Assessment of influence of self-healing behavior on water permeability and mechanical performance of ECC incorporating superabsorbent polymer (SAP) particles

The self-healing behavior of a series of pre-cracked engineered cementitious composites (ECC) incorporating superabsorbent polymers (SAP) with relative low crack width is investigated in this paper, focusing on water permeability and recovery of mechanical performance. Self-healing in ECC with different pre-cracked levels and different curing conditions (high/low relative humidity (RH) cycle and 95% RH) was studied. The water permeation test and uniaxial tensile test both were conducted to evaluate the influence of self-healing on water permeation and mechanical performance in ECC incorporating SAPs. Meanwhile, the process of self-healing and products both were measured by using Environment scanning electron microscope (ESEM) and energy dispersive X-ray spectroscopy (EDS). The test results, together with ESEM and EDS observations, further confirmed that when exposed to high/low relative humidity conditions, the self-healing process of ECC was accelerated by the help of SAPs which can absorb H2O from high RH condition and sustained release H2O during low RH conditions and more self-healing product was formed in crack. The findings of this study can be used to promote self-healing of ECC with SAPs in infrastructure application.