Mauro Coni

Runway Instrumentation and Response Measurements

This paper presents ongoing research to measure the in situ response to airplane traffic of flexible pavement on a runway at Cagliari-Elmas Airport in Italy. Understanding how pavement materials respond to traffic and environmental loading is fundamental to designing pavements and assessing their performance. The pavement material behavior is affected by many factors (i.e., load magnitude, material properties, and environmental conditions). The influence of these factors can be simultaneously taken into account by measuring in situ stresses and strains using embedded instruments. The pavement layers of the Cagliari-Elmas runway were equipped with 149 instruments: 36 linear variable differential transformers, 36 pressure cells, four time domain reflectometers, 28 T-thermocouples, and 45 hot-mix asphalt strain gauges. The instrumented area, 55 m2, allows measuring the responses during three main loading maneuvers: taking off, landing, and taxiing. The preliminary data acquired during and after the runways construction and before its opening to airplane traffic and its analysis show that the instrumentation process was a success. The instrument response testing includes falling weight deflectometer, truck, and airplane loading of various types, magnitudes, and speeds. The collected data were successfully compared with preliminary numerical simulations. Further data collection and research will be performed, particularly involving airplane traffic data. Data analysis will include the effect of the environmental data (i.e., moisture and temperature) and airplane configuration and speed. The collected data will be used to validate advanced pavement modeling and predict pavement runway performance. In addition, data resulting from this research have the potential to support and improve runway pavement design and to improve the evaluation process for new and existing runway pavement performance and damage prediction.

Three-Dimensional Finite Element Modeling of Instrumented Airport Runway Pavement Responses

A three-dimensional finite element model was used to analyze runway pavement responses under moving aircraft tire loading. The analysis modeled an instrumented runway at Cagliari Elmas airport in Sardinia, Italy, with a 350-mm asphalt layer, a 400-mm granular base layer, and subgrade. The finite element model characterized the asphalt layer as a linear viscoelastic material, and two interface bonding conditions between asphalt layers (full bonding and partial debonding) were used in the analysis. The aircraft tire loading was simulated with a nontraditional loading assumption that represented the nonuniform distribution of tire contact stresses along contact length and width under five ribs of an aircraft tire. Analysis results showed that a traditional loading assumption that assumed uniform contact stresses at the tire–pavement interface underestimated the critical tensile and shear strains in the asphalt layer. In particular, the relatively high contact stresses at tire edge ribs under heavy aircraft loading caused significant shear stresses at the pavement near-surface. The pavement responses under various loading conditions (aircraft type, wheel load, and speed) were calculated, and the critical responses were identified. Good agreements were achieved when the calculated pavement responses (vertical pressure and horizontal strain) at various locations were compared with the measured responses from field instrumentation. The model results showed that partial debonding between asphalt layers caused much greater tensile strains at the bottom of the whole asphalt layer.

Home-School Routes and Child Psychology: The Smartness in Small Steps

The smartness of a city can be built and developed through many elements that together contribute to its development. One pillar of this elements is the smart mobility, that not always involves technology, planning, infrastructure, but tend to work on the change of citizens behavior, even in the long term. Among them, home-school routes can play a fundamental role; in fact, these routes allow children to use and live public spaces now occupied by vehicles and traffic and to build a culture of sustainable mobility that will see great results when these children become adults. Kids are not small adults and they have a different perception of reality. For this reason, it is necessary to create road signs and markings that are comprehensible for children aged 6-14 when they are engaged in a road environment. Information that users can obtain are based on traffic control devices which are the combination of three elements: shape, color and pictogram. Therefore it is important that message generated by the three elements is understandable by children. In fact, children overcome the phase of syncretism after the age of 6, which corresponds to the phase in which children are unable to analyses and syntheses. The research target is to design road signs and markings for children, to ensure safety of home-school routes. This paper collects the main principles about children psychology and describes a traffic control devices study to be conducted for Cagliari’s project on road safety.

How has Cagliari Changed Its Citizens in Smart Citizens? Exploring the Influence of ITS Technology on Urban Social Interactions

The main purpose of this article is to evaluate and to achieve a deeper understanding of the changing role of Intelligent Transport Systems (ITSs) not only in transport habits, but also in urban traditional lifestyles of citizens, by using the city of Cagliari (Italy) as a case study. In fact, ITSs play a significant role in determining innovative sustainable transport, for a better use of urban space and time, enhancing also the people quality of life. ITSs help people to move around more easily, safely and economically, in a more environmentally friendly manner. Traditionally, ITSs were used to improve traffic flow, cars speed, easy parking and therefore encouraging the use of the cars, by causing negative impact on social interactions. Nowadays, cities are changing and use technology in order to greatly improve public transport and smart mobility. Specifically, this study analyzes the city of Cagliari (Italy) and its transition toward a smart, sustainable and green mobility, by showing the successful steps from a scenario based on a car-used city to a new scenario based on a free cars-used city due to an integrated, environmental, smart approach.

Analysis of Runway Deflectometer Campaign for Implementation on Airport Pavement Management System

Abstract The load-carrying capacity, is one of the indicators used to assess airfield pavement conditions. It could be estimated by evaluating the response of stationary dynamic loads, using a deflectometric device that simulates the stress inducted by an aircraft moving at moderate speed. This device is widely used because tests are nondestructive and rapid to execute and can be conducted for cyclic investigations, providing valuable support to maintenance and rehabilitation (M&R) decision makers through pavement management system (PMS). Pavement response is evaluated as a function of the deflection basin induced by the deflectometric device. It is well known that deflectometric measurements are influenced by external parameters such as weather conditions, especially temperature of upper layers or the percentage of water contained on unbounded layers. In this study the deflections basin response obtained for different load and weather conditions has been analyzed through the application of benchmarking values for immediately structural assessments. Tests were performed using the Heavy Weight Deflectometer (HWD) on 9 points along five longitudinal alignments from the centerline, 0.00 m, ± 3.00 m, and ± 5.20 m. The benchmarking methodology was used to evaluate and compare runway pavement performance under different weather conditions and testing loads. The applied benchmarking methodology resulted an easy and rapid assessment tool of pavement conditions at network-level.