The construction sector is not an environment-friendly activity from its origin. They are responsible for the consumption of natural resources for the manufacture of construction materials, which itself have large negative impact on the environment.
Now the world brings up ideas and innovation to have environmental friendly activities. That are activities that undergo a check and debate for sustainability. The construction industry now from the pollution free perspective bring a large advantage through the activity of recycling. The by-products from the construction industry, as well as the ones from all other industries, are now subjected to recycling. These transforms the waste into a new product, which is employed to make alternative products. This approach works well in reducing the environmental impacts contributed by the construction industry.
The ISO 14001 standards regarding the environmental management mention the elements that are necessary to maintain the sustainability of the construction industry. The aim of achieving both the environmental and economic impact can be carried out by the integration of other management requirements.
Sustainable Issues Related to Construction Industry
The below are some of the sustainable issues that are faced by the environment. Each issue has been explained by their connection with the construction industry activity.
- Global Warming : There is the higher emission of greenhouse gasses and carbon dioxide happening with the increasing industrialization. The extraction, manufacturing, installation, maintenance and disposal of construction materials results in green house gas emission. The construction materials gain energy that is in the form of carbon dioxide. These are emitted out during the construction life cycle.
- Depletion of Biodiversity and habitats: The land acquisition and resource consumption for construction activity bring the habitats to a tough situation for their existence.
- Air pollution :The construction activities mainly result in particles that are having a size less than micro meter diameter. This makes them invisible, causing risk to environment and humans. The mining of aggregates, equipment operation, material transportation are certain activities that result in the emission of these pollutants.
- Acidification :These are caused as a result of fossil fuel burning to undergo manufacturing and transportation of construction materials. These results in the emission of nitrogen and sulfur that are highly toxic when dissolved in water. These are one of the major cause of acid rain.
- Toxicity : Intolerable levels of heavy metals are poisonous to humans. These are caused as a result of fossil fuel burning to undergo manufacturing and transportation of construction materials.
- Deforestation and land loss :To face increasing urbanization, the land is cleared to a larger extent by undergoing deforestation. This has made the loss of agricultural land and forests.
- Water pollution and depletion : The variation in the hydrological cycle, water unavailability are caused due to water resource depletion and pollution. The construction process demands a large amount of water. Bringing up largely impermeable structures results in a reduction in groundwater discharge.
Environmental Impact from Construction Industry
A factor to which the environmental impact of the construction industry is proportional is the social obligations. The increasing demand for homes and infrastructure, due to the increasing population, increasing standard of living are the main cause. Destruction of natural flora and fauna by the construction industry are not appreciated. That is a proper balance of the environmental concerns has also been taken into consideration.
The consumption of natural sources for producing sufficient raw materials for the construction activity is directly proportional to the economic growth as well as the demand. With time the cost of these raw materials is also increasing. This increase is mostly due to the unavailability of the resources to meet the demand. The consumption of natural resources will leave a certain amount of waste products that may be toxic, or non-degradable or in rare cases, environmentally friendly.
An estimation has been made that the main reserves of the raw materials iron, copper, and zinc will run short within 79, 31 and 17 years respectively. The quarries subjected to continuous depletion for the production of aggregates has to lead to the depletion in a larger percentage. The different stages in the construction industry make use of a different amount of natural resources. The waste that is produced can be consumed for building construction, depends on the following factors:
- The extent of waste production
- The type of technology used
- The need for maintenance if any error
- The durability of the structures with the material
The impact on the environment has to reduced by the incorporation of recycled products and waste products. So preparation of these materials to meet the economic requirements without compromising the quality has to be employed.
Energy Consumption in Construction Industry
The countries that have undergone a high range of industrialization accounts for 40% energy consumption. This consumption is a net value for the energy consumed during construction of the building and through its useful life till its demolition. This range can be decreased by the usage of waste materials in the construction. The energy required for conveying the raw materials from the quarries to the site is far greater compared to that employed for the transportation of recycled aggregates. About 80% of the energy out of total building construction is used for the production and transportation of materials.
Need for Alternatives
Most of the developed countries are forced to go for recycled materials for construction, as the cost of raw materials is increasing along with the depletion of natural resources. The industry made use of a lot of plant-based products, plastics, composites, a variety of metals depending on the project type. This bulk amount demand is now essential to be faced by the recycled materials that would act as alternative materials for the conventional materials. They are supposed to have similar or appreciable properties compared to the conventional materials. This can be well explained by the use of siliceous materials, by the use of materials like fly ash, ground granulated blast furnace that is by-products of steel manufacturing or incinerators.
The use of GGBS, fly ash as a 50% replacement for ordinary Portland cement is found to show a decrease of 40% in the energy consumption, thus decreasing the amount of carbon dioxide, which is a greater environmental concern. This would help in decreasing the greenhouse effect.
Life-cycle Analysis of Construction Industry
The life cycle assessment is not only the evaluation of the performance of a product but also to assess the environment impact that is contributed by the usage of a particular product. Over decades the life cycle assessment [LCA] has spread to the different area, that employs scientifically based inventory as well as evaluation techniques, that would precisely assess the impact of the product on the environment. This is employed through the following stages:
- Extraction from the Source i.e. Raw materials
- The transportation and delivery
- Maintenance and repairs
The ISO standard 14040 marks the LCA principles as well as the framework based on which it has to be employed. As per the standard, LCA is a method, that undergoes the compilation of all the above-mentioned stages related to the accomplishment of a product along with the assessment of the environmental impacts caused by the same. The LCA provides the details on the emissions to the environment, that is controlled based on the limiting values provided by the ISO standards.