This investigation presents the influence of protective
coating on bond strength development of steel
with concrete. Pull-out test was conducted in the 1000
kN capacity Universal Testing Machine as per
procedure outlined in Indian Standards. The tested
rebar includes rusted (uncoated) rebar as
available in the site, acid pickled rebar (Rust free
rebar) and cement polymer anticorrosive coated
rebar obtained from a single source. Concrete of M25
grade were used and totally 18 specimens were tested.
The loads at the free end slip of 0.025 mm, 0.25 mm, loaded end slip of 0.25 mm
and ultimate pull out load were observed. The
load-versus slip behaviour was studied at the free end and loaded end using precision dial gauges. The bond stress
corresponding to the lowest load value of 0.025 mm FE slip and 0.25 mm LE slip was considered as the usable bond
strength. The test results revealed that a well
defined correlation exists between Load at 0.025 mm free end slip and 0.25 mm
loaded end slip. It was found that presence of
rust and cement polymer anticorrosive coating in the steel concrete interface appreciably increases the bond strength of
the order of 16%, 35% respectively for 16mm
diameter bars as compared to rust free rebar. For 20 mm dia. bars, marginal
reduction in bond strength for rusted rebars and
significant increase in bond strength for coated bars as compared to uncoated bars were observed. It is concluded that presence of
rust influences in reduction / increase in bond
strength depending on the nature of rust at the interface in the initial ages.
Application of cement polymer coating improves
the bond strength of the order of 30 – 35% due to excellent compatibility at the steel concrete interface, satisfies the
codal requirements of Indian Standards.
Author
(s) Details
Dr. D. S. Vijayan
Department of Civil Engineering, Aarupadai Veedu Institute of Technology,
Vinayaka Missions Research Foundation, Chennai, India.
C. Nivetha
Department of Civil Engineering, Aarupadai Veedu Institute of Technology,
Vinayaka Missions Research Foundation, Chennai, India.
D. Parthiban
Department of Civil Engineering, Aarupadai Veedu Institute of Technology,
Vinayaka Missions Research Foundation, Chennai, India.
S. Arvindan
Department of Civil Engineering, Aarupadai Veedu Institute of Technology,
Vinayaka Missions Research Foundation, Chennai, India.
R. Sanjay Kumar
Department of Civil Engineering, Aarupadai Veedu Institute of Technology,
Vinayaka Missions Research Foundation, Chennai, India.
View Book:- http://bp.bookpi.org/index.php/bpi/catalog/book/261
No comments:
Post a Comment