Results of compressive strength after aggressive treatment by
H2SO4 are presented in Fig. 4. Generally, strength in both NC and
MC are low among all immersion period since specimens were
introduced into the aggressive medium immediately after demoulding
as already explained under specimen preparations. While NC
entertained gradual increase in strength until 56 days where it
drops and later pickups at 84 days, MC-1.5% continue to experience
reductions until 84 days before it shows signs of strength development.
The other modifications; MC-5% and MC-10% continue to
depreciate throughout the 84 days observation period.