## 1 Introduction  
Much of Japan's infrastructure was constructed during the past half century, and parts of this infrastructure are undergoing severe deterioration due to environmental and loading actions. Road structures in cold and snowy regions are reported to deteriorate more quickly and severely than expected due to a combination of frost damage, chloride attack from de-icing agents, alkali-silicareaction (ASR), cracking and fatigue. For such structures, it is necessary to combat deterioration and ensure durability performance in design and to consider the inevitable environmental and loading actions during service. In November 2011, the Japanese government resolved to build \"Revival Roads\" in the Tohoku region to accelerate recovery from the Great East Japan Earthquake of March 2011. The Tohoku region experiences cold and snowy weather in the winter, so complex degradation involving multiple factors, such as those mentioned above, is anticipated. Thus, to enhance the durability performance of road structures, more particularly reinforced concrete (RC) slab decks, multiple countermeasures are proposed: a low water-to-cement ratio in the mix, mineral admixtures such as blast furnace slag (BFS) and/or fly ash to mitigate the risks of chloride attack and ASR, anticorrosion rebar and 6% entrained air for frost damage [1]. It should be emphasised here that such high durability specifications may contradictorily increase the risk of early age cracking induced by temperature and shrinkage due to the large amount of cement and the use of mineral admixtures. Meanwhile, to achieve the rational design, construction and maintenance of concrete structures, prediction of the performance of structures throughout their lifespan is crucial, from the beginning of the hydration reaction to the end of their service life, with consideration of various material and mix proportions, structural dimensions and curing and environmental conditions. [PERSON] et al. [2] proposed a thermo-mechanical model for computing strain and stresses whereby the effects are coupled. Once there is a thermal gradient, volumetric change would occur. If the volumetric change is not permitted, the thermal stresses would increase. On the contrary, once discontinuity occurs due to concrete cracking, the thermal field would be altered. In this model, the moisture equilibrium and transport is not considered. Furthermore, [PERSON] et al. [3] proposed thermo-hygro-mechanical simulations of early-age concrete cracking considering stress state, concrete creep, autogenous shrinkage and drying shrinkage to predict the early-age shrinkage and crack width. The hydration model was first fitted to the semi-adiabatic measurements on relatively small specimens, which are then scaled up to a structural level. In terms of computational process, various variables were required as the inputs for simulations such as sorption isotherms, intrinsic and relative permeability, porosity, Young's modulus, Poisson's ratio, compressive strength, and other parameters. While the former could not be extended for other durability issues which requires moisture transport such as chloride ingression, carbonation, ASR, calcium leaching and corrosion, the latter requires quite a high amount of material parameters that would be practically complicated. On the other hand, aiming for a unified approach to the evaluation of the behaviour of concrete structures in various conditions, the Concrete Laboratory of the University of Tokyo has been working to develop a multiscale integrated analysis platform, DuCOM-COM3 [4; 5]. The platform consists of two systems: a thermodynamic coupled analysis system, DuCOM, which integrates various micro-physical-chemical-based models of cementitious composites, and a nonlinear dynamic RC structure analysis system COM3, which deals with macroscopic mechanical responses and damage to RC structures.