Constitutive Modeling of Engineered Cementitious Composites (ECC)

Abstract

As research in ECC advances from material development to structural applications, the need for accurate constitutive models that capture ECC’s response under load becomes increasingly apparent. When combined with finite element method, constitutive models of ECC can be utilized to simulate structural response. Such simulations are useful to develop a better understanding of how the unique properties of ECC, such as tensile ductility and crack width control, can be translated into advantageous structural performances. Ultimately, high fidelity numerical simulation of ECC structural behavior can lead to a reduction in the amount of experimentation needed to gain confidence in full-scale structural deployment of ECC. Further, constitutive models can be helpful in the deployment of integrated structural and materials design approach, where targeted structural performance can be downlinked to composite properties and material composition and microstructures. Such scale-linkage provides an efficient basis for ECC material design for optimal structural performance.

While major advances have been made over the last decade on constitutive modeling of ECC, the goals identified above have yet to be realized. However, as this chapter demonstrates, a variety of constitutive models have successfully captured essential experimental trends. Specifically, this chapter presents two classes of constitutive models: phenomenological models and multiscale physics-based models. The phenomenological models account for 1D, 2D, and 3D stress states as well as monotonic, cyclic, and dynamic loading. These models have been verified with experimental data with various levels of successes. The multiscale model links microscale phenomena and material features to mesoscale and macroscale material and structural responses. The advantages of explicitly modeling the opening and sliding of multiple cracks of ECC are demonstrated. The models described lay the ground work for further much needed development in this field.