The objective of this project is to develop a multi-scale model for the representation of concrete materials, with emphasis on Ultra High Performance Concrete (UHPC). Symplectic Engineering will use the Phase I period to formulate and implement a prototype version of a hydration model suitable for UHPC representation. This model forms the first, and lengthwise-finest, component of the multi-scale material representation. To demonstrate its performance the model will be applied to simulate the hydration of a conventional cement as well as a UHPC mixture. The composition parameters for these two materials will be selected from the literature. Symplectic Engineering will also use the Phase I period to propose a framework for a full multi-scale model of concrete. In particular, emphasis will be placed on the selection of a mesoscale modeling approach that can be applied to the cement paste, mortar, and concrete scales. The proposed multiscale model framework will also encompass the homogenization strategy, which is required in order to use the results from a finer scale to represent a single material point within its immediately coarser scale. Conforming to the common practice in structural analysis, the macroscale, or structural scale, level will be modeled using a finite element representation.
