Effect of Temperature Fluctuations on the Bearing Capacity of Cold In-Depth Recycled Pavements

Andreas Loizos,Vasilis Papavasiliou

doi:10.3390/su14010426

Abstract

This study investigates the influence of the temperature fluctuations on the bearing capacity of cold in-depth recycled (CIR) pavements stabilized with foamed asphalt (FA). Aiming to achieve this goal, non-destructive testing was conducted during mild and high temperatures on a highway CIR pavement, utilizing mainly the FWD device. The back-calculated moduli values were utilized to estimate the strain values within the body of the pavement, while the strains induced using the FWD device were measured with a fiber optic sensors (FOS) system. Moreover, data from the fatigue behavior of the layer materials was also considered. The results of the related analysis indicate that for every 1 °C temperature increase within the body of the AC overlay, an approximately 5.7% increase of the critical tensile strain is expected. Moreover, for every 1 °C temperature increase within the body of the FA layer, an approximately 1.8% increase of the tensile strain at the bottom of the FA layer is expected. The new constructed layers, i.e., asphalt concrete (AC) and FA, sustain much more damage at high temperatures. This was more evident in the upper layer, i.e., the AC overlay.

Highlights

Aiming to reduce energy requirements, emissions, and environmental impact, multiple low-energy technologies have been introduced, focusing on constructing/rehabilitating sustainable pavements.The definition of a “sustainable” pavement is not unique considering that each project has different characteristics, such as available local materials, climate conditions, etc
Using the fatigue laws presented in Equations (2) and (3), the cycles to failure were calculated for the foamed asphalt (FA) and asphalt concrete (AC) materials, respectively
The present research aims to investigate the influence of pavement temperature variations on the bearing capacity of foamed asphalt cold in-depth recycled (CIR) pavements and to the sustainability of the aforementioned CIR technique

Summary

Introduction

Aiming to reduce energy requirements, emissions, and environmental impact, multiple low-energy technologies have been introduced, focusing on constructing/rehabilitating sustainable pavements. Information concerning the earlylife performance of CIR heavily trafficked pavements with FA using non-destructive tests (NDTs) as well as laboratory estimated fatigue characteristics of the FA and asphalt concrete (AC) materials has been published, among others, in [12]. The temperature susceptibility of the FA materials has been evaluated in the laboratory and in situ [5,13,14], indicating that the FA modulus is less sensitive to temperature changes in comparison to a typical, dense-graded AC mixture This finding does not provide information concerning the influence of pavement temperature on the field performance of CIR pavements using FA with a relatively thick AC overlay. More field data information is necessary to investigate potential changes of the structural adequacy of these pavements and the sustainability of the aforementioned CIR technique due to pavement temperature variations. The main findings and conclusions of the data analysis are presented and discussed in the present study

Foamed Asphalt Mix Design

Data Collection

Back-Analysis

Calculation of Strains

Fatigue Characteristics and Analysis

Fatigue Characteristics of AC Overlay Material

Fatigue Analysis Results

Conclusions