Title: Identification of viscoelastic behavior for early-age concrete based on measured strain and stress histories

Author(s): Seongcheol Choi, Soo Cha, Byung Oh

Publication: RILEM

Volume: 43

Issue: 8

Appears on pages(s): 1161-1175

Keywords: Compliance function, Early-age concrete, Indentification, Relaxation function, Viscoelastic property

DOI:

Date: 8/1/2010

Abstract:
In order to accurately predict the stress of concrete structures that undergo variations of temperature and moisture, a compliance function is required that considers the fast development of material properties in early-age concrete. The purpose of present study is to identify the viscoelastic behavior in actual concrete structures at early ages. To this end, a numerical method to identify the viscoelastic properties from measured strain and stress histories was investigated and a series of full-scale test members was fabricated, from which the behavior of early-age concrete was directly measured. The relaxation function was identified from measured data in the full-scale members and the existing compliance model, which is based on the solidification theory, was modified for incorporation into the early-age behavior. The modified compliance model described the highly viscoelastic behavior of concrete at very early ages and thus allowed more accurate evaluation of deformation and stress in early-age concrete.