碱硅酸激活,Slag-Fly灰绑定

结构和土木工程国际会议上的研究

2018年10月01-02,荷兰阿姆斯特丹

Waltraud m . Kriven Kaushik Sankar,安德烈Sutrisno和彼得Stynoski

材料科学与工程系,伊利诺伊大学香槟分校,乌尔班纳,伊利诺斯州,美国NMR / EPR实验室,化学科学学院,伊利诺伊大学香槟分校乌尔班纳,伊利诺斯州,美国陆军工程师研发中心(ERDC),建筑工程研究实验室(方面),香槟,伊利诺斯州,美国

ScientificTracks抽象:飞机

文摘

硅酸钠激活,slag-fly灰绑定(SFB)和slag-metakaolin绑定(SMKB)常温硬化粘结剂有良好的机械性能和显著降低碳足迹比普通硅酸盐水泥(OPC)。本研究的目的是三倍。第一个目标是研究前体的属性。粉煤灰、矿渣和商业偏高岭土具有使用能量色散x射线荧光(EDXRF), x射线衍射(XRD)、激光衍射,傅里叶变换红外(FTIR)光谱以及魔角旋转,核磁共振光谱(MAS-NMR)。第二个目标是开发一种方法来识别和量化所有poorly-ordered阶段(未反应的前体和产品)出现在SFB SMKB。这是通过选择性化学提取和MAS-NMR谱减法的绑定和提取残留物。第三个目标是观察nanostructural进化阶段的产品随着时间的推移,温度和熔渣/粉煤灰在SFB比率。这是通过deconvoluting MAS-NMR光谱。这是观察到真正的地质聚合物的比例目前只有0-15 %和高SMKB SFB相比。尽管C-N-A-S-H和地质聚合物共存SFB和SMKB C-N-A-S-H是主要产品阶段形成的。 The mean chain length (MCL) and structure of C-N-A-S-H gel were estimated as a function of time, temperature and slag/fly ash ratio. The MCL decreased with increasing slag/fly ash ratio and decreased with increasing temperature. While increasing the slag/fly ash ratio accelerated the strength development, the cure time was decreased due to the formation of calcium silicate hydrate (C–S–H), calcium aluminum silicate hydrate (C–A–S–H), and (Ca, Na) based geopolymer. No new crystalline phases evolved through 28 days in ambient- or heat-cured binders. Furthermore, the early age properties of slag - fly ash binders namely, set time, and heats of reaction were investigated. Set time was investigated using a combination of the ASTM C403 penetration testing, and s-wave ultrasonic wave reflectometry (SUWR). The discrepancy in set time identified by these two methods suggested the presence of a soft gel which eventually hardened with time. The composition of this soft gel was analyzed by suspending the chemical reaction of the binder after the soft gel formed, but before it hardened. In order to analyze the composition of the soft gel, selective chemical extractions were performed on the binder. 29Si MAS-NMR and FTIR spectroscopy were performed on binders and extraction residues. The soft gel contained a modified calcium silicate hydrate gel (C-N-S-H where N=Na), with a short mean chain length and no observable Al incorporation. Orthosilicate units were also found to be present in relatively high proportions when compared to hardened binders at later ages

传记

Waltraud m . Kriven是正教授,联合教师持有的材料研究实验室(最初)和材料科学与工程系。她收到了她的博士1976年在固态化学,南澳大利亚州阿德莱德大学的。理学士(荣誉)学士学位在物理,无机化学,生物化学,也在阿德莱德。Kriven教授国际公认的专长领域的地质聚合物,阶段转换无机化合物及其应用在结构陶瓷复合材料,和低温合成氧化物陶瓷粉末。除了她做出了大量贡献氧化物复合材料设计,通过电镜微观结构表征技术和相平衡。Kriven集团已开发出一种新的原位技术,热阶段(2000°C)的同步加速器研究陶瓷在空气中,包括一个图像板探测器能够高分辨率,衍射测量光谱在20秒。她写了282篇期刊和56个会议出版物,以及给定或合著超过432会议演讲。Kriven教授主编或参与合编了26个书。她给了34个主题/全体国际会议上演讲,以及218年邀请国内外讲座,包括美国,日本,德国,英国,瑞士,西班牙,土耳其,埃及,韩国,意大利,乌克兰,法国,澳大利亚、哥伦比亚、巴西。Kriven赢得了詹姆斯·a·穆勒教授奖(2017)从美国陶瓷协会的工程部门研究陶瓷。 She was awarded the Brunauer Award twice (in 1988 and 1991) from the American Ceramic Society for co-authoring the best research papers of the year.

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