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Parts of the road pavement is a concentrated expression of the service functions. Service life and quality of roads and road conditions are closely related. Therefore . Pavement Maintenance is the most important highway maintenance work. Conservation measures in the road . A representative of the type of thin pavement hot asphalt overlay , stone chip seal layer . Repair defects , such as micro-surfacing , including micro-surfacing become large traffic volume roads and highways regularly to restore its performance in a major preventive conservation measures . Micro-surfacing technology. That polymer modified asphalt emulsion slurry seal is a used in highways , urban lines and other high-grade pavement maintenance and preventive maintenance of proprietary technology . It consists of a polymer modified asphalt emulsion , graded aggregates, mineral fillers , water and necessary additives , according to a certain ratio with mixing . And use a dedicated slurry seal paving the car, once completed construction process mixing, paving process.
Micro-surfacing project pre- conservation technologies applicable
Repair and maintenance of the old road
Repair and maintenance of micro -surfacing over the road with a waterproof , skid , wear characteristics , pavement roughness increased significantly longer service life .
Bridge repair and maintenance
Because the micro -surfacing thin, both to improve performance and little bridge deck weight increase , especially for restricted weight of the bridge portion of the body , such as the cable-stayed bridge , suspension bridge and other , more suitable for the use of micro -surfacing to protect bridge surface to improve flatness, roughness and waterproof deck . There are also some asphalt cement concrete bridge deck pavement using micro -surfacing as a waterproof adhesive layer between the surface layer of asphalt and cement concrete bridge deck .
Conservation of the tunnel
Usually as a key node in the tunnel traffic , traffic large , http://www.ukassignment.org/jndessaydx/thus requiring routine maintenance operations as short as possible . Road tunnel micro -surfacing maintenance, either shorten the time closed to traffic , it will not affect the headroom of the tunnel.
Determined and compared with the construction plan design
Design
Through detailed traffic survey and analysis, decision to take a different Treatment programs for different types of diseases and the degree of damage.
Passing lanes and emergency stop Road fewer diseases that can be micro-surfacing directly .
Seepage serious but sections of the basic disease does not appear , the same way the full width paved surface micro-surfacing 10mm thickness.
Cracks have appeared , first pouring handle , both on the road before the pits and other diseases Wabu thoroughly , and then the micro-surfacing .
On Deflection small, and only partial destruction of roads , if core samples show that the surface layer of mixture performance to meet the basic requirement that the disease is limited to the surface , the surface layer excavation remediation , with AC - 13I hybrid
Material repair, and then overlay 10mm thick micro-surfacing .
For asphalt layer appears pits , loose and other diseases accompanied by local subsidence sections, if the grassroots , subbase basic carrying capacity , will be on 10mm thick overlay of micro-surfacing in the surface layer after Wabu ; carrying capacity for grassroots lack of serious diseases sections , use of cement stabilized gravel Treatment grass and fill good , the top layer of asphalt paving mixture, after Treatment
10mm micro- surfacing .
Treatment for rutting , in addition to road cleaning , milling and so ready , there should be material , machinery and equipment , traffic control isolation ready. Construction of the temperature should not be less than 10 ℃; surface water does not dry before the rain can not
Construction ; when filling ruts in order to ensure a strong bond , construction temperature should not be lower than 15 ℃.
Micro-surfacing mix design
Raw materials and graded . Micro- surfacing Mixture of modified asphalt emulsion , 100% rolling gravel , cement, additives, water and other five kinds of materials, each material can meet the technical requirements, grading Ⅲ type using graded .
Determining primary formulations . Choose dose of modified asphalt emulsion 10.5% , 11% , 11.5% , 12% , 12.5% for the test mixture , the mixing time can be measured and the consistency was observed , the part of the test results are shown in Table 2 . Table 2 shows that , under these conditions the amount of cement and water , modified emulsified asphalt content from 11% to 12.5% and a slurry mixing can meet state requirements. As the summer heat , consider micro-surfacing layer weeping possibility , consider using a smaller aggregate ratio , from the economic analysis is also possible to use a smaller aggregate ratio , after considering the selected amount of modified asphalt emulsion was 11.5% , the cement is 1.5% , water 10% cohesive force test conducted .
Test results meet the specification requirements , so micro-surfacing mix recipe primaries as : stone : modified asphalt emulsion : cement : water = 100: 11 5:1 5: 10. Modified asphalt emulsion solid content of 62% , calculated aggregate ratio of 7.13 percent .
Primary validation formulations . In accordance with the above, an initial micro-surfacing mix formula , wet wheel abrasion test and load wheel test .
Micro- surfacing technology in highway maintenance in
For sealing water , surface water seepage damage Treatment
Water damage is a major factor in highway subgrade and pavement damage . According to an investigation revealed that the use of more than one year of the highway, there are different degrees of water damage phenomenon . Mainly due to unevenness of paved highways , roads than the total porosity and the presence of some of the water can easily penetrate the free position , plus road , thereby some randomly distributed small holes like water damage . After using micro -surfacing technology for water seepage Treatment can delay and prevent the continued development of the disease and prevent further deterioration of Pavement . Avoid structural damage , maintain the use of the road , to postpone the date of the overhaul , effectively extending the pavement life .
When the surface of the attenuation function , and when not flat minor rutting, road restoration services
Whether it is on the highway , urban road or cross the road traffic volume , micro processing technology can table its unique way to solve a Paving the road to improve skid resistance , improved pavement performance or delete form fill seal cracks and other problems. Micro-surfacing technology. Can form a relatively compact , rugged wear layer of pavement on the road , the treatment of early Pavement . Extend the pavement life , saving bituminous material and money, improve maintenance quality . And the technology is different from the previous cooked asphalt paving , pavement can be reached in a relatively short period of daily use functions for general urban roads, urban freeway and highway repair pavement wear and tear . In addition , for bridge deck waterproofing layer , the tunnel concrete pavement overlay and semi- rigid base asphalt layer and link layer.
Highway Maintenance in the application of micro -surfacing issues that need attention
Micro-surfacing conservation measures suited to pavement disease lesser extent , yet serious damage to the asphalt pavement preventive maintenance . Can handle loose road surface , the surface of small cracks , ruts and pits and other various diseases , improve pavement skid resistance and water resistance , surface smoothness and improve driving comfort. Micro-surfacing construction convenient, low- cost , material environmental pollution . Forming a short time , does not affect traffic , significant economic and social benefits that can promote the use of the highway in conservation . Characteristics which really play to their strengths .
Micro-surfacing design, construction should be strictly carried out in accordance with relevant technical regulations . Around the same time should be based on the climate ( temperature, humidity , wind ) and applying an external device , such as a change in the conditions of the appropriate amount of each material micro adjustments to ensure the successful implementation of micro-surfacing .
Most qualitative difference emulsified asphalt and stone quality , pavement structure , climate, transportation , materials, etc. , so that the quality of construction of micro -surfacing there are gaps. Therefore, the specific implementation . Only in accordance with local conditions to develop the corresponding technical specifications , construction guidelines , to further enhance the level of application of micro-surfacing technology to better meet local highway pavement repair and maintenance requirements.
Epilogue
Micro-surfacing technology is of course the road has increased color contrast , permeable pavement to reduce and improve the slip road capacity, improve pavement performance, increase pavement life and other effects that can restore and improve the aging of the original pavement wear , pits , lubrication , etc. disease , but because it belongs to a high -tech construction technology, grasp the needs of its professional and highly qualified construction team to complete. To achieve the desired quality objectives, in the process of application of this technology , not only have skilled staff, good equipment. More importantly, while the entire construction process quality control. I believe that with the continuous development and improvement of this technology , it will become more broad application prospects .
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