Return to search

Strengthening rectangular beams with NSM steel bars and externally bonded GFRP

Master of Science / Department of Civil Engineering / Hayder Rasheed / The technology of FRP strengthening has matured to a great extent. However, there is always
room for performance improvements. In this study, external bonding of GFRP and near surface
mounting (NSM) of regular steel bars is combined to improve the behavior, delay the failure, and
enhance the economy of the strengthening. E-Glass FRP is selected due to its inexpensive cost
and non-conductive properties to shield the NSM steel bars from corrosion. On the other hand,
the use of NSM bars gives redundancy against vandalism and environmental deterioration of the
GFRP. An experimental program is conducted in which four rectangular cross-section beams are
designed, built, and tested in four-point bending. The first beam is tested as a control beam
failing at about 12.24 kips. The second beam is strengthened using two #5 steel NSM bars and 1
layer of GFRP, both extending to the support. This beam failed at 31.6 kips. The third beam is
strengthened with the same system used for the second beam. However, the NSM steel bars were
cut short covering 26% of the shear-span only while the GFRP was extended to the support. This
beam failed at 30.7 kips due to reaching the full flexural capacity of the section at the NSM bars
cut off point and the shear stress concentration at the steel bar cut off point. The fourth beam was
strengthened with same system as the third beam but then submerged in a highly concentrated
saline solution for six months and then tested. This beam failed at a maximum applied load of
29.8 kips, which shows that the GFRP sheet provided good corrosion resistance from the saline
solution.

Identiferoai:union.ndltd.org:KSU/oai:krex.k-state.edu:2097/15624
Date January 1900
CreatorsWuertz, Augustine F.
PublisherKansas State University
Source SetsK-State Research Exchange
Languageen_US
Detected LanguageEnglish
TypeThesis

Page generated in 0.0032 seconds