Los efectos de la forma de la onda de carga en la estimación de la vida a la fatiga de la capa asfáltica en la estructura del pavimento

M Gaertner,J Staub De Melo,J Villena

doi:10.4067/s0718-50732019000200136

Abstract

The phenomenon of fatigue can be considered as one of the main causes of the asphalt surface course failure. The Four Point Bending Apparatus is the widespread equipment used to determine the fatigue resistance of asphalt mixtures. Worldwide there are several standard procedures that rule this test. The main difference between them remains in the waveform, in which the load is applied, and in the failure criteria. This paper reports the influence from the waveform, haversine or sinusoidal, on the fatigue resistance of an asphalt mixture. In addition, through numerical simulation, it was evaluated the influence of the models obtained in the design of the thickness of the asphalt layer required for the structure of a pavement. The conclusion is that the use of haversine waves in fatigue tests results in a fatigue life of the asphalt surface layer almost 67 times bigger than the ones found on sinusoidal tests

Highlights

There are different devices for estimating the fatigue characteristics of asphalt mixtures, among them, the four-point bending fatigue testing machine, which is one of the most used worldwide
We must be careful when comparing fatigue models obtained by standardized procedures using different loading waveforms, because there can be a great disparity of results, mainly when loads are applied for estimating fatigue cracking of asphalt layers in a pavement structure
This paper reports the results of a comparative study on the influence of haversine and sinusoidal waveforms on fatigue strength models of an asphalt mixture, and their consequences and impact on the estimated bending fatigue of the asphalt layer in flexible pavement structure

Summary

Introduction

There are different devices for estimating the fatigue characteristics of asphalt mixtures, among them, the four-point bending fatigue testing machine, which is one of the most used worldwide. In Europe, the test standardization is regulated by the standard (EN12697-242004), in Australia by (AG-PT/T233 2006) of the Austroads Guide, and in the USA by the standards (ASTM D7460 2010) and (AASHTO T321 2014). The standards’ differences are mainly related to the waveform loading and the failure criterion. The European procedure and the AASHTO US standard (American Association of State Highway and Transportation Officials) indicate the use of sinusoidal loading waveform. The Australian and ASTM US standard recommend the haversine loading waveforms

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Materials

3.Method

Results and Discussion