Thermal activation and pozzolanic reactivity of calcined clay minerals for applications in Portland cement blends

In this paper, results of a solid-state nuclear magnetic resonance (NMR) analysis of white Portland cements blended with different calcined clays are reported. 27Al and 29Si MAS NMR spectra of blends before and after hydration have been acquired. Compressive strengths of mortars based on these blends have been determined depending on hydration time.
It has been stated that the addition of calcined clays to a Portland cement results in significant nanoscale changes in the formed C-S-H structure which have implications on the performance of the system.

Author: J. Skibsted, Z. Dai, K.E. Rasmussen, N. Garg

Section: Science and production

Keywords: solid-state NMR spectroscopy, white Portland cement, calcined clay, kaolinite, metakaolin, montmorillonite