Multi-level homogenization for the prediction of the mechanical properties of ultra-high-performance concrete

Ultra-high-performance concrete (UHPC), a multi-level cementitious composite that has properties influenced by constituents existing at different length scales, requires the combination of different modeling strategies to capture and understand its effective property. A multi-level (six levels) micromechanics-based homogenization is proposed to investigate the elastic mechanical properties of UHPC. Molecular dynamics and micromechanical theories based on Eshelby's inclusion model are adopted to investigate the effects of the properties of the various constituents, such as the fiber type, volume fraction, orientation, geometry, including the size and volume fraction of coarse aggregates on the elastic mechanical properties of UHPC. Experimental investigations incorporating a compressive strength test, scanning electron microscopy, and mercury intrusion porosimetry tests were conducted to validate the model. The proposed multi-level homogenization scheme is able to quantitatively prove the importance of each constituent and provide a modeling tool capable of facilitating a thorough investigation of the mechanical properties of UHPC.