Study on the Performances of Waste Crumb Rubber Modified Asphalt Mixture with Eco-Friendly Diatomite and Basalt Fiber

Wang Wang,Cheng Cheng,Tan Tan,Chen Chen,Lv Lv,Bai Bai

doi:10.3390/su11195282

Abstract

A sustainable and environmentally friendly society is developing rapidly, in which pavement engineering is an essential part. Therefore, more attention has been paid toward waste utilization and urban noise pollution in road construction. The object of this study was not only to investigate the mix proportion of waste crumb modified asphalt mixtures with diatomite and basalt fiber but also to evaluate the comprehensive performances including sound and vibration absorption of modified asphalt mixtures. Firstly, the mix proportion scheme was designed based on Marshall indices and sound and vibration absorption properties according to the orthogonal experimental method. Considering the specification requirements, as well as better performances, the optimal mix proportion was determined as follows: diatomite content at 7.5%, basalt fiber content at 0.3%, and asphalt-aggregate ratio at 5.5%. The range and variance analysis results indicated that asphalt-aggregate ratio has the most significant influence on volumetric parameters, diatomite has the most significant influence on sound absorption, and basalt fiber has the most significant influence on vibration reduction. Furthermore, the conventional pavement performances and sustainable sound and vibration absorption performances of modified asphalt mixtures were also analyzed. The results showed that the performances of modified asphalt mixtures were improved to different extents compared to the base asphalt mixture. This may be attributed to the microporous structure property of diatomite and the spatial network structure formed by basalt fibers. The pavement as well as sound and vibration absorption performances of the waste crumb modified asphalt mixture with diatomite and basalt fiber would be a good guidance for asphalt pavement design.

Highlights

Modern pavements need to satisfy the mechanical performances but they need meet the requirements of service performances in regard to security, smoothness, comfortable driving, and environmental effects according to different traffic environments
The range method was used to calculate the range (R) of each index, and the relationship trend between design indices and factor levels was plotted for the orthogonal experiment to determine the order and the optimal mix proportion of the three factors, i.e., the diatomite content, basalt fiber content, and asphalt-aggregate ratio
The vibration reduction of the diatomite and basalt fiber com0p.o04site modified asphalt mixture improv0e.d09, and the damping ratio (DR) improved by 10.9% compared with the base asphalt mixture, D R

Summary

Introduction

Modern pavements need to satisfy the mechanical performances but they need meet the requirements of service performances in regard to security, smoothness, comfortable driving, and environmental effects according to different traffic environments. In order to improve the physical and mechanical properties of asphalt mixtures, adding modifiers to asphalt has gradually become the focus of research and is a commonly used method [3,4]. Due to the urgent need for waste recycling, crumb rubber as one early used modifier is widely used in asphalt to improve the performances of asphalt mixtures [8,9]. La Rosa et al [10] used life cycle assessment to study the effect of styrene-isoprene-styrene by adding ground end-of-life tire rubber. Based on a large number of previous studies, crumb rubber has been proven as a very effective modifier for asphalt, and it has many advantages such as high- and low-temperature anti-deformation, noise absorption, moisture stability, and so on [13]

Objectives

Results

Conclusion