Initial sequence for alkali-silica reaction: Transport barrier and spatial distribution of reaction products
| Autor: | Mohammed Fouad Alnahhal, Parth Panchmatia, Arnaud Castel, Ailar Hajimohammadi, Quang Dieu Nguyen, Taehwan Kim |
|---|---|
| Rok vydání: | 2019 |
| Předmět: |
Imagination
Building & Construction Materials science Chemical substance Aggregate (composite) genetic structures media_common.quotation_subject 0211 other engineering and technologies 02 engineering and technology Building and Construction 021001 nanoscience & nanotechnology Chemical reaction Characterization (materials science) law.invention Magazine Chemical engineering law 021105 building & construction Alkali–silica reaction General Materials Science 0210 nano-technology Science technology and society media_common |
| Popis: | © 2019 Elsevier Ltd Alkali-silica reaction (ASR) is the result of complex chemical reactions. The exact sequence of ASR gel formation has yet to be fully understood. One promising hypothesis is that ASR gel starts to form only in localized regions where the availability of calcium is restricted. A transport barrier (C–S–H) around the aggregate has been hypothetically suggested. However, the existence of this physical barrier and the formation of ASR gel inside this barrier has been questioned because it has never been observed experimentally. This paper firstly presents a direct observation of the physical barrier, spatial distribution of reaction products, and crack formations in a reactive aggregate exposed to a model reactant system. Combined analyses using X-ray micro tomography and other chemical characterization techniques shows that ASR gel preferentially starts to form at localized areas covered by C–S–H, loosely packed reaction products with pores, and pre-existing defects. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|