Stage model of stress-strain relationship for concrete under short-term load Part 3. Descending branch

✍ Scribed by I. Blechman

• Publisher: Elsevier Science
• Year: 1989
• Tongue: English
• Weight: 587 KB
• Volume: 19
• Category: Article
• ISSN: 0008-8846
• DOI: 10.1016/0008-8846(89)90085-9

✦ Synopsis

While the distinctive feature of the ascending branch in the stress-strain diagram (SSD) of concrete is the atrophying effect, the descending branch (DB) is distinguished by progressive macrodestruction. It is shown that the DB model should consist of two macro-components: the central function, adopted through introduction of macrorigidity, and the internal friction potential. The macrorigidity function is seen to be a combination of the latter with the Gaussian of macrodestruction.

It is also established that the specific energy of the destruction process decreases linearly with strength, and that the absolute term of the function represents the internal friction potential -which is intensively manifested with the onset of macrocracking and subsequently "consumed" by the energy released in the process.

The DB model predicts adequately the course of the descending branch, including the friction "plateau"; it is thus essential for stress analysis of elements in bending and eccentric compression. It consists of a set of basic functions, each of them representing an aspect of the actual physical process taking place under load beyond the strength limit.