Moisture degradation in FRP bonded concrete systems : an interface fracture approach

(cont.) characterization, and kink criterion implementation, form a synergistic analysis of the mechanistic debonding behavior affected by moisture. Results have shown that moisture affected debonding is a highly complex phenomenon that involves physical changes in the bond as well as in its constituent materials. In particular, moisture can initially enhance or reduce the interface fracture toughness, depending on the epoxy formulation being used. The toughness can, however, decrease by as much as 60% and become asymptotic upon reaching a certain moisture concentration threshold, which can be attained in as short as 2 weeks in case of peel fracture. While various debonding modes have been observed for dry specimens, epoxy/concrete interface separation, which has generally been considered an unlikely debonding mode, is observed consistently in all wet fracture specimens. Interface fracture analysis indicates that this newly discovered interfacial debonding mode is attributed to various interfacial material toughening or weakening mechanisms, and has also hinted on the possible interphase formation as a consequence of moisture diffusion. The new knowledge and results obtained from this research provide a basis for further analysis directions and for design of FRP bonded concrete systems against moisture affected debonding.

Department dc:contributor.department

Massachusetts Institute of Technology. Dept. of Civil and Environmental Engineering.

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2005

Author dc:creator

• Au, Ching, 1977-

Advisor dc:contributor.advisor

• Oral Büyüköztürk.

• Civil and Environmental Engineering.

Statement dc:rights

• M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

en_US

Handle dc:identifier.uri

http://hdl.handle.net/1721.1/28932

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/28932