The rheological behavior of fly ash suspensions in alkali-silicate solutions used to prepare geopolymers is investigated. The transient stress response of fly ash suspensions at a constant applied strain rate is influenced by both the solids loading and the rheological behavior of the activating solution. The alkali-silicate solution itself behaves like a Newtonian fluid. The fundamental response of alkali-silicate fly ash suspension under constant applied shear strain rate exhibits a transition from a yield type to Maxwell flow. The variability in the Maxwell flow to yield type behavior depends upon the solids loading given by the solution to binder ratio and the composition of the activating solution. In both Maxwell flow and yield type responses, the maximum stress before initiation of flow is directly influenced by the viscosity of the activating solution. At specific solid loading, the transition between the Maxwell flow to yield type behavior is controlled by the composition of the activating solution. The viscous nature of the alkali-silicate solution produces a rate dependent transient response under constant applied strain rate.

中文翻译：

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粉煤灰悬浮液在碱金属硅酸盐溶液中的产率和麦克斯韦流体行为评价

研究了粉煤灰悬浮液在用于制备地质聚合物的碱金属硅酸盐溶液中的流变行为。粉煤灰悬浮液在恒定应变率下的瞬态应力响应受固体负载和活化溶液的流变行为的影响。碱金属硅酸盐溶液本身就像牛顿流体。在恒定外加剪切应变率下碱金属-硅酸盐飞灰悬浮液的基本响应表现出从屈服类型到麦克斯韦流的转变。Maxwell 流向屈服类型行为的可变性取决于由溶液与粘合剂的比率和活化溶液的组成给出的固体负载。在麦克斯韦流量和屈服类型响应中，流动开始前的最大应力直接受活化溶液粘度的影响。在特定的固体负载下，麦克斯韦流动与屈服类型行为之间的转变由活化溶液的组成控制。碱金属硅酸盐溶液的粘性在恒定应变速率下产生依赖于速率的瞬态响应。