Wadi gravel – a new concrete aggregate in Qatar: Part 2 –Alkali aggregate reactivity
| Autor: | Mohamed Attia, Ian Sims, Khaled E. Hassan, Ahmed Sidiq, Murray Reid, Abdulrahman Al Naemi, Mohammed bin Saif Al-Kuwari |
|---|---|
| Rok vydání: | 2019 |
| Předmět: |
geography
Aggregate (composite) Gypsum geography.geographical_feature_category 0211 other engineering and technologies Geochemistry Geology 02 engineering and technology engineering.material Geotechnical Engineering and Engineering Geology Petrography 021105 building & construction Rhyolite Earth and Planetary Sciences (miscellaneous) engineering Rock types Quartz Wadi 021101 geological & geomatics engineering |
| Zdroj: | Quarterly Journal of Engineering Geology and Hydrogeology. 53:400-412 |
| ISSN: | 2041-4803 1470-9236 |
| DOI: | 10.1144/qjegh2019-089 |
| Popis: | Deposits of Wadi gravel are available in many parts of the Gulf region, but not widely utilized as aggregate for concrete, mainly due to the possibility of internal sulfate attack, plus the perceived risk of alkali aggregate reactivity (AAR). This paper describes the investigations for AAR of the Wadi gravel in this case, as part of the wider study described in Part 1 of this paper. Wadi gravel from the Mekaines site in Qatar was subjected to petrographic analysis, plus the gel-pat and accelerated mortar-bar test methods. The AAR potential was found to be low to normal. The accelerated mortar-bar test exhibited ‘innocuous’ behaviour after 14 days of immersion in alkali solution. When separately testing the constituent rock types of the Wadi gravel, limestone and quartz returned innocuous results, while rhyolite, granite and quartzite returned potentially alkali silica reactive (ASR) results and some reaction was confirmed using post-expansion petrographic examination. Wadi gravel was classified as potentially reactive in the RILEM AAR-4.1 accelerated concrete prism test, but of ‘low reactivity’ in the BS 812-123 test over the longer period of 12 months. Overcoming the potential problems of gypsum content and AAR successfully provides a valuable local resource of Wadi gravel aggregate for concrete. |
| Databáze: | OpenAIRE |
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