Maputo Airport was initially constructed to serve mixed traffic of light and medium aircrafts. With its opening to heavier aircrafts such as B727, DC10, Airbus 340, etc. , structural improvements have become necessary...Maputo Airport was initially constructed to serve mixed traffic of light and medium aircrafts. With its opening to heavier aircrafts such as B727, DC10, Airbus 340, etc. , structural improvements have become necessary. For this purpose, structural evaluation were described and performed using falling weight deflectometer. Results show that while subgrade response to loads appears more consistent with depth, surface layer of the pavement is significantly influenced by the layer thickness as well as mechanical properties of pavement materials. Load magnitude also affects pavement performance. But loading conditions show an equivalent or even greater influence on pavement performance.展开更多
Pavements of airport runway and apron are subjected to stern stresses imposed by landing and ground movements of aircraft. The stresses are primarily concentrated in touchdown zone and wheel path areas of the pavement...Pavements of airport runway and apron are subjected to stern stresses imposed by landing and ground movements of aircraft. The stresses are primarily concentrated in touchdown zone and wheel path areas of the pavement structure. This paper proposes that this area can be designed using geosynthetic layer reinforcement to minimise deflection and deterioration of the structure. The reinforcement can reduce the vertical stresses on the underground fuel pipes in the apron area, if used. The concept of ditch conduit reinforcement is suggested where a geosynthetic layer is used within a soil backfill to redistribute load over a conduit leading to stress redistribution. It is observed that the vertical load is significantly reduced by the arching action of the soil mass overlying the conduit. The load can be reduced further by placing a geosynthetic reinforcement layer within the soil backfill above the conduit. It is suggested that the inclusion of a geosynthetic layer in the granular backfill reduces the vertical load on a ditch conduit and the amount of reduction depends upon the tensile modulus, deflection of the geosynthetic and soil arching action. This leads to believe that a reinforced pavement structure for runway and aerodrome apron area improves the load carrying capacity of the pavement to sustain the operations of heavy transport aircraft, including occasional overloading of the pavement. Hence, this paper explores a possibility of using a geosynthetic layer under the runway pavement to provide reinforcement.展开更多
This research explored the application potential of PUM thin-overlay technology on airport rapid maintenance.The rapid curing process of polyurethane binder determines the limited time window for mixing and constructi...This research explored the application potential of PUM thin-overlay technology on airport rapid maintenance.The rapid curing process of polyurethane binder determines the limited time window for mixing and construction of polyurethane-bonded mixture(PUM),which presents significant difference with hot-mix asphalt(HMA)technology.Therefore,this research investigated and optimized the mix design of PUM for airport thin-overlay technology based on its thermosetting characteristics.First,limestone and basalt were comprehensively compared as an aggregate for PUM.Then,the effects of molding and curing conditions were studied in terms of mixing time,molding method,molding parameters and curing temperature.Statistical analysis was also conducted to evaluate the effects of gradation and particle size on PUM performances based on gray relational analysis(GRA),thus determining the key particle size to control PUM performances.Finally,the internal structural details of PUM were captured by X-ray CT scan test.The results demonstrated that it only took 12 hours to reach 75%of maximum strength at a curing temperature of 50°C,indicating an efficient curing process and in turn allowing short traffic delay.The internal structural details of PUM presented distribution of tiny pores with few connective voids,guaranteeing waterproof property and high strength.展开更多
In this paper,we propose a new method to analyze airport pavement bearing capacity using vibration in runways during aircraft taxiing.The new method overcomes shortcomings of existing tests,such as flight suspension a...In this paper,we propose a new method to analyze airport pavement bearing capacity using vibration in runways during aircraft taxiing.The new method overcomes shortcomings of existing tests,such as flight suspension and simulated loading.Between aircraft take-off and landing,acceleration sensors are arranged on the surface of the pavement far from the centerline,and the in-situ responses of the pavement under aircraft loads are collected during aircraft operations.The fundamental frequencies of the pavement are obtained by fast Fourier transformation of the measured accelerations,and are used to modify the parameters of a pavement finite element model built according to a design blueprint.By comparing the fundamental frequencies of the measured and calculated signals,the soil modulus is back-calculated.To implement this test method and ensure the accuracy of bearing capacity evaluation,aircraft dynamic loads are obtained by solving dynamic balance equations of the aircraft-pavement coupled system,and the vibration response of the pavement and sensitivity analysis of the fundamental frequencies are introduced.The results show that the fundamental frequencies at the center of the pavement are basically the same as those at the far side on the cross section;the fundamental frequencies in the depth direction remain constant,but the amplitude of the frequency spectrum decreases.The effect of the soil resilient modulus on the vibration frequency is most significant.The fundamental frequency increases from 6.02 to 10.55 Hz when the soil dynamic resilient modulus changes from 91 to 303 MPa.The effects of surface thickness and base thickness on the vibration frequency are less significant,and there is minimal influence when changing the dynamic elastic moduli of the surface layer or base layer.Field test results indicate the efficacy of the method of vibration measurement at the pavement surface to estimate the layer modulus of airport pavement.展开更多
文摘Maputo Airport was initially constructed to serve mixed traffic of light and medium aircrafts. With its opening to heavier aircrafts such as B727, DC10, Airbus 340, etc. , structural improvements have become necessary. For this purpose, structural evaluation were described and performed using falling weight deflectometer. Results show that while subgrade response to loads appears more consistent with depth, surface layer of the pavement is significantly influenced by the layer thickness as well as mechanical properties of pavement materials. Load magnitude also affects pavement performance. But loading conditions show an equivalent or even greater influence on pavement performance.
文摘Pavements of airport runway and apron are subjected to stern stresses imposed by landing and ground movements of aircraft. The stresses are primarily concentrated in touchdown zone and wheel path areas of the pavement structure. This paper proposes that this area can be designed using geosynthetic layer reinforcement to minimise deflection and deterioration of the structure. The reinforcement can reduce the vertical stresses on the underground fuel pipes in the apron area, if used. The concept of ditch conduit reinforcement is suggested where a geosynthetic layer is used within a soil backfill to redistribute load over a conduit leading to stress redistribution. It is observed that the vertical load is significantly reduced by the arching action of the soil mass overlying the conduit. The load can be reduced further by placing a geosynthetic reinforcement layer within the soil backfill above the conduit. It is suggested that the inclusion of a geosynthetic layer in the granular backfill reduces the vertical load on a ditch conduit and the amount of reduction depends upon the tensile modulus, deflection of the geosynthetic and soil arching action. This leads to believe that a reinforced pavement structure for runway and aerodrome apron area improves the load carrying capacity of the pavement to sustain the operations of heavy transport aircraft, including occasional overloading of the pavement. Hence, this paper explores a possibility of using a geosynthetic layer under the runway pavement to provide reinforcement.
基金This study was supported by the National Natural Science Foundation of China under Grant number of 51861145402.
文摘This research explored the application potential of PUM thin-overlay technology on airport rapid maintenance.The rapid curing process of polyurethane binder determines the limited time window for mixing and construction of polyurethane-bonded mixture(PUM),which presents significant difference with hot-mix asphalt(HMA)technology.Therefore,this research investigated and optimized the mix design of PUM for airport thin-overlay technology based on its thermosetting characteristics.First,limestone and basalt were comprehensively compared as an aggregate for PUM.Then,the effects of molding and curing conditions were studied in terms of mixing time,molding method,molding parameters and curing temperature.Statistical analysis was also conducted to evaluate the effects of gradation and particle size on PUM performances based on gray relational analysis(GRA),thus determining the key particle size to control PUM performances.Finally,the internal structural details of PUM were captured by X-ray CT scan test.The results demonstrated that it only took 12 hours to reach 75%of maximum strength at a curing temperature of 50°C,indicating an efficient curing process and in turn allowing short traffic delay.The internal structural details of PUM presented distribution of tiny pores with few connective voids,guaranteeing waterproof property and high strength.
基金Project supported by the National Natural Science Foundation of China(No.51178456)the Fundamental Research Funds for the Central Universities(No.3122017039),China。
文摘In this paper,we propose a new method to analyze airport pavement bearing capacity using vibration in runways during aircraft taxiing.The new method overcomes shortcomings of existing tests,such as flight suspension and simulated loading.Between aircraft take-off and landing,acceleration sensors are arranged on the surface of the pavement far from the centerline,and the in-situ responses of the pavement under aircraft loads are collected during aircraft operations.The fundamental frequencies of the pavement are obtained by fast Fourier transformation of the measured accelerations,and are used to modify the parameters of a pavement finite element model built according to a design blueprint.By comparing the fundamental frequencies of the measured and calculated signals,the soil modulus is back-calculated.To implement this test method and ensure the accuracy of bearing capacity evaluation,aircraft dynamic loads are obtained by solving dynamic balance equations of the aircraft-pavement coupled system,and the vibration response of the pavement and sensitivity analysis of the fundamental frequencies are introduced.The results show that the fundamental frequencies at the center of the pavement are basically the same as those at the far side on the cross section;the fundamental frequencies in the depth direction remain constant,but the amplitude of the frequency spectrum decreases.The effect of the soil resilient modulus on the vibration frequency is most significant.The fundamental frequency increases from 6.02 to 10.55 Hz when the soil dynamic resilient modulus changes from 91 to 303 MPa.The effects of surface thickness and base thickness on the vibration frequency are less significant,and there is minimal influence when changing the dynamic elastic moduli of the surface layer or base layer.Field test results indicate the efficacy of the method of vibration measurement at the pavement surface to estimate the layer modulus of airport pavement.
