Hits:

Indexed by:期刊论文

Date of Publication:2016-10-01

Journal:COMPUTERS & STRUCTURES

Included Journals:SCIE、EI、Scopus

Volume:174

Issue:,SI

Page Number:66-78

ISSN No.:0045-7949

Key Words:Early-age concrete; Crack initiation; Cracking propagation; Geometry effect; Fracture mechanics; Restrained shrinkage

Abstract:An elliptical ring test method is proposed to replace the circular ring test recommended by ASTM and AASHTO for faster and more reliable assessment of cracking tendency of concrete. Numerical models are also established to simulate stress development and crack initiation/propagation in restrained concrete rings. Cracking age, position and propagation in various rings are obtained from numerical analyses that agree well with experimental results. Elliptical thin rings of certain geometry can shorten the ring test duration as desirable. In thin rings, crack initiation is caused by external restraint effect so that a crack occurs at the inner circumference and propagates towards the outer one. In thick rings, crack initiation is mainly due to the self-restraint effect so that a crack occurs at the outer circumference and propagates towards their inner one. Therefore, thick elliptical concrete rings do not necessarily crack earlier than circular ones as observed from experiment. (C) 2016 Civil-Comp Ltd and Elsevier Ltd. All rights reserved.