Fernando Silva Albuquerque

Development of Roughness Prediction Models for Low-Volume Road Networks in Northeast Brazil

Roughness evaluation is the most effective way to diagnose pavement condition for design and decision making. The index most commonly used worldwide to indirectly describe the surface condition of asphalt pavements is the international roughness index (IRI). However, few studies have tried to predict the pavement performance of low-volume roads (LVRs) on the basis of the IRI, especially for LVRs in tropical regions. In an attempt to remedy that lack of knowledge, this paper presents IRI-based prediction models developed for asphalt pavement LVR networks in northeast Brazil. The following independent variables were considered to affect the IRI: Thornthwaites aridity index, which describes local climate; the modified structural number, representing pavement bearing capacity; and the cumulative number of equivalent single-axle loads, representing the traffic applied to the pavements. A multiple regression analysis was carried out, and the results showed that the IRI increases exponentially over time. The analysis of the model parameters confirmed their significance, and the R-square values were 0.87 and 0.94, respectively, for low-volume roads with hot asphalt mixes and bituminous surface treatments. The hot-mix asphalt model was compared with that of the Highway Development and Management Model and with other models developed in research also sponsored by the World Bank. Because of regional differences (especially climate and materials), the models proposed in this paper provide a better estimation of roughness progression in LVRs of the northeast of Brazil.

Study of Mechanisms That Generate Traffic Noise in the Tire–Pavement Interface for Low-Volume Roads in Brazil

Traffic noise has a negative influence on society, and minimum acoustic comfort standards must be maintained for individuals to be able to perform their daily activities. When traffic speeds exceed 40 km/h, the predominant noise source is tire–pavement interaction. This study assessed noise generated in the tire–pavement interface at different traffic speeds (40, 60, and 80 km/h), for different types of asphalt coatings applied in low-volume roads in the state of Sergipe, Brazil. Coatings included conventional asphalt mix and polymer-modified hot-mix asphalt concrete, cold-mix asphalt, and double bituminous surface treatment. An increase in noise was directly proportional to increased traffic speed and also varied with changing parameters such as voids, surface texture, and roughness. Because of the upper microtexture, a double bituminous surface treatment can be used as a good solution for quiet pavements in low-volume roads.

Critérios para a tomada de decisão em obras rodoviárias sustentáveis

A tomada de decisao para a manutencao de rodovias deve ser pautada por mecanismos convenientes para manter os pavimentos em condicoes funcionais adequadas as necessidades dos seus usuarios, proporcionando a estrutura basica para o desenvolvimento economico e social da populacao. A priorizacao para intervencao em rodovias utilizando procedimento multicriterial e uma estrategia para avaliar as diversas oticas existentes. Este trabalho apresenta a aplicacao do Metodo de Analise Multicriterial PROMETHEE II na priorizacao para manutencao de rodovias, utilizando tres cenarios diferentes, considerando associacoes de criterios de categorias Tecnica, Economica, Social, Ambiental e de Trafego. A priorizacao foi aplicada a vinte e tres trechos de rodovias diferentes do estado da Paraiba, com o objetivo de avaliar as varias oticas do tomador de decisao: estritamente tecnica; razao beneficio/custo; e construcao sustentavel. O cenario que levou em consideracao a construcao sustentavel priorizou trechos de rodovias onde as populacoes tinham maiores necessidades de desenvolvimento social e que pouco interferem nas caracteristicas ambientais da localidade.