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Abstract: Cracking of early-age concrete can occur in the track beds of high-speed railways due to changes in material properties, environmental effects, and construction processes. This is a multi-field, time-varying issue involving hydro-thermo-chemo-mechanical coupling. However, to date, research has not adequately described the early-age cracking mechanisms in track beds, and few risk control measures have been proposed. To solve this problem, we incorporated the hydration degree of concrete into multi-field coupling equations for early-age concrete, and set boundary conditions that account for environmental influences and various stress factors that typically cause early creep of concrete. A four-field coupled risk prediction model was built based on hydro-thermo-chemo-mechanical properties, and was used to calculate and analyze various time-varying behavior (including the risk and form of cracking) in the hydro, thermo, chemo, and mechanical fields of early-age concrete. Finally, we focused on material-related factors (maximum heat of hydration and peak heat release time), environmental factors (temperature difference between day and night, average daily cooling rate, and intensity of solar radiation), and construction technique factors (molding temperature, pouring time, and thermal insulation coefficient). The influence of these factors on the early-age cracking risk of the track bed was analyzed, and risk control measures against early cracking were proposed accordingly.

早期道床多场时变行为及开裂机理研究

[1]CEB (Comité Euro-international du Béton), 1990. CEB-FIP Model Code 1990, First Draft. CEB Bulletin D’information, Lausanne, Switzerland.

[2]CerveraM, FariaR, OliverJU, et al., 2002. Numerical modelling of concrete curing, regarding hydration and temperature phenomena. Computers & Structures, 80(18-19):‍1511-1521.

[3]de SchutterG, 1999. Degree of hydration based Kelvin model for the basic creep of early age concrete. Materials and Structures, 32(4):260-265.

[4]de SchutterG, 2002. Finite element simulation of thermal cracking in massive hardening concrete elements using degree of hydration based material laws. Computers & Structures, 80(27-30):2035-2042.

[5]de SchutterG, TaerweL, 1996. Degree of hydration-based description of mechanical properties of early age concrete. Materials and Structures, 29(6):335-344.

[6]DuMY, 2015. Thermo-Hygro-Mechanical Model of Early-Age Concrete Based on Micro-Pore Structure Evolution. MS Thesis, Zhejiang University, Hangzhou, China(in Chinese).

[7]GawinD, PesaventoF, SchreflerBA, 2006. Hygro-thermo-chemo-mechanical modelling of concrete at early ages and beyond. Part I: hydration and hygro-thermal phenomena. International Journal for Numerical Methods in Engineering, 67(3):299-331.

[8]HuRP, ZhangRL, WangMS, et al., 2018. Experimental study on the cracking of concrete about the high speed railway in big temperature difference area of Gobi. Bulletin of the Chinese Ceramic Society, 37(6):2042-2047 (in Chinese).

[9]KünzelHM, 1995. Simultaneous Heat and Moisture Transport in Building Components. One- and Two-Dimensional Calculation Using Simple Parameters. Fraunhofer IRB Verlag Suttgart.

[10]MiaoCW, 2018. Early shrinkage cracking of modern concrete and its inhibiting technology. Journal of Xuzhou Institute of Technology (Natural Sciences Edition), 33(3):1-8 (in Chinese).

[11]MOHURD (Ministry of Housing and Urban-Rural Development of the People’s Republic of China), 2004. Code for Design of Concrete Structures, GB 50010-2002. National Standards of the People’s Republic of China(in Chinese).

[12]RenJJ, DengSJ, ZhangKY, et al., 2021. Design theories and maintenance technologies of slab tracks for high-speed railways in China: a review. Transportation Safety and Environment, 3(4):tdab024.

[13]RenJJ, ZhangQ, ZhangYC, et al., 2023. Evaluation of slab track quality indices based on entropy weight-fuzzy analytic hierarchy process. Engineering Failure Analysis, 149:107244.

[14]van BreugelK, 1995. Numerical simulation of hydration and microstructural development in hardening cement-based materials: (II) applications. Cement and Concrete Research, 25(3):522-530.

[15]ZhangJ, HouDW, SunW, 2010. Experimental study on the relationship between shrinkage and interior humidity of concrete at early age. Magazine of Concrete Research, 62(3):191-199.

[16]ZhangJ, GaoY, WangZB, 2013. Evaluation of shrinkage induced cracking performance of low shrinkage engineered cementitious composite by ring tests. Composites Part B: Engineering, 52:21-29.