The present research aims at the effect of early thermal gradient( initial setting) on o.c. concrete compressive strength with the aid of maturity concept:-
Standard cylindrical ∅ 150 * 300 mm concrete sealed specimens (( content by weight 400 kg/m3 cement) were subjected to a temperature of 4˚C for the duration of initial setting times ( 2 hrs. ) then later (removing sealed) on to standard temperature of 20 ˚C until 360 days at moisture and air curred conditions to be finally tested in compression at the prementioned dates . The same procedure was exactly repeated but the concrete specimens were subjected to 50˚C at the initial setting times . The final outcome showed that generally speaking the strength development was slower for the specimens subjected to 4˚C than those at 50˚C at the initial setting times but,beyond the age of 7 days approximately until 360 days the compressive strength gains more in strength for the specimens subjected to 4˚C than those at 50˚C as compared with same mixture subjected to 20˚C .