Author Contributions
Conceptualization, S.N. and M.P.; methodology, S.N. and M.P.; software, A.S.; validation, A.S., S.N., and M.P.; formal analysis, A.S.; investigation, P.M. and A.S.; resources, S.N.; data curation, A.S. and P.M.; writing—original draft preparation, S.N.; writing—review and editing, M.P.; visualization, S.N.; supervision, S.N. and M.P.; project administration, M.P.; funding acquisition, M.P. All authors have read and agreed to the published version of the manuscript.
Figure 1.
Measurements performed on a UHPFRC large plate using the magnetic probe and an LCR meter.
Figure 1.
Measurements performed on a UHPFRC large plate using the magnetic probe and an LCR meter.
Figure 2.
(a) Variation of µr,i and µr,mean with Vf and the measuring direction θi (preferential fibre orientation coincides with θi = 0°) (b) µr,mean linear increase with Vf.
Figure 2.
(a) Variation of µr,i and µr,mean with Vf and the measuring direction θi (preferential fibre orientation coincides with θi = 0°) (b) µr,mean linear increase with Vf.
Figure 3.
(
a) Linear increase of α
0,X with
(
b) Variation of α
0,iso with h
U/l
f ratio [
26].
Figure 3.
(
a) Linear increase of α
0,X with
(
b) Variation of α
0,iso with h
U/l
f ratio [
26].
Figure 4.
Specimens used in test series A (with original thickness).
Figure 4.
Specimens used in test series A (with original thickness).
Figure 5.
Successive removal of layers of the original cylinder.
Figure 5.
Successive removal of layers of the original cylinder.
Figure 6.
(a) Successive reduction of plate size; (b) Inductance measurements in the centre of the plate (original size).
Figure 6.
(a) Successive reduction of plate size; (b) Inductance measurements in the centre of the plate (original size).
Figure 7.
Casting of UHPFRC plates with moulds in (a) horizontal position; (b) vertical position.
Figure 7.
Casting of UHPFRC plates with moulds in (a) horizontal position; (b) vertical position.
Figure 8.
(a) Process of polishing the casting surface; (b) Surface after polishing.
Figure 8.
(a) Process of polishing the casting surface; (b) Surface after polishing.
Figure 9.
Final spread area of UHPFRC mixes with a fibre content of (a) 1% and (b) 4%.
Figure 9.
Final spread area of UHPFRC mixes with a fibre content of (a) 1% and (b) 4%.
Figure 10.
Variation of (a) μr and (b) with the measuring direction (specimens with hU = 100 mm).
Figure 10.
Variation of (a) μr and (b) with the measuring direction (specimens with hU = 100 mm).
Figure 11.
(a) Variation of μr,mean with hU; (b) Variation of normalised to with hU.
Figure 11.
(a) Variation of μr,mean with hU; (b) Variation of normalised to with hU.
Figure 12.
(a) Variation of μr with the measuring direction (Vf = 3%) for square specimens with varying size (plate H1); (b) Variation of μr,mean with the specimen size l (plates H1, H2 and V1).
Figure 12.
(a) Variation of μr with the measuring direction (Vf = 3%) for square specimens with varying size (plate H1); (b) Variation of μr,mean with the specimen size l (plates H1, H2 and V1).
Figure 13.
Variation of μr with the measuring direction for (a) HRM_i and (b) HOM_i specimens (moulded surface).
Figure 13.
Variation of μr with the measuring direction for (a) HRM_i and (b) HOM_i specimens (moulded surface).
Figure 14.
Variation of with the measuring direction for (a) HRM_i and (b) HOM_i specimens (moulded surface).
Figure 14.
Variation of with the measuring direction for (a) HRM_i and (b) HOM_i specimens (moulded surface).
Figure 15.
Increase of μr,mean as a function of Vf and corresponding fitting lines for (a) HR_i and (b) HO_i specimens.
Figure 15.
Increase of μr,mean as a function of Vf and corresponding fitting lines for (a) HR_i and (b) HO_i specimens.
Figure 16.
Increase of μr,mean results as a function of Vf and corresponding fitting lines for (a) VR_i specimens (b) all moulded surfaces.
Figure 16.
Increase of μr,mean results as a function of Vf and corresponding fitting lines for (a) VR_i specimens (b) all moulded surfaces.
Figure 17.
(a) Fibre distribution along the plate thickness for HR_i specimens (b) image of HR_4% along X-direction.
Figure 17.
(a) Fibre distribution along the plate thickness for HR_i specimens (b) image of HR_4% along X-direction.
Figure 18.
(a) Fibre distribution along the plate thickness (X-direction) for HO_i specimens; (b) image of HO_4% specimen along X-direction.
Figure 18.
(a) Fibre distribution along the plate thickness (X-direction) for HO_i specimens; (b) image of HO_4% specimen along X-direction.
Figure 19.
Fibre distribution along the plate thickness for VR_i specimens: (a) along X-direction, (b) along Y-direction; (c) image of VR_4% along X-direction.
Figure 19.
Fibre distribution along the plate thickness for VR_i specimens: (a) along X-direction, (b) along Y-direction; (c) image of VR_4% along X-direction.
Figure 20.
(a) Fibre distribution along the plate thickness (Y-direction) for HO_i specimens; (b) image of HO_2% along Y-direction.
Figure 20.
(a) Fibre distribution along the plate thickness (Y-direction) for HO_i specimens; (b) image of HO_2% along Y-direction.
Table 1.
Characteristics of the magnetic probe.
Table 1.
Characteristics of the magnetic probe.
U-Shape Ferrite Core | Copper Wire Coil |
---|
Reference | Relative Magnetic Permeability | Length | Cross-Section | Wire Diameter | Number of Turns |
---|
Siemens ferrite N47 | ~2000 | 189 mm | 28 × 30 mm2 | 0.5 mm | 1454 |
Table 2.
Mix-proportions of UHPFRC employed in this study (kg/m3).
Table 2.
Mix-proportions of UHPFRC employed in this study (kg/m3).
UHPFRC | Constituent Materials | Vf = 1% | Vf = 2% | Vf = 3% | Vf = 4% |
---|
Cementitious matrix | Cement | 794.9 |
Silica fume | 79.49 |
Limestone filler | 311.43 |
Water | 145.36 |
Superplasticizer | 30 |
Sp/c * | 1.51% |
Sand | 993.56 | 967.26 | 940.96 | 914.66 |
Steel fibres (straight) | lf = 9 mm/df = 0.175 mm | 39.25 | 78.5 | 117.5 | 157 |
lf = 12 mm/df = 0.175 mm | 39.25 | 78.5 | 117.5 | 157 |
Table 3.
NDT testing programme.
Table 3.
NDT testing programme.
Test Series: | A | B | C |
---|
Effect Being Evaluated: | Thickness | Area | Surface Roughness | Fibres Segregation (In-Depth) |
---|
specimen’s | cylinder | square plate | square plate |
geometry | h = 100 to 20 mm | l = 350 to 100 mm | l = 200 mm |
| ϕ = 150 mm | h = 30 mm | h = 30 mm |
total fibre content | 1% | 3% | 1% |
2% | | 2% |
3% | | 3% |
4% | | 4% |
number of specimens | 4 | 3 | 12 |
fibres orientation | random | random | random |
| | oriented * |
mould position | horizontal | horizontal | horizontal |
| vertical | vertical |
condition of the test surface | moulded | moulded | moulded surface |
| | casting surface |
| | polished surface |
Table 4.
Referencing of specimens from test series C.
Table 4.
Referencing of specimens from test series C.
Mould Position | Fibres Orientation | Condition of the Test Surface | Specimens Reference * |
---|
Horizontal | Random | Moulded surface | HRM_i | HR_i |
| | Casting surface | HRC_i | |
Smoothed surface | HRS_i |
Horizontal | Oriented | Moulded surface | HOM_i | HO_i |
| | Casting surface | HOC_i | |
| | Smoothed surface | HOS_i | |
Vertical | Random | Moulded surface A | VRMA_i | VR_i |
| | Moulded surface B | VRMB_i | |
Table 5.
Slump-flow diameter results (mm).
Table 5.
Slump-flow diameter results (mm).
Test Series | Casting Date | Reference | Vf = 1% | Vf = 2% | Vf = 3% | Vf = 4% |
---|
A | 22 May 2019 | -- | 294.5 | 295.0 | 291.5 | 263.0 |
C | 12 June 2019 | HR_i | 295.5 | 289.0 | 287.5 | 281.0 |
or | HO_i | 286.0 | 287.5 | 284.0 | 280.5 |
14 June 2019 | VR_i | 288.5 | 287.0 | 288.0 | 274.0 |
Average | 290.0 | 289.6 | 287.8 | 274.6 |
Standard deviation | 4.9 | 3.7 | 3.1 | 8.4 |
Coefficient of variation | 1.7% | 1.3% | 1.1% | 3.1% |
Table 6.
Calibrating constant and R2 of fitting lines.
Table 6.
Calibrating constant and R2 of fitting lines.
Mould Position | Fibres Orientation | Reference | kV | R2 |
---|
Horizontal | Random | HRM_i | 5.5 | 0.999 |
| HRC_i | 3.1 | 0.965 |
HRS_i | 3.5 | 0.965 |
Oriented | HOM_i | 4.2 | 0.992 |
| HOC_i | 3.4 | 0.980 |
| | HOS_i | 3.6 | 0.979 |
Vertical | Random | VRMA_i | 4.2 | 0.991 |
| | VRMB_i | 4.3 | 0.990 |
Table 7.
Total number of fibres (Nf) counted in a square area of 30 mm in size.
Table 7.
Total number of fibres (Nf) counted in a square area of 30 mm in size.
Fibre Content | HR_i | HO_i | VR_i |
---|
Vf | Along X | Along Y | Along X | Along Y | Along X | Along Y |
---|
1% | 89 | -- | 212 | -- | 217 | -- |
2% | 354 | | -- | 158 | | 152 |
3% | -- | 639 | 747 | | 713 | -- |
4% | 481 | -- | 953 | -- | | 583 |