Article published in july 2016 edition of Master Builder-Innovative green building technologies for PMAY scheme

Innovative Green Technology & Building Materials for Pradhan Mantri AwasYojana Scheme 

C A PRASAD
Director, Metey Engineering & consultancy Pvt. Ltd.

Review of HFA policy in briefly Scope
‘Housing for All’ Mission for urban area will be implemented
during 2015-2022 and this Mission will provide central assistance
to implementing agencies through States and UTs for
providing houses to all eligible families/beneficiaries by 2022.
Mission will be implemented as Centrally Sponsored
Scheme (CSS) except for the component of credit linked subsidy
which will be implemented as a Central Sector Scheme.
A beneficiary family will comprise husband, wife, unmarried
sons and/or unmarried daughters. The beneficiary family
should not own a pucca house either in his/her name or in the
name of any member of his/her family in any part of India to be
eligible to receive central assistance under the mission.
States/UTs, at their discretion, may decide a cut-off date on
which beneficiaries need to be resident of that urban area for
being eligible to take benefits under the scheme.
Mission with all its component has become effective from
the date 17.06.2015 and will be implemented upto 31.03.2022.
Coverage and Duration
All 4041 statutory towns as per Census 2011 with focus on
500 Class I cities would be covered in three phases as follows:
– Phase I (April 2015 – March 2017) to cover 100 Cities selected
from States/UTs as per their willingness.
– Phase II (April 2017 – March 2019) to cover additional 200
Cities
– Phase III (April 2019 – March 2022) to cover all other remaining
Cities
Ministry, however, will have flexibility regarding inclusion of
additional cities in earlier phases in case there is a resource
backed demand from States/UTs.
The mission will support construction of houses upto
30 square meter carpet area with basic civic infrastructure.
States/UTs will have flexibility in terms of determining the size
of house and other facilities at the state level in consultation
with the Ministry but without any enhanced financial assistance
from Centre. Slum redevelopment projects and Affordable
Housing projects in partnership should have basic civic infrastructure
like water, sanitation, sewerage, road, electricity etc.
ULB should ensure that individual houses under credit linked
interest subsidy and beneficiary led construction should have
provision for these basic civic services.
The minimum size of houses constructed under the mission
under each component should conform to the standards
provided in National Building Code (NBC). If available area of
land, however, does not permit building of such minimum size
of houses as per NBC and if beneficiary consent is available for
reduced size of house, a suitable decision on area may be taken
by State/UTs with the approval of SLSMC. All houses built or expanded
under the Mission should essentially have toilet facility.
The houses under the mission should be designed and constructed
to meet the requirements of structural safety against
earthquake, flood, cyclone, landslides etc. conforming to the
National Building Code and other relevant Bureau of Indian
Standards (BIS) codes.
The houses constructed/acquired with central assistance
under the mission should be in the name of the female head
of the household or in the joint name of the male head of the
household and his wife, and only in cases when there is no adult
female member in the family, the house can be in the name of
male member of the household.
State/UT Government and implementing agencies should
encourage formation of associations of beneficiaries under the
scheme like RWA etc. to take care of maintenance of houses
being built under the mission.
Implementation Methodology
The Mission will be implemented through four verticals giving
option to beneficiaries, ULBs and State Governments. These
four verticals are as below:
Details of Technology Sub-mission as listed in HFA policy
A Technology Sub-mission under the Mission would be set
up to facilitate adoption of modern, innovative and green technologies
and building material for faster and quality construction
of houses.
Technology Sub-Mission will also facilitate preparation
and adoption of layout designs and building plans suitable for
various geo-climatic zones. It will also assist States/Cities in
deploying disaster resistant and environment friendly technolC
A PRASAD
Director, Metey Engineering & consultancy Pvt. Ltd.
FOCUS: HOUSING FOR ALL
111 The Masterbuilder | July 2016 | www.masterbuilder.co.in
FOCUS: HOUSING FOR ALL
ogies.
The Sub-mission will coordinate with various regulatory
and administrative bodies for main¬streaming and up scaling
the deployment of modern construction technologies and
material in place of conventional construction. Technology
sub-mission will also coordinate with other agencies working
in green and energy efficient technologies, climate changes etc.
The Sub-Mission will work on following aspects: i) Design
& Planning ii) Innovative technolo¬gies & materials iii) Green
buildings using natural resources and iv) Earthquake and other
disaster resistant technologies and designs. Simple concept of
designs ensuring adequate sunlight and air should be adopted.
Centre and State would also partner with willing IITs, NITs
and Planning & Architecture institutes for developing technical
solutions, capacity building and handholding of States and Cities.

State or region specific needs of technologies and designs
would also be supported under this Sub-Mission.
The Scenario so far and Observations on the Built Houses for EWS
The houses so far built for EWS sector are like ghost houses
and turning into dilapated houses and are beyond maintenance
conditions too.
This shows that the built structures are not durable and is
in a went dilapated stage within few years of construction. This
shows that the quality of materials used are sub – standard.
The govt. also did not ear mark sufficient funds for these
houses, even though various schemes were launched and
asked states to take it further. The Govt., has always looked at
how cheaply it can be built, and in large numbers, instead of
giving priority to quality and durability in construction .
In some States, the house for EWS sector are built far away
from the Cities, and without basic Infrastructure and transportation
facilities too and thereby, they are not even occupied by
the beneficiaries in some locations
In the latest, HFA policy, the GOI have clearly outlined the
principles of construction stating that adoption of modern, innovative
and green technologies and building material for faster
and quality construction of houses is to be considered and in
addition stressed the need for basic Infrastructural facilities to
be provided.
GOI have also stated clearly that up scaling the deployment
of modern construction technologies and material in place of
conventional construction is the desired intent.
Conventional construction predominantly used bricks as
filler walls or load bearing walls. By giving up the bricks, excavation
of top soil from the agricultural fields will stop and does
lot of good to the agricultural fields
Considering the above, the author reviews the following
technologies suitable for construction of affordable houses,
such that they are durable, strong and stable against the earth
quake forces and list the advantages and disadvantages of each
system along with its costing details
Precast
EPS Insulated
Monolithic Casting
Composite Structure
Light gauge Steel Structures
Referring to Precast, Various Options are Available, viz.,
1. Precast walls + Hollow core slabs
2. Precast walls + Precast Composite Slabs
3. Precast walls + Precast slabs
Precast Walls Could be Made of Using
1. the battery mould type unit for Mass Hhousing of units
2. Tilting type Tables and Stationery Fixed Table moulds could
be used to construct units between 3 to 5 lakh units easily
duly taking the required tables thereby, capex will be lesser.
With Tilting type tables, walls and even precast slabs could
be cast and thus is cost effective too
3. Pallet or corrousel system also used for Mass Construction
Brief information about Precasting of walls using battery
moulds, Tilting / Fixed tables and Pallet or carrousel system is
presented herewith, viz.,
Battery Mould
Battery moulds are designed for the vertical manufacture
of single layer, large area reinforced precast elements of
varying dimensions. They consist of bulkheads between which
several concrete products can be simultaneously formed. The
number of bulkheads determines the number of pouring bays –
variably adjustable to suit the desired production capacity. The
bulkhead groups are confined by the tensioning walls with integrated
hydraulic clamping units. These walls clamp the entire
group during production. Vibrators are fitted to the bulkheads
to assure the effectiveness of the freshly poured concrete when
compacted. Battery moulds can be supplied in customized
sizes, number of pouring bays and as single or double battery
moulds.
Tilting table
Tilting tables are designed for the manufacture of large area
reinforced concrete elements, like walls and slabs. The surface
of the steel plate is ultra flat and guarantees a high-quality concrete
surface.
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Technology Methodology Merits Demerits Remarks
Monolithic shear wall construction
using Aluminum shuttering
“The elements like walls, beams and slabs made of RCC are
cast together at one go by using aluminum form work. Panels
of 2’(0.6m) wide X 10’(3m), floor height are connected
together with connectors.
Construction speeds can be achieved faster due
to light weight of forms and less labor required
for carrying the form work.
Quality of finish achieved is very good to
receive painting directly without plaster.
“Formwork components are durable and can be
used for 100 repetitions.
“5 to 7 days cycle is easily achieved in most of
the constructions and construction for overall
project is dramatically reduced.
“Initial investment on formwork is higher at the
rate of Rs.10,000/sqm
About 50 repetitions are easy to achieve and
there after maintenance is required to be done
for correctness of shape such that another 50
repetitions could be completed.
No. of sets of formwork to be decided based
on time of construction and the repetitions to
be achieved.
Insulated wall panel construction
using shotcreteing of concrete.
“System is conceived with insulated wall and roof panels of
corrugated expanded polystyrene(EPS), which consists of
zinc coated square mesh on either sides of it connected by a
shear connectors
Light weight, seismic resistant, sound and
thermal resistant.
Shotcreting means insitu work and needs
to be closely monitored and inspected.
Precast concrete
Prefabrication of structural concrete elements like beams,
columns, walls, slabs and stairs under factory conditions and
joining them together at site using dry and wet connections.
Production at factory conditions
All weather working
Better quality, finish and accuracy.
Less labour, wastage, cost
Faster cycle time
Scalability and repeatbility
Offsite working – parallel working
Standadisation – Design, engineering and
execution.
Suitable for certain applications
Cost and viability depends on volumns
Logistics (production, handling and erection)
because of urban infrastructure.
Flexibility – Opening and cutouts
Connection detail / method – Design
integration.
High equipment intensity
Damage or breakage during handling /
placement
Tax?Duty structure – centralized facility
Composite construction
Structural Steel columns and beams with Deck slab +
Concrete or Insitu concrete with shuttering is a method of
construction
Steel columns could be encased to get additional strength in
addition to steel.
Very faster construction
Concrete encasement makes the steel fire
resistant and protects from corrosion/ durability
Cost is higher by about 20 to 30% compared to
RCC type of construction
Fire resistant paint to be applied to structural
steel elements is very prohibitive
Light guage steel structuresLight
gauge steel or cold formed steel
construction
“Light weight cold formed steel sections for speedy low rise
building construction.
External and internal walls are to be covered with plaster
boards duly putting the rock wool in between them, which
will give the thermal insulation.
These could be used in industrial townships, residential and
commercial buildings, hospitals and schools etc.,
Gauge thickness from 0.7-2.0mm.
“Light weight, Seismic resistance, Thermal and
acoustic insulation. With rock wool insulation
inside, Air conditioning loads will be lesser.
Spacing of studs and joists will have an effect
on internal and external planning of structure
Plaster boards are required to be fire resistant
and should be durable against the external
environment, thereby, its cost is prohibitive
compared to conventional systems
Various Types of Technologies for Construction of EWS Mass Housing
FOCUS: HOUSING FOR ALL
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System Delivery per annum COST (Rs Cr) Total cost
(Rs cr) Rate /sft(Rs.) Remarks Availability in India
AREA (sft) UNITS (No’s)
(350 sft
plinth area)
Main cost
(Rs Cr)
Infrastructure
structure
Based
on plinth
area
Form work cost
based on actual
usage of walls
and slabs area
casting
Tilting and fixed
tables- of size
4mx12m. (7+3
no’s) with accessories
3,00,000 (20
lakh sft of wall
and slab area)
860 3 1 4 133/sft 20 A portal frame shed with
sides open, gantry crane or
Hydra, Truck for transport,
storing &, Mini Batching
plant
Indian Manufacturing exists
and could be sourced locally
Battery Mould with
10 no. chambers
with dual casting
5,00,000 sft
of plinth area
(33.50 lakh sft
of wall and slab
area)
1430 4 3 7 140 /sft 21 Steam curing is a must.
Batching plant of 30 cum/
hr is req
By tying up with factories from
abroad, these could be easily
manufactured in India. One
company in India by name
BIANCHI (Italian branch) is
about to start its manufacturing
in India
Pallet or carrousel
system with
accessories (20
tables)
10,000sft (67
lakh sft includes
walls and slabs)
5 5 10 100 /sft 15 Totally computerized system.
Plotting on table is an option.
Concrete from batching plant
automatically on suspended
rail system. Separate curing
chamber. Batching plant of
30 cum/hr capacity required
These could be easily
manufactured in India, with
little transfer of technology of
rail movement system from
abroad
Hollow core slab
with 8 beds of
120m long and two
cassettes
Floor slabs casting.
148.75lakh
sft in 5 years
9 8 17 11.5 Automatic system. Batching
plant of size 30cum/hr is a
necessity based on requirement.
Heating system below
the bed is a necessity
Except for the cassette system
costing Rs 50.00 lakhs
each, other things could be
manufactured duly forming
tie-up with manufacturer’s
from abroad Hollow core slabs with two beds of
120m long and two cassettes
37.20 lakh sft in
5 years
3 3 6 16 Automatic system. Batching
plant of size 30cum/hr is a
necessity based on requirement.
Heating system below
the bed is a necessity
Except for the cassette system
costing Rs 50.00 lakhs
each, other things could be
manufactured duly forming
tie-up with manufacturers
from abroad
Details of costing of each system based on its production and area development
Type of construction Elements Equipment Costing of equipment Remarks
Precast
Precast walls Tilting and fixed Table moulds Fixed table will cost Rs 12.00
lakhsapprox Preferred option 1
Precast slab Mini Batching plant Tilting table with hydraulic costs Rs
18.00 lakhs
Durability is good. Depending upon
number of units to be built
Insitu foundations Hydraulic aggregate, form moulds,
Magnets for fixing forms, etc.,
Monolithic construction using
Aluminum Formwork
Walls and slab cast together Aluminum formwork
Rs 8000 per sqm as initial Investment
and its cost comes down with
greater repititions
Preferred Option2, and also on par
with Option 1
For Wall thickness of 100/120mm,
Self compacted concrete(SCC) is
a necessity.
Mini Batching plant
Aluminum formwork is now
available in India too. 50 to 100
repetitions is possible, depending
upon handling
Where SCC is not possible, to
provide 150 thk wall with M25
concrete and needle vibrators
Durability is good, and structurally
stable
Insulated wall technology
Preferred Option 3
EPS panels with mesh on both
sides and inter connected to be
bought over from supplier
Shotcreting gun is a must and a
necessity for effective shotcreting
works
Rs 12 to Rs 14 lakhs for 1 no.
shotcrete gun
Shotcreting of minimum 50mm
thick on either side is a must. Reinforcement
of 0.12 % – 0.4% – 1%
vertical as per Design requirement,
and 0.20% horizontal – Cover to
reinforcement is to be maintained
Durability depends upon cover to
reinforcement and good shotcreting
FOCUS: HOUSING FOR ALL
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Integrated high-frequency vibrators facilitate optimal compaction
of the freshly poured concrete. On request, the tilting
tables can be equipped with a heating system to accelerate the
concrete curing.
The tilting table can be inclined by up to 75° to allow the
removal of the elements in an optimum manner for transporting.
The combination of various tilting tables can be used as one
entire mould surface. Furthermore, each tilting table can be
manufactured according to the customer’s precise demands.
The tables are available in various sizes
As with other stationary production procedures, tilting tables
can also be requipped with heating coils and compaction
plants.
– Tilting table(4X12 m) for precast concrete panels production
having the following general characteristics:
– Steel plate size 4m x 12.00 m;
– Steel casting plate 10mm thick stiffened by metal profiles
forming a strong frame; laid and welded on basic longitudinal
tubular structure;
– The steel surface is as natural iron;
– Hydraulic rotation with 75° maximum inclinations;
– Bottom side H=100 mm with linear profile with 10×10 chamfer
on the panel to be bolted on mould. Side Changeable
to make Panels of H=120mm, 150mm, 200mm, 250mm &
300mm
– Lateral sides H=100 mm with linear profile with 10×10
chamfer on the panel to be hinged on mould complete with
locking type pendini. Side Changeable to make Panels of
H=120mm, 150mm, 200mm, 250mm & 300mm
1. Pallets are Transported from workstation to work station by
Central / Side Shifter & are not need to be driven by Friction
drive wheel, hence very less wiring.
2. Concreting on pallet for precast elements can be done by
Speedy truck, which operates on diesel hence costly skip
Bucket & Concrete spreaders is not required for concreting.
3. Only one vibrating stations is required instead of multiple
vibrators under each table.
4. Only one Tilting stations is required instead of multiple Tilting
stations for various table.
5. No gantry crane is required in the plant as all work of gantry
crane can be done by Central / Side Shifter.
6. No transport carriages to bring out the ready elements of
the factory are needed can be done by Central / Side Shifter.
7. Plant can be installed Open to sky (or with temporary shed)
at Construction Project site, as Gantry cranes are not required
within plant.
8. If the space is large enough one can do Natural curing, as
our climate is hot & humid.
9. Very less wiring required hence less complication.
10. Very less power required.
11. Spares required is very less as fewer equipment’s are used
compared to standard carousal system.
12. Very easy to move Dismantle & Transport plant as there are
fewer equipment etc. like Pallets, Tiling table, Central shifter,
Rollers and rails can be easily removed.
13. Installation of plant can be very fast & easy to maintain.
14. Only 1 or 2 gantry crane is required to be installed outside
the plant for lifting precast element from titling table &
store the same in stockyard.
15. Expansion for more production is very easy
Conclusions
1. Technologies suitable for EWS
2. All the above technologies are suitable for construction of
EWS, LIG and other types of structures.
3. Investment on Machinery should be corresponding to the
plinth area to be constructed and time factor. By considering
those, it could be worked out in such a way that the precast
and other systems will be less costly or equivalent to conventional
systems and thus achieve speed in construction
4. The buildings will have concrete for walls and slabs and no
brick work is used in construction, and thus extraction of
clay from the agricultural fields is avoided. Temperature
inside the houses will be hot is a myth, and buildings could
be properly designed with good cross ventilation and heat is
not an issue in fully concrete walls.
5. Being concrete walls, they are strong against earth quake
forces
6. The concrete walls will not absorb water and will not develop
cracks unlike the brick wall structure, and will last long
giving good durability
7. There is no need to do the plastering on to the concrete
walls and painting could be carried out directly on the wall.
Thus buildings constructed using the above technologies
will have higher strength and last long giving good durability
All the stake holders involved in construction will be given
guidance for choosing of technology with due diligence on costing
by Metey Engg & Consultancy Pvt.Ltd, Hyderabadw
Pallet system or carrousel system
Using this system, precast walls and NON PRESTRESSED
slabs also could be cast
Economical Solution – Pallet circulating system by Central Shifter
Here pallets are Transported / moved from Workstation to
work station for shuttering, reinforcement, concreting, compaction,
leveling, trowelling, curing & tilting with the help of
Central / Side Shifter.
Advantages of Economical Concept for Pallet Circulating
System
FOCUS: HOUSING FOR ALL