Effect of sustained tensile loading on SHCC crack widths

Strain Hardening Cementitious Composites (SHCCs) exhibit multiple cracking when subjected to tensile loading and can achieve a strain capacity of more than 4% while resisting the full tensile load. Sustained tensile loading (creep) tests were performed to determine the time-dependant cracking behaviour of SHCC. The sustained load levels ranged from 40% to 80% of the ultimate tensile resistance. In this paper the crack widths during sustained tensile loading of SHCC were quantified. It was found that the average crack widths are not significantly dependant on the level of the creep load. The average crack widths were however found to increase significantly from around 70 μm to more than 200 μm after 7 days of sustained loading, even at a load of less than 50% of the ultimate tensile strength.