Pietro Leandri

Università di Pisa | UNIPI · Department of Civil and Industrial Engineering

The automotive industry is currently transforming, primarily due to the rise of electric and hybrid vehicle technologies and the need to reduce vehicle mass and energy losses to decrease consumption, pollution, and raw material usage. Additionally, road surface manufacturers emphasize improving pavement durability and reducing rolling noise. This n...

This paper focuses on the development of a statistical model that predicts the CPX-Level at 80 km/h of porous and semi-porous mixes as a function of porosity and texture band levels. The model was calibrated using data from six pavement sections laid on Italian motorway corridors, two paved with open-graded mixes and four with semi-open-graded mixe...

Stone pavement structures (SPS), also known as stone roads or stone-paved roads, are road pavements constructed using stones as the primary surface material. Different types of SPS exist; historically, irregular-shaped stones with downward protrusions have been often exploited since regular-shaped stones were difficult to be produced. More recently...

There is an urgent need to assess the condition of transport network in many countries all over the world as in Italy and, in this context, the consideration of non-destructive techniques has particular importance. These techniques, such as space-born systems, laser scanners, ground-penetrating radar (GPR), and monitoring tests, provide valuable da...

This paper focuses on the development of a statistical model that estimates the close proximity level (CPX-L) of bituminous mixtures usable in urban, extraurban, and motorway road networks as a function of survey speed, aggregate gradation, bulk properties, and age of the layer. The proposed equation derives from an existing model developed on Ital...

Cracks are fractures or breaks that occur in materials such as concrete, metals, rocks, and other solids. Various methods are used to detect and monitor cracks; among many of them, image-based methodologies allow fast identification of the distress and easy quantification of the percentage of cracks in the scene. Two main categories can be identifi...

In countries such as Italy, funds available for road monitoring may be limited, especially for the secondary road network. In such circumstances, there is a need to define expeditious and low-cost procedures that allow the development of reliable and objective pavement management strategies. In this research, a methodology for the management of roa...

Road surface properties have a major impact on pavement’s life service conditions. Nowadays, contactless techniques are widely used to monitor road surfaces due to their portability and high precision. Among the different possibilities, laser profilometers are widely used, even though they have two major drawbacks: spatial information is missed and...

Different types of Stone Pavement Structures (SPS) are employed in certain areas of European cities. Historically, irregular-shaped stones with downward protrusions have been often exploited since regular-shaped stones were difficult to find or be produced. More recently, regular cuboid stones can also be adopted in SPS. Accordingly, in new constru...

Four Accident Prediction Models have been defined for Italian two-lane rural, suburban, and urban roads by exploiting different Machine Learning Algorithms. Specifically, a Classification and Regression Tree, a Boosted Regression Tree, a Random Forest, and a Support Vector Machine have been implemented to predict the number of Fatal and Injury cras...

This paper proposes a methodology based on Artificial Neural Networks (ANNs) for integrating products derived by three on-ground Non-Destructive high-performance Techniques (NDTs) to estimate the International Roughness Index (IRI) of flexible road pavements. About that, IRI of 93 two-lane road sections has been detected by a Laser Profiler (LaP) a...

This paper proposes a methodology for correlating products derived by Synthetic Aperture Radar (SAR) measurements and laser profilometric road roughness surveys. The procedure stems from two previous studies, in which several Machine Learning Algorithms (MLAs) have been calibrated for predicting the average vertical displacement (in terms of mm/yea...

Vibrations induced by traffic are of concern for road authorities due to disturbance on the population, and the damage of buildings and structures. In the field of pavement engineering, the anti-vibration paving technologies by the so-called damping layer are under investigation to avoid the generation of excessive vibration and contains propagatio...

The use of rejuvenators (RJ) is critical to increasing the amount of recycled asphalt in new mixtures. However, their usage and classification have not achieved a consistent common practice. One of the properties that lacks a comprehensive investigation is their re-aging tendency. In this work, mineral oil from the automotive industry (MO), a waste...

Road authorities are challenged by traffic-induced vibrations due to their detrimental effects on humans and to the damage of buildings and structures. For this reason, asphalt mixtures designed as damping layer are investigated to resist vibration and noise caused by traffic loads, while a reliable design method to optimise for the mixes needs to...

This paper introduces a methodology for predicting and mapping surface motion beneath road pavement structures caused by environmental factors. Persistent Scatterer Interferometric Synthetic Aperture Radar (PS-InSAR) measurements, geospatial analyses, and Machine Learning Algorithms (MLAs) are employed for achieving the purpose. Two single learners...

The δ-method has been developed to estimate molecular weight distributions of bitumens from phase-angle master curves. The method uses a correlation between the cross-over frequency(ω C) and the molecular weight (MW) that was developed from average MW measured by vapour pressure osmometry. This study proposes a revised correlation whose parameters...

The applicability of the time-temperature superposition principle (TTSP) can breakdown in the case of highly oxidized bitumens and polymer-modified bitumens (PMBs). This study investigates such problem in Styrene Butadiene Styrene (SBS) modified bitumens subjected to high oxidative laboratory-aging levels. The effects of aging were investigated by...

The effects of polymer modification on the durability of Polymer Modified Bitumens (PMBs) still remain relatively unclear due to partial understanding of the combined effects of ageing and loading on damage accumulation. This paper investigates the effects of laboratory ageing on the damage tolerance of cross-linked SBS and EVA modified bitumens me...

In order to plan infrastructure maintenance strategies, Non-Destructive Techniques (NDT) have been largely employed in recent years, achieving outstanding results in the identification of infrastructural deficiencies. Nevertheless, the extensive combination of different NDT that can cover various factors affecting infrastructure durability has not...

In order to compare some innovative solutions of sustainable pavement surfaces containing crumb rubber modifier (CRM), a strengths, weaknesses, opportunities, and threats (SWOT) analysis of different technologies developed for production of low noise pavements (LNPs) has been carried out. CRM is one of the by-products obtained from end-of-life tyre...

Polymer additives are widely used to improve the performance of road bitumens including their resistance to hardening during oxidation, although their oxidative inhibitor effect has not been well documented. This study aims to investigate the effect of laboratory-simulated ageing on the microstructure, and rheological properties of Polymer Modified...

Increasing environmental awareness is pushing towards sustainable approaches to the design and management of transport infrastructures. A life cycle assessment of low noise pavements is carried out here, with the aim to evaluate and compare the use of warm mix asphalts containing crumb rubber (CR) from end-of-life tires (ELTs) and reclaimed asphalt...

Polymer additives are widely used to improve the performances of road bitumen and mixtures including their oxidative resistance. However, their effect on the oxidative mechanism remains unclear. This study includes the investigation of the changes in the rheological response of Polymer Modified Bitumen (PMBs) prepared with the Styrene Butadiene Sty...

Polymer additives are used to improve the properties of road bitumens including their oxidative resistance. However, their usage as anti-oxidative materials remains relatively unclear. This study aims to investigate the changes in the morphology and the rheological response of polymer modified bitumens used in road pavement construction caused by a...

The Shift-Homothety-Shift in time-Shift (SHStS) transformation, derived from the 2S2P1D model, represents one of the most convenient and simple solution for describing the rheological behavior of asphalt materials, when the transformation parameter α is known. In this paper, a simple expression for predicting the SHStS transformation parameter α is...

The determination of the rheological properties of the aged binder in Reclaimed Asphalt Pavement (RAP) materials is a challenging problem. Conventionally, extraction and recovery are used to obtain the RAP binder for further experimental characterisation; however, this procedure is not entirely reliable and accurate. Alternative and more precise ap...

The determination of the allowable percentage of Reclaimed Asphalt Pavement (RAP) that could be used in Hot Mix Asphalt without compromising fatigue cracking is a crucial task. The principal issue is related to the evaluation of the fatigue resistance of the aged binder contained in the RAP and how does it influence the fatigue resistance of the fr...

The book reports the results of field trials to test the use of river sediments decontaminated through landfarming and phytoremediation techniques for nursery productions carried out within the EU project Cleansed (Innovative integrated methodology for the use of decontaminated river sediments in nurseries and in the construction of roads - 2012-20...

Determining thermo rheological properties of the aged binder in reclaimed asphalt pavement (RAP) is a challenging problem. In the literature, there are different methods available, but some of them are considered not accurate, others are costly and time consuming. For these reasons, in this paper, a new methodology to evaluate RAP binder properties...

This paper proposes a new model for predicting the speed gradient of peak friction values on asphalt pavements on the basis of surface characteristics. The innovative feature of the proposed model is the reliable estimation of peak friction values experienced by vehicles equipped with an antilock brake system at a certain vehicle speed. To define t...

The principal advantage of introducing some percentages of crumb rubber in the production of asphalt mixtures is related to pavement environmental sustainability. A Crumb Rubber Modified Binder (CRMB) is produced by introducing a Crumb Rubber Modifier (CRM) in an asphalt binder. Due to its high viscosity, the product must be handled at very high te...

This paper proposes a tool to optimize the mix design of low-noise pavements. An experimental model was developed to predict the rolling noise of a reference car tire as a function of the composition and volumetric characteristics of mixes obtained from in-service pavements. The model enables an analyst to identify which composition parameters need...

To check the reliability of pavement design models, instrumentation such as strain gauges and pressure cells are embedded in pavement structures to measure pavement responses under loading. Many problems can arise during pavement instrumentation that determine the success or failure of the instrumented experiment. The paper documents the work condu...

The main advantage of introducing crumb rubber in the production of asphalt mixtures is related to pavement's environmental sustainability. The addition of crumb rubber allows a significant amount of industrial waste to be recycled, and, in some specific cases, it allows the reduction of tire/road noise emissions. There are some other not unanimous...

The RAP (Reclaimed Asphalt Pavement) utilization in bituminous mixtures highlights the need to evaluate the effects RAP binder produces in terms of stiffness and brittleness increase. The research is focused on the evaluation of the mechanical properties of a bituminous mixture containing a significant percentage of RAP and produced with a controll...

The aim of this study is to define an experimental model to predict acoustic absorption properties of porous asphalt concretes (PAC) as a function of composition and volumetric characteristics of mixes. The model can be used for the mix design of PAC and it enables to individuate which composition parameters to operate on in order to obtain optimum...

The aim of this paper is to analyse pavement profiles by using a theoretical approach in order to identify a reliable pavement profile data processing procedure for evaluation of pavement macrotexture according to the definition of the ISO 13473-1, and to verify the assumption of equivalence between the profilometric and volumetric methods. The eff...

Questo quaderno è il risultato di un’approfondita indagine del comitato tecnico AIPCR D2b “Pavimentazioni flessibili e semirigide”, gruppo B, dedicata alle problematiche del rumore stradale e alle procedure per la sua riduzione. Particolare attenzione è stata rivolta alle tecniche di mitigazione acustica alla sorgente che, anche secondo gli indiriz...

Tyre/road noise is a complex phenomenon which is function of tyre, surface properties and speed. This study aims to define a rolling noise prediction model for a reference tyre, as a function of speed, on dense asphalt surfaces with medium-low macrotexture levels. The model was defined by relating texture levels of pavement profiles and rolling noi...

The use of artificial aggregates such as expanded clay in the production of asphalt concrete makes it possible to reduce both natural aggregate extraction and the use of nonrenewable raw resources, greatly benefiting the environment. Moreover, the expanded clay production process allows nondangerous waste materials to be reclaimed and thereby avoid...

This paper presents key findings of a research project which is entrusted with setting up guidelines for monitoring and evaluation of pavement performance requirements with the aim of improving durability and both road safety and environmental sustainability. The study has investigated some techniques for monitoring structural and surface character...

Existing pavements of collector rural roads are often characterized by a strong dishomogeneity in pavement layer thicknesses and mechanical properties of materials. In order to evaluate structural conditions of these pavements, they must be delineated in homogeneous sub-sections with regard to variations both in the thickness and the mechanical pro...