Potential utilization of riverbed sediments by hydrothermal solidification and its hardening mechanism.
Potential utilization of riverbed sediments by hydrothermal solidification and its hardening mechanism.
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DOI：
10.1016/j.jenvman.2008.11.013
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发表时间：
2009-04
影响因子：
8.7
通讯作者：
Z. Jing;Fangming Jin;N. Yamasaki;H. Maeda;E. H. Ishida
中科院分区：
文献类型：
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作者：
Z. Jing;Fangming Jin;N. Yamasaki;H. Maeda;E. H. Ishida
在聚四氟乙烯（PTFE）内衬不锈钢水热装置中，于343- 473 K的饱和蒸汽压下，通过引入氢氧化钙，对河床沉积物（粉土）进行了2- 24 h的水热固化。托贝莫来石被证明是最重要的强度生产固化粉土的组成部分。较长的养护时间或较高的养护温度有利于雪硅钙石的形成，从而促进强度的发展;然而，过长的养护时间（24 h）似乎对强度的发展产生负面影响。硬化机制包括水热过程中的晶体生长/形态演变。从粉土中溶解出来的物质首先以细小颗粒的形式沉淀下来，然后部分颗粒似乎形成了水化硅酸钙（CSH）凝胶的基本形态。具有沉淀颗粒的CSH凝胶似乎引起基质内的一些重组，这使得基质更致密，从而产生初始强度发展。雪硅钙石是由CSH凝胶不可避免地转化而来，以其互锁结构增强基体，从而进一步促进强度的发展。
Hydrothermal solidification of riverbed sediments (silt) has been carried out in a Teflon (PTFE) lined stainless steel hydrothermal apparatus, under saturated steam pressure at 343–473K for 2–24h by calcium hydrate introduction. Tobermorite was shown to be the most important strength-producing constituent of the solidified silt. A longer curing time or a higher curing temperature was shown to be favorable to the tobermorite formation, thus promoting strength development; however, overlong curing time (24h) seemed to affect the strength development negatively. The hardening mechanism consisted of the crystal growth/morphology evolution during the hydrothermal process. The species dissolved from the silt were precipitated first as fine particles, and then some of the particles seemed to build up the rudimental morphology of calcium silicate hydrate (CSH) gel. The CSH gel, with precipitated particles, appeared to cause some reorganization within the matrix, which made the matrix denser and thus gave an initial strength development. Tobermorite, transformed inevitably from the CSH gel, reinforced the matrix with its interlocked structure, and thus further promoted the strength development.