of beam T90 in case of different fibre volumes