Role of pore size distribution in salt uptake, damage, and predicting salt susceptibility of eight types of Japanese building stones
Role of pore size distribution in salt uptake, damage, and predicting salt susceptibility of eight types of Japanese building stones
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DOI：
10.1016/j.enggeo.2009.05.007
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发表时间：
2010-10
影响因子：
7.4
通讯作者：
S. Yu;C. Oguchi
中科院分区：
文献类型：
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作者：
S. Yu;C. Oguchi
对8种广泛使用的日本建筑石材进行了三种破坏性盐的结晶侵蚀，以研究是否可以仅从它们的孔隙特征来评估这些石材的耐久性。此外，还考察了孔径大小及其分布对吸盐率和结晶损伤的影响。总孔隙率对盐分的吸收和引起的损害有显著的影响。考虑了五种不同的微孔率上限，以评价它们对盐结晶损伤的相对影响。实验结果证实了半径小于0.05(或0.1)µm的微孔是影响盐结晶损伤的关键因素的理论假设。然而，在浸渍-干燥型盐风化试验中，小于5µm的孔隙在液体吸收中起更重要的作用，实验前后的孔径分布证实了这一点。此外，这些孔似乎与较小的微孔协同作用，导致结晶损伤。结果表明，孔径分布在土壤吸盐和盐害过程中起着非常重要的作用。基于这些孔隙特征，可以很容易地从一次汞孔隙率测量中获得，提出了一种称为盐敏指数(SSI)的耐久性评估指标。估计的结果与测试岩石的实际干重损失显著相关。
Eight widely used Japanese building stones were subjected to crystallization attacks by three types of destructive salts to investigate whether it is possible to estimate durability of the stones solely from their pore characteristics. The influence of pore size and their distribution on salt uptake and salt crystallization damage was also evaluated. Total porosity was found to have a significant effect on the amount of salt absorbed and of damage induced. Five different upper limits of microporosity were considered in order to evaluate their relative influences on salt crystallization damage. The experimental results corroborate the theoretical supposition that micropores smaller than 0.05 (also 0.1) µm in radius are a critical influence on salt crystallization damage. However, pores smaller than 5 µm are more important in liquid absorption in the impregnation-drying type of salt weathering test, as confirmed by the pore size distributions of pre-and post-experiment specimens. Moreover, these pores seem to act synergistically with smaller micropores in inducing crystallization damage. The results indicate that pore size distribution plays a very important role in both salt uptake and salt damage processes. Based on these pore characteristics, which can readily be obtained from a single mercury porosimetry measurement, a durability estimator called salt susceptibility index (SSI) is proposed. The estimated outcomes correlate significantly with the actual dry weight loss of the rocks tested.