Avaliação estrutural de trechos de rodovias na Paraíba a partir de ensaios in situ e retroanálise.

Abstract

In the structural assessment of pavements, fundamental for the effective management of highways, software is used to perform retroanalysis based on deflection measurements carried out with equipment such as Falling Weight Deflectometer (FWD) with the aim of estimating the resilience modules (MR) of the layers of pavement. Currently, the Benkelman beam is used in Brazil because it is a simple, economically accessible and widespread equipment, however, most retroanalysis programs only use measurements carried out with the FWD, including BackMeDiNa. Given this situation, this work aimed to carry out a comparative analysis between retro-analyzed resilience modules, obtained from the use of the Benkelman beam, with those obtained in the laboratory from samples extracted as a way of verifying the effectiveness of these retro-analyses for this type of equipment. in specific. Data obtained through structural assessments of two road sections located in the state of Paraíba were used, with non-destructive, semi-destructive and destructive tests using a mechanistic-empirical approach. With the samples collected in the field, resilience modulus tests were carried out on the asphalt mixture, base and sub-base layers of the sections studied. The deflectometric basins had their parameters calculated and were used as input data in two retroanalysis software: BackMeDiNa and BAKFAA. The relationships between the back-analyzed resilience modules and the maximum deflections were also studied, and finally, the fatigue life and the increase in permanent deformation were estimated, with the aid of MeDiNa to analyze the evolution of the structural behavior of the pavements under study. In relation to the results obtained with the retroanalysis, BAKFAA generated smaller mean squared errors (RMS) when compared to BackMeDiNa, indicating that the calculated basins are closer to those measured in the field, in addition, the modules were smaller and closer to the modules of resilience obtained in the laboratory, with differences ranging from 0.28% to 31.65%. Regarding the regression models, strong and significant correlations were obtained, where higher deflection values reflected in lower resilience modules. The parameters of the deflectometric basin corroborate the behavior found in the field and the modulus values. For the useful life of the pavements estimated by MeDiNa, values were found close to the data collected over the three years of monitoring. Therefore, even using the Benkelman beam, it was possible to obtain close results between the retroanalyzed modules and those obtained in situ, satisfactory correlations, highlighting it as a good tool for the retro-analysis procedure.