same time. Therefore, it may not enough to explore only one type of deterioration mechanism to assess the whole deterioration of the buildings. The safety and service life of reinforced concrete buildings will be affected by the deterioration and corrosion of rebar.
In this study, the microstructure of cement paste as cement particles through modeling rate of hydration is simulated, and the influence of water, carbon dioxide (CO2), and chloride ingress in concrete are investigated through modelling one-dimension and two-dimension model. By considering the curing temperature, environment condition, cement properties, and water-cement ratio, thus the porosity, temperature rise, and water content in the concrete can be identified and the diffusion of carbon dioxide, as well as the diffusion of chloride ion can be calculated.
Finally, after calculating the carbonation and chloride ion impact on the reinforced concrete, the corrosion current density and corrosion rate of rebar under the deteriorated environment can be obtained to create the corrosion time-history curve.

References
[1] Van Breugel, K. (1997). Simulation of hydration and formation of structure in hardening cement-based materials, Ph.D. thesis, Delft University of Technology, Delft, The Netherlands.
[2] Xie, Shasha, Cheng, Zhiyuan and Wan, Li. (2019). Hydration and Microstructure of Astm Type I Cement Paste Science and Engineering of Composite Materials, vol. 26, no. 1, pp. 215-220. https://doi.org/10.1515/secm-2019-0004.
[3] Zhang, M., Ye, G., and van Breugel, K. (2011). Microstructure-based modeling of water diffusivity in cement paste, Construction and Building Materials 25(4), 2046-2052.
[4] Van Breugel, K. (1995). Numerical simulation of hydration and microstructural development in hardening cement-based materials (I) theory. W.D. Meinema, p. 295
[5] Tomosawa, F. (1997). Development of a kinetic model for hydration of Cement Proceedings of the 10th International congress on the chemistry of cement, Gothenburg, Sweden, 2ii051.
[6] Maruyama, I., Noguchi, T., Matsushita, T. (2006). Prediction of Adiabatic Temperature Rise in Portland Cement Concrete Using Computational Cement Based Material Model, 71(600), 1–8. (in Japanese)
[7] Lothenbach, B., Matschei, T., Möschner, G., & Glasser, F. P. (2008). Thermodynamic modelling of the effect of temperature on the hydration and porosity of Portland cement. Cement and Concrete Research, 38(1), 1–18. https://doi.org/10.1016/j.cemconres.2007.08.017
[8] Maruyama, I., Matsushita, T., Noguchi, T., Schlangen, E., & De Schutter, G. (2008). Numerical modeling of Portland Cement hydration. International RILEM Symposium on Concrete Modelling-ConMod’08, (May), 155–163.
[9] L.J. Parrot, D.C. Killoh. (1984). Prediction of cement hydration, Br. Ceram. Proc. 35 . 41–53.
[10] F. Lavergne, A. Ben Fraj, I. Bayane, J.F. Barthélémy. (2018). Estimating the mechanical properties of hydrating blended cementitious materials: An investigation based on micromechanics. Cement and Concrete Research, Elsevier, 2018, 104, pp.37 - 60.10.1016/j.cemconres.10.018. hal-01851380.
[11] Maruyama, I., & Igarashi, G. (2015). Numerical approach towards aging management of concrete structures: Material strength evaluation in a massive concrete structure under one-sided heating. Journal of Advanced Concrete Technology, 13(11), 500–527. https://doi.org/10.3151/jact.13.500.
[12] Maruyama, I. and Igarashi, G., (2011). Hydration model of Portland cement for structural integrity analysis. Proceedings of 4th International Symposium on the Ageing Management & Maintenance of Nuclear Power Plants (ISaG2010). Tokyo, Mitsubishi Research Institute, 123-144.
[13] Lin, M., Sasano, H. and Maruyama, I., (2013). Fundamental study on water diffusion coefficient of cement based material. Proceedings of Japan Concrete Institute, 35(1), 595-600. (in Japanese)
[14] Badmann, R., Stockhausen, N. and Setzer, M. J., (1981). The statistical thickness and the chemical potential of adsorbed water films. Journal of Colloid and Interface Science, 82(2), 534-542.
[15] Feldman, R. F. and Sereda, P. J. (1968). A model for hydrated Portland cement paste as deduced from sorption-length change and mechanical properties. Matériaux et Construction, 1(6), 509-520.
[16] Tomes, L. A., Hunt, C. M. and Blaine, R. L., (1957). Some factors affecting the surface area of hydrated Portland cement as determined by water-vapor and nitrogen adsorption. Journal of Research of the National Bureau of Standards, 59(6), 357-364.
[17] Maruyama, I., Nishioka, Y., Igarashi, G. and Matsui, K., (2014). Microstructural and bulk property changes in hardened cement paste during the first drying process. Cement and Concrete Research, 58(0), 20-34.
[18] Maruyama, I. and Igarashi, G., (2014). Cement reaction and resultant physical Properties of cement paste. Journal of Advanced Concrete Technology, 12(6), 200-213.
[19] Helmuth, R. A. and Turk, D. H., (1967). The reversible and irreversible drying shrinkage of hardened Portland cement and tri-calcium silicate pastes. Journal of the PCA Research and Development Laboratories, 9(2), 8 - 21.
[20] Maruyama, I. and Igarashi, G., (2010). Mechanism of moisture sorption hysteresis of hardened cement paste. Cement Science and Concrete Technology, 64(1), 96-102. (in Japanese)
[21] Maruyama, I. and Igarashi, G., (2011). Water vapor adsorption isotherm model of Portland cement paste. Journal of structural and construction engineering, 76(664), 1033-1041. (in Japanese)
[22] Igarashi, G. and Maruyama, I., (2012). Temperature dependency of virgin isothermal desorption and BET surface area of hardened cement paste. Proceedings of Annual AIJ Tokai Meeting, (50), 81-84. (in Japanese)
[23] Xi, Y., Bažant, Z. P. and Jennings, H. M., (1994). Moisture diffusion in cementitious materials Adsorption isotherms. Advanced Cement Based Materials, 1(6), 248-257.
[24] MC2010. (2010). Federation International du Beton, FIB Model Code for Concrete Structures. Lausanne, Switzerland.
[25] Masuda, Y., Tanano, H. (1991). Mathematical Model on Progress of Carbonation of Concrete. Concrete Engineering Dissertation Vol. 2, No. 1. (in Japanese)
[26] AIJ, Architectural Institute of Japan. (2016). Durability design and construction guidelines for reinforced concrete buildings and explanations. (in Japanese)
[27] AIJ, Architectural Institute of Japan. (2004). Durability design and construction guidelines for reinforced concrete buildings (draft) and commentary. (in Japanese)
[28] JSCE, Japan Society of Civil Engineers. (2001). Concrete Standard Specification-Maintenance. (in Japanese)
[29] JSCE336, Japan Society of Civil Engineers. (2008). Research Subcommittee (336 Committee) Results Report on Credibility Design Method for Concrete Structures. (in Japanese)
[30] Ye, W. Z., Zhang, J. Z., Huang, R., Hong, Q. Z., You, Y. C. (2010). A study of the measurement technology and evaluation criteria for rebar corrosion of RC structures. Institute of Architecture of the Ministry of the Interior of the Republic of China. (in Chinese)
[31] AIJ, Architectural Institute of Japan. (1997). Durability survey / diagnosis and repair guidelines (draft) / commentary for reinforced concrete buildings. Maruzen Co., Ltd. (in Japanese)
[32] Tu, F. J., Chiu, C. K. (2012). Study on Evaluation of Earthquake Resistance of RC School Buildings Considering the Effects of Deterioration and Earthquake Damage. [Master Thesis, NTUST] (in Chinese)
[33] CNS 13754 (1996) Standard test method for corrosion of metals and alloys-corrosivity of atmospheres-measurement of pollution. Bureau of Standards, Metrology & Inspection, Ministry of Economic Affairs of Taiwan, Taipei
[34] Maruyama, I., Noguchi, T., Matsushita, T. (2005). Hydration Model of Portland Cement. J. Struct. Constr. Eng., AIJ, No. 593, 1-8, Jul., 2005
[35] Maruyama, I., Noguchi, T., Sato, R. (2006). Prediction of Temperature and Moisture Distribution in High-Strength Mass Concrete Based on Heat and Moisture Transport Model. Achitectural Institute of Japan Structural Dissertation, 71(609), 1–8. (in Japanese)
[36] Choktaweekarn, P. (2008). Thermal properties and model for predicting temperature and thermal cracking in mass concrete, Master Thesis. Sirindhorn International Institute of Technology, Thammasat University.
[37] Dabarera, Arosha, Saengsoy, Warangkana, Kaewmanee, Krittiya, Mori, Kanako, and Tangtermsirikul, Somnuk (2017). Models for Predicting Hydration Degree and Adiabatic Temperature Rise of Mass Concrete Containing Ground Granulated Blast Furnace Slag. Engineering Journal, 21 (3), 157-171. https://doi.org/10.4186/ej.2017.21.3.157.
[38] Choktaweekarn, P., Saengsoy, W., & Tangtermsirikul, S. (2009). A model for predicting the specific heat capacity of fly-ash concrete. Science Asia, 35(2), 178-182.
[39] Bentz, D. (2007). Transient plane source measurements of the thermal properties of hydrating cement pastes. Materials and Structures, 40(1), 1073-1080.
[40] Saengsoy, W., & Tangtermsirikul, S. (2003). Model for predicting temperature of mass concrete. 4th Regional Symposium on Infrastructure Development in Civil Engineering. Bangkok.
[41] Q. Xu, J.M. Ruiz, J. Hu, K. Wang, R.O. Rasmussen. (2011). Modeling hydration properties and temperature developments of early-age concrete pavement using calorimetry tests. Thermochim. Acta, 512, pp. 76-85, 10.1016/j.tca.2010.09.003
[42] Powers, T. (1960). Physical properties of cement paste. Fourth International Symposium on the Chemistry of Cement, 1, pp. 577-613. Washington D.C.
[43] Neville, A. (1995). Properties of Concrete. London: Longman.
[44] Lam, L., Wong, Y., & Poon, C. (2000). Degree of hydration and gel/space ratio of high-volume fly ash/cement systems. Cement and Concrete Research, 30, 747-756.
[45] Ramachandran, V.S. (1984). Concrete Admixtures Handbook: Properties, Science, and Technology; Noyes Publications.
[46] Liu, H., Zhang, H. T., Xiao, H. (2013). Comparison of Antoine Equation Constants for Water Saturated Vapor Pressure.
[47] Shimomura, T. (1993). Dry shrinkage model of concrete based on pore volume distribution density function. [Doctoral Thesis. Tokyo University]
[48] Petrova, T., Dooley, R.B. (2014), Revised Release on Surface Tension of Ordinary Water Substance., Proceedings of the International Association for the Properties of Water and Steam.
[49] Takashi, S., Shimabukuro, I., Hidekichi, O. (2003). Analytical Study on pH Transition due to Carbonation of Concrete based on Alkali Ion Concentration. (in Japanese)
[50] Manabu, K., Tetsuro, M., Park, D., Takafumi, N. (2005). Research on a model for suppressing the neutralization of concrete by finishing materials for construction. Annual Proceedings of Concrete Engineering, Vol.27, No.1. (in Japanese)
[51] Lin, Z. Y, Chiu, C. K. (2019). Investigation on the Prediction Model of Time-dependent Corrosion Curve for Reinforcement Embedded in Carbonated Concrete [Master Thesis, NTUST] (in Chinese)
[52] Ueki, H., Gotou, T., Murakami, M., Mashiko, N. (2002). Modeling of the carbonation reaction based on pore-structures and chemical equilibrium in pore-water. Concrete Engineering Dissertation Vol. 13, No. 3. (in Japanese)
[53] Huang, X. Y., Chiu, C. K. (2019). Investigation on the Prediction Model of Time-dependent Corrosion Curve for Reinforcement Embedded in Concrete under Multi-Deterioration Environment [Master Thesis, NTUST] (in Chinese)
[54] Yokozeki, K., Watanabe, K., Hayashi, D., Sakata, N., Otsuki, N. (2003). Modeling of Ion Diffusion Coefficients in Concrete Considering with Hydration and Temperature Effects. JSCE Proceedings No.725 / V-58. (in Japanese)
[55] Garboczi, E.J., Bentz, D.P. (1992). Computer simulation of the diffusivity of cement-based materials. J Mater Sci 27, 2083-2092. https://doi.org/10.1007/BF01117921
[56] Tatsuhiko, S., Nobuaki, O., Shigeyoshi, N. (1996). Quantitative Estimation of Steel Corrosion in Mortar due to Carbonation. Proceedings of the Japan Society of Civil Engineers, No.532 V30. (in Japanese)
[57] Hiroshi, A., Tadashi, F., Yoshio, O. (1994). An Analytical Method of Moisture Transfer within Concrete Due to Drying. Proceedings of the Japan Society of Civil Engineers. (in Japanese)
[58] Yonezawa, T., Ashworth,V, Procter, R.P. M. (1998). The Mechanism of Fixing C1 Ions in the Pore Solution of Mortar by Cement Hydrate. Annual Papers on Concrete Engineering，V.10-2, pp. 475-480. (in Japanese)
[59] Maruya, T., TANGTERMSIRIKUL, T., Matsuoka, Y. (1998). Modeling of Chloride Ion Movement at The Surface Layer of Hardened Concrete. (in Japanese)
[60] Naomitsu, R., Yasuhiro, U. (2001). Effects of Admixtures on Chloride Ion Permeability and Immobilization. Concrete engineering，V.39, No. 7, pp. 19-24. (in Japanese)
[61] Nagataki, S., Otsuki, N., Wee, T.H. (1990), Condensation and binding of intruded chloride ion in hardened cement matrix materials. Proceedings of the Japan Society of Civil Engineers.
[62] Kobayashi, K. (1991). Carbonation of Concrete. Proceedings of the Japan Society of Civil Engineers.
[63] Shen, R. Z., Chiu, C. K. (2018). Discussion on Prediction Model of Rebar Corrosion Current in Concrete Neutral Environment [Master Thesis, NTUST] (in Chinese)
[64] Environmental Protection Agency, Executive Yuan, Annex to Regulations on Calculation Methods of Air Pollutant Emissions from Fixed Pollution Sources in Public and Private Places. (in Chinese)
[65] Liao, Nien Chi, Fumiki, T., Takafumi, N., Wei, Z. J., Kenji, H., Matsuhiro, K., Takahiro, H., Yuji, N. (2000). Corrosion protection in chloride-containing built reinforced concrete by nitrites corrosion inhibitor: Part 1. Differential corrosion inhibitor concentration in Concrete-Outline of Experiments. Summaries of technical papers of Annual Meeting Architectural Institute of Japan. A, Materials and construction, fire safety, off-shore engineering and architecture, information systems technology. 09150110. Architectural Institute of Japan. 1991-08.1991. 13-214. https://ci.nii.ac.jp/naid/110004191337/en/
[66] Ozumi, M., Uomoto, T. (2000). Prediction Method of Corrosion Rate of Reinforcing Bar in Concrete Based on Oxygen Diffusion Theory. Proceedings of the Japan Society of Civil Engineers, No.648/V-47. (in Japanese)
[67] Qinghai Meteorological Bureau，http://www.weather.com.cn/qinghai/dqhyl
[68] Suzuki, M., Naoyuki, F., Tsuyoshi, M. (2014). Establishment of A Coupled Analysis between Structure and Reinforcement Corrosion for Predicting Deterioration of Reinforced Concrete Structure by Salt Damage. (in Japanese)
[69] Maruya, T., Takeda, H., Horiguchi, K., Koyama, S., Hsu., K. L. (2006). Simulation of Steel Corrosion in Concrete Based on The Model of Macro-Cell Corrosion Circuit. Proceedings of the Japan Society of Civil Engineers, E Vol.62 No.4.
[70] Li, G. (2004), Durability behavior and basic models of reinforced concrete deterioration under climate environments. China University of Mining and Technology, Xuzhou.
[71] Iijima, T., Kudo, T., Tamai, Y. (2009). Effect of temperature on corrosion rate of reinforcing bar in concrete. RTRI report: 09142290. 2009-06. 23 6 11-16. https://ci.nii.ac.jp/naid/40016700383/en/ (in Japanese)
[72] Tottori, S., Miyagawa, T. (2004). Deterioration Prediction of Concrete Structures Concerning Rebar Corrosion Due to Carbonation. No.767/V-64. (in Japanese)
[73] Markeset, G., Myrdal,R. (2009), Modelling of reinforcement corrosion in concrete - State of the art.,COIN Project report 7., SINTEF Building and Infrastructure.
[74] Richardson, M. G. (1998). Neutralization of Reinforced Concrete: Its Causes and Management, Ireland: CITIS Ltd. Pp. 9-13.
[75] Zhan, S. M., Fang, Y. K. (2002). Research on the durability of cement mortar with combined deterioration of non-carbonization and salt damage. [Master Thesis, NCKU] (in Chinese)