Correlation Between Aggregate to Aggregate Contact and Mechanical Properties of HMA Mixture

Mahmod Reza Keymanesh,Hassan Ziari,Danial Kamrankho,Ali Nasrollahtabar

doi:10.5121/civej.2016.3303

Abstract

The mechanical properties of hot mix asphalt (HMA) mixture are directly related to the internal structure. Earlier studies have suggested that aggregate-to-aggregate contact maybe a significant contributor to the mechanical properties of HMA mixes. In this study, the mechanical properties of HMA mixture, quantified by Marshall Stability, Flow and Marshall Quotient, were related to the internal structure in terms of aggregate-to-aggregate contact. For development of a model, field core samples were taken from Binder and Topeka layers at different sites. A total of 21 different HMA mixes were obtained. An advanced 2-dimensional Image Processing and Analysis System (i.e., iPas) was used to characterize the internal structure of the cores. The test results indicated that there is a strong correlation between aggregate-to-aggregate contact and mechanical properties of HMA mixture. This is an indication that aggregate-to-aggregate contactis a significant contributor to the mechanical properties of asphalt concrete .

Highlights

The mechanical properties of hot mix asphalt (HMA) mixture are directly related to the internal structure indentified by air void distribution, aggregate orientation, and aggregate contact
The test results indicated that there is a strong correlation between aggregate-to-aggregate contact and mechanical properties of HMA mixture
The effects of aggregate-to-aggregate contact on the mechanical properties of HMA mixture are presented in terms of Marshall Stability, Flow, and Marshall Quotient (MQ)

Summary

Introduction

The mechanical properties of HMA mixture are directly related to the internal structure indentified by air void distribution, aggregate orientation, and aggregate contact. Once an internal structure image is obtained, image processing is required to enhance the quality of the image and allow a clear definition of the image components (air voids, mastic, and coarse aggregates).The last step is to analyze the processed image to obtain meaningful parameters that describe the internal structure of the mix. Parameters such as aggregate size distribution, aggregate orientation, aggregate segregation, aggregate contact points, and air void distribution highlight the main parameters that can be obtained from such analyses

Objectives

Methods

Results

Conclusion