制备了高韧性PVA-SHCC(聚乙烯醇-应变硬化水泥基复合材料)试件,通过吸水试验和中子成像试验,研究了未开裂和直拉多缝开裂情况下SHCC的吸水特性.结果表明:中子成像能够对无裂缝和多缝开裂SHCC试件的吸水过程进行可视化追踪和定量分析计算；SHCC在无裂缝时吸水很少,中子成像无肉眼可见的水分前锋；多缝开裂后,能够清晰探测到水分沿80～140 μm的裂缝迅速侵入材料内部,并通过遭横向拉拔破坏的纤维与水泥基体界面而充满裂缝区；在这种情况下,应从耐久性角度限制SHCC多重裂缝宽度.%High toughness PVA-SHCC (polyvinyl alcohol-strain hardening cement-based composite) specimens were prepared. Through water absorption test and neutron radiography, water absorption of SHCC with and without multi-cracks under direct uniaxial tensile loading was investigated. The results indicate that neutron radiography can achieve visualized tracing of water penetration process and quantification of water distribution in uncracked and multi-cracked SHCC. Uncracked SHCC absorbs only little water; consequently no water front can be observed from neutron images by naked eyes. For multi-cracked SHCC, however, water is penetrated into a specimen through the cracks at a width of 80-140 jzm, then filled in the multi-cracked zone and further along the damaged interfaces between PVA fibers and cement matrix. In this case, the width of multi-cracks in SHCC should be taken into account from the aspect of durability.
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