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Sustainable Materials. Are what we think of as sustainable materials, really sustainable?

Essay 2015 22 Pages

Environmental Sciences

Excerpt

Content

Introduction

Chapter 1 WOOD

Chapter 2 PLASTIC

Chapter 3 CONCRETE

Chatper 4 TRADITIONAL CYPRIOT BUILDINGS

Conclusion

Bibliography
Books
Websites
References

Introduction

One of the biggest issues the world is facing today is environmental pollution, which is increasing rapidly each year, resulting in serious and irreparable damage to earth. The construction industry had been a major source of pollution for many years. It is responsible for 4% emissions of particulate matter, causing more water pollution than any other industry, and thousands noise pollution annually. Even though the construction operations pollute the soil, the key fields of concern are air, water and noise pollution.

Activities such as purification of the land, diesel engines operation, demolition, burning and working with toxic materials are responsible for air pollution. In all construction sites, the levels of dust are high, most commonly from concrete, cement, wood, stone and silica use, causing a broad spectrum of health problems, such as respiratory illness, asthma, bronchitis and even cancer. Furthermore, the exhaust of diesel engine of vehicles and heavy equipment consists of soot, sulphates and silicates, and can be easily combined with other toxins in the air, increasing the health risks of particle inhalation. Carbon monoxide, hydrocarbons, nitrogen oxides and carbon dioxide emissions can be caused by diesel. Air pollution can also be caused from fumes from oils, glues, thinners, paints, treated woods, plastics, cleaners and other harmful chemical substances commonly used on construction sites.

Diesel fuel and oil, paint, solvents, cleaners and other harmful chemicals and building debris and dirt can result to water pollution. Water run-off contains pollutants from the site, like diesel and oil, toxic chemicals and building materials such as cement. If these substances get into waterways, they will poison water life.

Pollution prevention is an essential component of sustainability. To prevent pollution, the input of materials and energy, must be reduced. Careful consideration of construction materials can result to prevent pollution and contribute to a sustainable future. Sustainable materials includes examining aspects like transparency within the supply chain, local environmental repercussions during the period of extraction, harvesting and processing, and the ability to reuse and recycle them. Many materials can be defined as sustainable, but which materials are truly sustainable?

Chapter 1 WOOD

Wood is one of the most important construction materials, and the heart of modern construction because of its adaptability, abundance in nature and environmental compatibility. Wood is recognised as an environmentally friendly material, as well as bamboo which are one of the fastest growing plants, with a broad variety of applications in different fields. It is a tall, fast growing grass empty inside with an extensive root system that generates new bamboo shoots and does not need replanting.

Wood can be classified in two groups. The first is softwood, which is low in density and most often light in colour. They grow quickly and are cheap, soft and easy to work. Some examples of softwood are pine, spruce, cedar, fir and larch. The second is hardwood, which is a dark-coloured wood, with high density and thick cell walls. There are a much greater number of hardwood species than there are softwoods. Some examples of hardwood are birch, oak, ash, teak and elm.

Table 1 Regional distribution of softwood and hardwood forrests in the world

Abbildung in dieser Leseprobe nicht enthalten

*Confederation of the Independent States of the former Soviet Union

Figure 1

Jamal Khatib describes wood as a sustainable material, in his book 'Sustainability of Construction Materials'. Wood can be considered as a renewable and environmentally friendly material. With a sustainable management of the forests, (the harvested tree is replaced by another tree) wood can be regarded as a plentiful and reliable supply. Compared to materials like concrete, aluminium, steel, plastic and glass, wood has distinguishing environmental benefits. It is the most effective material, both in terms of embodied energy and environmental impact. It requires a very little energy to process from a tree trunk to a product, because it does not need any purification or melting in the extraction and finishing stages.

Table 2 Enrgy and enviromental performance of timber compared with other common construction materials

Abbildung in dieser Leseprobe nicht enthalten

GWP,global warming potential; AP, axidification potential; POCP, photochemical ozone creation potential

Figure 2

In terms of durability, wood can be both durable and not durable, depending on the type of wood. The term "physical resistance", when applied to timber refers to the ability to endure or resist wear because of its intrinsic properties. In suitable conditions, timber is able to persist for ages. Resistance of wood can be improved by maintenance and further treatment. Wood can be impregnated with deleterious chemicals to protect it from molds and insects. The application of paint can prevent wood distortion. However, these chemicals are not environmentally friendly because they can cause pollution.

University of Florida, published a paper called 'Sustainable Landscape Construction', which describes wood as a material with various qualities, and an ideal material for construction. It insulates carbon, it can be used easily, is structurally strong and aesthetically pleasing. It does not need much process, it needs low energy to manufacture and transport. Both this paper and Jamal Khatib state that the significant environmental effects of wood are the unviable growth and harvesting techniques used. These unsustainable techniques are resulting to the loss of habitat and topsoil, the use of pesticides and pesticide in tree plantations and the preservation of wood treatments downgrade the environment. Furthermore, this paper identifies another problem caused by wood, which is the large quantity of wood waste caused by the trimming of boards. Even thought this waste can be composted or recycled, wood waste which has been treated with pressure or containing glue or paint should not be recycled or burned.

Meg Calkins the authour of the book 'Materials for Sustainable Sites' indicated that the contemporary use of wood in construction has been heavily dominated by unsustainable practices. Standard harvesting techniques are destroying large areas of forests, resulting in the destruction of habitats. Rainforests are cut down and people create durable spaces that are shipped around the world. Conservative treatment injects heavy metals and insecticides wood that can leach into the soil and affect human health. Also, wood finishes, pollute the air, contributing to human respiratory problems.

Abbildung in dieser Leseprobe nicht enthalten

Figure 3

However, because of these issues and the construction industry leaning towards environmentalism, wood is now viewed as an unsustainable construction material. This resulted to the fast increasing of forest management and harvesting practices by forest certification and programs. Also, large quantity of reclaimed wood is available and less toxic wood treatments and finishes are being developed. Engineered wood and small timber units are available for exterior applications with low-toxicity binders. Strategies to use wood efficiently lowering waste and built lasting structures can are also available. Wood can be one of the most sustainable materials if specified properly.

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Details

Pages
22
Year
2015
ISBN (eBook)
9783668405752
ISBN (Book)
9783668405769
File size
1 MB
Language
English
Catalog Number
v354362
Grade
Tags
sustainable materials

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Title: Sustainable Materials. Are what we think of as sustainable materials, really sustainable?