Lead: With the continuous development of China's economy, the workload of highway construction is also increasing. The following is a model essay on highway engineering compiled by me, hoping to help!
In this paper, the application of compaction construction technology in highway engineering subgrade and pavement is deeply studied, and some measures to strengthen the compaction construction technology of highway engineering subgrade and pavement are summarized based on my own experience, including the application of compaction technology under high and low water content, the application of excavation and soil replacement technology and the application of roller. And contribute to improving the application level of compaction construction technology in China.
Keywords: compaction construction; Highway engineering; Subgrade pavement
In recent years, with the continuous improvement of China's economic level, the highway transportation industry in various cities has begun to get more development opportunities and growth space, and people have begun to put forward higher requirements for the service standards of the transportation industry. Usually, highway traffic is the most frequently used and widely used in the whole road traffic industry, so its own road quality, safety level and service level are all hot issues that people are very concerned about. Based on this, analyzing the application technology of subgrade and pavement in highway engineering in China is a subject that the author and all road builders need to take seriously.
1 Importance of compaction construction technology
First of all, compaction construction technology can effectively improve the strength of pavement. Many construction units are limited by many factors, such as funds and construction time, which will lead to thinner and thinner pavement. Proper compaction of construction foundation can achieve the due engineering quality level on the premise of ensuring pavement strength.
Secondly, compaction technology can make the pavement more stable. In the actual highway pavement construction process, the smaller the compactness of subgrade pavement, the larger the gap between engineering materials. If the pavement is soaked by rain for many times during use, the strength of the pavement will be greatly reduced, and then unsafe accidents such as pavement deformation or collapse will occur.
Thirdly, compaction construction technology can improve the smoothness of pavement. If the compaction degree of highway pavement is not good, the height of subgrade fill will be different. In this way, in the process of subgrade consolidation, the pavement will appear uneven, which is not conducive to the normal use in the later period;
Finally, compaction construction technology is the basic need to ensure the durability and safety of highway pavement. Simply put, the durability of highway pavement refers to the service life of pavement, which mainly includes the strength, stability and smoothness of pavement. When the highway pavement is officially put into use, any small mistake in the construction technology may lead to a significant decline in the compaction quality of subgrade pavement. Based on this, it is the most basic condition to ensure the application level of compaction technology in the construction stage.
2 Key points of compaction construction technology for subgrade and pavement of highway engineering
2. 1 ensures the uniformity of building materials.
In the process of highway engineering subgrade and pavement construction, the change of engineering material ratio will not have a serious impact on the water content of soil itself. However, the specific gravity of the mixture is quite different from that of the soil, so once the above situation occurs, the dry bulk density of the mixture will easily increase after the compaction operation is completed, and it is difficult to truly reflect the specific degree of compaction. Based on this situation, in the future highway engineering construction process, the construction party should regularly conduct detailed spot checks on the measurement of external admixture to ensure the uniformity of construction material ratio.
2.2 Ensure the scientific nature of water content
In the process of concrete construction, the level of soil moisture will directly affect the compactness of subgrade and pavement. Usually, if the soil water content is high, the dry density will also decrease, which will lead to the decrease of compactness. Therefore, the constructors should control the soil water content at about 2% as far as possible, which can fundamentally avoid the phenomenon of spring soil and lay a solid foundation for improving the compaction quality of subgrade and pavement.
2.3 Guarantee the standard of heavy compaction
In the process of engineering construction, the physical indexes contained in different specimens will be very different. Therefore, when choosing the standards of heavy compaction and light compaction, construction enterprises need to focus on the actual situation and construction conditions of subgrade and pavement. Generally speaking, heavy compaction standard will be selected for subgrade and pavement of highway engineering. The main consideration of the construction unit is that the center of gravity of the die selected by the heavy compaction standard will be 20% to 40% higher than that of the light compaction, which can effectively prevent pavement deformation.
3 Relevant measures to strengthen the compaction construction technology of subgrade and pavement of highway engineering
3. 1 application of compaction technology in the case of high and low water content
First of all, if the water content of subgrade soil in highway engineering is high, then the construction personnel should take the methods of drying and air-drying to deal with the precipitation in time, and ensure that the soil of each layer is rolled and turned over again to ensure that the standard of road leveling is fully met; Secondly, if the water content of the soil is in a low state, the builder can loosen the soil with a plow and crush the soil density to a standard state with a roller. It should be noted here that the whole operation time must not be too long, and the construction personnel should master the rhythm and frequency between soil covering and rolling operations to ensure that the water in the soil will not be lost as much as possible; Thirdly, if it rains during the construction, the construction personnel should level and compact the paved soil layer at the first time, and do the corresponding drainage work on the original basis. A large amount of water will remain in the subgrade soil after rainfall, so the construction personnel should add a certain amount of crushed stone soil, fly ash, crushed stone residue and other materials to ensure that its density fully meets the relevant requirements in the Technical Specification for Highway Subgrade Construction.
3.2 Application of excavation and soil replacement technology
Before the compaction of subgrade and pavement begins, if the thickness of soft soil layer is less than 2M, then excavation and soil replacement method can be tried. First, dig out all the soil in the base, and then fill it with excellent soil such as gravel and lime soil, which are strong and not easy to be infected and eroded by the external environment. What needs to be reminded to the construction workers here is that not all the objects of soil replacement are soil layers, for example, those bearing layers do not need to be replaced.
3.3 Application of Drum
During the construction of subgrade and pavement compaction technology, the constructors must ensure that the length of the rolling section of the road roller and the working speed between the road rollers are in a coordinated state, and at the same time maintain a stable state for a long time on the original basis. If the conditions of the construction site do not allow the application of road rollers, then you can also choose to use vibration compaction to complete the compaction operation. In addition, the construction personnel also need to comprehensively consider the temperature, wind speed, asphalt outlet temperature, mixture setting and other factors in the compaction process according to the setting conditions such as the length of the rolled section, and remember not to set them blindly according to the previous construction. It should also be noted that if the asphalt mixture on the highway pavement is in a cooling state, then it is not allowed to use compaction machinery or dump oil and mineral materials on it to ensure the cleanliness of the highway subgrade and pavement.
refer to
Chen Wen, Liu Peiyu, Song Yonggang. Influencing factors and control measures of compaction construction of subgrade and pavement in highway engineering [J]. Technology and Market, 2014,4 (7): 55-57.
[2] Ma Yun. Factors affecting the compaction of subgrade and pavement in highway engineering and matters needing attention [J]. New products of Guo Xin Science and Technology, 20 10, 10 (19): 88-90.
[3] Guo Guoguang and Wang Zhipeng. Analysis of compaction construction technical measures for subgrade and pavement of highway engineering [J]. China Hi-tech Enterprise, 2013,5 (9): 77-79.
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