Corrosion in cracked and uncracked concrete – influence of crack width, concrete quality and crack reopening

Magazine of Concrete Research - Tập 62 Số 6 - Trang 393-404 - 2010
Mike Otieno1, Mark Alexander1, Hans Beushausen1
1University of Cape Town

Tóm tắt

Cracks influence the durability of reinforced concrete (RC) structures in aggressive environments by accelerating the ingress of corrosive agents to the embedded steel. This study investigated the influence of crack width (0·7 mm, 0·4 mm and incipient cracks), binder type (100% CEM I (ordinary Portland cement – OPC) and 50/50 OPC/Corex slag blend), water-to-binder (w/b) ratio (0·40 and 0·55) and crack reopening on chloride-induced corrosion in RC specimens with constant cover of 40 mm. Over the study period (31 weeks), corrosion rates varied from passive values of 0·01 μA/cm2 to active values of 1·50 μA/cm2. Results indicate that corrosion rate is sensitive to crack width, concrete quality (i.e. binder type and w/b ratio) and crack reopening. For a given binder type and w/b ratio, corrosion rate increased with increasing crack width; however, this increase was smaller in Corex slag specimens (increases of 40% or more) than in OPC specimens (increases 210% or more). Corex slag specimens generally had lower corrosion rates compared to OPC specimens. For both OPC and Corex slag specimens, corrosion rate decreased with decreasing w/b ratio. Crack reopening increased the corrosion rate in the cracked specimens. This increase in corrosion rate was higher if the specimen was actively corroding prior to the crack reopening.

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Tài liệu tham khảo

ASTM (American Society for Testing and Materials). Standard Test Method for Half Cell Potentials of Uncoated Reinforcing Steel in Concrete, 1991, ASTM, West Conshohocken, PA, 48–58, Standard C876-91.

10.1016/0950-0618(95)00044-5

Andrade C, 2003, Materials and Structures, 36, 461, 10.1007/BF02481526

Arya C, 1996, Cement and Concrete Research, 26, 333, 10.1016/S0008-8846(96)85022-8

Arya C, 1995, The Relevance of Cracking in Concrete to Corrosion of Reinforcement

Bakker RFM, 1983, Proceedings of the CANMET/ACI First International Conference on the Use of Fly Ash, Silica Fume, Slag and Other Mineral By-products in Concrete, 1, 589

Beeby A, 1983, Concrete International, 5, 35

Bentur A , Diamond S , Berke N . Steel Corrosion in Concrete, Fundamentals and Civil Engineering Practice, 1997, E & FN Spon, London, 41–43.

CEB–FIP (Comité Euro-international du Béton–Federation Internationale de la Précontrainte), 1992, CEB–FIP Model Code 1990

Clear CA, 1985, The Effects of Autogenous Healing upon the Leakage of Water through Cracks in Concrete

Covarrubias JP, 2007, Concrete International, 29, 50

10.1016/0008-8846(88)90033-6

Gautefall O, 1983, Nordic Concrete Research, 25, 17

10.1016/0010-938X(94)00156-Z

Gowers KR, 1999, ACI Materials Journal, 96, 536

10.1016/S0963-8695(98)00010-3

10.1007/BF02481539

10.1007/BF02498563

Mackechnie JR, 2003, Structural and Durability Properties of Concrete Made with Corex Slag

10.1680/macr.1993.45.162.63

Mohamed B, 2003, ACI Materials Journal, 100, 38

Neville AM, 2002, Concrete International, 24, 76

Otieno MB, 2008, Corrosion Propagation in Cracked and Uncracked Concrete

Pettersson K, 1996, Proceedings of the 3rd ACI/CANMET International Conference on the Performance of Concrete in the Marine Environment, St Andrews-by-the-Sea, Canada, 163, 185

10.1680/macr.1994.46.167.81

10.1680/macr.2007.59.7.495

Stansbury E, 2000, Fundamentals of Electrochemical Corrosion, 10.31399/asm.tb.fec.9781627083027

10.1149/1.2428496

Suzuki K, 1990, Corrosion of Reinforcement in Concrete, 19

10.1016/S0008-8846(97)00031-8

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Magazine of Concrete Research

Tập 62 Số 6

393-404

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