status of Environment and Related luues

VoI.2 No.9

Build well with waste

T he construction industry in India is growing fast. The increase in the demand for ~

What is eco-friendly building material? Eco-friendly construction material are those

that have a lower effect on human health homes and commercial space has driven the sector to a growth rate of 9.2 per cent

Eco-Friendly and the environment when compared with competing products that serve the same purpose. every year, against the global average of 5.5 per

cent. Of late, concerns have been raised over the Construction

way residential apartments and commercial buildings are designed and constructed. Most of these concerns pertain to energy, environment, sustainable construction methods and technology.

The most common raw material used in construction are steel, cement, glass, aluminum, plastics, bricks, etc. All these are energy-intensive material and need to be transported across vast distances leading to more energy consumption. It is not possible to meet the ever-growing demand for housing by using only traditional energy­efficient material like mud, thatch, timber, bamboo, etc.

material Eco-friendly construction alternatives

Eco-friendly construction alternatives should necessarily have the following properties: + Derived from renewable source: like agricultural

waste. + Re-use of waste product: use of fly ash, iron ore

tailings etc. + Easy availability: for material not locally available,

transport costs could be significant, affecting cost­effectiveness.

+ Reduction in air, land and water pollution: use of _______________ .m_a.ten ... · a.l.w. h. i.chiiioiir.es.uliiiiiits. in. less or no VOC emission,

Thus there is a need for ,. or those which may not optimum utilization 0 Properties of eco-frlendly building materials and techniques result in water and lor the available energy Renewable source air pollution. resources and raw \ JBiodegradable +Durability & life span: material to produce material which are simple, energy-efficient, ~~~.:; d'Reuse/recycle durable and require environment-friendly Eco-friendly materials low maintenance and sustainable building Embodied ~ and techniques ~ + alternatives. It is in this energy...-v ~Aidsenergy Energy efficient: context that the eco- ~ A ~ efficiency in building Those which require friendly construction " 1f "'\ less energy for

Local availability a Durability and d ti' lik materl'al gal'n • I'fa proucon, epre-

Reduction in air, water I span importance. and land pollution cast slabs.

~--------------------------------------~ +Bio-degradable:

The demand-supply gap

In the last 50 years, the country's population has risen from 330 million to 1.07 billion. Between 1999 and 200 1, there was a requirement for 4,61,600 million bricks and 24,700 million roof tiles, a need that could not be met. Against a housing requirement of200 million units, only 175 million are currently available, leaving a huge gap between the need and availability.

material constructed from farm waste etc. + Reuse / recycle: products like aluminum and iron can

be reused.

These alternatives may serve all or some of the above mentioned criteria but generally they should be cost­effective so as to be financially viable for a potential customer. Cost-effectiveness may depend on a variety of factors like availability of raw material, its use for other

According to India's national report, by 2021 the country would face a housing shortage of 44.9 million units

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~hri. Subir Hart Singh, lAS, Principal Secretary to Government ~ousing Department ~ikas Soudha ~angalore 560001

02-04-2007

MESSAGE

With increase in population, burgeoning urban growth and general improvement in the standard of living of the people, the construction industry in the country is witnessing an unprecedented growth. While glass-and-aluminium structures are often seen as signs of prosperity and well-being, there are simple, energy-efficient, environment-friendly and sustainable building alternatives available.

Eco-friendly construction materials derived from easily available, renewable sources that are durable and bio-degradable is available as a less expensive option. Judiciously used, this allows the discerning citizen to build aesthetically-pleasing and comfortable homes and other structures while making a statement of his commitment to nurture environment.

In this backdrop, a word of caution to every citizen building his or her house is that they make sure of proper and timely disposal of construction waste generated during building dream houses in an environmentally friendly way. ! A ~l

purposes (competing uses), maintenance requirements and durability.

Conventional eco-friendly building material

--Bamboo, bamboo-based particle board & ply board, bamboo matting

.-Sun dried bricks '-Pre-cast cement concrete blocks, lintels, slabs.

Structural and non-structural modular elements '-Calcined phospho-gypsum wall panels '-Calcium silicate boards and tiles '-Cellular light weight concrete blocks '-Cementpaint '-Clay roofing tiles '-Water, polyurethane and acrylic-based chemical

admixtures for corrosion removal, rust prevention, waterproofing

'-Epoxy resin system, flooring, sealants, adhesives and admixtures

'-Ferro-cement boards for door and window shutters '-Ferro-cement roofing channels '-Fly-ash sand lime bricks and paver blocks '-Gypsum board, tiles, plaster, blocks, gypsum plaster

fibre jute / sisal and glass fibre composites '-Laminated wood plastic components '-Marble mosaic tiles '-MDFboards and mouldings '-Micro concrete roofing tiles '-Particle boards '-Polymerised waterproof compound '-Portland pozzolana cement fly-ash / calcinated clay

based '-Portland slag cement

(s!'ir~in~

'-RCC door frames '-Readymix cement concrete '-Rubberwood fingerjoint board '-Stonedust '-Waterproof compound, adhesive, polymer powder

Eco-friendly material / techniques and resource centres

~ Bagasse board- BMTPC }> Bricks from coal washery rejects CBRI, Roorkee }> Building blocks from mine waste SERC }> Burnt clay flyash bricks CBRI, Roorkee }>Coircementboard CBRI,Roorkee }>Compressed earth blocks BMTPC }> EPS composites and door shutters CBRI, Roorkee }> Fibre flyash cement boards BMTPC }> Fibre-reinforced concrete pre-cast elements, wall

panels, blocks, manhole covers SERC }> Fibrous gypsum plaster boards CBRI, Roorkee }> Flyash cellular concrete, flyash cement brick, blocks

BMTPC

Kamataka Rajya Nirmana Kendra (KARNIK), a Government ofKamataka enterprise, is promoting cost-effective building technologies through its network of'Nirmiti Kendras' in the State. It received a Government of India award for utilization of fly ash as an innovative building material on World Habitat Day 2006.

- ~!>roximate 100 million tonnes of fly ash is generated in india's thermal power plant per annum

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Hon'ble President A P J Abdul KaJam's VISion of construction in tbe fntnre

''The building of the future will have many new features of aesthetics and convenience. Their energy sources will be cleaner, based on solar power and hydrogen. The glass panes of windows

and doors may have conducting polymers to regulate transmission of solar rays into the room. The leakages during the monsoon will be a thing of the past due to improved design and construction methods. Above all, the time taken for construction ofhouses may be cut down to several weeks or a few months instead of years. This would be achieved thorough the use of prefabricated structures and various other factory-manufactured parts like advanced composite doors".

Issues to be addressed by the construction industry include: .. Minirnizjng the use ofhigh energy material

.. Use of environment-friendly technologies

.. Minimize transportation of material

.. Maximize the use oflocal material and resources

.. Utilization of industrial and mine wastes for the production of building material

Building technologies meeting these principles could become sustainable and facilitate sharing or resources especially in using energy more efficiently. This could minimize damage to the environment.

pollution. At present, fly ash is disposed of by mixing it with bottom ash and large quantities of water. The resultant slurry is sluiced to settle in a setting pond. This method makes heavy demand on land and has the potential to cause ground water pollution.

A remedy to this malady is to use fly ash for the manufacture of bricks, Portland pozzolana cement blocks, tiles, light weight aggregates and hollow blocks. Consisting mostly of silica, alumina and iron, fly ash is a pozzolana a substance containing aluminous and silicious material that forms cement in the presence of water. When mixed with lime and water, it forms a compound similar to portland cement. The spherical shape of the particles reduces internal friction thereby increasing the concrete's consistency. Improved workability also means less water is needed, resulting in less segregation of the mixture. Though fly ash cement itself is less dense than portland cement, it results in a smoother surface with sharper detail. Mechanized manufacture of fly ash lime bricks has already been undertaken in many parts of the country. The aim is to utilize bulk quantities of fly ash and help bridge the huge shortfall of bricks and other building material required by the

}> Flyash lime cellular concrete CBRI, Roorkee }> Flyash lime gypsum brick BMTPC }> Insulating bricks from rice husk ash Central Glass

and Ceramic Research Institute, Kolkata }> Jute fibre polyester BMTPC

construction industry. At present in India, fly ash is being used to manufacture ash blocks, floor tiles, terrazzo tiles, cellular lightweight concrete (CLC), MCR tiles, door and window frames, interlocking blocks and flowerpots.

}> Non-erodable mud plaster CBRI, Roorkee }> Ploytiles CBRI, Roorkee }>Timber from trees such as poplar, rubber, eucalyptus

BMTPC }> Precast wall and roofing components CBRI, Roorkee }> Prefab brick panel system CBRI, Roorkee

Let's now take a look at some of the eco-friendly construction material which are in use in India.

Fly ash bricks

Almost 70 per cent of the total power generated in India is through coal-based plants. This translates into 70 million tones of fly ash generation every year and the production may increase in the years to come. Management offly ash is a huge problem as it is light weight and can travel by air and result in reduced agricultural productivity and water

Fly ash products

There are about 50,000 tile and brick industries in the country.

4

90

20

14 1211

2 1.6 1.4

0

10

20

30

40

50

60

70

80

90

Millio

nto

nn

es

/y

ea

r

Agro wastes generated in India (million tonnes / year)

Series1 90 20 14 12 11 2 1.6 1.4

Bagasse Rice husk JuteRice wheat

Straw

Groundnut

shell

Saw mill

waste

Coconut

huskcotton stalk

Source: www.ics.trieste.it

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A model house from unconventional building material

Cost comparison of buildings constructed by conventional method and by using

Iron ore waste tailings products Totolcostof Total cost of

building building If

Nam. of building constructed constructed Over'llil using iron-ore .01 of savings wut8talling conventlona'

products prod .... Pilot plant 33.08.000 36.00.000 2.92.000 Demonstration unns

• • 135000 169000 34000 b 1,49.000 1.87.000 38.000

2. D. dra a Model house 1.33.000 1.67.000 34.00.000

Model house in R&D centre, Surathkal Total 37 000 4123000 398000

The house has clean lines and a compact design. It looks like any other well-designed urban, low-cost housing effort. What is different however is that it has been constructed out of unconventional building material. The doors are made out of a wood substitute, the walls from iron tailing blocks, and the ceiling sports rafters made from ferro­cement. A living room, a bedroom, a kitchen and bath-toilet make up the accommodation available in the house. The house can comfortably accommodate a family of four members (see table for cost comparison between constructing with iron ore waste tailing products and conventional products). , The model house has demonstrated that iron tailing products work well; additionally, the technology can also be replicated wherever there is a requirement for low-cost housing options. It offers, thus, a ray of hope for the housing sector and economically backward sections of society.

bonded particle board which can bring down the use of cement and brick. The cement board uses only 60 per cent of cement and the remainder 40 per cent is eucalyptus flakes and other agricultural waste. These boards can withstand the damage caused by fIre and earthquake and are waterproof too. They have four times the strength of ordinary cement and require less water to set. Bricks made from agricultural wastes are bio-degradable and lastionger.

Red mud utilization

Red mud jute fibre polymer composite: RFPC is a substitute for wood-based panel products. It is made up of easily available raw material like red mud, polymers and natural fIbres. During aluminum production, bauxite ore is digested with caustic soda, when most of the aluminum passes into solution as aluminate. The

muddy red residue consists of alumina, iron oxide, titanium oxide and small quantities of silica, calcium oxide and alka\i. India generates over 4 million tonnes of this by-product annually which is not otherwise put to any use. Red mud is usually disposed of in ponds. During the monsoon months this could lead to contamination of ground water.

RFPC composite contains ferric oxide, alumina and titanium oxide from red mud, 82.5 per cent cellulose and 11.3 per cent liguin from its jute component Gute is 15 per cent of the total volume of the shutter). RFPC is particularly suitable for door shutters, ensuring siguifIcant savings in initial as well as maintenance costs. There is a huge market for composite doors and panels, with the potential waiting to be tapped both in developing and developed countries.

Sisal plant Sisal fibre Red mud jute fibre polymer products

Estimated agricultural waste generated in India exceeds 500 million tones Jler year. -

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Indo-Norwegian Environment Programme Indo-Norwegian Environment Programme (INEP) is a collaborative venture between the Government of India and the Government of Norway. Through an agreement with the Department of Economic Affairs, the two governments have initiated pilot project in two Indian states, namely Karnataka and Himachal Pradesh. The pilot programmes are designed to create awareness on, and demonstrate corrective actions for serious and ~ent environment issues.

A project taken up in Karnataka under the INEP has addressed Iron ore waste tailings problem in an effective way. As part of this programme, the R&D Centre of the Karnataka Regional Engineering College at Surathkal has undertaken a project to develop a technology for using the abundantly-available iron ore as raw material in the construction industry. The products already manufactured include bricks, tiles and other material. The following products were developed at the R&D Centre with iron ore waste tailings:

• Roofmg tiles

• Bricks • Hollow blocks • Pavement bricks

• Coloured bricks • Glazed roofing tiles • Studio pottery • Wall tiles • Floor tiles

Outcome of the project:

> Environ Charitable Trust' a special purpose vehicle for technology transfer, entrepreneur development and dissemination of information set up under Deputy Commissioner, Dakshina Kannada and Udupi.

> Environmental protection and ecological balance by converting industrial waste into useful building material

> Over coming the paucity of clay > Preservation of topsoil for agricultural purposes. > Promotion of scope for rura1 based industries. > Transfer of technology to existing and new entrepreneurs.

Techno development in Iron Ore Waste Tailings based building products such as Roofing tile, Decorative tile, Bricks, Pavement blocks, Wall tiles, Floor Tiles.

> Spinn off technologies like custom designed RCC & FCC rafters developed.

R&D Centre, NITK, Surathkal Key contributors .nd tMlr rot. for 1M Im .. m .... lon of Iron 0 ... lailing baed building products.

...,." of pIrt of 1hc ftmd

Demo house constructed at Nirmithi Kendra, Dakshina #Cannada using Iron ore waste tailings products

RFPC can also be used for furniture, flooring, electrical switch box and insulation sheets for housing.

Plastic that cannot be further recycled can be used with fillers for processing composites useful for applications like fence posts, park benches, pallets and street furniture as substitute to timber and concrete products.

Plastic waste as building material:

With constant urbanization and industrialization, the problem of discarded items and their disposal through garbage has become a cause for concern. Items like plastic bags and related material abound in garbage dumps. The solution lies in recycling of plastic waste after segregation.

Mixed and multilayer plastics containing several grades of plastic material can be made into pallets. The pallets can take the shape of tile flooring, waste containers, planks, profiles, railway sleepers etc.

Recycled PET: Unsaturated polyester resin from recycled PET can replace the conventional high cost resin for use in GRP products, polymer concrete / polymer mortar, and industrial floorings. Phospho-gypsum as building material: Phospho-gypsum is waste generated by phosphoric acid, ammonium phosphate and hydrofluoric acid-producing plants. The fluoride content of phosphor-gypsum is a source of land and water pollution. It is possible to profitably utilize this pollutant for making cement, - In Kamataka, the requirement of clay for the tile and brick industries is about 3 million tonnes per annum,

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Products developed at the R&D centre with iron ore waste tailings.

Hollow Blocks

Wall tiles Penholders

gypsum board, partitions, ceiling tile, artificial marbles and fiberboards.

Phospho-gypswn can be gainfully utilized in the manufacture of expansive or non-shrinking cement, super-sulphated and anhydride cement, simultaneous manufacture of cement and sulphuric acid, as a hydraulic binder, as set controller in the manufacture of Portland cement, as mineraliser and in making gypswn plaster boards and slotted tiles.

Pre-cast concrete frames: Pre-cast concrete frame is one of the substitutes for timber. Traditionally timber has been a vital building material. Excessive deforestation is leading to an

Lakkya dam in Kudremukha, completely filled with iron ore waste tailings

Interlocking Pavers

Decorative pottery

ecological imbalance which could spell large-scale disaster for mankind. In fact, adverse effects of deforestation are already being felt in many parts of the globe. It is necessary to take urgent steps to conserve our forests. A substantial portion of wood is consumed in the construction industry directly or indirectly. It is imperative to reduce the consumption of timber in building applications by identification, development and promotion of alternate material which can partially / completely substitute wood.

Pre-cast concrete frames are made out of cement, sand aggregates and steel reinforcement. Fly ash and blast furnace slag can also be used as raw material. Commercial levels of production can be taken up at a low level of investment and with minimal labour training.

Advantages of pre-cast concrete frames:

'-Conservation offorestreserves of timber '-Tennite-proof '-Highquality and durable '-Much cheaper than timber alternatives '-Minimal requirement of raw material and high rate of

production '-Water and fireproof

Gypsum board:

Gypsum board is the generic name for a family of panel­type products consisting of a non-combustible core, primarily of gypswn, with a paper surfacing on the face, back, and long edges. Gypswn board is often called drywall, wallboard, or plasterboard and differs from

The world's urban population is growing 2.5 times faster than the rural po!'ulation.

products such as plywood, hardboard, and fiberboard because of its non­combustible core. Gypsum is a mineral found in sedimentary rock formations in a crystalline form knows as calcium sulfate dehydrate. One hundred pounds of gypsum rock contains approximately 21 pounds of chemically combined water. Gypsum rock is mined or quarried and then crushed. The crushed rock is then ground into a fine powder and heated to about 350 degrees F, driving off three fourths of the chemically-combined water in a process called calcining. The calcined gypsum is then used as the base for gypsum plaster, gypsum board and other gypsum products.

To produce gypsum board, the calcined gypsum is mixed with water and additives to form slurry which is fed between continuous layers of paper on a board machine. As the board moves down a conveyer line, the calcium sulphate recystallizes or rehydrates, reverting to its original rock state. The paper becomes chemically and mechanically bonded to the core. The board is then cut to length and conveyed through dryers to remove any free moisture.

Gypsum is also used as a raw material for some of the products briefed as below:

Glass reinforced gypsum boards:

In building material, I wood can partially be replaced by the use of glass reinforced gypsum (GRG). It is made from glass fibre distributed evenly in gypsum matrix to yield boards of 2m x 1m size with a thickness of 4mm and beyond. The material is pseudo-ductile in nature with a flexural strength in the range of 20-35 Mpa and impact strength of 10-26 N/mrn2. The boards can be utilized for making door and window panels, false ceilings, partitions, furniture, etc. These can be easily cut, drilled and other wood working operations carried out as with the conventional wood working tools. GRG boards can be painted, polished and decorated by conventional means.

GRG offers advantages over wood and other conventional board material, such as:

Pre-cost concrete frames

"'" It can be made to the required size and thickness thereby reducing labour, wastage and jointing cost.

"'"Being isotropic in nature, it has eqnal strength in all directions.

~ Any ornamental design can be incorporated at nominal cost.

"'"GRG panels are about 50 per cent cheaper than teak wood: the cost also compares favourably with plywood and particle boards. Industrial wastes like phosphor-gypsum and fibres from waste glass cu11ets can be utilized to further reduce the cost.

Medium density fibre boards:

Various types of agro and agro-industrial wastes are converted into fibers of the required size. The material is mixed with a thermosetting binder and pressed in a hydraulic press under specified conditions of temperature, pressure and time and the resultant boards are trimmed to the required size. The product is waterproof, termite resistant and fire resistant.

Source:

[1] Convertiog waste to wealth-Published by INEP [2] Article of Dr.Rajendra Jagdale, Director-General, Science & Techoology Park, University ofPune [3] Wikipedia.org [5] www.ics.trieste.it [4]TERI

ENVISTeam:

Chakravarthi Mohan K.A.S., Co-ordinator, ENVIS Centre, Vijay Bhat, Programme Manager, INEP, K.N. Koushik, IT Assistant.

ENVIS Centre - Karnataka Department of Forests, Ecology & Environment, Govemment of Kamataka

010 Indo Norwegian Environment Programme, 2nd noor, Parisara Bhavan , No 49, Church street Banga/ore - 560 001. /{amataka

Ph: 080-2559 1515 email: enviskal@dataone.in URL: http://www.parisaramahiti.kar.nic.in