1, the origin of the problem
2. Current situation
3, solve the goal
4. A general description of things
5. Economic expenses
Information:
The human settlement environment is also called "human settlement" or "human settlement environment". Meaning: the environment in which human beings live, engage in production and carry out various social activities. The narrow sense of human settlement environment is often understood as people's rooms, houses and their living areas. The generalized human settlement environment is a spatial continuum that can be divided infinitely. From rooms and houses for personal family activities, to various buildings and settlements, and then to the whole space on the surface of the earth for human development and utilization, it can be regarded as a living environment.
I. Development of human settlements
Development of human settlements
The human settlement environment developed from the concept of "common life" in the 1960s, and has a history of nearly half a century. A scientific human settlement environment system has been formed and recognized by the whole world.
1972, the United Nations held a conference on "Human Environment" in Stockholm. Representatives and organizations from 1 13 countries attended the meeting. This is the first time in human history that human environmental issues have been put on the world governments and international political agendas, and it is also the first time that representatives from all over the world discuss the impact of the environment on the earth.
From 65438 to 0976, the first international conference on human settlements held in Vancouver, Canada formally accepted the concept of human settlements.
1982, the World Conference on Environment and Development held in Rio de Janeiro, Spain, adopted the Rio Declaration on Environment and Development and 2 1 Century Agenda.
1in June, 1996, the second international conference on human settlements was held in Istanbul, Turkey, and the human settlements problem was further discussed.
1in March, 1994, China wrote "sustainable development of human settlements" as an important content in China 2 1 Century Agenda, which shows that the China government attaches great importance to environmental issues. From 65438 to 0998, the National Natural Science Foundation gave key support to the research on the sustainable development index system of human settlements. In 2000, it signed the Stockholm Convention on Persistent Organic Pollutants.
In 2002, the second Earth Summit-World Conference on Sustainable Development was held in Johannesburg, South Africa.
It can be seen that the problem of human settlements has attracted the attention of the whole world, and improving human settlements has become a universal program in the world. The problem of human settlements with the goal of sustainable development has become the strongest voice of the times.
(b) Problems faced by human settlements
The development of science has enabled human beings to control and dominate nature to a certain extent. However, once people indulge in the victory over nature, people's forgetfulness will bring harm and destruction to nature, resulting in the extreme waste of resources and the intensification of various pollution.
1. The population is expanding and various resources are facing a shortage.
From 65438 to 0999, the world population reached 6 billion, and the snowballing population undoubtedly brought heavy pressure to the earth. Some experts predict that by 2040, there will be a global food shortage. By around 2070, metal resources will be exhausted. By 2090, fossil fuels such as coal and oil will be exhausted. All these will inevitably have a negative impact on the living environment and quality of life of human beings.
2. Urban environmental pollution is serious.
The first is air pollution. In 2000, China's total SO2 emission has reached19.95 million tons, including industrial emission161200,000 tons. The soot emission is11650,000 tons, of which the industrial source emission is10.92 million tons. CO2 will cause "greenhouse effect", and acid rain produced by SO2 will also reduce water quality, acidify soil, destroy vegetation and erode buildings. Nitrogen oxides seriously stimulate human respiratory organs; Dust particles greatly increase the risk of heart and lung diseases and cancer.
Secondly, indoor environmental pollution. Nowadays, interior decoration is becoming more and more popular. Therefore, indoor air is polluted by decorative materials. The pollution caused by formaldehyde, volatile organic compounds (VOC), heavy metal particles, ammonia, radon and other harmful substances is several times higher than that of outdoor air, and people spend most of their time indoors. Therefore, the indoor environment is the focus of improving the living environment.
3. The impact of building materials on human settlements
Building materials have played an active role in human history and created human history and culture. However, with the increase of population and building scale, a large number of building materials are produced, and the production of traditional building materials also exposes some problems, which seriously harms the living environment of human beings.
Traditional building materials not only consume a lot of resources and energy, but also seriously harm the environment. Ironmaking requires mountain mining, which destroys the natural landscape. At the same time, the energy consumption for producing 1 ton steel is 1.66 ton standard coal and 48.6m3 water. Cement is more harmful to the environment. Every production 1 ton of cement consumption 1.4 ton of limestone, 0.23 ton of standard coal and 75 kwh of electricity, and CO2 and dust are simultaneously emitted. Gravel aggregate, which accounts for 70 ~ 80% of concrete volume, needs to cut mountains and dig river beds, which is easy to cause soil erosion and river bed diversion. High-density concrete makes the air permeability of urban space poor, and rainwater overflows in rainy days, but groundwater cannot be replenished. The temperature in cities is generally higher than that in suburbs. Some people call it a "grey heat island" or a "concrete forest".
It can be seen that the improvement of living environment is closely related to the clean production and greening of building materials. It can be said that the living environment needs green building materials, which create and improve the living environment.
Second, the development of green building materials
(A) the meaning of green building materials
Green building materials, that is, green building materials, refer to building materials with ecological, environmental and health attributes.
Its attribute is that it is a renewable resource of eco-friendly materials, and designers should design it from the perspective of sustainable development to achieve zero pollution in the whole process of raw material collection, production, processing and use and waste. Secondly, the "green" of green building materials should also be manifested in its function of digesting and utilizing industrial wastes and purifying the environment.
(2) Improve the living environment and develop green building materials.
Modern green civilization requires us to advocate nature, conform to nature, and integrate man with nature. As far as building materials are concerned, we should devote ourselves to the following research:
1. Green cement
The so-called "green cement" refers to other industrial waste residues and wastes that can be recycled by raising the utilization rate of resources and secondary energy to the highest level. Environmental protection technologies and measures have been strengthened in technical equipment; In addition to the comprehensive quality management system, the products also implement a comprehensive environmental protection guarantee system, and the emission of dust, waste residue and waste gas is almost zero, truly achieving zero pollution and pollution-free.
At present, 90% cement plants in China are in the stage of "extensive", and only about 2% cement plants can be regarded as "intensive" green cement plants. In order to protect the environment, we must adopt clean production technology, effectively use natural resources and energy, and make the amount of dust, harmful gases, harmful substances and waste residue discharged to the outside less than or far less than the amount allowed by each substance, so as not to endanger the ecological balance and achieve zero pollution. The content of CaO in traditional portland cement is high, which needs to consume a lot of limestone and emit a lot of CO2. The high content of C3S in clinker and its high sintering temperature not only increase the energy consumption, but also increase the consumption of refractories. At the same time, China's cement enterprises are facing the problems of outdated equipment, backward technology, low labor productivity, weak quality awareness of enterprises and low cultural quality of employees. Therefore, it is necessary to transform traditional cement enterprises and develop "green cement" industry. We should start from the following aspects:
(1) Improve the mineral composition of clinker, modify and modify the traditional clinker mineral cement, and develop new cement varieties with low energy consumption. If C2S-based high belite cement is produced, the consumption of limestone is small, the energy consumption is low, the waste gas is small, and the strength and durability are good. Park Zhengsu sulfate cement is a cement clinker with C4A3 instead of C3A, with low C3S content, energy saving, impermeability, frost resistance and wear resistance. In addition, there are sulfate belite cement, aluminate belite cement, iron aluminate belite cement and fluoroaluminate belite cement, all of which are green and energy-saving cement.
(2) Improve cement production technology, update production equipment, vigorously support large and medium-sized rotary kilns with economic scale, and eliminate small enterprises with backward technology, poor product quality, high energy consumption and heavy pollution.
(3) Make maximum use of industrial solid waste, fly ash, coal gangue and various tailings.
2. High performance concrete
The term high performance concrete was first put forward by National Institute of Standards and Technology (NIST) and American Concrete Association (ACI), and it has a history of more than ten years. It is an ideal concrete with excellent mechanical properties, good workability, high durability, good volume stability and reasonable economy. Excellent mechanical properties can make it reach high strength above 100MPa. Therefore, it can be used for high-rise and long-span structures. Good working performance can prepare high-fluidity, self-compacting and vibration-free concrete, thus reducing construction energy consumption and noise pollution. Good durability, not easy to be corroded by external environment, saving a lot of maintenance costs. At present, many important buildings have been designed according to the safe use period of 100, and land buildings with moderate climatic conditions have been designed according to the safe use period of 200 years. Japan is developing reinforced concrete with a service life of 500 years. In addition, ground slag, fly ash, silica fume and rice husk ash can be added, which not only saves cement, but also helps to absorb industrial waste residue. It also has the characteristics of high carbonation resistance, low moisture absorption and high frost resistance, and is an excellent building material. Therefore, high performance concrete is also called "green concrete" or "ecological concrete".
Although high performance concrete makes up for the defects of traditional concrete in many aspects, it is not perfect, and there are also some problems:
(1) Its compounding characteristics are determined by various properties: low water-cement ratio, selection of high-quality raw materials; Due to strict indicators in all aspects, the cost of production management will increase accordingly. It will be about 50% higher than ordinary concrete.
(2) Due to the low water-binder ratio, the early cracking problem is serious. In addition, the dosage of cement per unit volume is high, the hydration heat is high, and cracks are easy to appear.
3. Dry powder mortar
Dry mortar is also called mortar dry powder (mixture). It refers to a granular or powdery mixture produced by a special manufacturer, dried and screened, and mixed with inorganic thickening materials, mineral admixtures and additives in a certain proportion. It is a kind of "green building material", which overcomes the shortcomings of traditional mortar, such as poor quality, low efficiency and occupying construction site, and is favored by the whole world for its high strength, multifunction and good durability. At the same time, the application of dry powder mortar is also conducive to shortening the construction period, ensuring masonry quality, reducing labor intensity, reducing resource waste and improving the construction environment.
The characteristic of dry powder mortar is that it has been mixed as required before leaving the factory, and it is not necessary or allowed to add any other materials except water when using it.
Dry-mixed mortar is still in its infancy in China (it was first introduced in Shanghai). Because of its commercial production, the quality of mortar is guaranteed, so the cost is increased to some extent. But in the long run, its excellent quality, reduced maintenance cost and reduced environmental pollution control cost far outweigh the promotion cost, so it is an intensive building material. Therefore, it is of great significance to study the working performance of dry powder mortar, design clean production technology and strengthen its popularization and use to improve the living environment.
4. Other aspects
The above three aspects are all hot topics in the field of civil engineering. In addition, we should also study the following points:
(1) concrete separation technology: in-depth study of concrete separation technology, purification and reuse of one or more components. It is used to solve the problem of urban solid waste stacking and realize the recycling of resources.
(2) The transition layer between aggregate and cement stone is the weak part that affects the strength of concrete. If a reagent with good adhesion to concrete and aggregate is developed, the strength and durability of concrete will be greatly improved.
(3) Vigorously develop artificial aggregate, actively use domestic garbage and industrial waste, and reduce the consumption of natural aggregate.
(4) Using industrial waste liquid actively, the modified water reducer with black pulp as raw material was studied. On this basis, other additives are developed to help treat and absorb the waste liquid that is difficult to treat in other industries.
(5) Develop high-grade cement clinker, adjust the cement product structure, make it green cement, and reduce the cement consumption on the premise of meeting the engineering requirements.
(6) Develop new energy-saving wall materials and transform traditional wall materials.
(7) Vigorously promote commercial concrete, reduce noise pollution and dust pollution caused by on-site mixing, and help to control concrete quality.
(8) For urban ground, permeable and drainage ecological concrete and vegetation growth concrete should be developed to solve the problems of poor rainwater drainage, dry air and high temperature. The application of green concrete with vegetation on both sides of urban roads and waterside slope protection can give people more opportunities to get close to nature. At the same time, it also beautifies the urban environment.
(9) Research on healthy and environmentally friendly coatings that are environmentally friendly, pollution-free and beneficial to human health. Such as antibacterial self-cleaning coatings, air purification coatings, etc. Then there is the functional coating, which has the health care function and the function of releasing negative ions.
(10) Research intelligent materials that can self-diagnose, predict damage, self-adjust and self-repair.
(3) Measures to implement green building materials
1. Designers should design materials from the perspective of development.
In the design, we should give full consideration to the service life of the building, future expansion or transformation, and strive to make our own building not lag behind in the next few years or even decades, and minimize redundant construction.
2. Strengthen the publicity of green building materials.
In propaganda, we should advocate the application of green building materials. Let green products be recognized in people's minds.
3. The state should establish and improve laws and regulations.
Strengthen legislation and supervision, establish perfect laws and regulations, strengthen quality supervision, standardize the building materials market, and take compulsory measures when necessary to help promote green building materials.
Agricultural civilization has produced food for human beings and met the needs of people's survival; Industrial civilization has created wealth for mankind and met people's more and more material needs; And ecological civilization will make human beings live in a safer and better environment. Today in the new century, we need more green. We should live in harmony with nature, and harmony is the highest realm of civilization.
The field of human settlement environment is extensive and the boundary is vague. It can be understood as a material product, a process of change and a cultural phenomenon. This is the result of the development of the times. We should re-examine our behavior, pay more attention to our living environment and decorate our rooms with green building materials. It is green civilization that dresses up our hearts.
The outline is listed by yourself, and the information is found online. Just write the paper according to the outline I gave you.