Non-linear modeling of yield stress increase due to SCC structural build-up at rest

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• 作者：Thibaut Lecompte ; Arnaud Perrot ; ^{arnaud.perrot@univ-ubs.fr}
• 关键词：Yield stress ; Structural build-up ; Thixotropy
• 刊名：Cement and Concrete Research
• 出版年：2017
• 出版时间：February 2017
• 年：2017
• 卷：92
• 期：Complete
• 页码：92-97
• 全文大小：459 K
• 卷排序：92

文摘

It is commonly considered that the yield stress of SCC increases linearly at rest. This increase is due to the SCC structural build-up. This behavior can be explained by the cement particle nucleation at the contact points. During the first dozens of minutes, the cement particle nucleation induces a linear increase of the yield stress in time. However, recent studies have shown that the trend of the yield stress increase becomes non-linear when considering a longer time (before the setting time). This study aims to provide a theoretical frame to describe this non-linear increase. The proposed model tends toward the linear model during the first dozens of minutes and follows the observed exponential law for a longer resting time. The discrepancy with the linear model is explained by two phenomena: an increase in the solid volume fraction and a decrease in the packing fraction due to cement particle nucleation.