Cellulose Microfibril and Micronized Rubber Modified Asphalt Binder

Ang Li,Rahul Vallabh,Thomas Theyson,Abdu A Danladi,Umar Ishiaku,Abdel-Fattah M Seyam,Mohammed K Yakubu

doi:10.3390/fib9040025

Abstract

Cellulose microfibrils (CMFs) and micronized rubber powder (MRP) can be derived from low or negative-cost agricultural/industrial waste streams and offer environment-friendly and cost-effective pathways to develop engineering products. This study investigated the efficacy of adding these micromodifiers on the performance characteristics of asphalt binders. In this work, samples were produced using a mixture of slow-setting anionic asphalt emulsion with various combinations of MRP (at 0, 2 and 10 wt %) and four types of CMFs (hydrophobic and hydrophilic with crystalline ratios of 86% and 95%) at 0, 2 and 5 wt %. The performance of modified asphalt samples was assessed by penetration depth (PD), softening point (SP), and penetration index (PI). Linear regression analysis showed that adding CMFs and/or MRP reduced PD and increased SP values. The type of CMFs significantly affected the performance, which becomes more distinct with the increased weight content of CMFs. While hydrophilic CMFs caused increases in SP and PI values, no clear trend was seen to determine the effect of CMF crystallinity. It was also discovered that the combined addition of CMF and MRP achieved similar PI values at lower total weight content compared to using MRP alone.

Highlights

Increased traffic load combined with substantial temperature variations have been responsible for the asphalt pavement deterioration [1]
The objective of this work was to address the lack of research in this area by examining asphalt performance characteristics, such as softening point (SP), penetration depth (PD), and penetration index (PI)
The novelty of this research lies in the investigation of possible combined effect of using Cellulose microfibrils (CMFs) and micronized rubber powder (MRP) compared with the effect of adding either CMF or MRP alone

Summary

Introduction

Increased traffic load combined with substantial temperature variations have been responsible for the asphalt pavement deterioration [1]. Crumb rubbers have been claimed to improve the viscosity, rheological properties, rutting resistance and thermal cracking of asphalt binders [8]. It was found that the key properties of asphalt, such as penetration depth, softening point and ductility, improved with the addition of the waste fibers. Micronized rubber powder (MRP) made from discarded tires with new processing technology can be thoroughly cleaned and consistently sized to less than 100 μm It has the advantage of easy dispersion into many systems and applications, which may be more effective to be used modifying asphalt. Since most of the previous research on modified asphalt were conducted using synthetic and macroscale fibers, the utilization of microfibrils derived from agricultural waste to improve the asphalt properties is a potential alternative as well as a novel approach to realize more sustainable development

Materials

Asphalt Modifification

Findings

Penetration Index