Airfield Pavements Research Articles

Evaluation of Opportunities for Connected Aircraft Data to Identify Pavement Roughness at Airports

This paper reviews the construction and maintenance guidelines for airfield pavements, as well as the current methods for assessing pavement conditions. A study is performed on an airport’s taxiway to determine if acceleration data from airframe mounted accelerometers and on-board avionic systems can be used to provide an estimate of pavement roughness. A comparison of international roughness index (IRI), 3-axis accelerometer data, and normal acceleration data from the G1000 unit is presented based on a field study performed at the Purdue University Airport (KLAF). The paper concludes that there is a potential for crowdsourced data obtained from an aircraft’s on-board system such as the G1000 to act as an additional tool for airport managers to monitor surface conditions between routine and detailed inspections.

Investigating the effect of temperature variations on the measured airfield pavement skid resistance

Airfield temperatures can range between −30 °C and +50 °C. Therefore, it is critical to correct the measured skid resistance values for field temperatures. To achieve this, several asphalt slabs were prepared and tested using the British Pendulum Tester. A special fluid was used to conduct skid resistance tests at below freezing temperatures. Test results were used to develop correction models for skid resistance under temperature variations, to be used by airfield operators. The results of this research are unique and important where it is the first time to include below freezing temperatures in skid resistance measurements and correction models.

Mobile Composite Airfield Element of Security and Reliability in Air Transport

Abstract The problem of safety of the flight operations will be valid as long as there will be aviation, both civil and military. Ensuring the safety was, is and will be one the most important issues in the functioning and development of aviation. The safety of flight operations affect the implementation of all the elements involved in this process, which can be summarized in three groups, namely: man, the aircraft and the environment, including airfield pavements. Airfield pavements are elements that can be intentionally destroyed by military action as well as a result of random unexpected situation (failure, catastrophe, natural disaster). The reconstruction of airfield pavements in crisis situations and in military operations should enable to restore the operational availability of destroyed elements in the shortest possible time.

Application of similarity method of distance courses describing the elements content in concrete intended for airfield pavements

Application of similarity method of distance courses describing the elements content in concrete intended for airfield pavements

Application of Natural Mineral Additives in Construction

The article concerns the idea of using selected mineral additives in the pavement quality concrete composition. The basis of the research paper was the modification of cement concrete intended for airfield pavements. The application of the additives: metakaolonite and natural zeolite was suggested. Analyses included the assessment of basic physical properties of modifiers. Screening analysis, assessment of micro structure and chemical microanalysis were conducted in case of these materials. The influence of the applied additives on the change of concrete mix parameters was also presented. The impact of zeolite and metakaolinite on the mix density, oxygen content and consistency class was analysed. The influence of modifiers on physical and mechanical changes of the hardened cement concrete was discussed (concrete density, compressive strength and bending strength during fracturing) in diversified research periods. The impact of the applied additives on the changes of internal structure of cement concrete was discussed. Observation of concrete micro structure was conducted using the scanning electron microscope. According to the obtained lab test results, parameters of the applied modifiers and their influence on changes of internal structure of cement concrete are reflected in the increase of mechanical properties of pavement quality concrete. The increase of compressive and bending strength in case of all analysed research periods was proved.

Electrically Conductive Mortar Characterization for Self-Heating Airfield Concrete Pavement Mix Design

The overall objective of this paper is to investigate the types and proportions of nano-carbon based conductive materials (carbon powders and fiber), the mixing procedures, and the characteristics of conductive mortar, including the heating performance, with a focus on optimizing self-heating ECON mix design with desirable electrical and mechanical properties for airfield pavement deicing applications. A state-of-the-art review on relevant literature was conducted to identify the various conductive materials that have been investigated in the past, their optimal concentration levels to achieve desirable system-level engineering properties, and the various challenges in optimizing the ECON mix design and achieving a cost-effective ECON system. In the experimental investigation, mortar specimens modified with conductive materials at different concentration levels were compared with untreated (control) specimens in terms of electrical and mechanical properties. Conductivity and strength performance assessment of the experimental results revealed that 6-mm chopped carbon fiber (CCF) utilized in this study is capable of providing improved electrical conductivity in comparison to carbon based conductive powders without loss of strength and workability. Among carbon based conductive powders, the coarsest graphite powder provides acceptable electrical conductivity improvement and lesser loss of strength and workability. Heating characteristic of conductive mortar indicates that conductive materials which can enhance ECON conductivity could provide heating performance improvement for airfield pavement deicing application.

Airfield pavements as an element of critical infrastructure in the airport safety management process

Contemporary planes moving with high velocity and loads require well design, properly building and maintenance airfield pavements. The main objective of this factors is provide safety conditions for moving planes. Technical condition airfield pavements has a direct impact on the safety performance of air operations. This forces the need to have full knowledge of their condition, which will be allowed to take appropriate decisions to ensure their safe operation. In this paper the issues connected with the assessment of airfield pavements health, such as: methodology assessment of the degradation degree, bearing capacity, evenness, roughness and Polish Standards in force and Air Force Institute of Technology developed procedures are presented. Moreover, possible operating danger and realize research work for safety improvement are presented.

Identification of the additional exposure zone for ensuring a complete contact of the two-layered system

The problem of identification of the magnitude and zone of exposure on the upper layer of the two-layered structure under the action of a normally distributed load and its own weight for ensuring a complete contact is solved. To solve a direct problem, we use a variational formulation for the corresponding nonlinear boundary value problem with constraints. The possibility of applying the inverse problem method implemented with the recession vector method is investigated. A numerical analysis of the convergence of the model deformation elimination process depending on mechanical and geometric parameters of the system is made. It is found that the pressing zone is separated from the loading zone, the parameters of the zone being dependent on the properties of the layers, the height of the upper layer, the loading magnitude and the value of the coefficient of friction. As a result of the research, an algorithm that allows determining the state of the contact zone and the corresponding stress-strain state of the two-layered system under consideration was developed. The algorithm uses the finite element method and determines the values of characteristic functions on the basis of the values of variational inequalities. The effect of physical and geometric properties of the system on the parameters of the additional impact, ensuring the absence of a separation zone is investigated. It is shown that the account of friction small influences on the parameters of influence, a large role is rendered by geometrical parameters and level of basic ladening. The developed algorithms and conducted research will allow increasing the design reliability of airfield pavements, layered structures of industrial buildings, hydraulic structures, foundations of massive structures, wells in rocks, as well as machine parts

COMPUTER TECHNOLOGIES FOR CONCRETE AIRFIELD PAVEMENT DESIGN

The purpose of the research is to develop formulas, expressions and a computer program for concrete airfield pavement design under the impact of all Airbus 380 main landing gears taking into consideration the design factor of tensile stresses at the top and bottom of a concrete slab. The top-down cracking in concrete slabs has not been directly simulated in structural analysis models used for one- and two-layer concrete airfield pavement design by the Ukrainian Standard. Empirical formulas for the calculation of top tensile stress and the coverages to failure using the criterion of top tensile stress are obtained. Computer program “Aerodrom 380” has been developed for the design of concrete airfield pavement thickness. It provides the required thickness of a concrete slab needed to support an Airbus 380 over a particular subgrade and uses the bottom and top tensile stresses as design factors. “Aerodrom 380” contains a fatigue function for determining the number of coverages to failure permissible for a concrete slab before it has top-bottom and bottom-up cracks. The results obtained with this program are compared to other solutions using the Ukrainian Standard SNiP 2.05.08–85, “LIRA-SAPR”, software and the FAARFIELD computer program. The anticipated life of a concrete airfield pavement calculated using computer program “Aerodrom 380” is about 70% of the FAARFIELD pavement life.

Low Shrinkage Cement Concrete Intended for Airfield Pavements

The work concerns the issue of hardened concrete parameters improvement intended for airfield pavements. Factors which have direct or indirect influence on rheological deformation size were of particular interest. The aim of lab testing was to select concrete mixture ratio which would make hardened concrete less susceptible to influence of basic operating factors. Analyses included two research groups. External and internal factors were selected. They influence parameters of hardened cement concrete by increasing rheological deformations. Research referred to innovative cement concrete intended for airfield pavements. Due to construction operation, the research considered the influence of weather conditions and forced thermal loads intensifying concrete stress. Fresh concrete mixture parameters were tested and basic parameters of hardened concrete were defined (density, absorbability, compression strength, tensile strength). Influence of the following factors on rheological deformation value was also analysed. Based on obtained test results, it has been discovered that innovative concrete, made on the basis of modifier, which changes internal structure of concrete composite, has definitely lower values of rheological deformation. Observed changes of microstructure, in connection with reduced deformation values allowed to reach the conclusion regarding advantageous characteristic features of the newly designed cement concrete. Applying such concrete for airfield construction may contribute to extension of its operation without malfunction and the increase of its general service life.

Development of rapid three-dimensional finite-element based rigid airfield pavement foundation response and moduli prediction models

Abstract Designing pavement foundation for rigid airfield pavements and understanding the contribution of pavement foundation elements to overall pavement performance and pavement failure have been challenges for the rigid airfield pavement design community. While many models have been developed to best simulate pavement foundation behavior for rigid airfield pavements, many of them have focused only on the failure of Portland Cement Concrete (PCC) layer and did not sufficiently consider the contribution of pavement foundation to the failure. The Federal Aviation Administration’s (FAA’s) pavement design software, FAARFIELD, considers the maximum horizontal stress at the bottom edge of the concrete slab for bottom-up cracking failure of a PCC layer, but does not consider the critical responses for failure of subbase and subgrade layers in rigid pavement design. It is clear that incorporating critical pavement foundation responses into pavement design procedures is of great interest. The primary objective of this paper is to investigate the feasibility of developing rapid three-dimensional finite-element (3D-FE)-based pavement foundation response and moduli prediction models for design of both new and rehabilitated rigid airfield pavement structures. The three case studies investigated in the development of the models include: (1) rigid pavement foundation response prediction models for different wide body aircraft loading conditions, (2) rigid pavement foundation response prediction models for Heavy/Falling Weight Deflectometer (H/FWD) loading conditions, and (3) single rigid-pavement moduli prediction model. The development procedure and results based on rapid 3D-FE based prediction models are presented in this paper along with other significant findings and recommendations for employing the developed models in the structural design and evaluation of rigid airfield pavement systems. It was found that the developed models were able to successfully predict 3D-FE pavement solutions for all cases investigated in this study, could account for rigid pavement foundation related distresses, and could be potentially integrated into FAARFIELD as surrogate forward response prediction models in the future.

Precast concrete pavement – systems and performance review

Long-term traffic restrictions belong to the key disadvantages of conventional cast-in-plane concrete pavements which have been used for technical structures such as roads, parking place and airfield pavements. As a consequence, the pressure is put on the development of such systems which have short construction time, low production costs, long-term durability, low maintenance requirements etc.. The paper presents the first step in the development of an entirely new precast concrete pavement (PCP) system applicable to airfield and highway pavements. The main objective of the review of PCP systems is to acquire a better understanding of the current systems and design methods used for transport infrastructure. There is lack of information on using PCP systems for the construction of entirely new pavements. To most extensive experience is dated back to the 20th century when hexagonal slab panels and system PAG were used in the Soviet Union for the military airfields. Since cast-in-situ pavements became more common, the systems based on precast concrete panels have been mainly utilized for the removal of damaged sections of existing structures including roads, highways etc.. Namely, it concerns Fort Miller Super Slab system, Michigan system, Uretek Stitch system and Kwik system. The presented review indicates several issues associated with the listed PCP systems and their applications to the repair and rehabilitation of existing structures. Among others, the type of manufacturing technology, particularly the position of slots for dowel bars, affects the durability and performance of the systems. Gathered information serve for the development of a new system for airfield and highway pavement construction.

Fuzzy cluster approach for area FWD representative basin from deflection measurement spatial variability

ABSTRACTPavement evaluation surveys represent the key element for efficient pavement management and for assuring pavement mission capability. In the Department of Defense (DOD), the Unified Facilities Criteria (UFC) 3-260-03 Airfield Pavement Evaluation provides the current guidance for pavement structural evaluations. During structural surveys, FWD tests are executed at different locations within the same section, with the objective of obtaining a full assessment of the section’s structural capability. The availability of multiple deflection measurements for the same section raises the challenge of identifying the deflection basin best representing the entire section and its use in the backcalculation routine to determine the section’s structural strength. This manuscript proposes a fuzzy-based approach for the selection of a representative basin over multiple deflection basins collected for a specific section. The approach accounted for the spatial variability enclosed within the basin membership function obtained by fuzzy c-mean partitioning. The proposed methodology showed promising results for flexible pavements by offering more robust structural assessment that can account for spatial variability and thus minimise some aspects of mission risk that had a large effect on funding allocation and mission readiness.

Analysis of stiffness and fatigue resistance of cold recycled asphalt mixtures manufactured with foamed bitumen for their application to airfield pavement design

Cold recycled bound materials (CRBMs) provide an economic and environmental advantage for pavements since they decrease energy and raw material consumption. However, design methods for airfield pavements do not include key CRBM properties. In this paper an empirical-mechanistic method is used to study airfield pavement design with CRBM in order to develop design guidance. The aim of the paper is to obtain the inputs related to material properties needed for use in this method. For this purpose, CRBM containing reclaimed asphalt, with fly ash, cement and foamed bitumen as stabilising agents, was characterised. The methodology included indirect tensile stiffness modulus (ITSM) and indirect tensile fatigue tests (ITFT) in strain control mode. The inputs needed for a pavement design analysis with CRBM were then obtained. The results showed the importance of further study on CRBM fatigue to understand the behaviour of these mixes under cyclic loading.

Evaluation of the Federal Aviation Administration methodology for characterizing the nonlinear behavior of granular base and subbase materials

Abstract The major pavement test facility for airfields in the United States is the FAA William J. Hughes Technical Center in Atlantic City, New Jersey. This facility is the National Airfield Pavement Test Facility and is housed in a covered hangar on the outskirts of the Atlantic City Airport. Here, a variety of pavement cross sections have been constructed since the late 1990s and trafficked with different load carts, simulating a wide range of aircraft gear types, wheel loads and tire pressures. Arizona State University initiated a study to investigate the possibility of moisture movements in the subgrade clays were occurring due to climatic effects, particularly the thermal gradients. If the hypothesis were validated, it would have the potential to alter the initial design CBR strength parameters used in the performance analysis of the pavement-load sections. This study involved a variety of comprehensive research investigations, covering a wide range of technical topics. One major task of the overall project focused upon an assessment of the nonlinear moduli of the unbound base and subbase layers to investigate the effect of asphalt temperature on the stress state of the pavement profile. This task allowed for the comparison of nonlinear moduli results to the current FAA methodology used in FAA AC-150-5320-6E (FAA, 2009). This publication discusses and presents the moduli results obtained from a comprehensive multi-layer stress analysis of the CC-7 pavement section, for a wide range of load cart configurations, wheel loads and contact areas. While the overall average results of 243 separate pavement computer analysis were found to provide somewhat comparable modulus values, several analytical limitations were found that would lead to relative errors of resilient modulus of base and subbase materials ranging from −60% to +60%. Errors in the modulus of the underlying base and subbase layers are very important as they will lead to significant errors in predicting the subsequent fatigue cracking resistance and predictions of any asphalt surfacing layer.

Performance Evaluation of Elvaloy as a Fuel-Resistant Polymer in Asphaltic Concrete Airfield Pavements

This paper investigates the influence of fuel-resistant polymer on the consistency and performance properties of asphalt binder and hot mix asphalt (HMA) mixtures. The study uses wearing course gradation (nominal maximum size of 19 mm), penetration grade 60/70 bitumen, and Elvaloy reactive elastomeric terpolymers (RET) 4170 as a fuel-resistant polymer. Laboratory tests conducted on unmodified and modified (1-4% Elvaloy) mixtures include an indirect tensile (IDT) strength test and a resilient modulus (M) test for evaluating cracking potential and stiffness parameters, respectively; a Hamburg wheel tracker (HWT) test for quantifying the rut propensity; and a solubility test to determine the fuel-resistance capacity. The two-level factorial design of the experiment is conducted on the rheological properties of the binder including elastic recovery/complex modulus and creep stiffness values, which suggest that 1% polymer-modified binder (PMB) is least susceptible to high-temperature and low-temperature variations. Performance evaluation reveals that 1% PMB is an optimal proportion of Elvaloy in asphalt concrete mixtures, yielding maximum M values (both before and after conditioning in fuel), the lowest rut susceptibility, and high fuel resistance. This research is useful for public aviation/highway agencies and private contractors to minimize the deterioration caused by fuel slippage and to control foreign object debris damage to aircraft.

Influence of the condition of the airfield pavement structures on the operation safety of aircraft

Abstract The structure of the airfield pavement is a set of layers, whose task is to take over and transfer loads from moving aircraft to a ground subsoil in a safety manner. Airfield pavements are designed for a specific period of operation, assuming the forecasted intensity and the structure of the air traffic. The safety of air operations executed by the aircraft on airfield pavements depends primarily on the condition of their structure’s load capacity. In order to assess the load capacity of airfield pavements, the method ACN-PCN, which was introduced by the International Civil Aviation Organization ICAO and according to which the load capacity of the airfield pavement is expressed with the PCN index, is applied.

Skid resistance properties of airfield pavements as one of the safety assessment parameters of air operations

Abstract The article presents the method for determining the skid resistance properties by estimating quantities characterizing the conditions on the airfield functional elements’ pavements. The skid resistance properties characterise the aircraft’ tire grip to the airfield functional element’s pavements, and this is the ability to produce a friction force between the airfield functional element’s pavement and the aircraft’s wheels under mutual skid conditions. The adhesion is affected by the pavement type and its condition, as well as the presence of contamination, and atmospheric conditions in the vicinity of the airfield. Throughout the world, measures aimed at development of a model for assessing the conditions of the airfield functional elements’ pavements are undertaken. A key element of this process is the personnel identifying specific situations as well as the pilots using the information for safe manoeuvring, especially landing.

Decision-Making Guideline for Preservation of Flexible Pavements in General Aviation Airport Management

Proactive pavement preservation applies low-cost treatments frequently to mitigate deterioration, whereas the traditional approach to preservation is reactive to distresses, requiring intensive rehabilitation or reconstruction. Airfield pavement preservation requires adequate planning in order to efficiently mitigate pavement deterioration. Large airports generally have dedicated staff and specified budget for the management and maintenance of their pavement network; however, these resources may be lacking in many general aviation (GA) airports in the United States. Therefore, technical rules for pavement preservation should be documented and simplified for GA managers to inhibit quick deterioration and address proactive preservation. In this paper, a database and the development of guidelines for the selection of long-lasting and cost-effective treatments are introduced. A tool has been designed especially for nontechnical decision makers in GA. The developed guidelines cover both asphalt and concrete pavements, but this paper focuses on flexible pavements only. Selected treatments vary depending on different climate zones and airport traffic and service, which is reflected in airport categorization. Furthermore, the selection of an optimal treatment based on benefit-to-cost-ratio analysis is discussed.

Impacts of multiple-polymer components on high temperature performance characteristics of airfield modified binders

Polymer modified asphalt binders have been commonly used to improve the resistance of the airfield pavements to distresses, especially wheel rutting. The objective of this study was to investigate the rheological and chemical properties of the modified binders containing anti-rutting agent (ARA), polyethylene (PE) and styrene-butadiene-styrene copolymer (SBS) before and after a short-term aging procedure. Rotational viscosity, penetration degree, softening point as well as performance grade, multi-stress creep recovery (MSCR), frequency and amplitude sweep were performed to determine the effects of ARA and PE on rut depths at high temperatures. In addition, Fourier Transform Infrared Spectroscopy (FTIR) was conducted to determine the chemical properties of various polymerized binders. The test results showed that, as expected, the addition of PE and ARA polymer increased the rotational viscosity, softening point and rutting factor values and reduced the penetration degree. However, ARA could only increase complex modulus while PE had the influences on both the complex modulus and phase angle of the modified binders. In addition, the rising tendency of phase angle during frequency sweep test was totally different in terms of the binders with or without PE. Furthermore, the FTIR test results showed that the ARA has no significant effects on aging resistance, while the modified binders with PE have better resistance to aging.