A 500 metre road from Ratmalana to Borupana, South of Colombo had been paved with an asphalt mixture containing shredded and molten plastic extracted from municipal waste.
Non-recyclable plastic waste is taken from municipal waste (in Sri Lanka plastic, paper and food waste is now separated in households) shredded and heated with aggregates at 165 degrees centigrade.
"The molten waste-plastic-mix coats the heated aggregates before being coated with bitumen," the firm said.
"The new material – waste plastic modified asphalt concrete mix – will be applied for surfacing of roads under 150 degrees centigrate temperature. "
The plastic asphalt mixture not only solves the waste problem but cuts road construction costs and makes the pavements more durable.
Tests are conducted on the pilot project, the company said.
"Similar waste plastic modified asphalt mixes are successfully applied to road surfacing in countries such as UK, Canada, Netherlands, Philippines, India and Indonesia,"
The Plastic and Bitumen Mixture
Using recycled plastic for road building sounds simple, but it actually requires a complex process to create the right material. "Different plastics do different things to bitumen," he explains. "If you use the wrong mix, it actually can make the bitumen more brittle."
It is good to avoids using PET bottles and other types of plastic that are easily recycled, and instead concentrates on types of waste plastic that might otherwise end up buried in the ground. Reid declined to go into too much detail, so as not to reveal too much about MacRebur's proprietary process.
In addition to keeping plastic out of landfills, the company's plastic road materials can save about 1 ton (.907 metric tons) in carbon dioxide output for each ton of bitumen that the plastic replaces, according to this fact sheet from MacRebur's website.
சேகரிக்கப்பட்ட பிளாஸ்டிக் கழிவுகள், 1.60 மி.மீ. முதல் 2.50 மி.மீ. அளவுள்ள சிறு சிறு துகள்களாக வெட்டு இயந்திரங்களின் உதவியால் வெட்டப்பட்டு, சேகரித்து வைக்கப்படுகிறது. பின்பு இவை, தார்ச்சாலை அமைக்க சேகரிக்கப்பட்ட 110° செல்சியஸ் அளவிற்கு சூடுபடுத்தப்பட்ட கற்களுடன் சேர்த்து சுழற்சி முறையில் கலக்கப்படுகிறது. அவ்வாறு கலக்கப்படும் போது, கற்களில் உள்ள 1709 செல்சியஸ் வெப்பத்தினால், 30லிருந்து 60 வினாடிகளுக்குள் சிறு துகள்களாக நறுக்கப்பட்ட, பிளாஸ்டிக் துகள்கள் இளகி, கற்களின் மேல் போர்த்தியது போல், கற்களின் மேற்பரப்புகளை முழுவதுமாக மூடிவிடுகிறது.
இவ்வாறு இளகிய பிளாஸ்டிக் கழிவுகளுடன் சேர்க்கப்பட்ட கற்கள், உறுதியானவையாகவும், பிடிப்புத் தன்மையுள்ளதாகவும், மாறிவிடுகிறது. மேலும், கற்களின் மேற்பரப்பில் உள்ள சிறு சிறு நுண் இடைவெளி முழுவதுமாக மூடப்படுவதால், அதனுள், மழைநீர் அல்லது உப்பு கலந்த நீர் புகாமல் தடுக்கப்படுகிறது. இதனால், கற்கள் மழைநீரை உறிஞ்சி சிறு சிறு கற்களாக உடைவது தவிர்க்கப்படுவதுடன், சாலை குறுகிய காலத்திற்குள் பாழ்படுவது தவிர்க்கப்படுகிறது. இவ்வாறு, இளகிய பிளாஸ்டிக் கழிவுகளுடன் சேர்க்கப்பட்ட கற்களுடன், 1650 செல்சியஸ் வெப்ப அளவில் சூடுபடுத்தப்பட்ட தார் சேர்க்கப்படுகிறது.
மேலே கூறப்பட்ட வெப்ப அளவுகளில், தயார் செய்யப்பட்ட கலவையானது, 1109 - 1209 செல்சியஸ் வெப்ப அளவிற்குள்ளாக, தயார் நிலையில் உள்ள சாலைகளில் பரப்பப்பட்டு, கனமுள்ள சாலை உருளை வண்டி மூலம் இறுக்கம் கொடுக்கப்பட்டு, பிளாஸ்டிக் தார்ச் சாலை அமைக்கப்படுகிறது. 10 சதுர மீட்டர் அளவும் 25 மி.மீட்டர் கனமும் உள்ள பிளாஸ்டிக் தார்ச்சாலை அமைக்க, 27 கிலோ தார்க்கலவையும் 3 கிலோ பிளாஸ்டிக் நறுக்குகளும் தேவைப்படும். சாதாரண தார்ச் சாலை அமைக்க 30 கிலோ தார்க்கலவை தேவைப்படும். ஒரு பிளாஸ்டிக் சாலை அமைக்க தார்க்கலவையின் அளவில் 10 சதவீதம் பிளாஸ்டிக் நறுக்குகள் தேவைப்படும். இவ்வாறு அமைக்கப்பட்ட சாலைகள், உறுதி வாய்ந்தவையாகவும் மழைக்காலங்களில் சேதமடையாமலும் பிளாஸ்டிக் கழிவுகளின் பயன்பாட்டினால் புற ஊதா நிறக் கதிர் வெளிப்பாடு இல்லாமலும், அதிக கனரக வாகனப் போக்குவரத்தை தாங்கக் கூடியவையாகவும், குறைந்தது 7 வருடங்களுக்கு எந்தவித சேதாரம் இல்லாமலும் பயன்பாட்டில் இருக்கும்.
Alternative Method
தற்போது பல்கலைகழகங்களில், கழிவு பிளாஸ்டிக் பொருட்களைக்கொண்டு வீதி அமைத்தல் எனும் விடயத்தின் கீழ் (Using Waste Plastic in Road Construction) எனும் தலைப்பின் கீழ் பல ஆய்வுக்கட்டுரைகள் வெளி வந்துள்ளன. இதில் பாவிக்கப்படும் தாருக்கு சிபாரிசு செய்யப்பட்டளவு பிளாஸ்டிக் சேர்க்கப்பட்டு தார் வீதிகளுக்கு பாவிக்கலாம் என கூறப்பட்டுள்ளது. இதனடிப்படையிலேயே எனிவரும் காலங்களில் கார்பட் வீதிகளுக்கு போடப்படும் அஸ்போல்ட் கொங்கிறீட்டுடன் சிபாரிசு செய்யப்பட்ட அளவு பிளாஸ்டிக் சேர்க்கப்பட்டு கார்பட் வீதிகள் அமைக்கப்படவுள்ளது.
இவ்வாறு பிளாஸ்டிக் சேர்ப்பதனால் வீதியின் பாவனைக்காலம் கூடுதலாகவும் வீதிகள் உறுதியாகவும் இருக்கும் எனவும் கூறப்படுகின்றது அத்துடன் மிக முக்கியமான விடயம் நகரிலே சேகரிக்கப்படும் பிளாஸ்டிக் போத்தல்கள் மீள் பாவனைக்கு உட்படுத்தி சுற்றுச்சூழலை பாதுகாக்கவும் முடியும்.
திருகோணமலை நகராட்சிமன்றம் பரீட்சாத்தமாக இராஜவரோதயம் சதுக்கத்திலுள்ள சிறிய வீதியொன்றிற்கு துண்டுகளாக வெட்டப்பட்ட பிளாஸ்டிக் போத்தல்களை தாருடன் உருக்கி 12.03.2021 அன்று வீதி தாரிடும் வேலையை ஆரம்பித்தது. தாரினையும் பிளாஸ்டிக்கினையும் உருக்கிய கலவையைக்கொண்டு சிறப்பாக வீதியை அமைத்துக்கொண்டது.
‘Electronic Waste’. Electronic waste covers everything from home appliances like TVs, air conditioners, and fans to IT devices like computers and mobiles that have been replaced or have reached the end of their life cycle and need to be disposed of.
Waste electrical and electronic equipment (WEEE) is becoming a major threat to the whole world. Its toxic emissions mixed with virgin soil and air and causing harmful effects to the entire biota either directly or indirectly. Direct impacts include the release of acids, toxic compounds including heavy metals, carcinogenic chemicals and indirect effects such as biomagnification of heavy metals. Many private firms are involved in collecting, dismantling, separation and exporting e-wastes for recyclers. However, strict regulations are currently being followed as on approval of such firms such as e-steward certification by Basel action network in the USA, they also involved in public awareness programs; this review is based on collected information from various journal articles, websites including the technical note by Greenpeace international. Further, it analyzes the current progress on e-waste management worldwide.
Here’s an example to understand the scale of the problem, according to estimates by Ceylon Waste Management there are 7.6 Million CRT TVs and Monitors in Sri Lanka, and only 10% of that will be properly disposed. The remaining 90% will be around 67500 metric tons of CRTs, of which 8840 tons will be lead and 110 tons of arsenic. That’s a massive amount of poison that could leach into our ecosystem endangering both human and animal lives. Other methods must be employed to dispose of this waste.
What Happens to Devices at the End of Their Useful Life
Unfortunately, the majority of these electronic products end up in landfills, and just 12.5% of e-waste is recycled. According to a UN study, over 41.8 million tons of e-waste was discarded worldwide, with only 10%–40% percent of disposals appropriately done. Electronics are full of valuable materials, including copper, tin, iron, aluminum, fossil fuels, titanium, gold, and silver. Many of the materials used in making these electronic devices can be recovered, reused, and recycled—including plastics, metals, and glass.
In a report, Apple revealed that it recovered 2,204 pounds of gold —worth $40 million—from recycled iPhones, Macs, and iPads in 2015.
Benefits of E-Waste Recycling
Recycling e-waste enables us to recover various valuable metals and other materials from electronics, saving natural resources (energy), reducing pollution, conserving landfill space, and creating jobs. According to the EPA, recycling one million laptops can save the energy equivalent of electricity that can run 3,657 U.S. households for a year. Recycling one million cell phones can also recover 75 pounds of gold, 772 pounds of silver, 35,274 pounds of copper, and 33 pounds of palladium.
On the other end, e-waste recycling helps cut down on production waste. According to the Electronics TakeBack Coalition, it takes 1.5 tons of water, 530 lbs of fossil fuel, and 40 pounds of chemicals to manufacture a single computer and monitor. 81% of the energy associated with a computer is used during production and not during operation.
The Electronics Recycling Process
Electronics recycling can be challenging because discarded electronics devices are sophisticated devices manufactured from varying proportions of glass, metals, and plastics. The process of recycling can vary, depending on the materials being recycled and the technologies employed, but here is a general overview.
Collection and Transportation: Collection and transportation are two of the initial stages of the recycling process, including for e-waste. Recyclers place collection bins or electronics take-back booths in specific locations and transport the collected e-waste from these sites to recycling plants and facilities.
Shredding, Sorting, and Separation:After collection and transportation to recycling facilities, materials in the e-waste stream must be processed and separated into clean commodities that can be used to make new products. Efficient separation of materials is the foundation of electronics recycling. Shredding the e-waste facilitates the sorting and separation of plastics from metals and internal circuitry, and waste items are shredded into pieces as small as 100mm to prepare for further sorting.
A powerful overhead magnet separates iron and steel from the waste stream on the conveyor and then prepares it for sale as recycled steel. Further mechanical processing separates aluminum, copper, and circuit boards from the material stream—which now is mostly plastic. Water separation technology is then used to separate glass from plastics. The final step in the separation process locates and extracts any remaining metal remnants from the plastics to purify the stream further.
Preparation For Sale as Recycled Materials:After the shredding, sorting and separation stages have been executed, the separated materials are prepared for sale as usable raw materials for the production of new electronics or other products.
Electronics Recycling Associations
ISRI (the Institute of Recycling Industries):ISRI is the largest recycling industry association with 1600 member companies, of which 350 companies are e-waste recyclers.
CAER (Coalition for American Electronics Recycling): CAER is another leading e-waste recycling industry association in the U.S. with over 130 member companies operating around 300 e-waste recycling facilities altogether throughout the country.
EERA (European Electronics Recyclers Association):EERA is the leading e-waste recycling industry association in Europe.
EPRA (Electronic Products Recycling Association):EPRA is the leading e-waste recycling industry association in Canada.
Current Challenges for Electronics Recycling Industry
The E-waste recycling industry has a significant number of challenges, which the primary one being exporting to developing nations. Exporting e-waste, including hazardous and toxic materials, is leading to serious health hazards for the workers working for dismantling electronic devices in countries without adequate environmental controls. Currently, 50%–80% of e-waste that recyclers collect is exported overseas, including illegally exported e-scrap, which is of particular concern. Overall, the inadequate management of electronics recycling in developing countries has led to various health and environmental problems.
Although the volume of e-waste is increasing rapidly, the quality of e-waste is decreasing. Devices are getting smaller and smaller, containing less precious metal. The material values of many end-of-life electronic and electrical devices have therefore fallen sharply. Electronics recyclers have suffered due to sagging global prices of recycled commodities, which have decreased margins and resulted in business closures.
Another problem is that as time goes on, many products are being made in ways that make them not easily recyclable, repairable, or reusable. Such design is often undertaken for proprietary reasons, to the detriment of overall environmental goals. Organizations such as ISRI have been active in promoting policies to broaden the range of authorized companies allowed to repair and refurbish smartphones to avoid their needless destruction.The current rate or level of e-waste recycling is definitely not sufficient. The current recycling rate of 15%–18% has much room for improvement as most e-waste still is relegated to the landfill.
Electronics Recycling Laws
Currently, 25 U.S. states have laws mandating statewide e-waste recycling, and several more states are working toward passing new legislation and improving the existing policy. State e-waste recycling laws cover 65% of the U.S. population, and some states, including California, Connecticut, Illinois, and Indiana, e-waste is banned from landfills.
Potential Initiatives in Sri Lanka
Despite these initiatives, Sri Lanka is still far away in terms of e-waste management compared to most countries. Thus, existing bottlenecks need to be addressed in order for Sri Lanka to be a sustainable e-waste recycler. Strengthening policy and legislation is vital. Apart from the existing policy and regulation, the government could reinforce regulations, specifically on the imports of EEE. For instance, regulations should be enacted on discouraging the imports of used EEE, and to import equipment that has less hazardous elements; for example, LED/LCD monitors can replace CRT monitors, since CRT has more hazardous elements. In addition, suitable technology and skills need to be implemented in order to streamline the sustainable e-waste recycling system in the country. Proper mechanisms should also be developed to take out the informal market for e-waste recycling in the country. Improving the knowledge on e-waste within the community is crucial. Conducting programmes which highlight the social and ecological impacts of improper handling of e-waste, and the importance of disposing e-waste in proper places and in proper ways can be effective in raising public awareness. This can be provided through the public health staff, starting from grassroots levels. Also, the media can play a pivotal role in disseminating the message and making the mass community aware of the impacts of improper handling of e-waste as well as the proper mechanisms in recycling and its benefits.
‘E-waste’ should not be considered as normal ‘junk’. It may not impact you instantaneously, but could do so later in life. Therefore, much attention should be paid to this issue, considering the many health impacts that could be instigated by the e-waste around us.
The selection of green building materials and products represents a critical strategy in designing a green building. Green building materials offer specific benefits to the building owner and building occupants and are as follows:
Reduced maintenance/replacement costs over the life of the building.
Energy conservation.
Improved occupant health and productivity.
Lower costs associated with changing space configurations.
Greater design flexibility.
Building and construction activities worldwide consume 3 billion tons of raw materials yearly, or 40 per cent of total global use. Using green building materials and products promotes the international conservation of dwindling nonrenewable resources.
In addition, integrating green building materials into building projects can help reduce the environmental impacts associated with the extraction, transport, processing, fabrication, installation, reuse, recycling and disposal of these building industry source materials.
Selection criteria for green material
A) Resource efficiency:
Recycled Content: Products with identifiable recycled content, including post-industrial content, with a preference for post-consumer content.
Natural and renewable: Materials harvested from sustainably managed sources preferably have an independent certification (e. g., certified wood) and are certified by an independent third party.
Resource-efficient manufacturing process: Products manufactured with resource-efficient processes include reducing energy consumption, minimizing waste (recycled, recyclable and or source-reduced product packaging), and reducing greenhouse gases.
Locally available: Building materials, components, and systems found locally or regionally save energy and resources in transportation to the project site.
Salvaged, refurbished, or remanufactured: Includes saving material from disposal and renovating, repairing, restoring, or generally improving the appearance, performance, quality, functionality, or value of a product.
6) Reusable or recyclable: Select materials that can be easily dismantled, reused, or recycled at the end of their useful life.
7) Durable: Materials that are longer lasting or are comparable to conventional products with long life expectancies.
Evaluation Criteria for Green Materials
Due to phenomenal growth in the construction industry, there is tremendous pressure on depleting earth resources such as soil, sand, stones, wood, etc. Production of building materials leads to irreversible environmental impacts. Using environmentally friendly building materials is the best way to build an eco-friendly building. The following criteria can be used to identify green materials.
Local availability of materials
The embodied energy of materials
% of recycled/waste materials used
Rapidly renewable materials
Contribution to Energy Efficiency of buildings
Recyclability of materials
Durability
Environmental Impact
Using the abovementioned criteria and assigning a particular rating (R1-R8) to each standard, an overall evaluation of the material can be made by summating the score obtained by any material in these ratings. Guidelines for assigning a rating to each criterion are discussed in the following text.
i) Local availability of materials
As far as possible, locally available materials are preferred to minimize the energy spent in transporting the building materials. Energy consumed in vehicles is the total energy spent on transporting materials starting from the place of manufacturing. Depending upon the distance from the material's manufacturing place, points for rating R1 can be allotted to the materials based on the following guidelines.
ii) The embodied energy of materials
Embodied energy assesses the energy required to manufacture any building material. This includes the energy needed to extract raw materials from nature, the energy used to transport raw materials to the manufacturing unit and the energy used in manufacturing activities to provide a finished product. Every building is a complex combination of many processed materials, each of which contributes to the building's total embodied energy. Embodied energy is a reasonable indicator of the overall environmental impact of building materials, assemblies or systems. The embodied energy of some building materials is mentioned in Table-2. Depending upon embodied energy of the materials, points for rating R2 can be allotted based on guidelines given in Table-3.
(iii) Percentage of recycled/waste materials used
Building materials can be manufactured using recycled materials or using waste materials. Using recycled materials helps the environment and the economy in several ways. A significant effect is lessening the need for manufacture with virgin, non-renewable resources, saving precious resources, energy and cost. Waste materials that would have ended up in landfills after their useful life can be reprocessed for use in other products. The use of various types of waste materials, such as fly ash, blast furnace slag, red mud, waste glass, marble dust, cinder, rice husk, coconut husk, banana leaves, jute fibres, rubber from automobile tires, etc., is demonstrated by research. Table-4 specifies guidelines for rating R3 for this criterion.
(iv) Use of renewable resources
Materials manufactured with renewable resources (i.e. wood or solar power) rather than non-renewable (i.e. fossil fuels) shall be preferred. Depletion of the Earth's resources is occurring at an alarming rate. The entire ecosystem is affected due to the continuous extraction of raw materials worldwide. As fossil fuel stock is limited, it may get exhausted very soon. By utilizing renewable energies, such as wind, solar, tidal, and renewable materials, such as wood (certain certified species which are rapidly renewable), grasses or sand, the impact on biodiversity and ecosystems can be lessened.
(v) Contribution to Energy Efficiency of buildings
Building construction and operation utilize a significant portion of the total energy produced. With little careful effort, designers and builders can reduce energy loads on structures, reducing energy requirements and the strain on natural resources. With proper orientation of the building concerning solar radiation to receive maximum daylighting, operable windows for natural cross-ventilation, use of passive cooling techniques (eliminating or lessening the need for air conditioning), walling unit with lower U values, roof insulation, water-saving devices and more efficient appliances can all work to reduce energy needs. Consideration of alternate energy source use, such as wind, solar and tidal power, can help alleviate reliance on traditional fossil fuel sources. The Bureau of Energy Efficiency (BEE) was set up by Govt. of India, which has formulated the Energy Conservation Building Code (ECBC),
which defines specific minimum energy performance standards for buildings. ECBC specifies minimum values for U-factor (U-factor is thermal transmittance which is the rate of transfer of heat through the unit area of a structure for the unit difference in temperature across the network., unit is W/m2-0C), Solar Heat Gain Coefficient (SHGC - the ratio of the solar heat gain entering the space through the fenestration area to the incident solar radiation. Solar heat gain includes directly transmitted solar heat and absorbed solar radiation, which is then reradiated, conducted, or convected into space) and Visual Transmittance (VT – it indicates the percentage of the visible portion of the solar spectrum that is transmitted through a given glass) with guidelines to be Table 6 specifies procedures for rating R5 for this criterion.
(vi) Recyclability of materials
The recyclability of the materials can be judged from the number of materials recovered for reuse after the useful life of materials/products or after the demolition of the building. Table - 7 specifies guidelines for rating R6 for this criterion.
(vii) Durability
Material replacement puts a strain on the Earth, its resources and its inhabitants. In making materials more durable and easy to maintain, manufacturers can help eliminate a costly, damaging and time-consuming process replacement process. Materials which are long-lasting and need little maintenance are preferred. Rating R7 for this criterion can be considered as mentioned in Table-8.
(viii) Environmental Impact
All materials used for the construction of buildings must not
harm the environment, pollute air or water, or cause damage to the Earth, its inhabitants and its ecosystems during the manufacturing process and also during use or disposal after the end of life. The material should be non-toxic and contribute to good indoor air quality. Worldwide industrial production uses billions of tons of raw materials every year. Pollution caubydthe by the excavation, manufacturing, use or disposal of a product can have far-reaching consequences on the Earth's ecosystem. Poor indoor air quality caused by VOC emission costs billions in medical bills and lost productivity to companies every year. The manufacturing, use, and disposal of PVC pose substantial and unique environmental and human health hazards because of its uniquely wide and potent range of chemical emissions throughout its life cycle. It is virtually the only material that requires phthalate plasticizers, which frequently include heavy metals, and emits large numbers of VOCs. In addition, during manufacture, it produces many highly toxic chemicals, including dioxins (the most potent carcinogens measured by man), vinyl chloride, ethylene dichloride, etc. When burned at the end of life, whether in an incinerator, structural fire or landfill fire, it releases hydrochloric acid and more dioxins. Products made with PVC may be avoided as far as possible. The following points should be considered for evaluating the environmental impact of the building materials, allocating ratof ing R8.
Classification of materials based on a scale
After evaluating the material for the criteria mentioned above and allocating points for rating R1-R8, totalling a maximum of 100 points, materials can be classified based on total points scored per the following guidelines.
Using the criteria, some materials are classified assuming specific data, as mentioned in Table-11.
B) Indoor Air Quality (IAQ):
Low or non-toxic: Materials that emit few or no CFCs, reproductive toxicants, or irritants, as demonstrated by the manufacturer through appropriate testing.
Minimal chemical emissions: Products with minimal emission of Volatile Organic Compounds (VOCs). Products that also maximize resources and maximize efficiency while reducing chemical emissions.
Moisture resistant: Product and systems that resist moisture or inhibit the growth of biological contaminants in the building.
Healthfully maintained: Materials, components, and systems that require only straightforward, non-toxic, or low-VOC methods of cleaning.
Systems or equipment: Products that promote IAQ by identifying indoor air pollutants or enhancing air quality.
C) Energy Efficiency:
Material, components, and systems that help reduce energy consumption in buildings and facilities.
D) Water Conservation:
Products and systems that help reduce water consumption in buildings and conserve water in landscaped areas.
E) Affordability:
Building product life-cycle costs are comparable to conventional materials and are within a project-defined percentage of the overall budget.
Construction activities can generate large amounts of waste
materials that then need to be disposed of. In addition, at the end of a
building's life, it may be deconstructed or demolished, generating significant
amounts of waste. Construction waste includes the waste that is generated during
construction activities (such as packaging, or the products of demolition) and
materials that are surplus to requirements (as a result of over-ordering or
inaccurate estimating).
Typical construction waste products can include:
Insulation and asbestos materials.
Concrete, bricks, tiles and ceramics.
Wood, glass and plastic.
Bituminous mixtures, coal tar and tar.
Metallic waste (including cables and pipes).
Soil, contaminated soil, stones and dredging spoil.
Gypsum.
Cement.
Paints and varnishes.
Adhesives and sealants.
Increasingly, there are options available in terms of
reusing and recycling materials, and reducing the amount of waste produced in
the first place, but despite this, a large amount of construction waste is still
disposed of in a landfill. 32% of landfill waste comes from the construction and
demolition of buildings and 13% of products delivered to construction sites are
sent directly to the landfill without having being used (ref. Technology Strategy
Board)
This can be an expensive process, as the 1996 Finance Act
introduced a tax on waste disposal on all landfill sites registered in the UK.
To help tackle this, a site waste management plan (SWMP) can
be prepared before construction begins, describing how materials will be
managed efficiently and disposed of legally during the construction of the
works, and explaining how the re-use and recycling of materials will be
maximised. For more information, see Site waste management plan.
It may be possible to eliminate a certain amount of
construction waste through careful planning. For example, steel formwork
systems might be capable of being used for concrete works which can then be
reused elsewhere on the project/s in place of timber formwork which is classed
as waste once it has been used.
Other types of construction waste may be capable of being
minimised; for example, products which are provided with reduced packaging or
those which are composed of recycled materials. There can also be opportunities
to re-use materials and products which are in a suitable condition (e.g. doors,
windows, roof tiles and so on), or exchange them for other materials with a
different construction site.
Materials and products which cannot be eliminated, minimised
or reused may have to be disposed of as waste. Before sending waste for
disposal, it should be sorted and classified to allow waste contractors to
manage it effectively and ensure that hazardous waste is properly handled.
The Problem
Disposal of public fill at public filling areas and mixed construction waste at sorting facilities or landfills has been the major approach for construction waste management. For sustainable development, we can no longer rely solely on reclamation to accept most of the inert construction waste. As such, the government is examining ways to reduce and also to promote the reuse and recycling of construction waste. Nevertheless, there will still be a substantial amount of materials that require disposal, either at public fill reception facilities or at landfills.
Today, we are running out of both reclamation sites and landfill space. With the current trend, our landfills will be full in mid to late-2010s, and public fill capacity will be depleted in the near future. In 2013, the mixed construction waste accounts for about 25% of the total waste intake at the three existing landfills. If there are insufficient public fill capacity and waste reduction measures being implemented, more public fill would probably be diverted to landfills and the landfill life will be further shortened.
