Dust-free construction management in construction?

This paper introduces the hazards of dust in building construction, dust control technology and dust control measures, and discusses from solving dust problems in building construction, with a view to popularize dust-free management in building construction, improve construction site environment, and create a good image for building enterprises.

Keywords: dust-free management, dust, harm, treatment technology

The main pollutant of atmospheric pollution in China is total suspended particulate matter, among which dust has been aggravated in recent years due to the lack of government attention to its control and the continuous deterioration of the ecological environment around the city, and its contribution to urban particulate matter pollution has become increasingly prominent, which has become the main cause of urban particulate matter pollution.

Judging from the changing trend of dust pollution, due to urban construction, the existence of a large number of exposed ground and the deterioration of the ecological environment around the city, dust pollution in many cities has been further aggravated, and most cities have no signs of improvement. For a long period of time, particulate pollution caused by dust is the primary factor affecting urban air quality in China? Therefore, it is of great significance to attach importance to dust-free management in construction management.

Hazards, main sources and benefits of dust-free management. The harm of dust and the main source of particulate matter discharged from a single dust source enter the ambient air. Due to the action of gravity, some particulate matter will settle to the ground, roads, roofs of buildings, windowsills and other places where particulate matter can be accommodated. Under the influence of natural forces or human activities, these settled particles will enter the ambient air again and again to form dust.

Fine particles in the air will not only reduce the visibility of urban atmosphere, but also cause environmental problems such as photochemical smog, acid rain and climate warming. PM is the culprit leading to the decline of urban visibility, which increases traffic hazards. With the huge increase in the number of motor vehicles in modern cities, it is also easy to cause traffic accidents.

According to the latest pollution source analysis results, the annual contribution rate of construction cement dust to atmospheric particles is 65,438+08%, 65,438+02% in heating season and 23% in non-heating season. The annual contribution rate of construction cement dust to PM is 65,438+03%, 7% in heating season and% in non-heating season. With the rapid development of our national economy, urban infrastructure construction is at its peak. During the process of building, demolition and road construction, the construction dust generated by material handling, stockpiling and transportation will increase continuously, which will become one of the important reasons for TSP pollution. It can be seen that construction is the main cause of dust.

Dust in building construction mainly comes from: excavation and removal of muck; Backfill soil; A bare pile; Scatter garbage from top to bottom during demolition construction; Stacking construction waste; Slag removal; Mixing concrete on site, etc. The stacking of raw materials (such as cement and lime), the drying of flowing sediment on the road surface, the construction of muck yard and the construction of bank protection will also produce dust.

Benefits of dust-free management The economic benefits brought by dust-free management cannot be ignored. Strengthening on-site environmental management does not necessarily require a lot of investment, and the economic benefits are mainly manifested in the following aspects:

Increase the chances of contracting projects. In western developed countries, project owners often choose those contractors who can effectively carry out on-site environmental management as the winning bidders, while those contractors who are sued for environmental problems are difficult to be invited by the owners to participate in the bidding.

Reduce fines for poor environmental management.

Reduce the time and investment in harnessing the damaged environment.

Reduce the losses caused by waste. It is estimated that 10% of building materials are wasted in construction. Money is wasted not only on the purchase of materials, but also on the treatment of construction waste.

Effective environmental management can enhance the environmental image of the enterprise and improve the relationship with the government and local environmental protection departments, thus ensuring the smooth implementation of the project. In addition, it helps to improve employees' environmental awareness and recruit and stabilize the labor force.

Effective environmental management is not only beneficial to enterprises and projects, but also beneficial to individuals:

The project manager can improve the construction profit level; On-site management personnel can reduce workload; Construction workers share the increased benefits due to increased profits. 2. Dust-free technology in construction sites. 1 Wind-proof dust suppression wall According to the aerodynamic principle, when the wind passes through the wind-proof dust suppression wall, separation and adhesion appear behind the wall, forming up-and-down interference airflow, so as to reduce the wind speed of incoming wind, greatly lose the kinetic energy of incoming wind, reduce the turbulence of wind, eliminate the vortex of incoming wind, and reduce the shear stress and pressure on the surface of the pile, thus reducing the amount of dust raised by the pile. The test results show that the windbreak and dust suppression wall with the best ventilation coefficient has the best dust suppression effect. For example, when there is no windbreak, the dust amount of the material pile is 100%, the dust amount of the windbreak is still 10%, and the dust amount of the windbreak is only 0.5%.

At present, windbreak and dust suppression walls have been applied in domestic ports, docks and yards of iron and steel enterprises. Relevant data show that the wind speed is reduced by about 60% after passing through the wind and dust suppression wall, and the actual dust suppression efficiency is greater than 75%.

Greening dust-proof trees can reduce the causes of dust pollution;

Because it can reduce the wind speed, as the wind speed slows down, the amount of big dust carried in the airflow will decrease.

Because the surface of leaves is uneven and hairy, they can secrete viscous oil and juice and absorb a lot of dust.

In addition, the grain gaps on the branches of trees can also absorb dust. Different kinds of plants have different dust retention ability.

Generally speaking, plants with wide, flat, hard and rough leaves and more secretions have stronger dust retention ability. In addition, the ability of plants to absorb dust is directly proportional to the number of leaves.

Nanjing Forestry University measured the periphery of Nanjing Cement Plant, and the results showed that the dust in the green area was 37% ~60%_2 J less than that in the open area.

In order to control the dust pollution on the road construction site, we can also adopt advanced slope greening technology, including wet spray seeding technology and exotic soil spray seeding technology.

Dust suppressant Chemical dust suppressant is an effective road dust prevention method at present.

Generally speaking, this method has good dust suppression effect, long dust suppression period, low equipment investment, high comprehensive benefit and no pollution to the environment, which is the development direction of dust suppression in construction sites in the future.

Dust-free management measures Determine a reasonable construction scheme Before determining the construction scheme, the construction unit shall, together with the design, construction unit and relevant departments, inspect the surrounding construction site that may cause dust pollution, formulate corresponding technical measures, and incorporate them into the construction organization design.

Hard shielding walls shall be set around the construction site, and enclosure facilities of not less than a certain height shall be set around the construction site according to regulations; The fence should be tightly closed and kept clean and complete. The outside of engineering scaffolding must be fully enclosed with qualified dense mesh safety net, and the enclosed height should be higher than the working surface according to the actual situation, and it should be cleaned regularly, and replaced immediately if it is damaged.

Where cement, lime soil and gravel are piled on the construction site, a closed fence not lower than the pile height shall be set around it, or covered with a dense mesh screen to prevent dust from flying and waste and debris from floating. In the earthwork operation stage, measures such as sprinkling water and covering shall be taken to make the visual dust height in the operation area less than 1.5 m, and it will not spread outside the site.

Control of construction vehicles Vehicles carrying all kinds of building materials, construction waste and muck in bulk shall not be overloaded, and the carriages shall be firm and tight, and closed carriages shall be adopted to avoid dust caused by scattered materials. The transportation of bulk materials and liquid materials should be closely covered and protected to prevent throwing, sprinkling, dripping and leaking along the way during shipment. Construction transport vehicles are not allowed to drive out of the site with mud, and the tires are cleaned before driving out of the site.

On-site treatment should harden the roads and material processing areas on the construction site according to regulations, and the ground of the site should be flat and solid, without floating soil. The construction site that has been idle for a certain period of time or more shall be temporarily afforested or paved by the construction unit.

Control of Building Demolition When demolishing a building, the demolished building should be sprayed with dust, and three-dimensional protective facilities should be set up to keep out the dust. Before demolition of structures by blasting, a dust control plan should be made. Comprehensive dust suppression measures can be taken, such as cleaning dust, wetting the ground, pre-wetting the wall, applying water bags on the roof, storing water on the ground, installing high-pressure sprinkler system outside the building, erecting dust-proof grids, and dropping water bombs by helicopters. Choose the weather with less wind to carry out blasting operation. When the weather forecast wind speed reaches level 4 or above, the house blasting or house demolition should be stopped.

Other measures for mixing lime-soil and inorganic binder: Pre-mixing method should be adopted, and sprinkling water should be used to reduce dust when rolling.

For temporary and sporadic cement mixing sites, try to stay away from residential buildings when selecting sites. It is forbidden to load and unload muck, sand and other materials. It is forbidden to sweep garbage or dust directly from a height to the ground. Sprinkle water regularly on non-rainy days to suppress dust, keep surface soil moisture and control surface dust. After the completion of the construction project, the construction unit shall promptly dismantle the site fence, safety protection facilities and other temporary facilities, and clean up the site and the surrounding environment. Municipal roads and pipelines construction site, should take enclosure, covering, watering and other dust-proof measures to deal with the residual mud and muck. After the completion of the project, the remaining mud, muck and building materials must be cleaned up in time.

Conclusion Construction dust has become one of the important causes of TSP pollution, and it is more and more harmful to human body and environment. Research on dust-free management in building construction plays an important role in environmental protection and construction benefit. It can be predicted that adopting comprehensive, scientific and advanced dust control technology in project management will become an important direction for the development of construction technology management.

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