Análise de sobrevivência aplicada ao ensaio uniaxial de carga repetida em concreto asfáltico

Abstract

Survival analysis is a widely used statistical technique in various fields, particularly in studies involving the time until the occurrence of an event of interest, such as failures, mortality, or material degradation. In asphalt pavement engineering, understanding the durability and performance of mixtures is crucial for predicting service life and defining effective maintenance strategies. In this context, survival analysis emerges as a powerful tool for modeling the time to failure of asphalt mixtures, allowing not only the estimation of durability but also the comparison between different formulations and treatments. This study focuses on applying the Kaplan-Meier estimator and the Cox proportional hazards model in the survival analysis of asphalt mixtures. The Kaplan-Meier estimator is a non-parametric technique that enables the construction of a survival curve, providing a graphical representation of survival probability over time. The Cox model, a semi-parametric method, allows for the inclusion of covariates, facilitating the evaluation of different factors, such as binder type and aggregate gradation, on mixture durability. The results confirmed the potential of these techniques in assessing the resistance of asphalt mixtures to permanent deformation. The Cox model proved to be an essential tool for identifying the most influential factors in mixture durability, highlighting that rotational viscosity and binder content significantly impact mechanical performance. The comparative analysis revealed a strong correlation between gradation parameters, such as the Fine Aggregate Fraction (FAF), and the resistance to deformation of asphalt mixtures. The findings emphasize that a careful selection of components, combined with strict control over production and application, can maximize pavement lifespan, reduce maintenance costs, and improve structural efficiency. This study contributes to developing more robust methodologies for assessing mixture performance, enabling the design of more durable and cost-effective pavements. Permanent deformation, a common failure in the early life of pavements, is stronglyrelated to mixture gradation, a factor often underestimated in the mix design stage. Therefore,this study proposes a method to evaluate gradation and its impact on mixture resistance, contributing to more effective and durable formulations.