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Influence of elevated temperature on the engineering properties of ultra-high-performance fiber-reinforced concrete


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Fig. 1.

Fibers: (A) hooked-steel fibers; (B) polyvinyl alcohol fibers (C) polypropylene fibers
Fibers: (A) hooked-steel fibers; (B) polyvinyl alcohol fibers (C) polypropylene fibers

Fig. 2.

Individual time-temperature plots
Individual time-temperature plots

Fig. 3.

Specimen under testing
Specimen under testing

Fig. 4.

Prism specimen in flexure test
Prism specimen in flexure test

Fig. 5.

All samples after heating-cooling cycle
All samples after heating-cooling cycle

Fig. 6.

Destroyed concrete specimen from 500°C exposure
Destroyed concrete specimen from 500°C exposure

Fig. 7.

Representative samples after compression testing: (A) 100°C; (B) 300°C (C) 400°C
Representative samples after compression testing: (A) 100°C; (B) 300°C (C) 400°C

Fig. 8.

Stress-strain relations for UHPFRC cylinders at ambient temperature
Stress-strain relations for UHPFRC cylinders at ambient temperature

Fig. 9.

Stress-strain relations for UHPFRC cylinders at 300°C
Stress-strain relations for UHPFRC cylinders at 300°C

Fig. 10.

Stress-strain relations for UHPFRC cylinders at 400°C
Stress-strain relations for UHPFRC cylinders at 400°C

Fig. 11.

Load-deflection relations for UHPC and UH-PFRC beams (room temp. 26°C)
Load-deflection relations for UHPC and UH-PFRC beams (room temp. 26°C)

Fig. 12.

Load-deflection relations for UHPC and UH-PFRC beams (300°C)
Load-deflection relations for UHPC and UH-PFRC beams (300°C)

Fig. 13.

Load-deflection relations for UHPC and UH-PFRC beams (400°C)
Load-deflection relations for UHPC and UH-PFRC beams (400°C)

Fig. 14.

Mode of failure of some representative concrete prisms
Mode of failure of some representative concrete prisms

Fig. 15.

Temperature effects on UHPC and UHPFRC normalized compressive strength
Temperature effects on UHPC and UHPFRC normalized compressive strength

Fig. 17.

Temperature effects on the normalized splitting tensile strength of UHPC and UHPFRC
Temperature effects on the normalized splitting tensile strength of UHPC and UHPFRC

Fig. 16.

Temperature effects on the normalized flexural strength of UHPC and UHPFRC
Temperature effects on the normalized flexural strength of UHPC and UHPFRC

Fig. 18.

Effect of temperature on weight loss for UHPC and UHFRC specimens
Effect of temperature on weight loss for UHPC and UHFRC specimens

Fig. 19.

Secondary electron SEM images of concrete exposed to room temperature (a) mix M0-NF, (b) M1-S1, and (c) M3-S0.5+PVA0.5
Secondary electron SEM images of concrete exposed to room temperature (a) mix M0-NF, (b) M1-S1, and (c) M3-S0.5+PVA0.5

Fig. 20.

Secondary electron SEM images of concrete containing steel fibers (i.e., M1-S1) after exposure to 400°C
Secondary electron SEM images of concrete containing steel fibers (i.e., M1-S1) after exposure to 400°C

Fig. 21.

Secondary electron SEM images of concrete containing PVA fibers (i.e., M3-S0.7-PVA0.2-PP0.1) after exposure to 400°C
Secondary electron SEM images of concrete containing PVA fibers (i.e., M3-S0.7-PVA0.2-PP0.1) after exposure to 400°C

Properties of fibers

Fiber type Fiber properties
Shape Length (mm) Section dimension (mm) Specific gravity Modulus of elasticity (GPa) Tensile strength (MPa)
Steel fibers Hooked ends 35 φ 0.55 (Circular) 7.85 210 1225
Polyvinyl alcohol (PVA) straight 30 φ 0.66 (Circular) 1.3 23 900
Polypropylene (PP) straight 12 φ 0.022 (Circular) 0.90 4 550

UHPC mixture proportions for 1 m3

Material Weight (kg/m3)
Cement 900.0
Fine quartz sand 1000.0
Silica Fume 222.0
Water 164.0
Super-plasticizer 30

Fresh UHPC properties

Mix No. Unit Weight (kg/m3) Slump (mm)
M0-NF 2318 280.0
M1-S1 2363 257.0
M2-S0.7-PVA0.3 2325 256.0
M3-S0.7-PVA0.2-PP0.1 2294 250.0
M4-S0.7-PVA0.2 2310 255.0
M5-S0.5-PVA0.5 2285 251.0

Details of test matrix

Mix Compression and split Test Flexure Test
Room temp. 100°C 300°C 400°C Room temp. 100°C 300°C 400°C
M0-NF 6 6 6 6 3 3 3 3
M1-S1 6 6 6 6 3 3 3 3
M2-S0.7-PVA0.3 6 6 6 6 3 3 3 3
M3-S0.7-PVA0.2-PP0.1 6 6 6 6 3 3 3 3
M4-S0.7-PVA0.2 6 6 6 6 3 3 3 3
M5-S0.5-PVA0.5 6 6 6 6 3 3 3 3

Summary of test results of different concrete mixes

Mix Compressive strength (MPa) Flexure strength (MPa) Splitting strength (MPa)
Room temp. 100°C 300°C 400°C Room temp. 100°C 300°C 400°C Room temp. 100°C 300°C 400°C
M0-NF 120.3 124.1(+3%) 105.6(–12.5%) 88.32(–26.6%) 10.27 10.47 8.77(–15.1%) 7.50(–27.0%) 6.6 6.8(+3%) 5.7(–13.6%) 4.80(–27.3%)
M1-S1 139.8(16.2%) 143.8(+2.9%) 132.0(–5.5%) 104.68(–25.12%) 19.50(89.9%) 19.75 17.83(–9.0%) 16.20(–17.0%) 11.7(77.3%) 11.9(+3%) 10.8(–7.7%) 10.20(–12.8%)
M2-S0.7-PVA0.3 134.6(11.8%) 139.4(+3.6%) 123.4(–8.5%) 110.19(–18.2%) 19.00(85%) 19.53 17.24(–9.0%) 15.10(–20.5%) 12.3(86.4%) 12.7(+3%) 11.9(–3.3%) 10.70(–13%)
M3-S0.7-PVA0.2-PP0.1 131.7(9.5%) 133.7(+1%) 129.7(–1.0%) 102.62(–21.5%) 17.03(65.8%) 17.64 16.00(–6.0%) 15.20(–10.7%) 12.1(83.3%) 12.4(+3%) 11.4(–5.8%) 10.40(–14%)
M4-S0.7-PVA0.2 128.2(6.8%) 130.3(+1%) 124.0(–3.3%) 99.70(–22.3%) 17.77(73%) 17.85 17.01(–4.0%) 14.20(–20.0%) 11.7(77.3%) 11.8(+3%) 10.9(–6.8%) 9.50(–18.8%)
M5-S0.5-PVA0.5 127.8(6.5%) 131.8(+3.2%) 119.6(–6.4%) 97.4(–23.7%) 16.90(64.5%) 17.0 15.85(–6.0%) 12.90(–25.0%) 11.3(74.2%) 11.8(+3%) 10.8(–6.1%) 8.90(–22.6%)

Cement and silica fume properties

Type 1 Cement Silica Fume
Chemical composition (%) CaO 64.1 2.15
SiO2 21.8 89.5
AL2O3 5.25 0.43
Fe2O3 4.10 3.25
MgO 0.71 1.30
TiO2 0.3 0.0
SO3 2.4 0.74
Physical properties L.O.I 2.18 2.47
Mean particle size (μm) 40.1 0.32
Specific gravity 3.15 2.2

Percentage of fibers in concrete mixes

Concrete mix Fiber by volume (%)
Polyvinyl alcohol (PVA) Polypropylene (PP) Steel fibers (SF)
M0-NF 0.0 0.0 0.0
M1-S1 0.0 0.0 1.0
M2-S0.7-PVA0.3 0.3 0.0 0.7
M3-S0.7-PVA0.2-PP0.1 0.2 0.1 0.7
M4-S0.7-PVA0.2 0.2 0.0 0.7
M5-S0.5-PVA0.5 0.5 0.0 0.5
eISSN:
2083-134X
Język:
Angielski
Częstotliwość wydawania:
4 razy w roku
Dziedziny czasopisma:
Materials Sciences, other, Nanomaterials, Functional and Smart Materials, Materials Characterization and Properties