Fig 1.
Four kinds of fiber composites:(a) CFRP, (b) GFRP, (c) BFRP, (d) AFRP.
Fig 2.
Epoxy resin glue.
Table 1.
Properties of fiber composites and epoxy resin adhesives.
Fig 3.
Epoxy resin: (a) Epoxy resin specimen, (b)Specimen size diagram (unit: mm).
Fig 4.
Fiber composite material specimen: (a) Fiber composite specimen, (b) FRP sheet size (unit: mm).
Fig 5.
Fiber cloth reinforced concrete compression specimen: (a) CFRP, (b) BFRP, (c) GFRP, (d) AFRP.
Fig 6.
FRP reinforced bending specimen:(a) Unreinforced bending specimen, (b) Slotted bending specimen, (c) CFRP reinforced bending specimen, (d) BFRP reinforced bending specimen, (e) GFRP reinforced bending specimen, (f) AFRP reinforced bending specimen.
Fig 7.
Chemistry-freeze-thaw cycle coupled immersion environment.
Fig 8.
Specimen microscopic observation: (a) Epoxy resin, (b) FRP sheet, (c) FRP reinforced concrete, (d) FRP reinforced concrete cross section resin.
Table 2.
Numbers of epoxy resin and fiber sheets.
Fig 9.
Tensile mechanical test.
Table 3.
Summary of the number of acid-freeze-thaw coupled erosion specimens.
Fig 10.
Mechanical test device.
Fig 11.
Bending specimen size and strain gauge layout (unit: mm).
Fig 12.
Microscopic imaging of epoxy resin: (a) acid-freeze cycle erosion, (b) alkali-freeze cycle erosion, (c) salt-freeze cycle erosion.
Fig 13.
Microscopic imaging of acid-frost erosion FRP sheets: (a) CFRP, (b) BFRP, (c) GFRP, (d) AFRP.
Fig 14.
Microscopic imaging of alkali-freeze erosion FRP sheets: (a) CFRP, (b) BFRP, (c) GFRP, (d) AFRP.
Fig 15.
Microscopic imaging of salt-freeze erosion FRP sheets: (a) CFRP, (b) BFRP, (c) GFRP, (d) AFRP.
Fig 16.
Microstructure of cross section of unreinforced specimen(a) Under 50 cycles of acid freeze-thaw erosion conditions, (b) Under 100 cycles of acid freeze-thaw erosion conditions.
Fig 17.
Microstructure of FRP reinforced specimens: (a) CFRP reinforced specimens subjected to 50 cycles of acid freeze cycles, (b) CFRP specimens subjected to 100 cycles of acid freeze cycles; (c) BFRP specimens subjected to 50 cycles of acid freeze cycles, (d) BFRP specimens subjected to 100 cycles of acid freeze cycles, (e) GFRP specimens subjected to 50 cycles of acid freeze cycles, (f) GFRP specimens subjected to 100 cycles of acid freeze cycles, (g) AFRP specimens subjected to 50 cycles of acid freeze cycles, (h) AFRP specimens subjected to 100 cycles of acid freeze cycles.
Fig 18.
Microstructure of cross section of unreinforced specimen:(a) Under 50 cycles of alkaline freeze-thaw erosion conditions, (b) Under 100 cycles of alkaline freeze-thaw erosion conditions.
Fig 19.
Microstructure of the FRP reinforced specimen: (a) CFRP reinforced specimens subjected to 50 cycles of alkali freeze cycles, (b) CFRP specimens subjected to 100 cycles of alkali freeze cycles; (c) BFRP specimens subjected to 50 cycles of alkali freeze cycles, (d) BFRP specimens subjected to 100 cycles of alkali freeze cycles, (e) GFRP specimens subjected to 50 cycles of alkali freeze cycles, (f) GFRP specimens subjected to 100 cycles of alkali freeze cycles, (g) AFRP specimens subjected to 50 cycles of alkali freeze cycles, (h) AFRP specimens subjected to 100 cycles of alkali freeze cycles.
Fig 20.
Microstructure of cross section of unreinforced specimen.
Fig 21.
Microstructure of the FRP reinforced specimen: (a) CFRP reinforced specimens subjected to 50 cycles of salt freeze cycles, (b) CFRP specimens subjected to 100 cycles of salt freeze cycles; (c) BFRP specimens subjected to 50 cycles of salt freeze cycles, (d) BFRP specimens subjected to 100 cycles of salt freeze cycles, (e) GFRP specimens subjected to 50 cycles of salt freeze cycles, (f) GFRP specimens subjected to 100 cycles of salt freeze cycles, (g) AFRP specimens subjected to 50 cycles of salt freeze cycles, (h) AFRP specimens subjected to 100 cycles of salt freeze cycles.
Fig 22.
Damage pattern of epoxy resin:(a) EPN-F0, (b) EPAC-F100, (c)EPAL-F100, (d) EPSA-F100.
Fig 23.
Damage patterns of FRP sheets under acid-freeze coupling erosion.
Fig 24.
Damage patterns of FRP sheets under alkali-freeze coupling erosion.
Fig 25.
Damage patterns of FRP sheets under salt-freeze coupling erosion.
Fig 26.
Compressive failure modes of FRP reinforced specimens and unreinforced specimens: (a) Under acid freezing coupled erosion conditions, (b) Under alkaline freezing coupled erosion conditions, (c) Under salt freezing coupled erosion conditions.
Fig 27.
Failure modes of prismatic specimen under acid-freeze coupling erosion: (a) Failure modes of Carbon fiber reinforced prismatic specimen; (b) Failure modes of basalt fiber reinforced prismatic specimen; (c) Failure modes of glass fiber reinforced prismatic specimen; (d) Failure modes of aramid fiber reinforced prismatic specimen.
Fig 28.
Flexural failure patterns of FRP reinforced specimens and unreinforced specimens under alkali-freeze coupling erosion (a) Failure modes of Carbon fiber reinforced prismatic specimen; (b) Failure modes of basalt fiber reinforced prismatic specimen; (c) Failure modes of glass fiber reinforced prismatic specimen; (d) Failure modes of aramid fiber reinforced prismatic specimen.
Fig 29.
Flexural failure patterns of FRP reinforced specimens and unreinforced specimens under salt-freeze coupling erosion (a) Failure modes of Carbon fiber reinforced prismatic specimen; (b) Failure modes of basalt fiber reinforced prismatic specimen; (c) Failure modes of glass fiber reinforced prismatic specimen; (d) Failure modes of aramid fiber reinforced prismatic specimen.
Fig 30.
Stress-strain curve of fiber sheet in coupled acid-freeze-thaw cycle environment: (a) epoxy resin, (b) CFRP sheet, (c)BFRP sheet, (d) AFRP sheet, (e) GFRP sheet.
Fig 31.
Stress-strain curve of sheet under alkali-freeze-thaw cyclic coupling environment: (a) epoxy resin, (b) CFRP sheet, (c)BFRP sheet, (d) AFRP sheet, (e) GFRP sheet.
Fig 32.
Stress-strain curves of epoxy resin and FRP sheet in coupled salt-freeze-thaw cycle environment: (a) epoxy resin, (b) CFRP sheet, (c)BFRP sheet, (d) AFRP sheet, (e) GFRP sheet.
Fig 33.
Compressive strength and strength loss rate of cylindrical specimens under different freeze-thaw cycles:(a) acid-freeze cycle erosion, (b) alkali-freeze cycle erosion, (c) salt-freeze cycle erosion.
Fig 34.
Uniaxial compressive stress-strain curve of cylindrical specimen under coupled acid-freeze erosion: (a)CFRP reinforced specimen, (b) BFRP reinforced specimen, (c) GFRP reinforced specimen, (d) AFRP reinforced specimen, (e)Control group specimen.
Fig 35.
Uniaxial compressive stress-strain curve of cylindrical specimen under coupled alkali-freeze erosion: (a)CFRP reinforced specimen, (b) BFRP reinforced specimen, (c) GFRP reinforced specimen, (d) AFRP reinforced specimen, (e)Control group specimen.
Fig 36.
Uniaxial compressive stress-strain curve of cylindrical specimen under coupled salt-freeze erosion: (a)CFRP reinforced specimen, (b) BFRP reinforced specimen, (c) GFRP reinforced specimen, (d) AFRP reinforced specimen, (e)Control group specimen.
Fig 37.
Flexural strength and loss rate: (a) coupled acid-freeze-thaw cyclic erosion; (b) coupled alkali-freeze-thaw cyclic erosion; (c) coupled salt-freeze-thaw cyclic erosion.
Fig 38.
The fitting formula of compressive strength and ultimate strain of acid-freeze-thaw cyclic coupled erosion group:(a) compressive strength, (b) ultimate strain.
Fig 39.
The fitting formula of compressive strength and ultimate strain of alkali-freeze-thaw cyclic coupled erosion specimen:(a) compressive strength, (b) ultimate strain.
Fig 40.
The fitting formula of compressive strength and ultimate strain of salt-freeze-thaw cyclic coupled erosion specimen.
Table 4.
Stress-strain curve parameters.
Fig 41.
Comparison of calculated and experimental, (a) stress-strain curves, (b)maximum stress.
Table 5.
Modified Lam-Teng model equation.