3 4 4 2.1 4 2.2 5 2.3 6 6 7 4.1 RC 7 4.2 RC 8 4.3 9 10 5.1 10 5.2 10 11 12 13-1 -
Bond Behavior Between Corroded Rebar and Concrete Ema KATO* Mitsuyasu IWANAMI** Hiroshi YOKOTA*** Hajime ITO**** Fuminori SATO***** Synopsis Port and harbor concrete structures suffer from the chloride attack that may cause deterioration of materials. For example, expansion of rebar due to corrosion may induce cracks in concrete and consequent fall of cover concrete. The material deterioration decreases structural performances. However, the relationship between the degree of rebar corrosion and structural performance has not been made clear. In this study, the relationship between the states of rebar corrosion and deterioration of bond property between rebar and concrete has been experimentally investigated. It was evaluated that the effects of degree of rebar corrosion and deterioration of bond property on tension stiffening and crack distribution of reinforced concrete member. The experimental results showed that the tension stiffening and crack distribution were influenced by deterioration of bond property between rebar and concrete depending on the cross-sectional loss of rebar. Non-linear FEM analysis focusing on the deterioration of structural performance was conducted. In the analysis, the cross-sectional loss of rebar and the deterioration of bond property obtained by the experiments were taken into account. As a result, the quantitative evaluation method of bond behavior between rebar and concrete was proposed in the analysis. Key Words: reinforced concrete, rebar corrosion, bond property, tension stiffening, crack distribution * Researcher of Structural Mechanics Division, Geotechnical and Structural Engineering Department ** Senior Researcher of Geotechnical and Structural Engineering Department *** Head of Structural Mechanics Division, Geotechnical and Structural Engineering Department **** Trainee of Structural Mechanics Division, Geotechnical and Structural Engineering Department ***** Former Trainee of Structural Mechanics Division (Maeda Corporation) 3-1-1 Nagase, Yokosuka, 239-0826 Japan Phone+81-0468-44-5059 Fax+81-0468-44-0255 E-mailkatoh-e@pari.go.jp - 2 -
* ** *** **** ***** * ** *** **** ***** 239-0826 3-1-1 0468-44-5059 Fax0468-44-0255 E-mail : katoh-e@pari.go.jp - 3 -
2002 1970 2001 1998 1999 AE 2000 2001 1991 (1) 200mm 150mm2000mmD19 1 750mm1250mm 2150mm 75mm2 W/C (kg/m 3 ) G max s/a (%) W C S G SP 20 56.5 43.3 160 284 790 1080 0.568 C:S:G:SP:AE (N/mm 2 ) (N/mm 2 ) (N/mm 2 ) 39.3 3.1510 4 3.40 40.7 3.1510 4 3.50 (N/mm 2 ) (N/mm 2 ) (N/mm 2 ) D19 362 418 1.9010 5 D6 401 474-4 -
4000 1250 2000 750 150 D19 SD345 200 100 200 100 30 150 75 150 75 30 140 30 a) b) 30 90 D6 SD345 @150 or @ 75 :mm 1900 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1-5 -
(2) 8.5A/m 2 100mm 100mm 1 2 10% 100mm (%) 20 15 10 5 0 R 2 = 0.96 150mm 75mm 0 0.5 1 1.5 2 mm Qi 1999 150mm 75mm 4 2001-6 -
(kn) 100 50 0 0.0% 0.8% 2.5% 2.7% 5.3% 10.2% 0 500 1000 1500 2000 (µ) (N/mm 2 ) 2.5 2.0 1.5 1.0 0.5 0.0 0.0% 0.8% 2.5% 2.7% 5.3% 10.2% 0 500 1000 1500 2000 (µ) RC (1) 2000µ 0.0% (2) (1) σ c,av P As,av Esε av = (1) A c σ c,av P A s,av E s ε av A c (1) (1) (3) - 7 -
N 0 N cor,n 2000µ w 0 w cor,n 1998 10.2% 5.3% 10.2% RC 10.2% (kn) N Ncor, n cor,n / N0 / N 0 100 50 0 0 500 1000 1500 2000 (µ) 1.0 0.5 0.0 0 5 10 (%) 2.0 1.5 1.0 w wcor, n / w0 cor,n / w 0 (2)(1) 10% 75mm 75mm 1300µ 150mm 12.0% 75mm 1500µ 1996 1989-8 -
(kn) (N/mm 2 ) 100 50 2.5 2.0 1.5 1.0 0.5 0.0 0-0.0% -10.2% 150mm-12.0% 75mm-10.1% 0 500 1000 1500 2000 (µ) -0.0% -10.2% 150mm-12.0% 75mm-10.1% 0 500 1000 1500 2000 (µ) 10% 75mm (J/m 3 ) 3000 2500 2000 1500 1000 500 150mm 75mm 0 5 10 15 (%) (2) W = ( σ ε ) (2) b c,av av W b σ c,av ε av 5.3% 2001 100mm100mm1000mm 1 D19-9 -
5% 1991 4 σ n f t σ i ε cr ε i ε f αn f t 50mm (3) ( α ) n ( ε i cr ) ft log σ n = exp ε ε f ε n (3) ε cr ε f 2000µf t α n ε f 0.05 1.0% von Mises 0.1mm h - 10 -
τ (N/mm 2 ) (kn) 100 75 50 25 0 125 100 75 50 25 0 h 0 0.5 1 1.5 2 γ (10 6 ) S 5.3% 0.0% 0mm 0.0% Gs150 tmax75 5.3% 1.0mm 5.3% GS60 tmax50-5% 0 500 1000 1500 2000 (µ) S γ(4) (5) S γ = (4) h τ = G s γ (5) γτ 5.3% 2001 G s G s τ 5% 5.3% 33% G s 60% G s 1) 2) 3) 4) - 11 -
20021115 2000 RC No.978 No.6 pp.95-97 1991 Vol.13, No.2, pp.139-144 2001RC No.1006 2002 No.44 1989 RC No.402/V-10, pp.105-114 Qi, L., 1999 Vol.21, No.2, pp.1033-1038 1991 69pp.37-47 2001 1998 2001 Vol.23, No.3, pp.1327-1332 1996 No.50, pp.534-539 - 12 -
0.8% 2.5% - 13 -
2.7% 5.3% 10.2% - 14 -
150mm12.0% 75mm10.1% - 15 -
(%) 0.8 2.5 2.7 5.3 10.2 (mm) 0.16 0.35 0.47 0.91 1.32 0.03 0.08 0.07 0.17 0.19 (mm) (mm) 0 100 0.15 0.38 0.25 0.75 0.95 100 200 0.18 0.35 0.40 0.85 1.15 200 300 0.20 0.30 0.38 0.95 1.35 300 400 0.18 0.28 0.40 0.95 1.40 400 500 0.18 0.35 0.43 0.90 1.40 500 600 0.18 0.40 0.48 0.95 1.45 600 700 0.15 0.40 0.53 1.00 1.45 700 800 0.15 0.43 0.53 1.00 1.50 800 900 0.15 0.43 0.53 0.95 1.55 900 1000 0.18 0.37 0.48 0.95 1.35 1000 1100 0.18 0.35 0.45 1.00 1.25 1100 1200 0.13 0.38 0.50 1.00 1.60 1200 1300 0.13 0.38 0.45 0.95 1.65 1300 1400 0.15 0.36 0.41 0.90 1.30 1400 1500 0.15 0.36 0.43 0.90 1.30 1500 1600 0.13 0.33 0.50 0.83 1.30 1600 1700 0.10 0.27 0.55 0.73 1.15 1700 1800 0.10 0.22 0.53 0.60 1.15 1800 1900 0.10 0.20 0.53 0.50 1.25 1900 2000 0.10 0.15 0.48 0.45 1.00 (%) (mm) 0.8 2.5 2.7 5.3 10.2 0.44 0.60 0.53 0.98 1.88 (%) 0 100 1.10 2.36 2.86 2.54 9.56 100 200 1.24 3.80 3.83 4.56 11.85 200 300 1.16 3.98 2.70 5.61 11.65 300 400 1.05 2.76 1.54 5.59 11.05 400 500 1.04 3.56 1.60 5.81 13.48 500 600 0.94 3.20 2.73 4.25 12.34 600 700 0.65 3.47 2.71 4.65 10.89 700 800 0.52 2.71 1.95 5.46 9.57 800 900 0.65 2.90 2.48 4.84 10.37 900 1000 0.83 1.67 2.48 6.58 10.03 1000 1100 0.04 1.81 2.79 6.60 9.50 1100 1200 0.09 2.51 2.98 6.71 9.01 1200 1300 0.34 2.86 3.26 5.36 8.90 1300 1400 0.31 2.89 2.18 5.71 11.43 1400 1500 0.14 2.71 2.17 5.28 15.04 1500 1600 0.46 2.44 2.52 5.57 9.94 1600 1700 0.55 2.54 2.25 5.31 8.24 1700 1800 0.89 2.44 2.10 5.06 7.85 1800 1900 1.04 3.08 2.39 6.88 9.72 1900 2000 1.71 2.40 2.33 5.04 7.45-16 -
150mm 75mm (mm) (mm) (%) (mm) (%) 0.47 12.0 0.45 10.1 0.06 3.83 0.06 3.51 0 100 0.50 6.29 0.33 7.29 100 200 0.48 13.33 0.38 13.07 200 300 0.50 12.15 0.41 9.58 300 400 0.50 10.90 0.46 6.36 400 500 0.48 8.77 0.48 5.41 500 600 0.48 7.80 0.48 10.16 600 700 0.53 6.86 0.50 13.84 700 800 0.58 6.05 0.55 17.11 800 900 0.53 10.13 0.50 12.63 900 1000 0.48 17.40 0.43 7.96 1000 1100 0.48 19.40 0.43 7.94 1100 1200 0.48 18.01 0.50 10.32 1200 1300 0.48 13.57 0.53 17.45 1300 1400 0.45 13.15 0.50 10.72 1400 1500 0.40 9.15 0.48 7.96 1500 1600 0.40 11.21 0.45 10.00 1600 1700 0.43 14.48 0.40 11.06 1700 1800 0.42 13.41 0.37 9.30 1800 1900 0.35 14.92 0.39 15.15 1900 2000 0.38 10.91 0.37 5.75 150mm 75mm (mm) (%) (mm) (%) 100 53.24 63 34.10 250 32.85 138 6.62 400 10.74 213 10.44 550 7.48 288 3.50 700 17.11 363 4.11 850 4.51 438 4.45 1000 56.61 513 18.96 1150 26.12 588 9.53 1300 60.92 663 21.78 1450 3.48 738 38.13 1600 44.77 813 12.34 1750 38.31 888 5.13 1900 51.11 963 2.61 1038 8.46 1113 2.63 1188 21.84 1263 46.04 1338 12.34 1413 6.48 1488 9.57 1563 29.55 1638 6.86 1713 7.55 1788 8.63 1863 44.68 1938 4.00-17 -