New Construction Techniques of Airport Road
一、Brief introduction and award of airport construction of No.4 Engineering Company Ltd.
The airport projects of which No.4 Engineering Company Ltd. participated in construction since 1985 include Shaanxi Yanliang Airport, Xi'an Xianyang Airport, Ji'nan Yaoqiang Airport, Macao International Airport, Tianjin Binhai International Airport, Shanghai Pudong International Airport, Shanghai Hongqiao Airport, Capital International Airport, Wenzhou Yongqiang Airport, Jiangxi Yaohu Airport, Heilongjiang Jiansanjiang Airport, the new Qingdao Airport, Harbin Taiping Airport, Changchun Longjia Airport, Sanya Phoenix Airport, Changsha Huanghua Airport, Urumqi International Airport, the new Beijing Airport and other key projects. The cumulative airport concrete pavement area is up to 9,560,000m2, and various ground treatment area of the airport is up to 6,300,000m2.
Macao International Airport, Shanghai Pudong International Airport, Beijing Capital International Airport and Beijing New Airport have become the brand project of airport construction of our company, which are particularly striking.
1、Macao International Airport Road Project
Macao International Airport is the first sea artificial island airport in China, and is also the largest construction project in Macao since the beginning of history. Our company undertakes the airport road project of 318,000m2 at the south of the artificial island, including 3360m long and 60m wide runway and 1662m long and 44m wide taxiway.
During construction of concrete pavement of the runway and the taxiway, No.4 Engineering Company Ltd. successfully introduced the concrete paver, concrete vibrating beam, concrete pavement groover and other advanced equipment, which accelerates the construction period, improves quality, reduces cost, and increase benefits.
The complete technique of artificial island project construction of Macao International Airport won the first prize in science progress of the Ministry of Transport in 1999 and the second prize in national scientific and technological progress in 2001.
The artificial island road of Artificial island won the second national Zhan Tianyou civil engineering prize in 2002.
Macao International Airport Road Project
2、Shanghai Pudong International Airport Project
Pudong International Airport is located in Pudong New District of Shanghai, and is the key project during the "Ninth Five-year Plan" of the nation. The comprehensive commencement ceremony was convened on October 25, 1997. Comrade Jiang Zemin, the general secretary of the CPC Central Committee and president at that time, laid the foundation for the project.
The project of "construction and research of Shanghai Pudong International Airport project", as the main completion unit, won the first prize of 2000 Shanghai science and technology progress award.
"Research on airport road construction technique in the high-temperature and pluvial area" on which Shanghai Pudong International Airport relies won the third prize in 2017 highway engineering technological innovation achievement review.
（1）Phase I project of Pudong International Airport
Including Phase I flight area runway, south lot of taxiway road work, Phase I parking apron work, flight area apron and fourth lot of taxiway road work. The project mainly includes the pavement structure work, earthwork, drainage work, fire water supply pipeline work and so on; the building area of Phase I parking apron work is 380,000m2, and the concrete pouring amount is 150,000m3. The project of flight area apron and fourth lot of taxiway road work mainly includes the earthwork, drainage work, pavement work and so on.
Phase I project of Shanghai Pudong International Airport formally passed national acceptance in August 2000, and the project assumed by our company won the "Shanghai municipal engineering gold award" and "China municipal engineering golden cup award".
The special apron work of Pudong International Airport is the special parking apron built to welcome "five-nation summit" and convene informal meeting of national leaders of Asia-Pacific Economic Cooperation (APEC) in Shanghai in 2001. It is listed as No.1 project among Top 10 key projects in Shanghai in that year, is the major project with international political significance, and is also the project representing the national image. The project contents mainly include the earthwork, drainage work, lime-fly ash macadam base course, pavement concrete work, fire water supply pipeline work, high-pole lamp foundation work, service lane work and so on
（3）Pudong International Airport east-west linking taxiway project
Earthwork ground treatment and apron road work of east-west linking taxiway of Phase II flight area is constructed to connect Phase I and Phase II main runways. The apron road engineering includes lime-fly ash macadam base course, concrete surface layer and drainage work. The total area of the pavement is 120,231m2, the construction lime-fly ash macadam is 124,109m2, the drainage ditch is 2,131m, and the fire water supply pipeline is 1,508m.
Earthwork ground treatment and apron road work of east-west linking taxiway of Phase II flight area won the gold cup award of China municipal engineering golden cup award. During Phase II, the company assumes three among four experimental sections of the project, and projects accurate and detailed data for the project. During Phase I and Phase II construction of Pudong International Airport, No.4 Engineering Company Ltd. won the title of "Shanghai civilized construction site" twice, and is praised as the "excellent collective of key project in Shanghai".
（4）1 and 3 runway docking engineering of Pudong International Airport
1 and 3 runway docking engineering is located between airport runway 1 and new runway 3. The largest distance from the construction position to the runway center line is 146m, and runway 1 shall be penetrated for construction. It belongs to non-suspend air construction in the true sense.
 Pudong International Airport Project
3、Beijing Capital International Airport
In April 2005, our company won the bid to undertake air side emergency reconstruction of the west region of Capital Airport with rich airport construction performance - east runway parallel taxiway reconstruction project and north region road bridge (No.6 and 7 sliding bridge) project.
The project is located between the east runway in the west region of Capital Airport and the special apron, parking apron and terminal building. It is the project with the largest non-suspend air construction area, difficult safety management, highest civilized construction requirements and largest political influence in China.
Beijing Capital International Airport Engineering
4.Beijing New Airport
Beijing New Airport Project is the national-level key project, No.1 Project of Beijing "Twelfth Five-year" major infrastructure development planning and civil aviation "Twelfth Five-year" key project. It is the important infrastructure support to promote Beijing-Tianjin-Hebei integration development, lead new normal China economy, and create update of China economy. The New Airport is located among Yufa Town and Lixian Town, Daxing District, Beijing and Guangyang District, Langfang, Hebei. The airport is positioned as the large international aviation hub, and Beijing New Airport is rated as the first of "New 7 Wonders of the World".
The floor area of FXQ-CD-003 lot of flight area road project of Beijing New Airport undertaken by our company is about 1,744,000m2 (1260m×1377.5m). The main construction contents include construction of some runways and taxiways in flight area west I and II, construction of site soil surface area, construction of No.5 under-crossing tunnel, construction of drainage work of the flight area, 2# snow removal preparation area (mainly including 4 snow removal garages, 1 field service commuter garage and 2# snow removal preparation building, 6 housing construction works in total) and other construction contents. The contract amount is 528,000,000 yuan.
Our company introduces the digital construction equipment during construction, and application research of the digital monitoring technology in the airport road project won the third prize in 2017 highway project technological innovation achievement review.
 Beijing New Airport Engineering
二、 Scientific and technological achievements of airport road construction
1）Application of variable-frequency row-type vibrator in airport road concrete construction
The airport concrete road in China requires that the pavement must have good durability and small concrete shrinkage. Therefore, the road cement concrete generally adopts the dry hard concrete. The original artificial vibration mode is layered vibration, and the upper and lower concrete shall be paved in layers. There is cold joint difference during the period. Meanwhile, it is difficult to guarantee sufficient and uniform vibration and no incomplete vibration through manual operation.
The high-frequent vibrator has the advantages of strong excitation force, dense vibration, less bubbles and other advantages, and is suitable for vibration of the stiff and plastic concrete. After the high-frequent vibrating frame is used, one-time paving and vibration can be conducted, which effectively improves concrete vibration quality and concrete uniformity and integrity, and meanwhile greatly accelerates construction speed.
2）Construction technique of airport cement concrete pavement
Airport road construction is to apply the high-frequent vibrating instrument to implement vibration to the stiff concrete and guarantee concrete compaction, and the pavement flatness, texture depth and so on can satisfy use requirements for civil airport pavement through a series of surface finishing processes. The following construction techniques and processes are mainly adopted:
（1）Adopt the stiff concrete to obtain very high bending strength when the cement content is very low;；
（2）Adopt the self-propelled high-frequent row-type vibrating instrument for vibration, and effectively guarantee dense vibration of concrete without excessive vibration;
（3）Adopt the template stamped and formed with 5mm thick steel plate, add the champ plate between templates, and solve conflict between saw seam and form removal time;
（4）Adopt the purifying slurry thickness detector to detect the purifying slurry thickness, and control the surface purifying slurry thickness, so as to control the surface texture depth.
（5）Concrete leveling, kneading, leveling and surface process
3）Airport road concrete feathering construction technique
The airport road project adopting the concrete pavement structure is used for aircraft sliding. Therefore, the concrete surface must have certain roughness. The feathering process can form the texture with consistent depth and uniform thickness at the pavement surface, so as to provide reliable frictional resistance for use.
Pavement feathering is to drag the special feathering tool on the concrete surface after pavement concrete pouring and before initial setting of concrete, so as to leave the texture with consistent depth and uniform thickness on the concrete surface with self-weight of the brush.
4）Airport pavement grooving construction technique
In order to improve skid resistance of the airport pavement, large friction resistance can also be generated between the pavement and the aircraft tire even if there is water on the runway, so as to prevent aircraft floating skid and improve capability of the runway in all weather protection of aircraft flight. We adopt the pavement grooving construction technique.
Pavement grooving is to utilize the high-speed rotation of the special mechanical tool to apply the friction force at the concrete surface, so as to form the regular notch with consistent depth on the surface, which is favorable for increasing friction resistance of the pavement and horizontal drainage of the pavement.
5）Non-suspend air construction technique of airport road
Non-suspend air construction of the forbidden zone is to take certain technical measures to conduct ground construction within the operation safety control zone of the airport aircraft without closing the airport (i.e., normal operation) on the premise of satisfying the minimum airworthiness requirements of the airport. Construction shall be conducted in close cooperation with navigational lighting aid, operation safeguard, command center and other departments and units to guarantee normal use of over 10 kinds of pipelines embedded underground.
Non-suspend air construction has the features of "many underground pipelines, high construction difficulty, much construction at night, high labor intensity, short effective time, high organization difficulty, much interwoven construction and much coordination work". During construction in such case, the slightest mistake will also cause extremely serious consequences even is the aircraft is only dozens of meters from the constructor. Therefore, non-suspend air construction in the forbidden zone must guarantee "air defense safety, operation safety, pipeline safety and construction safety", so as to be "perfectly safe"
6）Reaming and chamfering process of the airport pavement
It is found through long-term summary that the cement concrete pavement seam is always the high-risk position with damage during use of pavement. Process improvement is made in the form of seam initiatively during construction of three runway system road project of Pudong Airport. Through theoretical analysis and project test, it is determined to adopt the advanced chamfering construction method in the form of reaming, and change the stress state of the original seam position, so as to effectively reduce the possibility in damage to the seam and corners.
The form of chamfer cutting seam is adopted for cement concrete pavement seam, which can effectively reduce local stress concentration caused by traditional right-angle cutting seam. It has the positive role in improving concrete stress state at the cutting seam position and lowering the probability in seam fissure. However, it also increases difficulty in cutting seam construction. The novel form of filleted corner or bevel angle has not been adopted for the cement concrete pavement cutting seam of civil airport in our county up to now. On the one hand, the corresponding construction machinery and mature construction process lack; on the other hand, influence of novel chamfer on the pavement service performance is indefinite, especially influence on pavement flatness and bump after chamfering. These shall be checked and verified through the project test.
7）Construction technique of airport concrete pavement caulking
The total building area of west cargo apron (third lot) of Shanghai Pudong Airport is 190,000m2, the caulking length is 107,477m, the caulking width is 0.6cm, and the thickness is 4cm. The top surface of the caulking material shall be 3mm from the concrete pavement according to technical requirements.
Compared with the general building project, the environment of the airport pavement caulking material is harsh. It shall be subject to effects of various natural factors of wind, rain, frost snow, freezing, sun exposure and so on. Large displacement and deformation shall also be generated under various stress effects of thermal expansion and contraction, moisture expansion and drying shrinkage. In addition, influence of high-temperature wake of the aircraft and fuel included in the wake on damage to the caulking material is very obvious. Caulking construction is a key to guarantee caulking quality. Through summary of construction for many years, the caulking material of "polysulfide rubber - epoxy resin" is selected for caulking construction. Through effective control of various links, standardized construction is implemented in west cargo apron work, which fully guarantees intrinsic and apparent quality of caulking. The caulking material, construction technique and work quality adopted in the project have been at the leading level in China.
8）Airport road construction technique in the high-temperature and pluvial area
The summer of the Southern China is hot and pluvial, and is the golden season for pavement concrete construction. High temperature and raininess have unfavorable influence on the pavement. The test code for ordinary concrete mix ratio is generally referred. Considering less factors, the optimum mixture ratio cannot be obtained for the stiff concrete.
Main factors are analyzed and determined as per above situation, and partial test is conducted according to all level matching of various factors. The better mixture ratio finally proposed is not always in the test conducted, which is just an advantage brought by balanced dispersibility of the orthogonal table; the self-propelled row-type high-frequent vibrating instrument is adopted for one-time vibration of the stiff concrete; apply the independently applied patent - concrete surface feathering brush for texture construction, so that the texture depth satifies design requirements, and form the texture with uniform and straight surface and uniform depth; Improve the all-weather canopy, appropriately increase the width, and hang the bamboo curtain surrounding, which is retracted when it is hot. It is used for sun protection during concrete construction and reduce influence of high temperature on construction; the bamboo curtain is lowered in case of any rain, so as to prevent influence of rainwater on the newly poured pavement. The method of foam bonding square timber is adopted to prevent erosion of rainwater against the new pavement, and practically satisfy requirements for airport road construction in the high-temperature and pluvial area.
9）Application of digital monitoring technology in the airport road project
Conduct research on digital monitoring technology of dynamic compaction and compaction during ground treatment project. Based on Internet technology and by means of modern surveying and mapping technology and electronic information technology, realize integration of digitalization, visualization and intelligence of project construction management.
Digital monitoring system of dynamic compaction. The system imports the construction drawing, installs GNSS equipment at the top of the carbody and the pulley, and completes positioning of the dynamic compaction body and hammer ram in the construction drawing; the system utilized realization of tamping point layout and hammer ram positioning calibration on the monitor to substitute the traditional tamping point layout procedure; Digital monitoring platform of dynamic compaction. Utilize the platform for management and control of digital monitoring construction, utilize the data transmit unit to transmit the dynamic compaction construction state to the platform and convert it into the visible image and text message, conduct statistics and analysis of the information, distinguish and classify them according to the construction parameters, intuitively distinguish construction quality of various tamping points through the color display method, and substitute the traditional side station recording mode; it can output construction report of the appointed construction scope, and the output parameters include the construction vehicle information, longitude and latitude, dynamic compaction construction period, pass rate, single point tamping times, single-point construction period, tamping energy, pass rate and so on.
Digital monitoring system of compaction. The system consists of GNSS receiver carried on the carbody, data transmission radio station, compaction degree sensor on the roller bearing and monitor in the operation room. For display mode, the system adopts the color histogram for real-time reflection of the roller compaction times and compaction degree, such as 8 times of roller compaction. 8 colors from yellow to green are adopted to represent different roller compaction times, so that the operator can more intuitively understand roller compaction situation, and improve quality control capabilities.