**3.3 Strength activity index**

Mirza et al. [14] directed a few tests on strength activity index according to standard method ASTM C618 for bentonite blends at various temperatures, shown in **Figure 2**. A more prominent strength activity index was seen in 150o C warmed bentonite contrasted and various temperatures. Ahmad et al. [16] revealed 87.3 and 85.23% SI for bentonite at 7 years old and 28 days. 3% bentonite-concrete blends show better strength activity index at 7days, remaining stirs up to 21% displays best similarly among all mixes. A slight decrement in the strength action was seen by bentonite joining in concrete mortars [23].
