This research proposes the development of a multi-scale model for the evolution of multi-scale structure of early stage concrete. This model can predict concrete behaviors from its mineral and chemical constituents and macro curing environment. Experiments will be conducted to investigate the effects of concrete constituents on their physical, dielectric and mechanical behaviors. A special designed broadband measurement system integrating the dielectric spectrum and mechanical spectra measurement will be utilized to non-destructively probe the multi-scale behaviors. The multi-scale model, which embraces nano, micro, meso, and macro scale structural characteristics, will be an evolutional model whose growth rate is decided by cement hydration kinetics. The model will start from fundamental physical-chemical principles to describe the nano-scale concrete structures. The chemical reaction theory and diffusion theory will be utilized to establish the transfer functions between models at different scales. By use of this multi-scale model, the behaviors of early stage concrete at different scales and their evolution can be predicted from the inherent properties (such as the chemical and mineral constituents) and the external factors (such as thermal and moisture exchange with the surrounding environment).
If successful, the results of this research will lead to enhanced mechanism understand of fresh concrete behaviors. It will make distinctive contribution to the understanding and model description of hydration phenomena. The multi-scale approach helps to unveil the underlying mechanism for macroscopic concrete properties. It will contribute to the state of knowledge on the evolution of the multi-scale structure of concrete. This research will also provide a new spectra tool and test methodology for study concrete hydrations. The tool features the advantage of being inexpensive, non-destructive and providing real time data. Successful implementation of this research will contribute to the construction of high quality infrastructure and significantly improve the current design and construction practice.
