Cement hydration mechanisms through time – a review

Abstract

In this article the progress of the research on cement hydration mechanisms is critically reviewed, starting with the work of Le Chatelier and Michaelis during the late nineteenth century. Proposed mechanisms are discussed in the light of experimental data to highlight the role of new or improved analytical techniques. The focus of this article lies on the dormant period and the silicate reaction. Today many of the mechanisms proposed throughout time cannot withstand experimental evidence and need to be rejected, including the classical protective hydrate layer theory. However, it seems likely that hydrated surface species are involved in the mechanism. Theories that aim to explain the rate changes solely based on the nucleation and growth of portlandite can also not withstand experimental evidence. Nevertheless, the retardation of portlandite crystal growth through silicate ions is a relevant factor. Especially since it might present a mechanism for the nucleation of calcium silicate hydrate (C–S–H), backing up theories that propose C–S–H and portlandite to grow from the same nuclei. Finally, an overview over facts, that are currently considered to be valid and hence need to be regarded in the future mechanisms is given.

Relevance of Specific Surface of Mixed Oxide Derived from Layered Double Hydroxides on the Rheological Properties and Porosity of Cement Pastes

“…Dissolution and precipitation processes are closely linked, while the formation of portlandite crystals is restricted by the presence of silicate ions. Recent findings suggest that C–S–H and portlandite might both originate from the same initial points . The dynamic interaction nature of dissolution, saturation, nucleation, and growth in cement chemistry is demonstrated by the opposing effects of different quantities of Ca(OH) 2 .…”

“…Recent findings suggest that C−S−H and portlandite might both originate from the same initial points. 72 The dynamic interaction nature of dissolution, saturation, nucleation, and growth in cement chemistry is demonstrated by the opposing effects of different quantities of Ca(OH) 2 . Small amounts slow down the hydration process by altering saturation levels, whereas the introduction of more significant quantities of portlandite reduces this delay, due to the increased availability of nucleation sites.…”

Modification mechanism of calcium lignosulfonate on cementing cement

“…The orientation and intensity of the spatial distribution of these diffraction lines are closely related to the crystal structure. Each crystal produces a unique diffraction pattern that reflects the atomic distribution within the crystal 32 , 33 . This is the fundamental principle of X-ray diffraction.…”

Evaluation of Physico-Chemical Characteristics of Cement Superplasticizer Based on Polymelamine Sulphonate

“…Cement is used widely in waste repositories due to its ability to buffer a high pH value of water, to maintain many radionuclides as low soluble hydroxides, to lead a substrate for sorption, and thus to retard the migration of long-lived radionuclides [37][38][39][40]. An important feature of cement systems is the formation of high-pH conditions [41].…”