Past measuring attempts at natural abundance of Ca show promise , but are, however, limited by the length and resolution (signal-to-noise ratio) of the spectra obtained. Nevertheless, it is expected that the situation might improve in the future as larger fields (> 20 T) become readily available and better routines for signal enhancement are developed. Further, due to the advances in atomistic modeling techniques over the past 10 years a better atomic-level understanding of the anhydrous and hydrated phases of Portland cement has been obtained. Particular advances were achieved in elucidating the C-S-H structure , where it was shown that combining DFT predicted chemical shieldings with experimentally measured ( 1 H, Al and Si) NMR spectra can be successfully used to gain atomic-level insight into the C-S-H structure .