Environmental Impact due to Repairs by Surface Treatment on Concrete Structures Exposed to Chloride Environment

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This paper presents the environmental impact in terms of CO2 and service life extension due to repairs by surface treatment on concrete structures exposed to time-dependent chloride attack. The service life extension is defined as the difference between the corrosion-free service life of concrete before and after surface treatment by silanes. The corrosion-free service life is predicted based on considering the mechanism of chloride diffusion which can be described using the partial differential equation (PDE) of the Fick’s second law. With the surface treatment, solving the PDE is complicated due to non-constant diffusion coefficient. Furthermore, if the diffusion coefficient is time-dependent, it is even more complicated to solve the PDE. Therefore, numerical computation by the Crank-Nicolson based finite difference method is introduced as a computational tool. From computation, the chloride profiles before and after different surface treatment strategies can be calculated considering time-dependent chloride attack. Furthermore, the environmental impact in terms of CO2 due to surface treatment is also presented. Finally, numerical examples to calculate the service life extension after surface treatments and the environmental impacts are compared.

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974-981

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September 2016

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© 2016 Trans Tech Publications Ltd. All Rights Reserved

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