Implantação, acompanhamento e análise de desempenho de trechos monitorados em Santa Maria – RS

Abstract

Highways have high economic and social importance in the state of Rio Grande do Sul because is through them that most production and people dislocate daily to different regions. The most common solution in construction and restoration of highways are flexible pavements with surface layer formed by asphalt concrete. The knowledge about mechanical behavior of these asphalt mixtures in field and in laboratory is very important to design and specifications of the structure layers. Thus, this research monitored in field the behavior of five test sites in the city of Santa Maria – RS. They are nominated as Roraima Avenue, Hélvio Basso Avenue, BR 158 – Trevo dos Quartéis, ERS 509 – Faixa Velha and ERS 509 – Viaduto. Besides, the execution of the last site constructed was supervised (ERS 509 – Viaduto), and were made mechanical tests, backcalculation with BAKFAA software and design with LVECD software. Also, traffic control quantitative and classificatory were made every six months, aiming to calculate de number of equivalent axle load to each experimental site and then relate with the site tests and develop predictive models. These models were developed to each experimental site, except ERS 509 – Viaduto, once that are not enough data to provide an adequate analysis. The tests conducted in the field were: sand patch method, British pendulum test, laser profilometer, rutting, cracked area, Benkelman beam and Falling Weight Deflectometer (FWD). In the laboratory were made the following tests: resilient modulus, fatigue by indirect tensile stress test, complex modulus, uniaxial repeated load, direct tension-compression fatigue test. The site tests showed the bad condition of the pavement in BR 158 – Trevo dos Quartéis in the land with higher load, with 99.2% of cracked area. The laboratory tests pointed an influence of the binder type related to rutting deformation and the accumulated damage level of fatigue. In general, the results of rutting deformation were low and the mixture with rubberized binder presented the highest value between them, highlighting its good behavior to rutting. The mixtures with rubberized binder presented better results to fatigue than conventional mixtures. With the design of LVECD software it was possible to find an good result to experimental site ERS 509 – Viaduto, showing that cracked area will not be higher than 30% by the time of 15 years. Finally, is noted that a good pavement management must exist so that laboratory and field could relate, once that many times laboratory tests do not predict the lifetime of pavement because of poor execution.