Investigation of corrosion parameters relationship of reinforcement by vapor permeability in the surface protected concretes

Authors
H. Ashegh 1
A. A. Shirzadi Javid
P. Ghoddousi 2
A. Habibnejad Korayem 3
M. A. Oraie 4
1 school of civil engineering at IUST
2 Iran University of Science and Technology(IUST)
3 The School of Civil Engineering at IUST
4 Engineering and construction managment
Abstract
The surface protection materials have effective results to prevent concretes from corrosion. Reinforced concrete structures have the potential to be very durable and capable of withstanding a variety of adverse environmental conditions. However, failure in the structures does still occur as a result of premature reinforcement corrosion. There are corrosion protection systems and methods to extend the long-term durability of steel reinforced concrete. For example, application of zinc rich or cement based protective primers to reinforcement, surface protection systems of concrete, Cathodic protection using sacrificial zinc anodes, and conductive anode overlays within an impressed current cathodic protection system. In general, the main duty of surface protection is controlling both physical and chemical damages to concrete in order of preventing or reducing from steel bar corrosion and creating a coat of safekeeping against penetration of chloride ion, carbon dioxide, oxygen, and most importantly water. According to European Norm, three types of protection materials are existed based on function mechanism. Coating, hydrophobic impregnation, and impregnation materials are these systems, and two types of them used in this study. In this study, two materials of surface protection have used on the surface of three types of concrete. Two types of self compacting concrete with different w/c ratio and one ordinary concrete with similar mixture design to one of those SCC were used for estimating of durability of concrete. Epoxy resin and silane-siloxane were two types of surface treatment materials used in this study. SEM analysis and water contact angle test were done to study the function mechanism of surface protection material. The other tests are water vapor permeability, corrosion potential, and corrosion intensity. Some of the results of this study is that using this materials have effective impact on declining of corrosion potential, decreasing of corrosion intensity, and after all increasing durability of concrete. As shown in this paper, all of the protected samples except one, until 49th week did not have a sign of corrosion active phase. Increasing in ratio of W/C in the substrate makes weakness in function of this materials. In the other hand, results of half-cell potential of unprotected samples show SCC2 with 0.55 w/c ratio and NC with 0.45 w/c ratio shift from passive to active state in first days and SCC1 with 0.45 w/c ratio attained its active state in 5 weeks. However once corrosion has started in SCC2-EP in 8 weeks, corrosion rate was lower than unprotected samples. In the presence of surface protection systems, due to their ability to reduce water ingress in concrete, the corrosion intensity in all samples were lower than 0.23 µA/ cm^2. The results of water vapor permeability test showed that epoxy can decrease the water vapor permeability up to 65% instead of unprotected concrete. In the meantime, silane-siloxane doesn't have effective results in concrete breathability and have a similar performance to unprotected concrete. The results show using SCC don't have much different effect on quality of the materials function instead of ordinary concrete. Another important result is that protection materials which don't let to enough evaporate, are cause of much corrosion in compare of those that let concrete to breath.

Keywords

Subjects

1-Almusallam, A., et al., Effectiveness of surface coatings in improving concrete durability. Cement and Concrete Composites, 2003. 25(4): p. 473-481.
2-McCurrich, L., G. Whitaker, and M. Humpage. Reduction in rates of carbonation and chloride ingress by surface impregnation. in Proceedings of 2nd International Conference on Structural Faults and Repair. 1985.
3-Shaw, J., Water repellent systems. Construction Repair, 1989: p. 8-9.
4-Almusallam, A.A., Effect of degree of corrosion on the properties of reinforcing steel bars. Construction and Building Materials, 2001. 15(8): p. 361-368.
5-Ghodousi, P., et al. The use of surface treatment compounds to enhance durability of reinforced concrete. in Concrete Repair, Rehabilitation, and Protection: Proceedings of the International Conference Held at the University of Dundee, Scotland, UK on 24-26 June 1996. 1996. Taylor & Francis.
6-Hou, P., et al., Characteristics of surface-treatment of nano-SiO 2 on the transport properties of hardened cement pastes with different water-to-cement ratios. Cement and Concrete Composites, 2015. 55: p. 26-33.
7-Medeiros, M. and P. Helene, Efficacy of surface hydrophobic agents in reducing water and chloride ion penetration in concrete. Materials and Structures, 2008. 41(1): p. 59-71.
8-pfeifer, D.W., Carbonation of silane treated reinforced concrete. 1986.
9-Scarfato, P., et al., Preparation and evaluation of polymer/clay nanocomposite surface treatments for concrete durability enhancement. Cement and Concrete Composites, 2012. 34(3): p. 297-305.
10-Zhu, Y.-G., et al., Influence of silane-based water repellent on the durability properties of recycled aggregate concrete. Cement and Concrete Composites, 2013. 35(1): p. 32-38.
11-EN, B., BS EN 1504-2 , Products and systems for the protection and repair of concrete structures. Definitions, requirements, quality control and evaluation of conformity. Surface protection systems for concrete. 2004.
12-Basheer, L. and D.J. Cleland, Durability and water absorption properties of surface treated concretes. Materials and structures, 2011. 44(5): p. 957-967.
13-Basheer, L., J. Kropp, and D.J. Cleland, Assessment of the durability of concrete from its permeation properties: a review. Construction and building materials, 2001. 15(2): p. 93-103.
14-Smith, M.D., Silane chemical protection of bridge decks, Oklahoma department of transportation. 1986.
15-Ghoddousi, P., A. Raiss Ghasemi, and T. Parhizkar. The effect of concrete quality on performance of surface treatment materials. in Proceedings of the International Conference on Sustainable Construction Materials and Technologies. 2007.
16-Self-consolidating concrete instructon, Road, Housing and Development Research Center, Journal No.706 (In Persian).
17-Concrete- Compressive strength of specimens- Test method, 1992 (In Persian).
18-ASTM, ASTM D7334-08-Standard Practice for Surface Wettability of Coatings, Substrates and Pigments by Advancing Contact Angle Measurement. 2013.
19-ASTM, ASTM E96 / E96M-16, Standard Test Methods for Water Vapor Transmission of Materials, ASTM International, West Conshohocken. 2016.
20-ASTM, ASTM C876-15, Standard Test Method for Corrosion Potentials of Uncoated Reinforcing Steel in Concrete, ASTM International, West Conshohocken,. 2015.
21-Song, H.-W. and V. Saraswathy, Corrosion monitoring of reinforced concrete structures-a. Int. J. Electrochem. Sci, 2007. 2: p. 1-28.
22-Broomfield, J.P., Corrosion of steel in concrete: understanding, investigation and repair. 2006: CRC Press.
23-Dang, Y., et al., Accelerated laboratory evaluation of surface treatments for protecting concrete bridge decks from salt scaling. Construction and Building Materials, 2014. 55: p. 128-135.
24-Basheer, P., et al. Durability of surface treated concrete. in Protection of Concrete: Proceedings of the International Conference, University of Dundee, September 1990. 2003. CRC Press.
25-Barbucci, A., M. Delucchi, and G. Cerisola, Organic coatings for concrete protection: liquid water and water vapour permeabilities. Progress in Organic coatings, 1997. 30(4): p. 293-297.
26-Czarnecki, L. and A. Garbacz. Evaluation of polymer coating-crack-bridging ability. in International Colloquium “Industrial Floors. 1995.
27-Delucchi, M., A. Barbucci, and G. Cerisola, Crack-bridging ability and liquid water permeability of protective coatings for concrete. Progress in Organic Coatings, 1998. 33(1): p. 76-82.
28-Delucchi, M., et al., Study of the crack-bridging ability of organic coatings for concrete: analysis of the mechanical behaviour of unsupported and supported films. Progress in organic coatings, 2002. 44(4): p. 261-269.
29-De Muynck, W., et al., Bacterial carbonate precipitation as an alternative surface treatment for concrete. Construction and Building Materials, 2008. 22(5): p. 875-885.
30-Fürstner, R., et al., Wetting and self-cleaning properties of artificial superhydrophobic surfaces. Langmuir, 2005. 21(3): p. 956-961.
31-Ji, T., Preliminary study on the water permeability and microstructure of concrete incorporating nano-SiO2. Cement and Concrete Research, 2005. 35(10): p. 1943-1947.
32-Alonso, C., et al., Factors controlling cracking of concrete affected by reinforcement corrosion. Materials and structures, 1998. 31(7): p. 435-441.
33-Gowripalan, N., V. Sirivivatnanon, and C. Lim, Chloride diffusivity of concrete cracked in flexure. Cement and Concrete Research, 2000. 30(5): p. 725-730.
34-Song, H.-W., et al., Predicting carbonation in early-aged cracked concrete. Cement and Concrete Research, 2006. 36(5): p. 979-989.
35-Ghodousi, P., et al. Study of the polymeric surface protection materials performance on permeability of self-consolidating concrete. National conference on polymer in construction , p 133-141.(In Persian)
36-Basheer, P., et al., Surface treatments for concrete: assessmentmethods and reported performance. Construction and Building Materials, 1997. 11(7): p. 413-429.
37-Safiuddin, M. and K.A. Soudki, Water vapor transmission and waterproofing performance of concrete sealer and coating systems. Journal of Civil Engineering and Management, 2015. 21(7): p. 837-844
Modares Civil Engineering journal
Volume 18, Issue 2
July and August 2018
Pages 202-194