Production of Pre-Cast
Elements using LC3
Why
Precast/Pre-fabricated Technology?
As per statistics, the
Indian real estate market is expected to touch US$ 180 billion by 2020
while the housing sector alone contributes 5-6% of the country's GDP. In
countries such as India, where there is massive shortage of housing and
dearth of time for fulfilling the targets, pre-cast technology is a
boon.
According to the
current estimation of the Government of India, the target of mass
housing which is due to be achieved by 2020 with low capital investment
can be possible by replacement of conventional methods with precast
technology and other intermediate type methodologies.
Precast and offsite
construction technologies help in creating products such as pillars,
columns, beams or walls by casting concrete in a mould followed by
curing in a controlled environment. These technologies are found to be
most interesting by clients because of their good deliverability of
highly complex structures in half the time without any compromise in
quality compared to other conventional technologies.
One of the reasons
behind the rapidly growing demand of these precast technologies is not
only its cost effectivity but also the timely high-quality deliverance.
These technologies are very reliable because of their capability of
fulfilling situation specific requirements, easy adaptability to the
location with making optimum usage of locally available construction
materials and transportation facilities.
Advantages of Precast Technology:
• Proper curing in
controlled environment
• Greater control over
material quality and workmanship
• Better management of
quality compared to onsite casting
• Ensures safety
throughout the project
• Saves a lot of time
• Affordable
• High profitability
• Less usage of cement,
water, steel and labour
• Produces less waste
• Produces much smaller
CO2 than in cast-in-situ construction
• Works in virtually
all environments cold, hot, moist or dry
Commonly used
Precast Products include:
• Facades from sandwich
to cladding and gray walls
• Floors with
hollow-core, half, ribbed or solid slabs
• Foundations with
precast concrete piles
• Frames with beams,
columns, slabs etc.
• Stairs, shafts and
other special products
Industrial
Production of Pre-Fabricated/Precast Elements using LC3 at
Supercast Limited, Noida (Supertech Group):
One of most desirable
precast products, which have been recently produced at Supertech Limited
in Noida in one of its building projects is hollow core slabs using the
new kind of industrially produced cement i.e. Lime Stone Calcined Clay
Cement (LC3). The objective of this project was to determine
the technical feasibility of pre-stressed hollow core slabs with LC3
at production scale level and establish the properties thereof and to
take this product from lab to commercial use. Hollow core slabs are
pre-stressed concrete elements which have a constant cross section,
manufactured using high tensile strength pre-stressed strands or single
wire which are embedded within the element. These slabs are widely used
for flooring and wall panels in industrial, commercial, residential and
infrastructure construction including different supporting structures
such as concrete constructed walls, brick built walls, steel structures,
on-site concrete cast structures, prefabricated beams etc. Research
trials have been done at IIT Madras with both Ordinary Portland Cement
(OPC) and LC3 for M50 hollow core slabs. Lab trials were also
done at Supertech, Noida with LC3 and OPC after the getting
the desirable spectacular strength at the trials done in IIT Madras.
Demonstrating the viability and robustness of the technology, the LC3
obtained was used to manufacture hollow core pre-stressed precast slab.
Good results were obtained and test data of LC3 samples are
comparable with available conventional cement.
Along with earlier
strength development, the new cement has less porosity and it is more
difficult for the chloride to get in and damage the steel. This gives
the new cement and the structures a longer service life.
■
Pankaj Phulwari
Development Alternatives
pphulwari@devalt.org
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