Crack Self-Healing Behavior of High Performance Fiber Reinforced Cement Composites Under Various Environmental Conditions

摘要

In this research, the self-healing phenomenon of cracked High Performance Fiber Reinforced Cementitious Composites [HPFRCC] with two types of deformed high strength steel fibers was investigated under various environmental conditions such as water submersion, sea water and oil water. HPFRCC for the verification of self-healing capability were prepared following tensile test. Crack width was controlled by tensile test and then some specimens were fully pulled out in order to survey interfacial matrix damage. Morphology and the shape and size of precipitated particles in the cracks were examined by Digital 3D microscopy, SEM-EDS and TG-DTA. 3D X-ray microtomography (Micro CT) has been also used for the healing process after put-out test. The results show that most of the cracks (below 50 μm) were fully filled by newly-formed hydration products in short term period when re-cured in water after cracking. And then, self-healing capability of HPFRCC was largely dependent on the crack width. From these results, it is considered that HPFRCC also has a high potential for self-healing capability in some underwater structures.