带横向荷载裂缝钢筋混凝土梁的钢筋锈蚀形态研究
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摘要
对荷载作用下恒电流通电锈蚀的带荷载裂缝钢筋混凝土梁进行研究,绘制通电锈蚀前后横向裂缝和顺筋锈胀裂缝分布图,探究横向荷载裂缝对通电锈蚀过程及锈胀裂缝开展的影响。通过三维激光扫描对锈蚀钢筋表面特征进行分析,对比通电锈蚀和自然锈蚀条件下钢筋锈蚀的纵向不均匀性和锈胀裂缝发展。研究发现,通电锈蚀和自然锈蚀下,横向裂缝的存在都会加速该处钢筋的锈蚀截面损失,但通电锈蚀下横向裂缝处的钢筋会出现明显的"颈缩"现象。钢筋截面周长锈蚀率和截面锈蚀率的分布规律相同,截面周长锈蚀率同样可以较好地反映钢筋锈蚀程度。通电锈蚀和自然锈蚀钢筋的平均截面面积与最小截面面积的比值能反映钢筋锈蚀的不均匀性,其值满足Gumbel分布。
In this paper, a reinforced concrete beam with loading cracks was studied under the action of electrified corrosion with constant current. The distributions of transverse cracks, rust expansion and reinforcement cracks were drawn before and after electrified corrosion, and the influence of transverse loading cracks on the process of electrified corrosion and expansion of cracks was explored. The surface characteristics of corroded steel bar were analyzed by three-dimensional laser scanning. The longitudinal inhomogeneity of reinforcement corrosion, the development of corrosion and expansion cracks were compared under the condition of electrified corrosion and natural corrosion. Results indicate that the existence of transverse cracks accelerate the corrosion section loss of steel bar at transverse cracks, but a significant necking phenomenon at the transverse cracks under electrified corrosion can be observed. The distribution of section corrosion ratio and circumference corrosion ratio is the same, and the circumference corrosion ratio can also reflect the degree of corrosion of steel bar. The ratio of average cross-section area to minimum cross-section area of the corroded rebar under natural and accelerated corrosion can reflect the inhomogeneity of rebar corrosion, and its value satisfies the Gumbel distribution.
In this paper, a reinforced concrete beam with loading cracks was studied under the action of electrified corrosion with constant current. The distributions of transverse cracks, rust expansion and reinforcement cracks were drawn before and after electrified corrosion, and the influence of transverse loading cracks on the process of electrified corrosion and expansion of cracks was explored. The surface characteristics of corroded steel bar were analyzed by three-dimensional laser scanning. The longitudinal inhomogeneity of reinforcement corrosion, the development of corrosion and expansion cracks were compared under the condition of electrified corrosion and natural corrosion. Results indicate that the existence of transverse cracks accelerate the corrosion section loss of steel bar at transverse cracks, but a significant necking phenomenon at the transverse cracks under electrified corrosion can be observed. The distribution of section corrosion ratio and circumference corrosion ratio is the same, and the circumference corrosion ratio can also reflect the degree of corrosion of steel bar. The ratio of average cross-section area to minimum cross-section area of the corroded rebar under natural and accelerated corrosion can reflect the inhomogeneity of rebar corrosion, and its value satisfies the Gumbel distribution.
引文
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[2] VIDAL T, CASTEL A, OIS R F. Corrosion process and structural performance of a 17 year old reinforced concrete beam stored in chloride environment[J]. Cement and Concrete Research, 2007, 37(11): 1551-1561.
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[12] KHAN I, OIS R F, CASTEL A. Prediction of reinforcement corrosion using corrosion induced cracks width in corroded reinforced concrete beams[J]. Cement and Concrete Research, 2014, 56: 84-96.
[13] 张伟平,李崇凯,顾祥林,等. 锈蚀钢筋的随机本构关系[J]. 建筑结构学报,2014,17(5): 920-926. (ZHANG Weiping, LI Chongkai, GU Xianglin, et al. Stochastic model of constitutive relationship for corroded steel bars[J]. Journal of Building Structures,2014,17(5): 920-926. (in Chinese))
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[15] 周彬彬. 海洋大气环境下钢筋混凝土基本构件服役寿命设计方法研究[D]. 上海: 同济大学, 2015. (ZHOU Binbin. Study on service life design method of reinforced concrete structural members under marine atmospheric environment[D]. Shanghai: Tongji University, 2015.(in Chinese))
[16] 赵羽习. 钢筋锈蚀引起混凝土结构锈裂综述[J]. 东南大学学报(自然科学版),2013,43(5): 1122-1134. (ZHAO Yuxi. State-of-art of corrosion-induced cracking of reinforced concrete structures[J]. Journal of Southeast University (Natural Science Edition),2013,43(5): 1122-1134. (in Chinese))
[17] 曾严红,顾祥林,张伟平,等. 混凝土中钢筋加速锈蚀方法探讨[J]. 结构工程师, 2009, 25(1): 101-105.(ZENG Yanhong, GU Xianglin, ZHANG Weiping, et al. Accelerated corrosion technique for reinforcement steel bar in concrete[J]. Structural Engineers,2009,25(1):101-105.(in Chinese))
[18] FU C, JIN N, YE H, et al. Corrosion characteristics of a 4-year naturally corroded reinforced concrete beam with load-induced transverse cracks[J]. Corrosion Science, 2017, 117: 11-23.
[19] WANG X, SONG X, ZHANG M, et al. Experimental comparison of corrosion unevenness and expansive cracking between accelerated corrosion methods used in laboratory research[J]. Construction and Building Materials, 2017, 153: 36- 43.
[2] VIDAL T, CASTEL A, OIS R F. Corrosion process and structural performance of a 17 year old reinforced concrete beam stored in chloride environment[J]. Cement and Concrete Research, 2007, 37(11): 1551-1561.
[3] OTIENO M, ALEXANDER M, BEUSHAUSEN H. Corrosion in cracked and uncracked concrete-influence of crack width, concrete quality and crack reopening[J]. Magazine of Concrete Research, 2010, 62(6): 393- 404.
[4] OTIENO M,BEUSHAUSEN H, ALEXANDER M. Towards incorporating the influence of cover cracking on steel corrosion in RC design codes: the concept of performance-based crack width limits[J]. Materials & Structures, 2012, 45(12): 1805-1816.
[5] GAO Z, LIANG R, PATNAIK A. Effects of sustained loading and pre-existing cracks on corrosion behavior of reinforced concrete slabs[J]. Construction and Building Materials, 2016, 124: 776-785.
[6] ZHU W, FRAN?OIS R, ZHANG C, et al. Propagation of corrosion-induced cracks of the RC beam exposed to marine environment under sustained load for a period of 26 years[J]. Cement and Concrete Research, 2018, 103: 66-76.
[7] 王晓刚,杜相波,闫军印,等. 混凝土构件中钢筋锈蚀的电加速技术对比试验研究[J]. 建筑结构学报,2015,36(1): 104-110. (WANG Xiaogang, DU Xiangbo, YAN Junyin, et al. Experimental comparison of galvanostatic methods for accelerated corrosion of steel bars in RC members[J].Journal of Building Structures,2015,36(1): 104-110. (in Chinese))
[8] YU L, FRAN?OIS R, DANG V, et al. Development of chloride-induced corrosion in pre-cracked RC beams under sustained loading: effect of load-induced cracks, concrete cover, and exposure conditions[J]. Cement and Concrete Research, 2015, 67: 246-258.
[9] CASTEL A, VIDAL T, OIS R, et al. Influence of steel-concrete interface quality on reinforcement corrosion induced by chlorides[J]. Magazine of Concrete Research, 2003, 55(2): 151-159.
[10] VIDAL T, CASTEL A, OIS R. Analyzing crack width to predict corrosion in reinforced concrete[J]. Cement and Concrete Research, 2004, 34: 165-174.
[11] ZHANG R, CASTEL A, OIS R. Concrete cover cracking with reinforcement corrosion of RC beam during chloride-induced corrosion process[J]. Cement and Concrete Research, 2010, 40(3): 415- 425.
[12] KHAN I, OIS R F, CASTEL A. Prediction of reinforcement corrosion using corrosion induced cracks width in corroded reinforced concrete beams[J]. Cement and Concrete Research, 2014, 56: 84-96.
[13] 张伟平,李崇凯,顾祥林,等. 锈蚀钢筋的随机本构关系[J]. 建筑结构学报,2014,17(5): 920-926. (ZHANG Weiping, LI Chongkai, GU Xianglin, et al. Stochastic model of constitutive relationship for corroded steel bars[J]. Journal of Building Structures,2014,17(5): 920-926. (in Chinese))
[14] ZHANG W, ZHOU B, GU X, et al. Probability distribution model for cross-sectional area of corroded reinforcing steel bars[J]. Journal of Materials in Civil Engineering, 2014, 26(5): 822-832.
[15] 周彬彬. 海洋大气环境下钢筋混凝土基本构件服役寿命设计方法研究[D]. 上海: 同济大学, 2015. (ZHOU Binbin. Study on service life design method of reinforced concrete structural members under marine atmospheric environment[D]. Shanghai: Tongji University, 2015.(in Chinese))
[16] 赵羽习. 钢筋锈蚀引起混凝土结构锈裂综述[J]. 东南大学学报(自然科学版),2013,43(5): 1122-1134. (ZHAO Yuxi. State-of-art of corrosion-induced cracking of reinforced concrete structures[J]. Journal of Southeast University (Natural Science Edition),2013,43(5): 1122-1134. (in Chinese))
[17] 曾严红,顾祥林,张伟平,等. 混凝土中钢筋加速锈蚀方法探讨[J]. 结构工程师, 2009, 25(1): 101-105.(ZENG Yanhong, GU Xianglin, ZHANG Weiping, et al. Accelerated corrosion technique for reinforcement steel bar in concrete[J]. Structural Engineers,2009,25(1):101-105.(in Chinese))
[18] FU C, JIN N, YE H, et al. Corrosion characteristics of a 4-year naturally corroded reinforced concrete beam with load-induced transverse cracks[J]. Corrosion Science, 2017, 117: 11-23.
[19] WANG X, SONG X, ZHANG M, et al. Experimental comparison of corrosion unevenness and expansive cracking between accelerated corrosion methods used in laboratory research[J]. Construction and Building Materials, 2017, 153: 36- 43.