Study on the mechanisms of retardation of cement hydration by zinc and acceleration of hardening by sodium aluminate from crystallographic phase analysis
{"title":"Study on the mechanisms of retardation of cement hydration by zinc and acceleration of hardening by sodium aluminate from crystallographic phase analysis","authors":"Kazuo Yamada, Tsuneki Ichikawa, Hiroyuki Arai, Takahito Yasukochi, Kazuto Endo","doi":"10.1007/s10163-024-02059-6","DOIUrl":null,"url":null,"abstract":"<div><p>Zinc was focused on as an element causing hardening retardation due to delayed hydration of Ordinary Portland Cement (OPC), and its hardening inhibitory effect and the mechanism of hardening enhancement by sodium aluminate were analyzed by X-ray diffraction and scanning electron microscopy/energy dispersive X-ray spectroscopy. The addition of zinc hydroxide retarded hardening at more than 0.3 mass%, as previously reported, and zinc produced calcium zincate hydrates (qatranaite) and inhibited the hydration of tricalcium silicate (C<sub>3</sub>S), the main component of hydration of OPC. After the zinc had been fully consumed in qatranaite formation, C<sub>3</sub>S started normal hydration. The addition of sodium aluminate caused earlier re-hydration of C<sub>3</sub>S, which was inhibited by hydration, as the hydrates produced appeared to consume zincate anions. The rapid setting effect of sodium aluminate addition was also delayed by zinc hydroxide, but it was estimated that the addition of the same amount of zinc would ensure initial strength through early formation of hydrocalumite. In the longer term, strength was considered to be more enhanced by the onset of C<sub>3</sub>S hydration.</p></div>","PeriodicalId":643,"journal":{"name":"Journal of Material Cycles and Waste Management","volume":null,"pages":null},"PeriodicalIF":2.7000,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s10163-024-02059-6.pdf","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Material Cycles and Waste Management","FirstCategoryId":"93","ListUrlMain":"https://link.springer.com/article/10.1007/s10163-024-02059-6","RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"ENVIRONMENTAL SCIENCES","Score":null,"Total":0}
引用次数: 0
Abstract
Zinc was focused on as an element causing hardening retardation due to delayed hydration of Ordinary Portland Cement (OPC), and its hardening inhibitory effect and the mechanism of hardening enhancement by sodium aluminate were analyzed by X-ray diffraction and scanning electron microscopy/energy dispersive X-ray spectroscopy. The addition of zinc hydroxide retarded hardening at more than 0.3 mass%, as previously reported, and zinc produced calcium zincate hydrates (qatranaite) and inhibited the hydration of tricalcium silicate (C3S), the main component of hydration of OPC. After the zinc had been fully consumed in qatranaite formation, C3S started normal hydration. The addition of sodium aluminate caused earlier re-hydration of C3S, which was inhibited by hydration, as the hydrates produced appeared to consume zincate anions. The rapid setting effect of sodium aluminate addition was also delayed by zinc hydroxide, but it was estimated that the addition of the same amount of zinc would ensure initial strength through early formation of hydrocalumite. In the longer term, strength was considered to be more enhanced by the onset of C3S hydration.
期刊介绍:
The Journal of Material Cycles and Waste Management has a twofold focus: research in technical, political, and environmental problems of material cycles and waste management; and information that contributes to the development of an interdisciplinary science of material cycles and waste management. Its aim is to develop solutions and prescriptions for material cycles.
The journal publishes original articles, reviews, and invited papers from a wide range of disciplines related to material cycles and waste management.
The journal is published in cooperation with the Japan Society of Material Cycles and Waste Management (JSMCWM) and the Korea Society of Waste Management (KSWM).