Relating Ettringite Formation and Rheological Changes during the Initial Cement Hydration: A Comparative Study Applying XRD Analysis, Rheological Measurements and Modeling

In order to gain a deeper understanding of the rheological development of hydrating ordinary Portland cement (OPC) pastes at initial state, and to better understand their underlying processes, quantitative X-ray diffraction (XRD) analysis and rheological measurements were conducted and their results combined. The time-dependent relation between phase development and flow behavior of cement paste was investigated at two different temperatures (20 and 30 °C), over a period of two hours. Regarding the phase development during hydration, ettringite precipitation was identified as the dominant reaction in the first two hours. For both temperatures, the increasing ettringite content turned out to correlate very well with the loss of workability of the reacting cement paste. An exponential relationship between ettringite growth and flow behavior was observed that could be explained by applying the Krieger-Dougherty equation, which describes the influence of solid fraction on the viscosity of a suspension.

[1]  Wolfram Schmidt,et al.  Characterization data of reference cement CEM I 42.5 R used for priority program DFG SPP 2005 “Opus Fluidum Futurum – Rheology of reactive, multiscale, multiphase construction materials” , 2019, Data in brief.

[2]  Ming Jen Tan,et al.  Printability region for 3D concrete printing using slump and slump flow test , 2019, Composites Part B: Engineering.

[3]  D. Stephan,et al.  Investigation of the Early Cement Hydration with a New Penetration Test, Rheometry and In-Situ XRD , 2019, RILEM Bookseries.

[4]  P. Sarker,et al.  Mitigation of the potential alkali–silica reaction of FNS using ground FNS as a supplementary binder , 2019 .

[5]  X. Kong,et al.  The early hydration of OPC investigated by in-situ XRD, heat flow calorimetry, pore water analysis and 1H NMR: Learning about adsorbed ions from a complete mass balance approach , 2018, Cement and Concrete Research.

[6]  T. Hertel,et al.  Study of hydration potential and kinetics of the ferrite phase in iron-rich CAC , 2016 .

[7]  P. Monteiro,et al.  Advances in understanding hydration of Portland cement , 2015 .

[8]  F. Goetz-Neunhoeffer,et al.  Quantitative analysis of C–S–H in hydrating alite pastes by in-situ XRD , 2013 .

[9]  Moncef L. Nehdi,et al.  Only tall things cast shadows: Opportunities, challenges and research needs of self-consolidating concrete in super-tall buildings , 2013 .

[10]  Nicolas Roussel,et al.  The origins of thixotropy of fresh cement pastes , 2012 .

[11]  S. Gauffinet-Garrault.  5 – The rheology of cement during setting , 2012 .

[12]  J. Bullard,et al.  Mechanisms of cement hydration , 2011 .

[13]  Christopher B. Stabler,et al.  A remastered external standard method applied to the quantification of early OPC hydration , 2011 .

[14]  L. Wadsö.  Operational issues in isothermal calorimetry , 2010 .

[15]  Moncef L. Nehdi,et al.  Coupled Effects of Time and High Temperature on Rheological Properties of Cement Pastes Incorporating Various Superplasticizers , 2009 .

[16]  Itai Panas,et al.  Early hydration and setting of Portland cement monitored by IR, SEM and Vicat techniques , 2009 .

[17]  J. Pakusch,et al.  The ettringite – superplasticizer interaction and its impact on the ettringite distribution in cement suspensions , 2009 .

[18]  J. Gołaszewski.  Influence of cement properties on rheology of fresh cement mortars without and with superplasticizer , 2008 .

[19]  M. Nehdi,et al.  Effect of Chemical Admixtures on Rheology of Cement Paste at High Temperature , 2007 .

[20]  Frank Winnefeld,et al.  Effect of temperature on the pore solution, microstructure and hydration products of Portland cement pastes , 2007 .

[21]  L. Struble,et al.  Rheological changes associated with setting of cement paste , 1995 .

[22]  Leslie J. Struble,et al.  Viscosity of Portland cement paste as a function of concentration , 1995 .

[23]  A. Nonat.  Interactions between chemical evolution (hydration) and physical evolution (setting) in the case of tricalcium silicate , 1994 .

[24]  I. Odler,et al.  On the origin of Portland cement setting , 1992 .

[25]  G H Tattersall,et al.  Workability and quality control of concrete , 1991 .

[26]  H. Uchikawa,et al.  Influence of character of clinker on the early hydration process and rheological property of cement paste , 1985 .

[27]  H. Rietveld.  A profile refinement method for nuclear and magnetic structures , 1969 .

[28]  Thomas J. Dougherty,et al.  A Mechanism for Non‐Newtonian Flow in Suspensions of Rigid Spheres , 1959 .