Influence of micro-cracking on the permeability of engineered cementitious composites

Engineered Cementitious Composites (ECC) forms multiple micro-cracks under tension when loaded to beyond the elastic stage. Unlike normal concrete, such tight cracks help to maintain low water permeability even in the cracked stage. Therefore ECC shows great potential for application in hydraulic structures, such as dams and levees for which water seepage control is critical for their performance. In this paper, the permeability of ECC under constant tensile load was experimentally studied using a specially designed displacement-control loading device, providing permeability data for ECC under realistic loading conditions. In addition, an analytical model capable of predicting permeability property of ECC composite based on tensile strain and crack patterns has been proposed and experimentally verified on two different ECC mixtures. The findings of this research are expected to support future design and application of ECC for hydraulic structures.