Airport Pavement Research Articles

Co-modifying geopolymer composite by nano carbon black and carbon fibers to reduce CO2 emissions in airport pavement induction heating

CO2 emissions during airport pavement induction heating for ice and snow melting are primarily determined by the electrothermal behavior of electrically conductive layer (ECL). A single type of conductive filler is difficult to significantly improve the electrothermal performance of ECL while maintaining its mechanical properties. This work introduces nano carbon black (NCB) into carbon fiber-reinforced geopolymer to prepare NCB-carbon fiber co-modified geopolymer composites (NMGC) with great potential to dramatically improve the electrothermal performance of ECL and reduce CO2 emissions during induction heating. Furthermore, in order to provide guidance support for the ECL design, the evolution mechanisms of the electrothermal and mechanical properties of NMGC were inquired through electrochemical impedance spectroscopy (EIS) analysis and geopolymerization rate characterization, respectively. Results show that introducing 1 wt% NCB into the carbon fiber-reinforced geopolymer can effectively increase the reaction rate within NMGC and improve its electrothermal performance due to the enhanced electron transition. Indoor induction heating tests further indicate that the optimized NMGC can reduce the CO2 emissions by 13.7 kg/m2 comparing to the NMGC without NCB during 30 min of induction heating.

Essential characteristics of rigid concrete airport pavements under cyclic traffic loading revealed from a thermodynamic perspective

The increasing global air traffic has placed higher demands on airport pavement design. However, the behavior of rigid concrete airport pavement (RCAP) under traffic loading is very complex, and the existing reliability theory and empirical concrete pavement analysis methods cannot detect the precise RCAP failure point. Based on this background, this paper attempts to study the failure of RCAP under traffic loading from a thermodynamic perspective. It selects the Federal Aviation Administration (FAA) test in Construction Cycle 8 (CC8) phase 3 as the research material. We apply the structural stressing state theory to equate the RCAP under traffic loading to a thermodynamic system with a phase transition, i.e., we model the whole process strain data as state variables. Then, analogous to the renormalization group method of Wilson's phase transition theory to reveal the critical point of the system, this study establishes matrixes (Modes) and Hamiltonians (Characteristic parameters) that can characterize the RCAP full-process stressing state evolution under traffic loading by accumulating the difference of state variables. We attempted to verify the effectiveness of this method under such complex working conditions, which can also be applied to many other high-speed time-variant loading conditions. By applying the clustering analysis criterion, we can reveal the phase transition points of the RCAP: elastoplastic branch (EPB), failure starting (FS), and progressive failure (PF) points, respectively. Taking the NW group as an example, the variances of EPB, FS, and PF points revealed by the mode and characteristic parameter curves conducted by the two homogeneous measured point selections, respectively, are 7.7,6.4, and 6.4, which are of exceptionally high stability. We also used thermodynamic modeling to reveal the phase transition points of the remaining three RCAPs and compared the effect of different joints on the phase transition points. Finally, this study also explores the feasibility of EPB-based concrete airport pavement design.

An experimental and numerical study on the hybrid effect of basalt fiber and polypropylene fiber on the impact toughness of fiber reinforced concrete

As the civil aviation industry advances, higher requirements are put forward for the performance of airport cement pavement. The frequent takeoffs and landing of aircraft will cause continuous and large impact load on airport pavement, and combined with long-term natural factors, there will be various structural diseases. These diseases not only affect the service life of pavement, navigation safety. To enhance the impact resistance and durability of concrete, the incorporation of fiber has proven an effective approach, and basalt fibers (BF) and polypropylene fibers (PF) are selected as reinforcement materials in this study. Firstly, the effects of single BF and hybrid BF and PF on the mechanical properties of concrete were explored through compressive and flexural tests considering fiber volume contents (0.1%, 0.15, 0.2%) and lengths (6 mm, 9 mm, 12 mm). Then, the drop hammer impact test method, recommended by ACI committee 544, was refined to evaluate the impact resistance toughness of concrete. Finally, the numerical simulation of the impact test was established to explain the concrete impact damage mechanism. The results show that under less than 0.15% volume content, the single BF can effectively enhance the compressive strength, flexural strength, and impact resistance of concrete. Compared with the single BF, the combination of 12 mm BF and 6 mm PF yields favorable results, encompassing improved mechanical properties and impact resistance, thus exhibiting a positive hybrid effect. The increase in PF length (9 mm) leads to a reduction in compressive strength but an improvement in flexural strength and impact resistance. The simulation of the impact test is constructed and the accuracy is confirmed by comparing the impact times and failure patterns of the specimens. The tensile damage of plain concrete is much greater than the compressive damage, and the cracks will spread rapidly from the upper surface to the lower surface. Compared with plain concrete, the crack width of hybrid fiber reinforced concrete is larger, but the damage degree is more uniform. Fiber can absorb a large amount of impact energy, reduce the emergence of micro-cracks, and improve the impact toughness and toughness coefficient of concrete.

Utilization of Pavement Condition Index on Runway Pavement Sultan Babullah Ternate Airport

The Pavement Condition Index (PCI) assessment is one method used to assess the state of airport runway pavement. The runway (flexible pavement) of Sultan Babullah Ternate Airport, which has a size of 2300 m by 45 m, served as the site for PCI research in this study. The ASTM D5340-12 procedure (Standard Test Method For Airport Pavement Condition Index Surveys) was used to examine this PCI. The average PCI value of the entire sample was calculated from the results of the overall PCI study by averaging all PCI values for each sample, the results for the average PCI value of the entire sample were obtained at 60 (medium). Damage to STA 0+700 is on a bad scale with a PCI calculated value of 41, Damage to STA 0+750 is on a bad scale with a PCI calculated value of 41, Damage to STA 0+850 is on a bad scale with the value of the PCI calculation result is 31, Damage to STA 0+900 is on a bad scale with a PCI calculation result value of 36, Damage to STA 0+950 is on a bad scale with a PCI calculation result value of 34, Damage to STA 1+1050 is on a bad scale with a PCI calculation result value of 59.

Airport Pavement Distress Analysis

Airport Pavement Distress Analysis

The expansion and mechanical property-based cavity expansion model for polyurethane grouting underneath the airport pavement

The cavity beneath the pavement will be further expanded by the self-expansion pressure of polyurethane foam after grouting, leading to a decline in its density and mechanical properties of the polyurethane foam. This study proposed a cavity expansion model that coupled the influence of expansion characteristics of polyurethane foam and the mechanical behavior of surrounding soil, thus, the cavity expansion performance with declining expansion pressure and changing mechanical parameters in confined soil and pavement was accurately characterized. The study sequences are as follows: (1) a series of confined expansion tests and uniaxial compression tests were conducted via a self-developed device under various densities and material ratios of the polyurethane foam, thus the prediction formula of expansion pressure with material ratio and density was obtained, and the variation of the ultimate compressive strength and elastic modulus of polyurethane foam can also be quantified; (2) a cavity expansion model considering the decrease of expansion pressure and compressive strength of polyurethane foam during the expansion was proposed based on the combination of the conventional cavity expansion model and the conducted expansion test results; (3) the parametric analysis was conducted to investigate the influence of the initial density (ρ0, refers to the density when the self-expansion pressure starts to apply on the surrounding soil), material ratio of polyurethane foam and the original cavity size on the expansion radius, so the evolution of mechanical properties after cavity expansion under the pavement was revealed based on the density change after expansion (ρ). The feasibility of the improved model for the expansion of polyurethane foam in soil was evaluated in this study, which can provide a reference for the design and optimization of a polyurethane foam filling scheme for the cavity underneath a pavement.

Performance evaluation of non-oil permeable creep rubber waterproof material for airport pavement joints

A frequent condition of cement concrete pavement at civil airports is slab cavity caused by surface water infiltration, which is a significant safety risk in the regular operation of airports. Mitigation methods to lessen surface water penetration is strongly required. This study examines the tensile and adhesive properties of custom-designed non-oil permeable creep rubber waterproofing (NCRW) material. Direct tensile tests were used to assess the tensile characteristics of NCRW material aged in various modes. Pull-off-healing tests were used to assess the adhesive and self-healing abilities of NCRW material treated with various aging modes to various slabs under various test situations. Fluorescence tests and infrared spectroscopy were also used to explore the aging mechanism of NCRW material. The results showed that NCRW material can offer good self-healing and anti-aging capabilities, as well as great tensile and adhesive properties, so it can meet the needs of airport pavement use. As a result, NCRW material is advised to be used in the airport pavement joints.

Energy Harvesting on Airport Pavements Traffic Dependent: A321 (Narrow-Body) Aircraft Case Study

Research into novel methods for reducing greenhouse gas emissions is being carried out with the use of energy-harvesting systems. On road pavements, energy-harvesting technology has been successful in finding solutions and applications. This study discusses a solution for airport pavements that aims to produce electric energy from aircraft traffic. The new system is simulated in Simulink/MATLAB with all the components for producing technical data being provided by the manufacturers. The system is internally subdivided by simulating the aircraft in 3DOF and the energy harvesting in 1DOF. The energy-harvesting simulations achieved an energy density of up to 6.80 Wh/(m.vehicle) and a 24% conversion rate. This paper contributes to the exploration of solutions to enable energy-harvesting systems to be placed in airport pavements. These solutions are traffic dependent and require an innovative system to control the operation due to the specifications of airport pavements.

An exploratory framework for accelerated airport pavement testing using the geotechnical centrifuge

ABSTRACT Full-scale Accelerated Pavement testing (APT) has been regarded as an essential step to bridge the gap between research and practice for pavement design because it can fully mimic a large number of heavy wheel loading on pavements. Despite being able to test pavements in an accelerated manner compared to Long-term Performance Monitoring (LTPM), conducting one full-scale APT experiment is still demanding in terms of monetary cost, space, time, etc., and the accessibility to APT facilities is only available in a few countries nowadays. In this study, an exploratory APT study with a down-scaled pavement model in a high-g environment created by geotechnical centrifuge was performed with up to half a million simulated aircraft load repetitions. Through this test, it was proved that the centrifuge APT can reproduce the full-scale airfield pavement responses, including rutting, cracking, material fatigue, etc. The transient and permanent deflection of the pavement surface, variations in stress and strain states within the pavement structure over its lifespan can be well captured for analysis. This framework of centrifuge APT provides a new methodology for pavement testing and can significantly save the current cost and time of full-scale APT.

Assessment of the technical condition of the airport runway surface using an UAV

The technical condition of airport pavements not only has a significant impact on the performance of air operations in the ground movement area but also affects the comfort of aircraft movement on the airport pavement, which determines the safety of air operations. The requirements for airfield pavements are specified in defense standards, as well as in civil documents, e.g. (International Civil Aviation Organization), EASA (European Union Aviation Safety Agency), FAA (Federal Aviation Administration), where exploitation parameters in the field of airport pavement construction are defined. The article presents the methodology of the initial assessment of the technical condition of airport pavements in terms of existing damage, as well as anomalies of the existing gradeline, which may indicate inadequate evenness of the pavement. The assessment was made using an aerial photogrammetry kit and the test results were presented. This work focuses on the use of an aerial photogrammetry set, which made a flight over the runway of a military airport providing its full imaging.

Runway Pavement Structural Analysis Using Remote Laser Doppler Vibrometers

Structural analysis is crucial for airfield pavement evaluation and plays a critical role in ensuring airfield operation safety and efficiency. Traditionally, the evaluation has relied on the Heavy Weight Deflectometer (HWD) test. This method encounters challenges, including interruptions in airfield operations, limited coverage of inspection locations, and extensive time required for data collection and analysis. In the presented research, a remote method for the measurement and analysis of runway pavement structural deflection induced by transiting aircraft was introduced, employing a Remote Laser Doppler Vibrometer (RLDV). First, a test system was developed to acquire deflection measurements of airport pavements using RLDV. To address inaccuracies arising from minor angle measurements and fixed-end beam vibrations, vibration correction methods were developed and validated. Thereafter, a linear regression model was constructed using data from both RLDV and HWD measurements, yielding a correlation coefficient of 0.94. This correlation highlights the reliable utility of RLDV in analyzing pavement structural response. The objective of this research is to present a novel approach for the evaluation of pavement structural performance.

Influence of iron powder content on the electromagnetic and mechanical performance of soft magnetic geopolymer composite

In the induction heating of airport pavement to remove snow and ice, soft magnetic geopolymer composite (SMGC) can be used to gather the dissipated electromagnetic energy, thus enhancing the energy utilization efficiency. The aim of this work is to analyze the influence mechanism of iron powder content on the electromagnetic and mechanical performance of SMGC, so as to provide theoretical guidance for the design of soft magnetic layer within airport pavement structure. The results show that the increase of iron powder content reduces the resistance and magnetoresistance of SMGC by decreasing the content of non-magnetic phases between iron powder. However, the reduction of iron powder spacing also provides a shorter transmission path for the inter-particle eddy currents in the SMGC specimen, which enhances the exchange coupling between iron powder, thus increasing the electromagnetic loss. Therefore, the compatibility between magnetic permeability and electromagnetic loss should be considered comprehensively in the mix design of SMGC. In addition, although iron powder can enhance the mechanical properties of SMGC by improving the density of geopolymer matrix, the excessive amount of iron powder can lead to a weak interfacial transition zone between geopolymer matrix and iron powder. According to the induction heating results, optimized SMGC can improve the energy transfer efficiency of induction heating by 24.03%.

Effect of deicing agents on the performance of airport asphalt pavement

Deicing agents are widely used to remove ice and snow on airport pavement, ensuring air traffic operation and safety. However, excessive spraying may affect the performance of airport pavement. The effects of different chloride deicing agents on the performance of airport asphalt and mixture have been assessed by previous studies. The three deicing agents (NaCl, KHF-1A, and NW056) were selected. Conducting various tests to examine their influence on the performance of asphalt and asphalt mixture. The tests include the DSR test, BBR test, indirect tensile test, bending test of small beam, and freeze-thaw splitting test. The results indicate that the asphalt anti-rutting factor G*/sinδ varies by 25%–45%, the asphalt creep stiffness increases by 15%–50%, and the anti-fatigue factor (G* sinδ) increases by 10%–40% under the effect of the deicing agents. The splitting strength of the mixture decreases by 10%–40%, the bending stiffness modulus increases by 6%–20%, and the freeze-thaw splitting strength ratio does not change significantly under the effect of the deicing agents. NW056 deicing agent has minimal effect on the performance of airport pavement and has optimal performance. The replacement of traditional chloride deicing agents helps to prolong the service life of airport asphalt pavement.

Refined evaluation methods for preventive maintenance of project-level asphalt pavement based on confusion-regression model

Accurate evaluation of the performance of airport pavement can help managers make scientific and systematic preventive maintenance (PM) decisions, ensuring pavement safety and extending service life. To this end, firstly, this paper sorted out the pavement performance evaluation index system, based on which a multi-dimensional evaluation system for PM was proposed, including control indexes, macroscopic indexes, and microscopic indexes. Then, the pavement decay model based on the pavement condition index (PCI) was developed, and the regression model between PCI and International roughness index (IRI) and friction coefficient (μ) was established. Finally, by converting the PM decisions for project-level pavement into a binary classification problem in machine learning, the optimal maintenance thresholds and intervals for PM of each index were determined using receiver operating characteristic (ROC) curve and Kolmogorov-Smirnov (K-S) curve. The optimal threshold represents the threshold when the index can separate the binary classification problem (PM decisions) with maximum probability. Based on confusion-regression model, the pavement performance can be evaluated more comprehensively, and the timing of PM can be accurately determined. The model helps airport managers develop accurate PM plans to address future maintenance needs.

Strain-rate sensitivity analysis of the fracture behaviour of polyoxymethylene-fibre-reinforced airport-pavement concrete

Polyoxymethylene (POM), a novel type of fibre, can be incorporated into airport-pavement concrete as a reinforcing fibre. Airport pavements are thin-plate concrete structures continuously subjected to various complex random loads. Thus, understanding the fracture behaviour of POM-fibre-reinforced concrete under various strain rates is essential. In this study, ordinary airport-pavement concrete and POM-fibre-reinforced airport-pavement concrete were subjected to three-point bending fracture tests at five strain rates (10−6, 10−5, 10−4, 10−3 and 10−2 s−1), and the effects of fibre content and strain rate on the fracture performance of these concrete were systematically investigated. The results showed that POM fibres could enhance the crack resistance of concrete used in airport pavements; for a POM fibre concentration of > 1.2 vol%, the fracture toughness increased by ∼ 50 %. The analysed critical crack propagation rates demonstrated the ability of POM fibres to inhibit fracture propagation. Although PFAPC showed distinct strain-rate-dependent fracture characteristics, this dependency weakened as the fibre concentration increased. Finally, statistical analyses of the fractured surface were performed to assess the fracture behaviour of PFAPC under various stresses and quantify the contribution of POM. These results provide a critical foundation for the practical application of PFAPC in airport pavements.

The combined effect of steel fiber and MgO on the deformation and mechanical properties of high-strength concrete

Shrinkage cracking of concrete is one of the main problems affecting the durability of high-strength concrete. One of the main measures to solve this problem is to use expansion agents to compensate for the shrinkage of concrete. But on the other hand, excess expansion, while compensating for shrinkage, is likely to have a detrimental effect on mechanical properties of concrete. Especially for bridge decks and airport pavement with high requirements for impact resistance, toughness, and crack resistance, the use of expansion agents alone cannot meet the performance requirements. In this study, the mechanical properties and autogenous shrinkage of concrete were studied when MgO expansion agent (MEA) and steel fiber were used simultaneously. The results showed that the expansion produced by MEA increased the porosity while compensating for the shrinkage of concrete. Compared with plain concrete, the porosity increased by 4.4% when MEA was incorporated alone. After MEA and steel fiber were used simultaneously, the steel fiber constrained the expansion of MEA through the adhesive friction between fiber and matrix, which made the interface transition zone (ITZ) between cement paste and fiber densified. In this way, the shrinkage of concrete was avoided without reducing the mechanical properties. Especially when 8% MEA and 1% steel fiber were used simultaneously, the compressive strength and splitting tensile strength of concrete were increased by 20.6% and 65.0% respectively, and the porosity was decreased by 20.9%. The expansion of concrete at 410d when used simultaneously was 371 × 10−6, which was 20.7% lower than that of MEA alone, avoiding the possible adverse effects of excessive expansion of MEA. The research results have guiding significance for improving the crack resistance and impact resistance of concrete.

Study on the Evolution Behavior of Humidity Fields in Cement Concrete Pavements of a Coastal Airport During Early Stages in Humid and Hot Areas.

Airport pavements are prone to early defects during the construction phase, and their early performance during the construction phase is significantly affected by the external temperature field. This article takes the concrete pavement of Xiamen Xiang'an New Airport as an example and uses a three-dimensional (3D) humidity simulation program for cement concrete pavement to study the evolution behavior of the early stage humidity field of the pavement in a humid and hot climate environment. The results indicate that the evolution law of the humidity field of the concrete pavement slab was consistent with the environmental field, presenting a 24 h periodic variation. The environmental field had a significant impact on the humidity of the surface layer of the pavement slab, and the humidity decreased rapidly with time. There was a humidity gradient on both the horizontal plane and the cutting plane of the slab, the horizontal humidity was concentrated from the boundary into the middle of the slab, and the sectional humidity was concentrated from the top to the bottom of the slab. Environmental parameters, construction parameters, and material and structural parameters all influenced humidity through humidity exchange or by changing the saturated vapor pressure inside the slab. The humidity field was most sensitive to environmental humidity and maintenance methods, but less sensitive to material parameters and structural parameters. Through analysis, it is advisable to avoid hot seasons, choose periods of increased environmental humidity, adopt appropriate maintenance methods during construction to reduce humidity stress on the slab, and therefore decrease early stage deterioration and improve service life.

Sustainability in the Airports Ecosystem: A Literature Review

The global challenges of sustainability are transforming the economy of the 21st Century. Economic, social, and environmental sustainability impacts regulators and businesses, particularly in the aviation industry, and facilitates access to productive services and market linkages. Airport stakeholders are increasingly pressuring companies to consider their socioeconomic impacts and manage them sustainably and resiliently. Business is paramount to airport companies in this competitive and economically sensitive climate. Many studies have addressed the issue of airport sustainability from specific perspectives. These perspectives include economic sustainability, benefits related to economic and environmental sustainability, and the impact of operations on the airport environment. This report summarises the current state of airport environmental sustainability practices, including greenhouse gas emissions from airport pavements, energy management strategies for airport buildings and operations, water conservation, and waste management. We aim to provide a clear and integrative picture of these impacts on airport sustainability through a systematic literature review while advancing knowledge A systematic literature review was performed using the PRISMA guidelines (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) methodology. This systematic literature review sought to consolidate knowledge on the subject. In order to illustrate the link between major categories and their corresponding trends, authors used VOSviewer scientific software. The compilation of existing knowledge on the three components of sustainability likely underscores the importance of overall airport sustainability. It is suggested that further studies be conducted.

Airport pavement performance evaluation of pavement fog seal based on optimized test technology

Fog seal technology is widely used in airport asphalt pavement. The research on the performance and application of fog seal material is basically at the level of modified emulsified asphalt. The fog seal test method in the existing specification has defects. Three kinds of fog seal materials with different substrates were selected in this paper. Based on the characteristics of fog seal treatment and the relevant specifications of fog seal and airport pavement. Wet Track Abrasion Test (WTAT), Cantabro test, Water seepage test, and Pendulum instrument tester pavement friction coefficient test were improved. Test the pavement performance of different types of fog seals. The results show that the mass loss of material C was less than 10% after 200 and 400 cycles of wear. The improvement effect of material C on raveling resistance and impermeability was far better than that of materials A and B. The improvement of material C on the raveling resistance of the mixture could reach 50%. The immediate improvement effect on the impermeability was nearly 100%. The skid resistance performance of the three fog seal materials decreased after treatment. The decrease in material C was more significant than in materials A and B. In constructing material C, the dose of emery should be appropriately increased. It was advisable to not be less than 0.35 kg/m2. The fog seal layer improves pavement performance. It has reference significance for using fog seal technology to treat early airport pavement diseases.

Petrographic Evaluation of Aggregate from Igneous Rocks: Alkali–Silica Reaction Potential

A thorough petrographic evaluation of aggregates from igneous rocks in terms of their alkali–silica reaction (ASR) potential is crucial in ensuring the durability and long-term performance of concrete structures, especially those where access to additional alkalis is possible, such as from de-icing agents. The aim of the research was to assess the potential reactivity of aggregates from igneous rocks, as only such aggregates are used for concrete airport pavements in Poland. Petrographic analysis was conducted to identify the reactive minerals in the aggregate, and it was extended by quantitative image analysis. The strained, microcrystalline and cryptocrystalline quartz were found to be reactive components but significantly differed in content. It was found that aggregates from igneous rocks were characterized by different susceptibility to ASR and that methods to mitigate the occurrence of ASR should be considered to be used in airfield concrete. A relationship between the content of analyzed reactive minerals and the expansion of mortar bars in AMBT, as well as of the concrete prism in the CPT method, was revealed.