Rheological behavior of a novel quick-setting binder under resting and mixing and its relations to hydration and microstructure
Jiandong Wang, Guanzhao Jiang, Aixiang Wu, Yiming Wang, Shenghua Yin, Yong Wang
Abstract
Quick-setting binders are very popular in many engineering fields. It is well known that hydration plays an important role in the flowability loss of these binders. The top priority to solve this problem is to understand the time-dependence of rheology (TDR) fundamentally. In this paper, the rheology under resting and mixing conditions, hydration and microstructure of a novel quick-setting paste were investigated by a unique combination method of rotational rheological tests, isothermal calorimetry, environment scanning electron microscope, focused beam reflectance measurement, etc. A mathematical model, called LinExp model, is first proposed to predict rheological parameters at a given resting or mixing time. Besides hydration, particle settling and initial static gel strength are found to be important drivers of the TDR, especially in early stage. With the hydration of the binder, the formation of interlocking structures and the increase of large mixed particles in the paste lead to the significant TDR under resting and mixing, respectively.