SUBMITTED BY:
2K10/PS/010 Chandana
2K10/PS/012 Dhruv Sapra
2K10/PS/019 Kshitij
2K10/PS/021 Madhurima Baral
2K10/PS/026 Nirmal
INTRODUCTION:
Narrow alleys circling huts with plastic roofs, open drainages jammed with poly bags and heaps of stinking mud, piles of garbage accumulating in corners and dark passages. This is not the plot of any Hollywood movie depicting life after end-of-the-world but is the truth in which a large chunk of population is struggling. Slums are the realities we are ashamed of. Urban well off scorn at their sight, shudder and wish these souvenirs of rapid industrial growth disappear from the face of their otherwise beautiful cities but to their dismay, it does n’t happen.
According to U.N.’s biennial report this year, the total number of poor in the world has grown to 827.6 million powered by migration and population growth. Although some 227 million people escaped the clutches of slums from 2000 to 2010, the increase of 55 million is still a big addition. In India, Dharavi- Asia’s biggest slum spans over 1.75 square kilometers and includes an estimated 600,000 to 1 million dwellers. It is said that 55% of the population of Mumbai lives in slums, which cover only around 6% of the city’s land.
These deeply engraved pictures of a shantytowns in our minds is the result of what we notice from air conditioned cabinets of our cars but a slum goes much beyond that. The bitter pill which we have to swallow is that without these slums, the machinery of the urban lands will break down miserably. These slums support the small industries by supplying labor and semi finished goods without which the middle and large scale industries will suffer a massive blow. Leather dying, garment embroidery, recycling centers, bakeries, soap-making and clay-pot manufacturing are some of them. To clear the air about the quality of these outputs, the leather tanning and dyeing factories currently produce material for big name brands such as Gucci.
If we gaze back in history, we will find that the existence of a slum goes long back in time. It is something universal. In early 19th century when the present superpowers (America and Europe) were not so powerful, they witnessed migration of people from small towns to urban cities sniffing employment opportunities and better access to basic amenities. This lead to the emergence of poorly built and overcrowded housing facilities. But unlike India, These countries took timely steps and introduced legislations to build low-income housing facilities with minimum standards.
The scenario is fast changing to the good of the dwellers as well for the city. Slum development in India is the new wave which is sweeping the down trodden areas and converting them into habitable and hygienic living spaces. Providing basic infrastructure, sanitation, education facilities, lightning and community spaces are the top priorities in the minds of the change makers. Polymer technology can greatly contribute in achieving these goals to improve the condition of slum dwellers, and a few of the models on how our branch can contribute in this endeavor have been discussed here.
MODEL I: USE OF RCC SLABS FOR ROOFING PURPOSE
Houses in slums are made from a variety of materials ranging from plastics, poly bags to concrete. However nowadays a transition from the ‘kutcha’ makeshift homes to the permanent concrete houses has been prominently made in a majority of slums. But the existing roof in such houses is that of AC Sheets over the brick walls which is of no drastic help either. During rainy season, AC sheets’ roofing gets damaged which thus results in water leakage and dampening of the walls. Furthermore, the drainage system in between the tenements ordinarily doesn’t function properly and thereby causes frequent choking of drains due to steep slopes. A pertinent solution to this problem could be use of Reinforced Cement Concrete (RCC) slab roofing.
To enhance the load carrying capacity of concrete it is reinforced with steel bars (Rebars) of different diameters provided in an appropriate manner. Such concrete is called Reinforced Concrete and the rebars are called the reinforcement. These rebars are provided at various locations in the required number and diameters to resist the internal forces, which are developed due to the loads acting on the structure. The brick tiles being porous and moreover laid on mud and mud-plaster duly grouted with cement sand mortar do not gain too much heat in summer and thermo-action is negligible, therefore cracks do not occur in the joint of brick tiles. Whereas the marble/ kotah stone or terrazzo tiles which are generally laid over a bed of cement mortar after laying brick-ballast concrete on R.C.C. roof, gain heat too much and due to thermo-action, hair cracks occurs in the joints of stone slabs and tiles even in the first summer. When there is a continuous rain, the water penetrates in the roof through the hair cracks in the joints and dampness will appear under the roof slab. Slab under the bed of stone slabs and tiles in terrace floors and floors of bathrooms etc. The rich concrete without proper reinforcement is prone to cracks due to thermo-action. Some professionals and masons suggest the laying of "Kuba" i.e. brick-bats grouted with sand mortar on the R.C.C. Slab which is also not suitable.
Low Cost Housing is a new concept which deals with effective budgeting and use environmentally friendly materials which are substitute for conventional building components like use R.C.C. Door, floor and window frames in place of wooden frames.
Generally, the stone/tiles laying contractors and masons mix the cement sand mortar with water minimum for half day work, when the ordinary Portland cement mortar begins to set after 30 minutes and completely set after 600 minutes. When the setting of cement mortar starts, the unused cement sand mortar will start to lose strength gradually.
It is not out of mention here that even the stone flooring of toilets & kitchen washbasin give dampness in walls due to leakage through the joints of junction because their back surface is not made water/damp proof. Similar is the case of stone cladding of outer walls during the rains. It happens because stone has no cohesive property being of plain surface and gaining more heat being homogeneous. In outer walls it some time disintegrate during summer and causes fatal accidents
Waterproof coating system goes deep into providing classy performance along with minimum disturbance, waste and pollutants to the occupants and surroundings. The range covers right from New RCC Roof Waterproofing up to Load-free Waterproofing on old porous Lime-terrace. Even in standalone cement modifier range, the Products stands out in quality by technical advantages like sub-zero-tg, non-migrating plasticizer & core-shell molecular structure.
The Waterproofing systems are conveniently made up of unit modules, which are permuted and combined to build various Systems depending on required service and conditions. The 'Solution' System approach and uncompromised quality of Products deliver foolproof reliable performance.
Fig: Filler Slab
Normally 5″(12.5 cms) thick R.C.C. slabs is used for roofing of residential buildings. By adopting rationally designed insitu construction practices like filler slab and precast elements the construction cost of roofing can be reduced by about 20 to 25%.
Various Ratios of RCC
RCC denotes Reinforced Cement Concrete in which cement, sand and bajri are laid with the help of mild steel. This is most important part of the structure. Generally 1:2:4 and 1:1.5: 3 ratios of RCC are used in construction work.
RCC 1:2:4
Where cement concrete 1:2:4 is used; it means 1 part of cement 2 parts of fine aggregate/coarse sand and 4 parts of coarse aggregate. This ratio of cement concrete gives high strength of cement concrete and is recommended for following works.
• For general RCC work in buildings
• Bed plates
• Lintels
• RCC shelves
• Pavement etc.
RCC 1:1.5:3
Where cement concrete 1:1.5:3 is used; it means 1 part of cement 1..5 part of fine aggregate/coarse sand and 3 parts of coarse aggregate. This ratio of concrete also gives very high strength of cement concrete and is recommended for following works.
• Structure carries in heavy loads
• Important RCC structure such as columns, beams, slabs, cantilever, Chhajja, porch, and balcony etc.
• Minimize the effects of earthquake.
• Gives more strength accordingly if Tor or Ribbed steel is used with cement concrete 1:1.5:3.
Advantages of RCC Slab
● Energy efficient.
● Does not catch fire.
● Provides solid and durable roofing.
● Very versatile and provides greater protection.
● Reduces costs of insurance and has resale value.
Economics associated with this model:
The building construction cost can be divided into two parts namely:
Building material cost : 65 to 70 %
Labour cost : 65 to 70 %
Now in low cost housing, building material cost is less because we make use of the locally available materials and also the labour cost can be reduced by properly making the time schedule of our work. Cost of reduction is achieved by selection of more efficient material or by an improved design.
The above specified model was implemented by Government of Andhra Pradesh in Balaji nagar Tenement Nos. 01 to 1060 at Tirumala in 2011. There are 1060 (one thousand and sixty) tenements available at Balaji Nagar, Tirumala and the total cost works out to Rs.1998 lakhs based on the then current rates duly making provision for improvements, providing RCC roof slab with necessary sanitary & electrical requirements.
In case the government is due to some reason unable to allocate funds for this matter then on an individual level slum dwellers can switch to RCC roofing themselves. A rough estimate gives the cost of making use of concreting RCC 1.2.4 to be Rs 30 to 35 per sq ft (as per the rates of 2009).
Areas from where cost can be reduced are:
1) Reduce plinth area by using thinner wall concept.Ex.15 cms thick solid concrete block wall.
2) Use locally available material in an innovative form like soil cement blocks in place of burnt brick.
3) Use energy efficiency materials which consumes less energy like concrete block in place of burnt brick.
4) Use environmentally friendly materials which are substitute for conventional building components like use R.C.C. Door and window frames in place of wooden frames.
5) Pre-plan every component of a house and rationalize the design procedure for reducing the size of the component in the building.
6) By planning each and every component of a house the wastage of materials due to demolition of the unplanned component of the house can be avoided.
7) Each component of the house shall be checked whether if it’s necessary, if it is not necessary, then that component should not be used.
MODEL II: USE OF RCC SLAB ROOFING FOR RAINWATER HARVESTING
In addition to the many benefits, RCC Slab Roofs can be used for rainwater harvesting. This can be carried out in the following manner:
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| In houses with sloping roofs the rain water may be collected to the half cut PVC pipes fitted along the sloping sides and it may be directed to either sump/open well/bore well or recharge well. | Check the weather the rain water drain pipes extend up to the bottom of the building. | Interconnect the rainwater drain pipes if there exist more than one. |
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| To collect rainwater in a sump construct a filter chamber of size 2/1/2' * 2/1/2' * 2/1/2' | The bottom half of the filter chamber has to be filled either with broken bricks/blue metal/pebbles and followed by one feet of coarse river sand. A nylon mesh has to be provided in between the two layers. The top portion of the filter chamber should be covered with RCC slab. | The inlet rainwater drain pipe should be on the top of the filter chamber and the outlet pipe connecting the filter chamber to the sump should be at the bottom. |
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| Surplus spill over water from the sump may be connected with the existing open well/bore well or to the recharge well. | In the absence of sump,filter chamber may be connected to the existing open well / bore well. | In the absence of sump,open well and bore well the rain water may be recharged through percolation pits and the bottom of bit should be in the sandy formation. |
MODEL III: Point-of-use water purification using rechargeable polymer beads
POU water purification can pare the cost of pure, safe water to meet the needs of the neediest. This breakthrough holds the promise of reducing the impact of water borne diseases throughout the developing world. HaloPure: a new and enabling technology for POU. One such “enabling” technical advance is the development of an entirely new biocidal medium in the form of chlorine rechargeable polystyrene beads that is based on patented chemistry inventions from the Department of Chemistry at Auburn University (U.S. Patent Nos.5,490,983 and 6,548,054 B2).
The fundamental principles of the HaloPure reversibly binds chlorine. There is a shift in attitudes on
improving safe water access. Unchlorinated technology are deceptively simple to understand, although
their incorporation into a reliably reproducible and practical medium for water sanitation has taken years of intense effort and research. Porous polystyrene beads are similar to those used for water softener resin beds, are modified chemically so as to be able to bind chlorine or bromine reversibly in its oxidative form. One way to think of this compound is as solid-state chloramines, biocidal in its own right, by virtue of giving up their chlorine to microbes that come in contact with them. But, unlike chloramines in a swimming pool, these surfaces are quite capable of repetitively taking up chlorine and establishing a stable chlorine bond. All that is required is enough free chlorine to surround the binding site. Almost no free chlorine is released when the beads are placed into the water flow. Typical levels range from 0.05 ppm to 0.20 ppm free available chlorine. This is not enough to kill anything without lengthy incubation. Hence, the swift efficacy of HaloPure depends on intimate contact between the microbes and the bound halogen on the polymer. We have, then, is a solid surface, effectively biocidal on contact to contaminants in the water and repeatedly rechargeable when periodically exposed to free halogen. In this way, a powerful antimicrobial component can be introduced into a water purifier that will not run out of steam, and have to be discarded. Instead, it can have its power regularly and conveniently “topped up” by the user.
Organisms make contact with the display of chlorine, for example, on the surface of the beds, and pick up enough halogen to inactivate them in short order. Those not killed within seconds suffer a near-death experience, and succumb quickly in the product water as the adherent chlorine slowly damages the organism to the point of fatal consequences. Interestingly, because the halogen attaches to the organism it can be stripped off as well. In the case of bacterium, if the halogen is stripped off before it has killed the organism, the bacterium can recover.
However, for viruses such as polio, the damage is irreversible.
Diagrammatic representation of purification
Harnessing power and economic advantages
The economic advantages of this kind of medium are immediately apparent. All you need is to ensure availability of that source of “topping up power” — in the form of free chlorine — and the user can potentially have the continuous benefits of halogen-based disinfection of drinking water but without having to wait for local authorities or international agencies to install and run purification plants, pumps, distribution system pipes, and so on.
· And because the efficacy is not dependent on adding free chlorine to the water, many of the disadvantages normally associated with that approach are avoided entirely. The challenge, however, has been to find a means of embedding this elegant disinfecting medium into the core of a practical, easy-to-use device, designed for household use in developing countries.
· Success in meeting this challenge was the theme of the ASTMH symposium. It drew together and presented all the evidence for the effectiveness of the concept, and then showed how other elements of an ideal water purification device could be assembled around it to meet the demands of the original objective — an economical, robust, convenient, easy-to-use, highly reliable in-home POU system for generating safe water, that would still be within the reach of people on the lower rungs of the economic ladder in developing country communities.
· The very durability and unprecedented low operating costs of the halogen rechargeable medium raised the stakes even higher. The elements of purification that needed to be assembled around the bead medium have to ensure that the microbiologically safe water also looks good, smells good, and tastes good — all qualities that are important to water consumers the world over, even those most deprived of reliable access to safe water.
· The assembly of such purifier is relatively cheap while more sophisticated and multifaceted as compared to a regular purifier. Durability and easy recycling plays a vital role in cost reduction. vital role in cost reduction.
Elements of a POU purification system
Some finished filters available
A breakthrough in POU water purification the technology holds the promise of reducing the impact of water borne diseases throughout the developing world. Its widespread use could contribute to the realization of UN goals for access to safe water for all by 2015. And it could do so without resort to the massive infrastructure investments that are needed to reach this goal using more conventional centralized sanitation and distribution approaches. Recent research has shown how powerful the effect on family and child health can be from the introduction of simple POU water purification measures, even when these are not accompanied by significant improvements in sewage disposal.
MODEL IV: PEEPOO BAGS
Across all large slum dwellings in India what one finds common is the persistent stench that arises from guttural waste. Poor sanitation in slums has always been an issue and the open drains invite a host of diseases like diarrhoea, cholera and become breeding sites for mosquitoes.
Also, a major headache for those who live in slums is shortage of water. Despite all the promises made by successive governments water shortage remains an unsolved problem at large and the problem is aggravated by the fact that migrant rural population is going to need more of this already scarce resource.
The hand to mouth existence in slums leaves basic hygiene practises unattended. According to a very recent report in ‘The Hindu’ “Half of India's homes have cellphones, but not toilets”.
The above figures call for a solution which is accessible, cost effective, eco-friendly and can be implemented in minimum possible time frame. Here comes the role of PEEPOO bags.
Makeshift Toilets
The PeePoo bag serves as an alternative to open toilets. Construction from bioplastics ensures that environmental leakage does not occur. An inside lining of urea crystals decomposes poop into ammonia and carbonate using enzymes naturally present in feces. This raises the pH of the poop and subsequently kills most pathogens within a few weeks.
Environmentally Friendly and Useful for Agriculture
Better yet, the PeePoo bag does not cause additional environmental problems of its own and is actually practical for large-scale Third World implementation. The bag itself is biodegradable and currently constructed from 45% recycled materials. Once the hygienization process is complete, the leftover ammonia can be put to use as fertilizer.
It is important that the Peepoo bag technology be employed. This simple technology will cater for the extreme situation by moving away from hard structures into a soft approach to sanitation and excreta management giving the individual inhabitant a choice to hygienic and sustainable personal sanitation.
Evaluation
The proposed technology will be a universal remedy for prevailing human waste disposal facing slum residents. Remarkably slim, measuring 14X39 cm, the Peepoo bag, essentially a bioplastic bag containing urea powder, sanitises human excreta shortly after defecation. It requires no water, as after use the bag breaks down and disintegrates, and the treated faeces become fertiliser with a high market value. It doesn't need any supporting structure, but, for convenience, a small bucket can help a lot.
1 This option is affordable and will improve the quality of life with minimal lobbying and negotiation with the residents. There will be need for awareness campaigns and sensitization on the use of the bags and the organic manure.
2 The organic manure utilization component relates to income generation and is expected to develop into a cottage industry, which will attract a significant proportion that will derive direct benefits from the initiative and build a sustainable micro-enterprise.
3 These technologies will not involve the construction of new infrastructure leading to the displacement of people, i.e. this proposed intervention will not touch on the existing settled areas.
The PEEPOO technology combats various problems mentioned in the introduction in the following manner
Price to set for the Peepoo bag
The biggest concern about the bag is the cost per bag which is expected to be Rs. 2.61. However, this is cheaper than building a flush toilet connected to a sewer or septic tanks which costs $400 to $1500. Even a communal toilet or basic bit latrine is between $10 and $40. In a country where those earning a wage of less than Rs. 37 per day are considered to be lying below the poverty line, it shouldn’t be much of a problem to start making use of PeePo bags. However provision of government aid can certainly boost the usage of such eco-friendly bags.
Portable toilets:
Sanitation is a major problem in city slums as there is not enough space to accommodate a normal toilet and also lack of awareness in people. Therefore it is quite necessary to have compact and clean sanitation solution: Portable toilets. It is made up of light-weight sheet plastic, such as polyethylene. In this model we focus on providing the same to the city slums which are basically made from low weight polymers and also have the advantage of hygiene and easy cleaning.
Pictorial representation of the working of the portable toilets
Since safe disposal of plastic wastes in particular is one grave issue that needs to be paid heed to so we propose an efficient recycling of plastic wastes. For working on this front, ragpickers could be employed to perform the valuable work of collecting, sorting, and where possible selling for reuse or recycling, the remaining waste. Normally, ragpickers in such a situation are self-employed, and because of this it has often been hard for them to organise effectively to protect their rights. By giving them employee identity cards and encouraging them to organise into groups that they run themselves, they can be made to have a more stable and secure income.
Model V: Polymer Furniture
With the growth of polymer industry and innovations in the field, furniture market has experienced a rapid growth with the availability of a new, cheap and better replacement for the conventional wood furniture- Plastic furniture. This type of furniture is commonly made from solid molded polyethylene marine grade polymer.
Advantages:
1. Low cost material, Flame retardant, U.V. Resistant, outdoor durability.
2. Very strong, can be light or heavy depending upon need.
3. Economical and eco friendly
This type of furniture can be used in slums to develop local schools, and to provide cheap home furniture, one of the major advantages of this remains its flame retardant capabilities that prevents losses in case of common slum fires, and its UV resistance, that ensures its long life.
Model V: Polymer Pavements and roads
Slums especially in Delhi have a very poor connectivity to roads; these roads are either in accident prone condition or aren’t very permanent in foundation. A poor road leads to difficulty in bringing Healthcare and other facilities in times of need to these areas, and often is the cause for poor sanitation, disease spread, etc. therefore proper long lasting pavements and roads can be constructed by using polymers.
Here is a comparative study to compare the conventional roads and the new polymer roads, with SoilTech polymers, a brand of Polymer pavements as an example.
Polymer stabilization, in most instances, minimizes the need for borrow-pit materials.
In-situ aggregates and other materials, normally discarded for road construction, can used with SoilTech polymers and Polymer technologies are immeasurably more carbon friendly than traditional layered, cement-stabilized roads. *Independent reports have shown SoilTech polymers, from Polymer Pavements, produces a meager 2,4% carbon in comparison to cement stabilized, layered roads. One kilometer of cement stabilized road, seven meters wide, will produce 50,449 tons of carbon into the air as opposed to 1,217 tons produced by our polymer stabilized road!
Case study: South Africa – Nkomati Mine – Heavy Haul Roads, July 2010
Table. 1 Nkomati – Comparative Tests – Before and After
| Dry Test (June 2010) | Wet Test (soaked for 40 mins) |
| Average Reading on Treated Dry Road CBR 160% UCS 1308 kPa E-Modulus 509 MPa | Average Reading on Treated Wet Road CBR 148% UCS 1217 kPa E-Modulus 475 MPa |
| Average Reading on Untreated Dry Slag Road | Average Reading on Untreated Wet Slag Road |
| CBR 48% UCS 453kPa E-Modulus 187 MPa | CBR 36% UCS 352 kPa E-Modulus 147 MPa |
| Dry Test (9 March 2010) | Wet Test (soaked for 2 hours) |
| Average Reading on Treated Dry Road CBR 135% UCS 1121 kPa E-Modulus 440 MPa | Average Reading on Treated Wet Road CBR 102% UCS 875 kPa E-Modulus 347 MPa |
The result of the study was that the use of such materials significantly enhanced functional performance and load bearing capacity of these roads.
Advantages:
1. Waste management: The junk plastic used here helps us to manage effectively and economically.
2. Environment Friendly: CO2 emissions during construction are 32 times less than the conventional roads.
3. Economically cheaper than using Bitumen, used as a binding agent to hold together the base and the sub-layers of the road.
4. Cuts down on labor costs, water costs, and construction time.
5. Long Life: doesn’t crack under stress.
Model VI: Polymer Composites as Construction Materials
Title: Eco-Composites
Target Audience: Civil and Structural Engineers, Architects, Building
Specifiers
Overview of application/summary:
Eco-composite is a term which is used to describe composite materials with environmental and ecological advantages over normal composite materials such as FRPs. The drive towards sustainable construction and environmental legislation such as the End of Life Vehicle Directive and Landfill Tax has resulted in considerable interest in the use of reclaimed waste such as plastic packaging for construction materials, as well as the use of natural plant fibers, wood, and bio-derived resins and adhesives. An eco-composite may contain natural fibers such as hemp, sisal, jute or flax, or consist of a natural polymer matrix derived from cashew nut shell liquid (CNSL). Plastic materials can also be produced from corn, and even chicken feathers. Eco-composites can be produced from combinations of reclaimed waste such as wood, newspaper, and plastics. Natural composites based on starch can be produced which have the important advantage of biodegradability. Softwood timber can be chemically modified using waste cellulose from agriculture to produce a composite material with the properties of a tropical hardwood. A composite which is easier to recycle such as an all polypropylene material may also be termed an eco-composite.
Impact of Application
Financial:
· Eco-composites may be produced from cheap raw materials or waste.
Environmental:
1. Eco-composites may contain natural fibers or resins, reducing need for either petroleum derived plastics or glass fibers.
2. Eco-composites may be composed of waste material such as post-consumer plastic or newspaper.
3. Eco-composites may be made to be biodegradable or easier to recycle.
Social:
Ø Some natural fibers and resins are obtained from the Developing World, improving trade with those countries.
Ø Provides a potential alternative crop for farmers.
Engineering:
1. Certain combinations of natural fiber are lighter than the alternative glass reinforcement, however generally the structural performance of the composite is lower which limits the applications. Plant fibers can be stiffer than glass; however tensile strength and impact resistance are lower.
2. Plant fibers also do not lend themselves to many of the advanced production processes of polymer composites such as pultrusion
Future developments and estimated time-scale:
High interest in this area of research due to increased pressure for sustainable construction.
These materials because of their low cost provide cheap & good alternatives to slum dwellers in parts of Delhi.
