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Behavior of Exterior Beam-Column Joints
Reinforced Internally
with Threaded GFRP Reinforcements
-- Saravanan Jagadeesan and Kumaran G
Totally eight number of exterior beam-column joints reinforced with GFRP reinforcing bars were
cast and tested under axial compression and uniaxial bending. Axial compressive load applied on
columns was kept constant and the beams were subjected to increasingly monotonic loading. Two
different types of joints, with and without stirrups, were adopted. The effect of shear at the joint of the
beam was observed for all the specimens. The performance of the GFRP reinforced exterior
beam-column joint specimens was compared with similar type of conventionally reinforced
beam-column joints. It was found that the efficiency of the joint was increased with an
additional stirrup at the joint both for steel and GFRP specimens.
© 2010 IUP. All Rights Reserved.
Study on the Strength Characteristics
of Scc with Ggbs and Rha as Mineral Admixtures
-- M Swaroopa Rani, K Jagannadha Rao and M V Seshagiri Rao
Normal conventional concrete has been widely used as a construction material throughout the
world because of its advantages of high compressive strength, durability, mouldability, etc. The
current global scenario shows increased construction of large and complex structures with heavy
reinforcement and complicated shapes. Using normal concrete in such situation may often result in
inadequate compaction, affecting performance and long-term durability of structures. One solution for
the achievement of durable concrete structures is the use of Self-Compacting Concrete (SCC). In
the present work, the behavior of fresh and hardened state properties of SCC of three different
grades M20, M40 and
M60 was investigated experimentally. The results indicated encouraging strengths of
SCC with Ground Granulated Blast Furnace Slag (GGBS) and Rice Husk Ash (RHA). The optimum
quantities of GGBS and RHA were arrived for the three grades of SCC to achieve fresh state properties
without compromising the strengths.
© 2010 IUP. All Rights Reserved.
Durability of Fly Ash Concrete
to Chloride Ingress
-- Thilgavathi S, Dhinakaran G and Venkataramana J
Concrete structure exposed to marine environments is very susceptible to chloride ion ingress into
the concrete, which in turn corrodes the steel reinforcing. The loss, in terms of repair of damaged
structures and reduction in design life of structures, is very high. Therefore, this paper presents the
laboratory investigations conducted to study the chloride permeability characteristics of admixed
concrete specifically with Fly Ash (FA). The influence of various parameters such as water/cement (w/c)
ratio, age of concrete and percentage of mineral admixture were undertaken. Rapid Chloride
Permeability Test (RCPT) was used to study the chloride permeability characteristics of concrete. RCPT adopts
a voltage of 60 V to measure the resistivity of concrete. This is the inherent disadvantage of
RCPT. Because of this higher voltage, the specimen gets heated up, increasing the chances for
encouraging chloride permeability. Hence, in the present work, experimental investigations for various
voltages were performed. The outcome of this paper is to suggest an optimized percentage of FA suitable
for concrete in an aggressive environment and to develop correlation between various parameters,
which are responsible for chloride permeability.
© 2010 IUP. All Rights Reserved.
Cement and Polymer-Based Concrete Composites
for Retrofitting of Structures
-- Balamuralikrishnan R and Antony Jeyasehar C
The paper presents the results of experimental and analytical studies concerning the flexural
strengthening of Reinforced Concrete (RC) beams using externally bonded cement-based composite like Slurry
Infiltrated Mat CONcrete (SIMCON) laminates and polymer-based composites like Carbon Fiber Reinforced
Polymer (CFRP) laminates. A total of seven reinforced concrete beams were cast and tested in the laboratory
over an effective span of 3,000 mm. Five beams were strengthened with bonded SIMCON and CFRP
laminates at the bottom under virgin condition and tested until failure; the remaining two beams were used
as control specimens. The static responses of all the beams were evaluated in terms of strength,
stiffness, ductility ratio, energy absorption capacity factor, compositeness between laminate and concrete, and
the associated failure modes. The theoretical moment-curvature relationship for the test specimen and
the load-displacement response of the strengthened beams and control beam were predicted using FEA
software ANSYS. A comparison was made between the numerical (ANSYS) with the experimental and
theoretical results. The results showed that the strengthened beams exhibit increased flexural strength,
enhanced flexural stiffness and composite action until failure.
© 2010 IUP. All Rights Reserved.
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