X-ray computed tomography proof of bacterial-based self-healing in concrete
X-ray computed tomography proof of bacterial-based self-healing in concrete
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DOI：
10.1016/j.cemconcomp.2014.07.014
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发表时间：
2014-10
影响因子：
10.5
通讯作者：
Jianyun Wang;J. Dewanckele;V. Cnudde;S. Vlierberghe;W. Verstraete;N. Belie
中科院分区：
文献类型：
--
作者：
Jianyun Wang;J. Dewanckele;V. Cnudde;S. Vlierberghe;W. Verstraete;N. Belie
自修复策略被认为是一个有前途的解决方案，以减少混凝土基础设施的高维护和维修成本。在本工作中，研究了使用水凝胶包裹细菌孢子（生物水凝胶）的基于细菌的自我修复。通过光学显微镜定量研究了含/不含生物水凝胶试样的裂纹闭合行为。为了观察标本内部的自我愈合，使用了高分辨率X射线计算机显微断层扫描（X射线μCT）。研究了愈合产物在整个基质中的总量和分布。该研究表明，与仅使用纯水凝胶的参考样品相比，掺入生物水凝胶的样品具有明显改善的愈合效率。对于小于0.3 mm的裂纹，生物水凝胶试样的愈合率在70%至100%的范围内，比纯水凝胶高50%以上;最大裂纹桥接约为0.5 mm（7 d内），而纯水凝胶仅允许愈合约0.18 mm的裂纹。含生物水凝胶的标本中愈合产物的总体积比为2.2%，比含纯水凝胶的标本（1.37%）高约60%。
Self-healing strategies are regarded as a promising solution to reduce the high maintenance and repair cost of concrete infrastructures. In the present work, a bacterial-based self-healing by use of hydrogel encapsulated bacterial spores (bio-hydrogels) was investigated. The crack closure behavior of the specimens with/without bio-hydrogels was studied quantitatively by light microscopy. To have a view of the self-healing inside the specimens, a high resolution X-ray computed microtomography (X-ray μCT) was used. The total amount and the distribution of the healing products in the whole matrix were investigated. This study indicates that the specimens incorporated with bio-hydrogels had distinct improved healing efficiency compared to the reference ones with pure hydrogel only. The healing ratios in the specimens with bio-hydrogels were in the range from 70% to 100% for the cracks smaller than 0.3 mm, which is more than 50% higher than for the ones with pure hydrogel; and the maximum crack bridging was about 0.5 mm (in 7 d), while pure hydrogels only allowed healing of cracks of about 0.18 mm. The total volume ratio of the healing product in the specimens with bio-hydrogels amounted to 2.2%, which was about 60% higher than for the ones with pure hydrogel (1.37%).