مساهمة التغير الحراري المبكر ضمن فترة التماسك الابتدائي و طريقة المعالجة علي مقاومة الانضغاط لخرسانة الاسمنت الاعتيادي باستخدام مفهوم الانضاج

Contribution of early thermal gradient within initial set period and curing methods on O.C. concrete compressive strength with the aid of maturity concept

Kirkuk University Journal /Scientific Studies (KUJSS) Volume 12, Issue 3, June 2017 ISSN 1992 – 0849 Email: kirkukjoursci@yahoo.com,www.kujss.comWeb Site: kirkukjoursci@gmail.com Nayyef Dwerij Hameed naiefdwerige@gmail.com Civil Engineering Dept. / College of Engineering /University of Mosul Abstract 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 .