Table 3.

29Si MAS NMR chemical shifts (δ) from cement materials–bentonite interfaces in several experiments: HB4 and HB5 from medium-cell experiments; D-1C and D3 from the small-cell 5 mortar–bentonite interface; and a sample at 2 cm from the interface, respectively. Mont60 and 120: montmorillonite-portlandite batch experiments at 60 and 120°C at molar ratios of 2:1. Mmt indicates the untreated <2 µm size fraction of FEBEX bentonite.

Sampleδ Quartz (ppm)δ Q3 (ppm)δ Q2(0Al) (ppm)δ Q2(1Al) (ppm)
Mmt–93.8
HB4–93.3
HB5–93.6Shoulder
D1-C–107.4–93.5–85.1–81.4
D3–93.6
Mont60–93.6–85.3
Mont120–93.6–86.4–83.2