USING NANOCLAY HYDROPHILIC BENTONITE AS A FILLER TO ENHANCE THE MECHANICAL PROPERTIES OF ASPHALT

Wail Asim Mohammad Hussain,Abdulrasool Thamer Abdulrasool,Yasir N Kadhim

doi:10.5937/jaes20-35111

Wail Asim Mohammad Hussain, Abdulrasool Thamer Abdulrasool + Show 1 more

Open Access

https://doi.org/10.5937/jaes20-35111

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Abstract

Higher traffic loads on the wheels, increased traffic volumes, and exposure to changing weather conditions result in increasing the road stresses and strains, putting the paving layers in danger of degradation such as fatigue, stripping, cracking, and rutting. A tremendous number of studies and trials have been conducted to modify asphalt to have a longer service life, less maintenance, be cheaper, and be more environmentally friendly. Recently, nanotechnology has proven very beneficial in all industries, including asphalt. It can be used to enhance the asphalt's mechanical properties. Using nano clay in asphalt is expected to improve the mechanical properties and the service life of the asphalt. So the main objective of this study is to investigate the performance of nano clay hydrophilic bentonite in improving the physical characteristics of asphalt concrete. This study uses nano clay with various replacement ratios as fillers to the ordinary used limestone filler in asphalt concrete. The used replacement percentages were (0%, 20%, 40%, 60%, 80%, and 100). The experimental tests that were conducted in this study include Marshall Stability (MS), Marshall Flow (MF), voids in mineral aggregate (VMA), theoretical maximum specific gravity (Gmm) and air voids (AV).The results showed a noticeable enhansment in the behavior of the asphalt mix with increasing the replacement percentage by nanoclay. Also, it was found that the 60% replacement rate by nanoclay has the highest Marshall stability with an increase of 93%, also the lowest flow with a decrease of 25% compared to the control asphalt mix.

Highlights

A huge amount of asphalt is produced annually all over the world for construction projects
The mechanical tests that were conducted in this study are including Marshall Stability (MS), Marshall Flow (MF), Voids in Mineral Aggregates (VMA), Voids Filled with Asphalt (VFA), Air Voids (VA), and Theoretical maximum specific gravity (Gmm)
There is a positive relationship between the GMM values and the percentage of the nanoclay filler in the asphalt mix

Summary

Introduction

A huge amount of asphalt is produced annually all over the world for construction projects. Due to the particle size of Nano materials, which ranges between 1 to100 nm, the resulting surface area is a lot more than the surface area of the particles of the same material on a micro scale This leads to increased functional density, high sensitivity, special surface effects, large surface area, high strain resistance, and catalytic effects (Yang and Tighe 2013). Razavi and Kavussi (2020) Razavi and Kavussi (2020) suggested to use nano hydrated lime as replacement of the conventional filler in order to increase the bitumen resistance to water Because of their abundance in nature, low cost of manufacturing, and tiny amounts required for asphalt modification, researchers have lately proposed the use of nanoclays (NC) as asphalt modifiers (Crucho et al 2019). According to Abdelrahman et al (2014), the addition of nanoclay to asphalt caused significant changes in the physical behavior and nature of asphalt, which appear to be the consequence of molecular interactions between asphalt and nanoclay, and it has enormous potential to alter the properties of asphalt

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