Binder system No. of days Average bulk density (± 0.001 g/cm3) nickel
   Control  500 ppm 1000 ppm
Cement + fly ash 1 2.303 2.303 2.303
28 2.381 2.359 2.388
Table 5: Average bulk density values of solidified products on 1 and 28 days of curing.