|
Problems
in excavation and lining of 30-m diameter surge shaft
of Teesta Hydro Electric project - Stage V
M.P.
Srivastava
This
case study presents the problems faced in excavation
and lining of 30-m diameter, 92-m deep surge shaft,
which was damaged owing to the sliding of hill slope,
while full widening of shaft was in progress at a
depth of 86 m. Two-third of the shaft circumference
was damaged to a depth of 64 m and was filled with
60,000 m3 of loose soil. The feature describes the
restoration measures.
Effect
of rebar corrosion on the behaviour of bond in reinforced
concrete
S.
Bhaskar, J. Prabakar, P. Srinivasan and A. Chellappan
The
effect of rebar corrosion on the behaviour of bond
is investigated using pull-out test . Concrete specimens
of M40 grade were cast and tested in accordance with
procedures laid down in IS 2770 (part I). To induce
desired level of corrosion in rebars, specimens were
subjected to accelerated corrosion for different duration.
The behaviour of bond was studied for uncorroded and
corroded specimens at four corrosion levels. The paper
describes the results of the study.
Behaviour
of reinforced hollow block masonry infill in multistorey
RC frames under lateral loading
S.
Prabavathy, M.S. Palanichamy and A.R. Santhakumar
An
experimental investigation was conducted to study
the effect of reinforced masonry infill on the performance
of the reinforced concrete frame. The focus of the
study was to assess the behaviour of reinforced masonry
infill when subjected to lateral loading. Three quarter
scale, two-bay, five-storey reinforced concrete (RC)
frames without infill, with hollow block infill and
with reinforced hollow block infill were tested. Results
demonstrated the effectiveness of the infills with
respect to ductility, stiffness, strength and hysteretic
characteristics. Reinforced infill exhibited a better
performance in resisting the lateral loads. The experimental
results indicated that infill panels can significantly
improve the performance of RC frames.
Confinement
of steel fibre-reinforced HSC short columns
Umesh
Kumar Sharma, Pradeep Bhargava and S. K. Kaushik
An
experimental study was carried out to investigate
the behaviour of steel fibre-reinforced high strength
concrete short columns confined by circular spirals
under monotonically increasing concentric compression.
The test variables included aspect ratio, volume fraction
of crimped steel fibres and volumetric ratio of transverse
spiral reinforcement. The effects of these variables
on the uniaxial behaviour of high strength concrete
columns are presented and discussed. The results indicate
that the addition of fibres to the high strength concrete
mix prevented the early spalling of the cover and
increased the load carrying capacity and ductility
of the columns as compared to non-fibre columns.
Stability
of axially loaded slender reinforced concrete columns
G.S.
Venkatasubramani, Ruben Selvaraj and P. Parameswaran
A
simple, rational criterion is evolved to determine
the buckling load of axially-loaded slender reinforced
concrete columns with and without imperfections through
stability equations, taking into account non-linear
stress-strain characteristic and the extent of cracking
of concrete. The method is applied to pin-ended columns
deforming in single curvature. The proposed method
is validated with test results from experiments conducted
by authors. A good and conservative correlation is
observed. Based on the proposed method charts are
prepared for design applications..
|