Mechanical properties, thermal and chemical effect of polymer cotton bars reinforced with carbon / glass fiber

Figures & data

Figure 1. Materials used in the manufacture of FRP bars.

Table 1. Mechanical properties of carbon, Cotton, fibre and matrix resin.

Mechanical properties	Resin	Carbon Fiber	Glass Fiber	Cotton Fiber
Tensile stress (MPa)	69	2800	1265	320
Elastic modulus (GPa)	3.5	160	81.7	11.7
Strain (%)	3.1	0.85		7.0
density (g/cm3)	1.15	1.6	2.8	1.5
mixed viscosity(cP)	127	——		——
bristle diameter(μm)	——	6-8	19	30-40

Figure 2. Tensile test of epoxy treated cotton rope braids.

Figure 3. Repeated coating method for FRP bars.

Figure 4. Manufacturing method of C_ot.FRP,C_ot.CFRP, and C_ot.GFRP bars.

Figure 5. Prepare samples for tensile strength testing.

Figure 6. Prepare samples for bonding testing with concrete.

Figure 7. Tensile test for samples Seel, Cot.FRP,Cot.CFRP, and Cot.GFRP bars.

Table 2. Tensile properties of Seel, Cot.FRP,Cot.CFRP, and Cot.GFRP bars.

Type of Bar	Density (g/cm3)	Yield Tensile Stress (MPa)	Ultemate Tensile Strength (MPa)	Young’s modulus (GPa)	Failure Strain (%)
Steel	7.45	624	778	218	4
Cot.CFRP	1.33	688	——	55	1.2
Cot.GFRP	1.42	477	——	42	1.1
Cot.FRP	1.19	284	——	31	1.0

Table 3. Mechanical and physical properties of GFRP rebars(al-khafaji 2021).

Rebar size (mm)	Nominal Area (mm^2)	Guaranteed Tensile Strength Mpa))	Ultimate Tensile Load Kn))	Modulus of Elasticity (Gpa)	Ultimate Strain (%)
13	127	758	95	46	1.64
19	285	690	196	46	1.49

Figure 8. Failure shape for Cot.FRP, Cot.CFRP, and Co_t.GFRP bars.

Figure 9. Flexural and bending testing for Cot.FRP,Cot.CFRP, and Cot.GFRP bars.

Figure 10. Shear testing for Cot.FRP, Cot.CFRP, and Cot.GFRP bars.

Table 4. Mechanical Properties of the Cot.FRP, Cot.CFRP, and Cot.GFRP bars.

Type of Bar	$f_u$ (MPa)	${\tau }_u$ (MPa)	$\mathit{E}$ (GPa)	${\epsilon }_u$ (%)
Cot.CFRP	693	180	43	1.9
Cot.GFRP	433	123	31	1.6
Cot.FRP	227	72	22	1.2

Figure 11. Bonding test for Cot.FRP, Cot.CFRP, and Cot.GFRP bars.

Figure 12. Bond strength for Cot.FRP, Cot.CFRP, and Cot.GFRP bars.

Figure 13. Thermogravimetric curve for Cot.FRP, Cot.CFRP, and Cot.GFRP bars. .

Figure 14. Heat effect on Cot.FRP, Cot.CFRP, and Cot.GFRP bars.

Figure 15. Resistance test to moisture, alkaline solutions, and acid for for Cot.FRP, Cot.CFRP, and Cot.GFRP bars.

Figure 16. Effect of 10% sulfuric acid on Cot.FRP bars for 6 months.

Al-khafaji, Ali Fadhil. 2021. “Scholars ’ Mine Fiber Reinforced Polymer Bar Investigation : Long-Term in-Situ Durability and Bond Strength Assessment in Conventional and Sustainable Concrete.” 50–59.

 Google Scholar