Per §10.10 (High Strength Concrete Mix), the addition of Condensed Sil…

Question

Per §10.10 (High Strength Concrete Mix), the addition of Condensed Silica Fume (CSF) at about 10-15 percent by mass typically pushes concrete strength toward:

Accepted Answer

D. {'text': 'About 100 N/mm-square in laboratory results', 'label': 'D'}

1. §10.10(b): 'Condensed Silica flumes addition by about 10 to 15 per cent increases the concrete strength considerably. Concrete of strength 100 N/mm² has been achieved by using CSF.'
2. CSF works by filling the gel-pore-scale voids and producing a denser hydrated cement matrix.
_Source: IGNOU ET-522 Block-3 Unit-10 Concrete Mix Design, §10.10, p. 24_

Answer

{'text': 'About 5 N/mm-square (low strength) only', 'label': 'A'}

Answer

{'text': 'Below 20 N/mm-square (medium strength)', 'label': 'B'}

Answer

{'text': 'Negligible change in concrete strength', 'label': 'C'}