A model for two types of calcium silicate hydrate in the microstructure of Portland cement pastes

Comparison of the characteristic leaching behavior of cements using standard (EN 196-1) cement mortar and an assessment of their long-term environmental behavior in construction products during service life and recycling

Upgrading the quality of mixed recycled aggregates from construction and demolition waste by using near-infrared sorting technology

https://josbrouwers.bwk.tue.nl/publications/Journal132.pdf

High performance of treated and washed MSWI bottom ash granulates as natural aggregate replacement within earth-moist concrete

Reactions that occur between a radioactive waste and a cement matrix being used for encapsulation can compromise the integrity of the resulting wasteform. The present paper describes some of the interactions that can occur within Portland cement based systems. It highlights the fact that to achieve successful encapsulation of the wide range of waste types that make up the legacy or historic wastes present in the UK, a toolbox or formulary of different cement systems with differing chemistries is needed. Some potential alternative cement systems are discussed.

Reactions in cement encapsulated nuclear wastes: need for toolbox of different cement types

This report constitutes a synthesis of the literature relating to the formation, structure, analysis, and characterization of ettringite from a variety of sources including hydration of portland cement, calcium aluminates, expansive cements, rapid-set cements, hydration of fly ash and coal combustion by-products, and laboratory synthetic processes. The major focus of the review is on the formation and properties of oxyanion-substituted ettringites. Substituted ettringite structures generally contain oxyanions of amphoteric heavy metals such as chromium, boron, arsenic, and selenium. Such amphoteric metals, under the elevated pH conditions of hydrating portland cement, usually will form water-soluble oxyanion species such as chromate. However, it has been established that the ettringite structure can accommodate many such heavy metals oxyanions in place of the usual sulfate anion, and will thus exhibit a very high degree of insolubility at those pH values where heavy metal water-soluble oxyanions will readily be subjected to water leaching.

Ettringite and oxyanion-substituted ettringites -- their characterization and applications in the fixation of heavy metals: a synthesis of the literature

W A Klemm

Papers

Ettringite and oxyanion-substituted ettringites -- their characterization and applications in the fixation of heavy metals: a synthesis of the literature