Impacts of Artificial Sand Grading on Strength and Self-healing Properties of Hydraulic ECC Materials.

Hydraulic ECC materials are characterized by large deformation ability, strong crack resistance and good self-healing capacity. In this paper, two strength grades of hydraulic ECC materials with water-binder ratio of 0.35 and 0.25 are prepared, and the influence of artificial sand grading on compressive strength and splitting tensile strength of hydraulic ECC materials is studied. Moreover, key factors affecting the self-healing capacity of hydraulic ECC materials are analyzed by using compressive strength ratio as evaluation index. Experimental results reveal that artificial sand grading has a significant effect on the workability of hydraulic ECC materials, while there is no notable correlation between artificial sand grading and compressive strength, and self-healing capacity and while splitting tensile strength increases slightly with the decrease in artificial grading. Hydraulic ECC material has good strength growth characteristics and self-healing capacity, and the compressive strength at 90 d age can be 30%~40% more than that of 28 d age. It is worth noting that hydraulic ECC materials strength after healing is possibly more than that of undamaged sample in early stage. [ABSTRACT FROM AUTHOR]