Through comparison on the characteristics of all fracture sections,we can find that the loading stress level during the tests had an influenceon the area ratio of the extension zone and the instant fracturezone. Since crack propagation reduced the effective bearing area of thespecimen, which caused the stress on the remaining section graduallyincrease. The specimen developed final transient fracture as the residualsection was inadequate for resisting stress caused by externalloads. Therefore, a higher loading stress range leads to a smaller thearea of the crack extension zone but a proportional increase in the areaof instant fractures.