The construction industry in Tanzania includes transportation infrastructures, real estates, and civil works, including water supply. According to the Tanzania National Bureau of Statistics (NBS), the Construction industry contributed 13.6% to Tanzania’s GDP during 2015, reaching almost USD6b. From 2016 to 2017 the government of Tanzania had budgeted TZS5.47t, which is to 25.4% of the total budget, excluding public debt service, for infrastructure development projects. As seen it is a big industry not only in Tanzania but also all over the world.
The building industry is a part of the construction industry. Green building technology is that buildings are environmental friendly and utilize efficiently the resources through out their lifespan, since the designing stage till construction. Green buildings are designed to reduce the overall impact on the natural environment by; efficiently using energy, water, and other resources and reducing waste, pollution and environmental degradation. Tanzania Green Building Council was established on 31st January 2014, with the mission of driving the sustainable development of Tanzania’s built landscape. One of its agendum is to promote the use of green materials in building. These materials are such as green concrete. Green materials are those, which are generally more efficient than traditional products because they require fewer resources to produce. In addition, materials that help cut down a building’s water or energy consumption can be considered sustainable. One of these materials is green concrete.
The construction industry has a lot of impacts to the environment and economy of the society. As seen recently the rise of global temperatures due to the effect of greenhouse gasses produced in our daily industrial activities. There is a need to address and act on this to reduce the effects of global warming to the planet. Researchers all around the world have made several actions and solutions. One of them is the use of green materials in building such as green concrete. In Tanzania the use of green materials especially green concrete is significantly a new concept and process as seen the Tanzanian green building council was established in 2014 to promote green building in Tanzania. The effectiveness of the introduced concept in our building industry has to be tracked and see the success of the innovative solution presented. The impacts green concrete has made as a sustainable building material to the environment and economy of the construction industry. Is the use of this material significant enough? Has the industry made a choice of switching to the new sustainable green concrete from the traditional concrete? These are the questions which have to be answered. This research will focus on answering this questions and recommend on possible solutions to the factors hindering the wide use of green concrete in Tanzania.
Main Objective The main objective of the research is to assess the effectiveness of green concrete as a construction material to improve green building in Tanzania. Specific Objectives The specific objectives are; To determine the properties and behavior of green concrete. To evaluate factors influencing the choice of the concrete type in building. To implement and evaluate the performance of green concrete as a construction material. To develop a sustainable and innovative construction tool in the building industry in Tanzania.
This study will add knowledge on the use of green materials in our building industry and long-term goal of promoting green building. This will give room to more research to be made until the building industry in Tanzania will all be green building. This is important for the future generations in our country and the world at large.
Green Building Green building technology is that which its byproducts such as Buildings or structures, are environmental friendly and utilize efficiently the resources through out their lifespan, since the designing stage till construction. Green buildings are designed to reduce the overall impact on the natural environment by: Using energy, water and other resources efficiently.Reducing environmental degradation and pollution. Also reducing waste byproducts. This research will discuss about green concrete’s application to the green building initiative.
Green materials Generally, there are two categories of sustainable building materials. Renewable materials, these are made from natural resources or recycled resources. Green materials, these are those, which require less resource to produce than the natural products. They are more efficient. Materials that can help cut down a building’s water or energy consumption are considered as sustainable materials. There is a higher demand of sustainable materials, as property owners, developers and regulators put an emphasis on cost savings, environmental protection, and energy conservation. Growth in sustainable building materials will be given a further economic boost by the expected recovery in overall construction activity.
Green Concrete A new insight into new technological and social developments guides the introduction of green building. As a sustainable material, concrete is also easily and affordably reused and rehabilitated. It is concerned that at least 5 percent of humanity’s carbon footprint comes from the concrete industry, both from energy use and the carbon dioxide (CO2) byproduct from the production of portland cement, one of concrete’s principal components. Portland cement (the binding component with large energy and CO2 footprints) manufacturing is a complex and massive industrial process undertaken by large organizations. Portland cement in turn holds the key ingredient of concrete, which is the most widely manufactured material on earth. In order to obtain green concrete, innovative approaches are necessary from the manufacture and shipment of cement to the blending and application of concrete to reduce energy use, capture and utilize emissions from cement manufacturing, as well as build energy-efficient and durable structures.(Lu, 2013) Green concrete is made from materials which are mostly industrial by products of manufacturing processes. These byproducts such as fly ash, silica, slag. Fly ash comes from the process of creating energy from burning of coal; they are very fine powder that remains from the process. Slag is a byproduct from the blast furnace in the production of iron. These materials are used as cement replacements in concrete production. It is as present, billions of tons of this industrial by product materials are used for land filling material just as soil. Their binding property as cement is unutilized. In 2008 the average replacement of cement as a binding material in concrete by this industrial by products was 14%. This is because the chemistry of these industrial byproducts is not fully known. Because the chemical behavior of IBP materials has not been fully understood, variations in the IBP material properties from multiple sources can have un-predicted consequences, and correcting for these changes becomes particularly challenging. Some modern practices involve the replacement of cement in concrete by these industrial by products by 30% to increase the performance of the concrete. 100% replacement of cement is now common to create concrete known as geo-polymers. These concrete made by replacing cement with an industrial byproducts is referred to as green concrete.(Lu, 2013)
Efficiency and performance of Green Concrete Green concrete as a sustainable material has to Cleary prove itself by its performance and effectiveness. Long service life and high performance. Reinforced concrete’s durability ensures that the structure will retain its structural capabilities for many years due to the high performance concrete, e.g. anti-corrosion and anti-cracking concrete. The carbon footprint and large energy consumption from cement industry are minimized when the need to replace or repair the structure is not necessary. (Lu, 2013)Maximized recycling materials usage and minimized environmental impact. Concrete producers can replace significant amounts of cement in their mixtures with industrial by-products such as silica fume and blast-furnace slag. Their use in concrete removes them from landfills and minimizes cement consumption, even producing a more durable concrete. Waste industry products can be recycled and in turn result in reduced waste release in the environment.(Lu, 2013) Minimized transportation cost. Take the advantage of local materials, reinforced concrete components can be made locally anywhere in the world. This turns out to be the key element in reducing emissions due to transportation.
Through the utilization of local materials, the impacts of transportation and energy consumption are minimized. (Lu, 2013) The effectiveness of green concrete as proved by various building agencies, in Tanzania the Tanzania Green Building Council is established with the mission of driving the sustainable development of Tanzania’s built landscape. One of its agendum is to promote the use of green materials in building. These materials are such as green concrete.
To emphasis the green technology applicability to concrete and its ingredients, the ongoing research will overcome the technical barriers to increase the percentage of industrial by products in concrete by providing the industry constructability and durability of green concrete. The global cement manufacturing industry has embraced sustainability and the triple bottom line: economic, social, and environmental. Two major examples of sustainability programs are the Cement Sustainability Initiative, a global effort under the auspices of the World Business Council for Sustainable Development (CSI) , and the Portland Cement Association’s Cement Manufacturing Sustainability Program , which involves facilities in the United States and Canada. (Lu, 2013) In addition to the technical viewpoint, there is a perspective from economic performance. As awareness of environmental sustainability and energy efficiency is turning widespread, there’s also a matter of return on investment. As electricity rates go higher along with prices for natural gas, the costs to heat and cool buildings are expected to increase gradually. Buildings that use innovative, energy-efficient materials help residents contend with escalating utility bills to promote the use of energy-efficient and sustainable materials that lead to less electricity and water usage. In general, the construction industry consumes 40% of the total energy and about one-half of the world’s major resources. Hence, it is imperative to regulate the use of green materials and less energy consumption in construction industry. Sustainable usage of resources plays an important role in the development of sustainable construction. However, unless the means of making these green buildings affordable for the common people are developed, we cannot attain full sustainability.
A truly green building should be energy efficient, incorporate concrete that contains the least amount of portland cement, and use large volumes of supplementary cementitious materials and recycled concrete. To implement the sustainability and innovative infrastructure technology, green building eventually requires the conversion of green concrete technology into construction sites.
Scope of the research The research will involve selecting a sample of building projects in Dar Es Salaam region initiated from year 2015 to present since the launch of the Tanzania green building council. 1.6.2 Questionnaire design Questionnaires will be designed to collect data from Contractors, Consultants and Clients of the selected building projects. The contents of the questionnaire for contractors will contain questions on the following items: Knowledge on sustainable green materials.Willingness to use green concrete.
Performance to cost ratio of the green concrete compared to the traditional concrete.Preference of new sustainable green material such as green concrete to the traditional concrete.Problems encountered when switching to new materials that is green concrete.Problems encountered working with green concrete compared to traditional concrete.Factors hindering or preventing the widespread of the technology in the industry.Availability of the green concrete for use.Average number of building projects done per year and involves the use of green concrete. The questionnaire for Consultants and Clients of the selected building projects will collect information on: Knowledge on the green technology such as green concrete. Design, select or recommend green concrete as the material to be used rather than the traditional concrete. Expected performance and durability of green concrete compared to traditional concrete. Willingness to spread the knowledge on green concrete and normalize the use of this material in building industry. Expected number of future building projects that will involve the use of green concrete (All, Some, None).
Field work, sample size and sampling procedure A sample of 100 Contracting firms, 50 consulting firms and 50 clients will be drawn for the questioner to be administered to. These are all from projects around all the districts in Dar es Salaam. Representation basis and element selection technique will be used as sampling procedures during sampling. Representation basis, the sample that will be used will be probability sampling, which based on the concept of systematic selection. On element selection basis, the sample which will be used will be unrestricted sampling, where an individually sample element will be drawn from the population. Criteria for selection of sample Contracting, Consulting firms and Clients will be based on: Group of the contractors selected should be from class 1 to class 7. All consultants, clients and contractors should be based in Dar es salaam city. The contractors and consultants selected should have completed successfully a high rising building at least 2 stoley and a time around 1 year since the project was completed. All consultants and contractors should be from Tanzania, no international contractor or consultant is considered.
Sample size selected. The sample size drawn from the population will be 200. And will carry the questionnaires formulated above. The formula that will be used to calculate is as follows, and is derived from (http://www.raosoft.com/samplesize.html). x = Z(c/100)2r(100-r) n = N x/((N-1)E2 + x) Where N is the population size, r is the fraction of responses that you are interested in, Z(c/100) is the critical value for the confidence level c, n is sample size to be calculated and E is margin of error.
Data analysis plan The data collected from the questioner technique is analyzed using computer program. BIOGEME software is utilized; this software will evaluate the factors that will influence the choices. The data used for choice model will include: Availability of green concrete, performance to cost ratio of green concrete compared to traditional concrete, size of the project, class and experience of the firm contractor and consultant. The data is used to create a Multinomial logit (MNL) model for concrete type of choice (either green concrete or traditional concrete). Data collected for assessing the effectiveness of green concrete is analyzed by SPSS computer software program in order to determine the overall performance of green concrete compared to the traditional concrete and conclude by recommending the use of new sustainable green technology. High consultation will be involved with all stakeholders to reach to the conclusion. It will help the building industry in Tanzania, in the adaptation of green concrete which is sustainable building material and will improve green building in the country. Awareness will be raised to all stakeholders in the building industry so as to reach the objective of having a green building industry in Tanzania and also introduce and uplift other green building materials which are sustainable and very beneficial to all stakeholders including our dear planet and future generations.