Airport Pavement Research Articles

Numerical modeling of steel fiber reinforced concrete spallation exposed to medium loading rate

Properties of unreinforced concrete and cement-based matrix are well understood. One of the issues with the cement-based matrix is its inherently brittle failure when exposed to loading. As such, steel fibers were proposed to enhance the ductility of cement-based and concrete materials. Ever since, Fiber-Reinforced Concrete (FRC) has become a commonly used building material in many construction activities such as bridges, airport pavements, shotcrete, and many others. According to previous research, the addition of steel fibers, typically from 20 to 50 kg/m3 into the conventional concrete, can significantly enhance many of the desired engineering properties of hardened concrete such as flexural strength, tensile strength, micro-cracks as well as splitting. This research presents a study aimed to numerically investigate the influence of steel fibers on the dynamic behavior of Plain Concrete (PC) exposed the tensile loading at medium strain-rate. The influence of steel fibers is investigated using different fiber volume fractions ranging from 0.0 to 4.5%. The Modified Split-Hopkinson-Bar (MSHB) apparatus is employed to investigate the dynamic tensile behavior of PC and Steel Fiber-Reinforced Concrete (SFRC). Validation of the finite element model and constitutive material behavior is carried out with the comparison of computed and measured experimental pull-back velocities of the specimen’s free end. The results showed that impact properties of steel fibers exhibit significant improvement in the toughness and the dynamic tensile strength of concrete and higher fiber volume fraction is more effective in enhancing the mechanical properties of SFRC composite.

Development of Korea Airport Pavement Condition Index for Panel Rating

Airports strive to prevent safety issues, such as foreign object debris (FOD), by pavement management using the pavement condition index (PCI). The index is used in decision-making processes for overall pavement maintenance and repair, such as the prevention of additional damage due to cracks and the like. However, considering the current situation in Korea where mostly mid-sized and large commercial airports exist, problems regarding direct applications of the existing PCI deduct value have been consistently pointed out. In addition, as the relationship between the PCI and whether maintenance and repair are required is unrealistic, there have been difficulties in communication between maintenance and repair staff and decision makers. Therefore, to resolve these problems, this study first analyzed the calculation procedure of the existing PCI and then redefined the main distress type of Korean airport pavements. In addition, a deduct value curve (DVC) in terms of the severity level for six main distress factors of asphalt pavements and eight main distress factors of concrete pavements and a corrected deduct value curve (CDVC) for multiple distresses in terms of the pavement form were developed using panel rating, which is an engineering approach, by forming an airport pavement expert panel. Finally, a Korea airport pavement condition index (KPCI) was proposed using the curves, and the field application results were compared against the existing PCI to examine the adequacy of the KPCI. As a result, the developed criteria showed an overall trend lower than existing PCI. Moreover, it was verified that this trend increases with worsening pavement condition. It appears that a more discriminating evaluation may be possible when determining pavement conditions by PCI results of the developed criteria.

Optimization of polyurethane-bonded thin overlay mixture designation for airport pavement

Optimization of polyurethane-bonded thin overlay mixture designation for airport pavement

Study on Flexural Fatigue Properties of POM Fiber Airport Pavement Concrete.

Polyoxymethylene (POM) fiber is a new polymer fiber with the potential to improve the performance of airport pavement concrete. The effect of POM fiber on the flexural fatigue properties of concrete is an important issue in its application for airport pavement concrete. In this study, four-point flexural fatigue experiments were conducted using ordinary performance concrete (OPC) and POM fiber airport pavement concrete (PFAPC) with fiber volume contents of 0.6% and 1.2%, at four stress levels, to examine the flexural fatigue characteristics of these materials. A two-parameter Weibull distribution test of flexural fatigue life was performed, after examining the change in flexural fatigue deformation using the cycle ratio (n/N). A flexural fatigue life equation was then constructed considering various failure probabilities (survival rate). The results show that POM fiber had no discernible impact on the static load strength of airport pavement concrete, and the difference between PFAPC and OPC in terms of static load strength was less than 5%. POM fiber can substantially increase the flexural fatigue deformation capacity of airport pavement concrete by almost 100%, but POM fiber had a different degree of detrimental impact on the fatigue life of airport pavement concrete compared to OPC, with a maximum decrease of 85%. The fatigue lives of OPC and PFAPC adhered to the two-parameter Weibull distribution, the single- and double-log fatigue equations considering various failure probabilities had a high fitting degree based on the two-parameter Weibull distribution, and their R2 was essentially over 0.90. The ultimate fatigue strength of PFAPC was roughly 4% lower than that of OPC. This study on the flexural fatigue properties of POM fiber airport pavement concrete has apparent research value for the extension of POM fiber to the construction of long-life airport pavements.

Effect of Modified Tetraethyl Orthosilicate Surface Treatment Agents on the Permeability of Airport Pavement Concrete

In this paper, three modified tetraethyl orthosilicate surface treatment agents were prepared by using tetraethyl orthosilicate (TEOS) as the preparation monomer, isobutyltriethoxysilane (IBTS) as the hybridizer, and acrylic acid, phosphoric acid, and hydrochloric acid as the catalysts. The effects of the three modified tetraethyl orthosilicate surface treatment agents on the permeability of airport pavement surface concrete were investigated by water absorption tests, water contact angle tests, water penetration resistance tests, chloride ion penetration resistance tests, and carbonation tests, and the mechanisms of action of the modified tetraethyl orthosilicate surface treatment agents were analyzed by microscopic tests. The results showed that all three tetraethyl orthosilicate surface treatment agents could significantly improve the impermeability of concrete, among which the modified tetraethyl orthosilicate surface treatment agent with hydrochloric acid as the catalyst had the most obvious effect on the improvement of the impermeability of concrete. Acrylic acid was weaker than hydrochloric acid as the catalyst of a modified tetraethyl orthosilicate surface treatment agent for the improvement of concrete impermeability; it was only slightly stronger than hydrochloric acid as the catalyst of modified tetraethyl orthosilicate surface treatment agent in terms of the improvement of concrete’s resistance to water penetration, and the difference between the two was not significant. Phosphoric acid as a catalyst of the modified tetraethyl orthosilicate surface treatment agent was the least effective for concrete impermeability; it was only stronger than the other two modified tetraethyl orthosilicate surface treatment agents in the improvement of concrete resistance to carbonation, and the carbonation depth of the concrete was only 1 mm in 28 days. SEM and MIP tests showed that the modified tetraethyl orthosilicate surface treatment agents improved the impermeability of concrete mainly by producing additional hydrated calcium silicate gel to plug microcracks and pores, reduce the total porosity of the concrete and the number of multi-harmful and harmful pores, and improve the compactness of the concrete. The test results can provide a reference for the development of modified tetraethyl orthosilicate surface treatment agents and their application in airport pavement surface engineering.

Implementation of the system for maintenance management of road structures at the Nikola Tesla Airport in Belgrade

At the Nikola Tesla Airport in Belgrade, the need for the introduction of the Airport Pavement Management System (APMS) has been recognized for a long time, which would improve the existing procedures and enable the most optimal use of funds intended for maintenance. In 2019, testing and configuration of such a system began. The paper presents the characteristics of the system itself and the challenges that arose during implementation.

Methods of deep modification of low-bearing soil for the foundation of new and spare air runways

Abstract: After analyzing the impact of aircraft on the airport pavement (parking spaces, runways, startways), it was considered advisable to consider the problem of deep improvement or strengthening of its subsoil. This is especially true for low-bearing soil. The paper presents a quick and effective method of strengthening the subsoil intended for the construction of engineering structures used for civil or military air operations. It allows the use of wastelands, wetlands, swamps, etc. for the above-mentioned purposes, thus creating a dispersed network of landing sites increasing the security of the country and increasing the availability of air transport for large society groups. Keywords: Runways; Runways load; Ground reinforcement; Blasting agents

Study on Fiber Reinforced Concrete Using Asbestos

Abstract: Concrete is one of the widely used construction materials for structures. Cement concrete is an artificial stone produced by hardening mixture of cement, sand, stone chips and water. Since cement concrete is very good in compression but weak in tension, steel reinforcement are to be provided in tension zone. The low tensile strength and brittle character of concrete have been bypassed. Such combination of concrete and steel is called Reinforced Cement Concrete (RCC). The inclusion of small fraction (usually 0.5 to 2% by volume) of short fibers to the concrete, mortar and cement paste can enhance many of the engineering properties of basic materials such as fracture toughness, flexural strength and resistance to fatigue, impact and spalling. The incorporation of fibers into concrete has been found to improve several properties primarily cracking resistance, impact and wear resistance and ductility. For this reason, Fiber Reinforced Concrete (FRC) is now being used in increasing amounts in structures such as airport pavements, highway overlays, bridge decks and machine foundations. Fiber reinforced concrete (FRC) is concrete containing fibrous material which increases its structural integrity. So we can define fiber reinforced concrete as a composite material of cement concrete or mortar

PELATIHAN SOFTWARE COMFAA BAGI MAHASISWA TEKNIK SIPIL DI KOTA SEMARANG

Technological developments really help a civil engineering graduate in designing in the civil engineering field. There are a lot of software that can be used to design runway pavement thicknesses, one of them is COMFAA. In this service activity, the service team conducted training about the calculation of the runway pavement thickness at the airport using COMFAA software for civil engineering students and construction workers. The purposes of this service activity are to give deep understanding about the design of pavement layers on airport runways, to develop knowledge in pavement thickness designs, and to enhance the engineering student’s competence in using COMFAA to plan airport pavement layers. The implementation of this service was carried out in Semarang for Civil Engineering students and Construction Actors. The result was an understanding enhancement of runway pavement analysis from 0% to 77%.

Thermosetting characteristics and performances of polyurethane material on airport thin-overlay

The slow curing speed of traditional cement materials for airport pavement maintenance tended to cause unacceptable delays on the daily operations of airport aircraft. It was indispensable to select organic polymer materials to achieve rapid maintenance effect with high quality. At present, polyurethane had been adopted to achieve special demands for functional pavements. However, the application of polyurethane on rapid thin-overlay maintenance technology for airport pavement had not been researched extensively and there were also no standardized material design and construction procedures. This research conducted investigations on the thermosetting characteristics, component optimization and performance evaluation of polyurethane as rapid thin-overlay maintenance material for airport concrete pavement. First, the effects of micro-phase separation with different component ratios on polyurethane binder were analyzed. Three kinds of polyols were compared and selected comprehensively with corresponding optimal content ratio. Then, the thermosetting characteristics of polyurethane binder were evaluated, in terms of curing duration and curing temperatures. The curing process model of polyurethane molecules with gelation point was illustrated. The optimum polyurethane binder content was determined according to the properties of polyurethane-bonded mixtures and the optimal interlayer structure of the PUM composite overlay was considered. The characteristics of cement concrete and polyurethane-bonded mixture were compared, including mechanical property, durability and permeability. Finally, the internal structural details of cement concrete and polyurethane-bonded mixture were reconstructed and analyzed through X-ray CT scan. This research promoted the application potential of polyurethane as the rapid maintenance material with thin-overlay technology for airport pavement.

Development and thermo-mechanical behavior of cement-based composite for the runway concrete of F-35B joint strike fighter

The current study aims at increasing the strength and heat resistance of concrete that can be used in airport pavements for vertical take-off and landing of new generation F-35B combat aircraft by improving concrete mixtures. For this purpose, two different mixtures with lightweight (expanded glass aggregate) and traprock (basalt) aggregate were prepared. The mechanical properties and thermal conductivity of the mixtures were determined, 3D maps of cracks that occurred with the flexural tensile strength tests were examined using fractal analysis, and the fracture energy of the samples was obtained. A statistically significant extremely high correlation was found between fractal dimension and flexural tensile strength. No significant compressive strength losses were observed in samples after heat exposure. We determined that the mechanical properties of the basalt aggregate mixture were better than the expanded glass aggregate mixture, however, its thermal conductivity was higher.

Evaluation of Small Uncrewed Aircraft Systems Data in Airfield Pavement Crack Detection and Rating

Current practice for airport Pavement Management Program (PMP) inspection relies on visual surveys and manual interpretation of reports and sketches prepared by inspectors in the field to quantify pavement conditions using the Pavement Condition Index method set forth in ASTM D5340. In recent years, several attempts have been made, both by the industry and by airport operators, to use small Uncrewed (Unpersonned/Unmanned) Aircraft Systems (sUAS), or “drones,” to conduct various types of imaging and inspection of airport pavements. As part of a comprehensive study on the use of such sUAS to evaluate airfield pavement conditions, the objectives of this study were to assess the performance of various sUAS platforms and sensors in detecting and rating a subset of crack-based pavement distresses and to evaluate the use of a combination of different sUAS datasets to complement current methods used to support airport PMP. Two airports in Michigan were selected for sUAS data collection, and five sUAS platforms equipped with eight different sensors were flown at these airports at different altitudes to collect red, green, and blue (RGB) optical and thermal data at different resolutions. RGB orthophotos, digital elevation models, and thermal images were visually analyzed to study their usefulness in detecting and rating longitudinal and transverse cracks in flexible/asphalt pavements and longitudinal, transverse, and diagonal cracks, corner breaks, and durability cracks in rigid/concrete pavements. This study demonstrated the capability of using sUAS data in detecting and rating multiple crack-related distresses in both flexible and rigid airfield pavement systems.

Development and Application of an Integrated Monitoring and Early Warning Platform for Land Transportation Infrastructure under Special Engineering Conditions

To ensure the safety service performance of land transportation infrastructure under special engineering conditions, centering on the characteristics of structures such as the road high-steep slope, high embankment, special subgrade, railway track, and airport pavement, an integrated monitoring and early warning platform based on health monitoring and safety evaluation was built through the combined design of the safety indicator module, monitoring data module, information processing module, numerical simulation module, inversion prediction analysis module, and safety early warning module. The data interaction between the integrated platform and five monitoring subplatforms was realized by the B/S mode, and the related function interfaces were established. The research results show that as the monitoring data storage analysis and early warning carrier, the integrated monitoring and early warning platform not only presents key data such as comprehensive early warning information, evaluation indicators, and monitoring elements but also realizes the intelligent, automatic, and visual presentation of monitoring data. In addition, relying on the high-steep slope of the Hohhot-Bikeqi Highway (section: K528+215~K528+525), through the application of the high-steep slope monitoring and early warning subplatform system in the practical project, it is verified that the platform has a good monitoring and early warning effect, which provides a reliable platform guarantee for the health monitoring and safety operation of the project.

Airport pavement design considering areal load distribution

ABSTRACT In this paper, the wheel track areal distribution of a short takeoff and landing aircraft was tested by using the self-developed airport pavement wheel track test system. The transverse and longitudinal distribution regulations of the wheel track of single-aircraft takeoff, dual-aircraft takeoff and landing were statistically analyzed, and the coverage of each point on the pavement were obtained. The joint simulation of MATLAB and ABAQUS was utilised to realise the fast calculation of the stress state at each point of the pavement. The longitudinal load of the pavement calculated based on the six-degree-of-freedom aircraft taxiing model was substituted into the finite element model, and the allowable coverage at each point on the pavement was calculated combined with the fatigue equation of concrete. Furthermore, an airport pavement design method based on the cumulative damage areal distribution was proposed, which could provide damage characteristics at any point on the pavement. The case analysis shows that the thickness of pavement within 600 m at both ends of the pavement for Aircraft A can be designed as 22 cm, and that of the middle pavement can be designed as 19 cm.

Planning maintenance and rehabilitation activities for airport pavements: A combined supervised machine learning and reinforcement learning approach

Maintenance and Rehabilitation (M&R) of airport pavement assets involves considerable financial resources. As such, even modest improvement in M&R activity planning could lead to non-trivial savings. The state-of-the-practice for planning M&R activities mostly relies on condition thresholds and engineering rules, while the state-of-the-art often requires untested assumptions and relies critically on complete knowledge about pavement deterioration. This study proposes a machine learning (ML)-based approach that integrates pavement condition prediction using supervised ML with M&R activity planning empowered by reinforcement learning (RL), for which the Q-learning method is adopted. Supervised ML involves minimum a priori assumptions while characterizing the relationship between pavement deterioration and its influencing factors, and can yield higher-accuracy prediction of future pavement conditions than traditional methods. Similarly, RL learns the optimal action-value functions in a model-free environment. The integrated ML approach is implemented and demonstrated using real-world data from Chicago O’Hare International Airport. The results show the effectiveness of the proposed approach which can lead to reduced M&R cost compared to practice.

ANALISIS KERUSAKAN JALAN PERKERASAN LENTUR RUAS JALAN BATU SANGKAR – OMBILIN STA 5+000 – 10+200, SUMATRA BARAT

The structural and functional condition of the damaged road is very influential and can result in areduced ability of the road so that it cannot provide optimal service to the road users. The decline in the optimal quality of roads occurs due to damage to road infrastructure caused by repeated high traffic volumes. According to the indicators, it can be seen from the condition of the road surface, both structural and functional conditions that have suffered damage. The purpose of this study was to find out the types of damage that occurred and what kind of handling should be done as well as the priority values for repairing damage to the Batusangkar - Ombilin road section by requiring survey data directly to the field to obtain clear data on the dimensions of the damage. The research was conducted using the Pavement Condition Index method which, according to Shahin 2004, determines the PCI value based on 3 main factors, namely the type of damage, severity, and density of damage where the PCI method is a method from the American Guidelines and Procedures for Maintenance of Air Port Pavement (1982) and the Bina Method. Marga which is a method from Indonesia which measures damage based on the Procedures for Compiling a Road Maintenance Program 1990, to get the results and the handling that must be done. This study shows the Pavement Condition Index method, the average yield obtained on the Batusangkar – Ombilin road section, the pavement condition is 50.42 Moderate (Fair) and the Bina Marga analysis, the repair priority value is in the 4-6 range, namely the road is included in the periodic maintenance program with damage. on the Batusangkar - Ombilin road section, namely longitudinal cracks, alligator cracks, patches, holes, grain release, and stripping.

Airport Cement Concrete with Ceramic Dust of Increased Thermal Resistance.

The impact of aircraft on airport pavements is varied and closely related to their operational durability. The article presents the impact of the annealing process related to the forced impact of airplanes on airport pavements. The composition of cement concrete with ceramic dust, which is characterized by increased thermal resistance, has been proposed. Two research cycles were programmed, differentiated by the annealing scheme and the way in which the temperature influences the annealing time. Samples stored at a temperature of 20 ± 2 °C were subjected to testing. The tests were carried out for two diagrams: A and B. The first—diagram A—included the continuous impact of the flue gas stream on the samples for a period of 350 min with a test step every 25 min. For the second—diagram B—the samples were alternately heated (1 min) and cooled (15 min). The influence of the proposed pavement mix on changes in the internal structure of cement concrete and the increase in its resistance to high temperatures was determined. In the microstructure of the CC-1 concrete matrix, it was found that there were plate-granular portlandite crystals up to 10 µm in size and ettringite crystals with a length of 8 µm. In the CC-2 concrete, the ettringite crystals were less numerous and had a length of up to 5 µm, there were also continuous contact zones between the aggregate grains and the cement matrix (diagrams A). The alternating annealing/cooling (diagram B) resulted in the ettringite crystals in the CC-1 matrix being up to 10 µm long, and in the CC-2 concrete up to 7 µm long. The contact zone between the aggregate grain and the matrix in CC-2 concrete was continuous, and the microcracks in CC-1 concrete were up to 8 nm. Regardless of the heating diagram, in the surface zone, there were larger microcracks in the CC-1 concrete than in the CC-2 concrete. For diagram A they were 14 µm and 4 µm and for diagram B they were 35 µm and 5 µm, respectively. It was found that concrete with ceramic dust is characterized by a lower and more stable temperature increase. In scheme A, the average temperature increase on the heated surface ranged from 46 °C to 79.5 °C for CC-1 concrete, and from 33.3 °C to 61.3 °C for CC-2 concrete. However, in scheme B, the temperature after 350 heating cycles for CC-1 concrete increased to 129.8 °C, and for CC-2 concrete to 116.6 °C. After the cooling period, the temperature of CC-1 and CC-2 concrete was comparable and amounted to 76.4 C and 76.3 °C, respectively. CC-2 concrete heats to lower values, and favorable changes in internal structure translate into higher strength and durability (after 350 heating cycles according to scheme A, the strength of CC-1 concrete was 67.1 MPa and of CC-2 concrete 83.9 MPa, while in scheme B, respectively, 55.4 MPa for CC-1 and 75 MPa for CC-2).

Preliminary evaluation of the ACR-PCR system for reporting the bearing capacity of flexible airfield pavements

Assessing and reporting the bearing capacity of airfield pavements have always been significant tasks in airport engineering, since they support the decision making procedure, which is a core element of Airport Pavement Management Systems (APMS). The official reporting system utilized worldwide during the last four decades is the Aircraft Classification Number – Pavement Classification Number (ACN-PCN) system. However, recently an updated system has been introduced, aiming to overcome the defects of the ACN-PCN system that have been observed during its implementation. This system, referred as the Aircraft Classification Rating – Pavement Classification Rating (ACR-PCR), aims to incorporate the latest advances in airfield pavement design and evaluation and is expected to be fully applicable about 2024. Since this is a transfer period, the current investigation aims to identify any critical aspects arising from the application of the updated system, based on recent Federal Aviation Administration (FAA) airfield pavement evaluation techniques. On this basis, the transferability between the two system is examined, providing useful commentary and remarks for airport authorities, who would like to implement the ACR-PCR method to its full extent. The analysis shows that the transferability between the two systems seems not to be feasible and the implementation of the updated ACR-PCR may present several issues, such as the modification of the existing reported bearing capacity.

Roughness and condition prediction models for airfield pavements using digital image processing

Based on the assessment of three runways at mid-size Chilean airports, the aim of this article is twofold. First, it discusses the potential empirical relationship that may exist between two parameters traditionally used to measure pavement roughness and condition, i.e. the International Roughness Index (IRI) and Pavement Condition Index (PCI), both measured using industry-standard, semi-automated processes. Second, it proposes an automated and parsimonious methodology for estimating the IRI and PCI, based on a digital image processing algorithm that accurately determines the total amount of cracking in pavements and which essentially requires no human curation. On one hand, a direct correlation between IRI and PCI has been obtained that can be considered statistically significant. On the other hand, highly reasonable estimates for the IRI and PCI can be achieved based solely on the total cracking percentage of a unit sample. The models proposed can be used for airport pavement management purposes.

Airport Pavement Stiffness Monitoring and Assessment of Mechanical Stabilization using Bender Element Field Sensor

The bender element (BE) field sensor is a newly developed embedded pavement instrumentation that measures shear wave velocity to estimate constructed layer moduli of unbound aggregate bases and subbases. This paper presents findings related to monitoring stiffness characteristics of airport pavement base courses instrumented with BE field sensors and tested under full-scale accelerated pavement testing during Construction Cycle 9 (CC9) of the National Airport Pavement Test Facility (NAPTF) by the U.S. Federal Aviation Administration (FAA). The CC9 aggregate base courses were constructed following FAA’s P-209 specification for a geosynthetic experiment using a biaxial geogrid installed at the bottom of the 8-in. (203-mm) thick base in the north test section, while the control pavement in the south test section was built without a geogrid. Two BE field sensors were installed in the north and south test sections approximately 1 in. (25 mm) above the base–subbase interface. Multiple stages of aircraft gear loads, including static dual-gear, dynamic slow-roll (moving wheel), and dynamic proof-roll, were applied to the test sections. BE field sensor data collected throughout multiple loading stages were used to investigate the stiffness characteristics of the pavement base. These preliminary tests conducted at the NAPTF CC9 experiment revealed the effects of static and dynamic aircraft gear loads on the stiffness of the aggregate base layer and how confinement influenced the moduli of the geogrid-stabilized base. Further, previously observed anti-shakedown effects caused by vehicle load wander could be quantified through changing base course modulus and deformation behavior from the BE field sensor data analysis.