The uptake of radium by calcium silicate hydrates and hardened cement paste

Effects of High Temperature on Carbonated Calcium Silicate Cement (CSC) and Ordinary Portland Cement (OPC) Paste

This paper presents a comparative study on the effects of high temperature (~500°C) on carbonated calcium silicate-based cement (CSC), hydrated ordinary Portland cement (OPC), and hydrated OPC with 20% fly ash (FA) paste samples. The CSC is primarily composed of calcium–silicate minerals with different calcium to silica atomic ratios, such as wollastonite, rankinite, and pseudowollastonite. The...

Macro- and microspectroscopic study of Nd (III) uptake mechanisms in hardened cement paste.

Cement is an important component in repositories for low-level and intermediate-level radioactive waste. Nd uptake by hardened cement paste (HCP) has been investigated with the aim of developing a mechanistic understanding of the immobilization processes of trivalent lanthanides and actinides in HCP on the molecular level. Information on the microstructure of HCP, the Nd distribution in the cem...

Structure and Physical Properties of Hardened Portland Cement Paste

Nanostructure of calcium silicate hydrates in cements.

Calcium silicate hydrate (CSH) is the major volume phase in the matrix of Portland cement concrete. Total x-ray scattering measurements with synchrotron x rays on synthetic CSH(I) shows nanocrystalline ordering with a particle diameter of 3.5(5) nm, similar to a size-broadened 1.1 nm tobermorite crystal structure. The CSH component in hydrated tricalcium silicate is found to be similar to CSH(I...

The Surface Area of Hardened Cement Paste as Measured by Various Techniques

Hydrated cement paste has a high specific surface area due almost entirely to the calcium-silicate-hydrate reaction product. The surface area of cement paste is closely related to many crucial properties, including strength and permeability, and is therefore a useful predictive measurement. It is also a useful parameter for studying the nature of the calcium-silicate-hydrate gel itself. Unfortu...