To study the effects of capillary crystalline cement additive(CCCA)on the mechanical,chloride ion penetration resistance and self-healing properties of polyethylene(PE)fiber reinforced engineered cementitious composites(ECC),PE/ECC was used as the control group and mixed with different mass fractions of CCCA(2wt%,4wt%,6wt%,8wt%,10wt%),and the mechanical,anti-chloride ion permeability and self-healing properties of PE/ECC were investigated by compressive,flexural,tensile,electric flux method and pre-loaded strain damage method,and the self-healing products were analyzed by XRD and SEM-EDS for their physical composition,micro-scopic morphology and elemental composition.The results show that:The mechanical and anti-chloride ion per-meability of PE/ECC increase and then decrease with the increase of CCCA doping,and when the doping of CCCA is 4wt%,the mechanical and anti-chloride ion permeability of PE/ECC is most obviously improved by CCCA,and the compressive strength,flexural strength and ultimate tensile stress increase by 55.5%,10.8%,and 79.4%,respectively.The ultimate tensile strain does not change much,and the electrical flux decreases by 38.6%.The self-healing test shows that the recovery rate of tensile strength and strain energy of PE/ECC is significantly improved after doping with CCCA,and the self-healing performance is enhanced.When the pre-damage strain is 0.5%,the tensile strength and strain energy of PE/ECC specimens doped with CCCA are higher than those of the original matrix after 84 days of maintenance,which are 10.41%and 2.83%higher than those of the original matrix,respectively.The tensile strength and strain energy of PE/ECC specimens without CCCA are lower than those of undamaged specimens under three strain damages.The XRD and SEM-EDS results show that the CaCO3,calcium silicate hydrate(C-S-H),and ettringite(AFt)intensity diffraction peaks increase in the hydration products of PE/ECC with CCCA,and the self-healing products are mainly C-S-H crystals,and the distribution is denser in the PE/ECC with CCCA.
capillary crystalline cement additiveengineered cementitious compositesanti-chloride ion per-meabilityself-healingmicroscopic morphology
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