Title: Analysis of the Developing Damage of Concrete Due to Heating and Cooling

Author(s): K. Kordina, W. Wydra, and C. Ehm

Publication: Symposium Paper

Volume: 92

Issue:

Appears on pages(s): 87-114

Keywords: concretes: cooling: crack prop d igh temper .ef ormation; heating; h agation; creep properties; ature; stresses; ultrasonic

Date: 6/1/1986

Abstract:
Experiments were carried out ith measurements of the total defo ission in order to investigate the evelopment and deformation behavio y temperature conditions.S purpose specimens were loaded wi th different stress le- on normal concrete specirmation and of the acou-correlation between ur of concrete during vels and heated up to maximum temperatures between 150 "C and 750 OC. After a holding period the specimens were cooled under load. The creep deformations showed strongly increasing rates at about 450 OC during heating and at the beginning of the cooling phase. , In the heating phase the activity of acoustic emissions increased considerably. During the holding period no remarkable activity e observed. A new increase of the acoustic activity could rly observed at the beginning of the cooling phase. rmal concrete specimen, the main a.ctivity in the damaging occurs during unsteady temperature conditions, and is nt on the maximum temperature reac hed. parison between acoustic emission activity and creep de-formations shows that the acoustic emission activities are high at e time that creep deformations areI high.