RECENT TRENDS IN
CIVIL ENGINEERING PRACTICES
SUMITA DEY
General Manager (Engineering)
Mani Square Limited
Kolkata
25th September 2014
PREAMBLE
Civil Engineering is regarded to be the mother of all engineering.
Although building homes, roads, bridges, sewerage etc. is as old
as civilisation itself, we continually see new trends emerging.
New thoughts, innovations and
techniques are fast replacing age
old
practices
and
traditional
methods of construction.
Like in every other field, the real
estate sector has also seen a
number of such innovations and
adoption of the state-of-the-art in
construction techniques.
SOME RECENT INNOVATIONS
TALL BUILDINGS
All over the world builders are starting to build higher and
higher. In India, mainly in the metropolises, the skyline has
risen.
In Kolkata, due to a set of new
building laws, builders have started to
add floors to buildings already under
construction.
New buildings are being planned for heights
hitherto unheard of in the city of Kolkata.
The structural engineer has to find ways and
means to make the structure capable to
withstand the additional loads, to reduce the
loads or simply to make more correct
assumptions and recalculate loads.
ADVENT OF SOFTWARE
The advent of latest and powerful software and hardware take
seconds to analyse the model of a huge multi-storeyed building.
This makes innumerable iterations possible in no time.
REDUCTION OF LOADS
AAC Blocks
Air entrained autoclaved blocks are
basically lightweight bricks. The
specific gravity of these bricks are
less
than
half
compared
to
conventional clay or fly-ash bricks.
Steel Floor Plates
Extending an RC building by using
steel columns/steel beams and a thin
layer of concrete slab for buildings
whose foundations and lower level
columns
have
already
been
constructed.
REDUCTION OF LOADS (cont’d)
RC Load Bearing Walls
Walls may be designed
as RC load bearing
members.
Use
of
aluminium
formwork
system like ‘Mivan’, in
which 160 mm thick RC
external and internal
walls carry the loads. As
a result… no columns, no
beams and reduced slab
thickness due to smaller
panels.
What has made tall buildings possible in Kolkata
where the sub-soil conditions are hardly
conducive to weighty structures?
Other than social and psychological barriers,
Kolkata was probably missing the ‘structural’
atmosphere to build structures that would kiss
the clouds.
SOME MORE RECENT INNOVATIONS
HIGH GRADE CONSTRUCTION MATERIAL
For reinforcing steel, Fe 250 gave way to
Fe 415, which made way for Fe 500. We now
use Fe 550 or Fe 600.
For concrete, M 15 gave way to M 20, which
made way for M 25. The number after ‘M’
kept on increasing and reached the
improbable figure of 70 i.e. M 70, which is
quite common these days.
TYPICAL DESIGN MIX FOR M40 GRADE CONCRETE
o
o
o
o
o
o
o
Cement (OPC)
Flyash
20 mm down aggregates
10 mm down aggregates
Sand (Zone II)
Water
Admixture
–
–
–
–
–
–
–
360 Kg
120 Kg
592 Kg
484 Kg
718 Kg
158 Kg (w/c ratio = 0.33)
2 Kg (@0.4%)


Strength at 7 days
Strength at 28 days
– 32 to 36 MPa
– 45 to 49 MPa
METHODS OF SHUTTERING/STAGING AND DETAILING
The ’Rail Climbing’ system have helped to increase the speed of
construction manifold.
METHODS OF SHUTTERING/STAGING AND DETAILING
In another system of staging, the props are left in place and
only the shutters are removed.
METHODS OF SHUTTERING/STAGING AND DETAILING
Use of couplers instead of lapping of bars has helped reduce
congestion and wastage. It is also possible to have 100% lap at
one place, as per code.
METHODS OF SHUTTERING/STAGING AND DETAILING
Creation of safety platform has helped in enhancement of
worker productivity by creating a psychological feeling that
they are working at ground level. This has contributed to a
large extent in increasing the speed of work.
CONCLUSION
This presentation dealt with only a particular sector of Civil
Engineering and some of the recent trends being adopted.
I have, however, scratched only the surface.
Scores of innovations and modern techniques have come in
vogue during the last decade, both in design and execution.
Every day, some new technique
is being introduced at some
part of the globe thereby
encouraging smarter designs,
slicker structures, robust and
safer construction practices.
THANK YOU