XRD and SEM analysis showed that the main composition of the white substance which formed in cracks is CaCO3, which can block cracks and is probably the main cause of self-sealing.

• 对试件裂缝中沉积的白色物质做SEM、XRD分析得出其成份主要为CaCO_3，CaCO_3堵塞裂缝应该是引起自愈现象的主要原因；