Physical Properties and Environmental Impact of Sound Barrier Materials Based on Fly Ash Cenosphere

Hui Xie,Ercan Kahya,Yajing Li,Xiyun Ge,Bo Wang,Guanda Li

doi:10.3390/buildings12030322

Abstract

Traffic noise and solid waste pollution are two major problems that restrict urban development and affect urban environments. In this study, a new kind of cement-based material for sound barriers was prepared using industrial waste fly ash cenosphere to explore the material ratio of the sound absorption, sound insulation, and composite layers and to optimize the material’s properties. The research findings showed that the compressive strength had significant effects on the material properties of the sound absorption layer, with the optimal compressive strength range being 0.2–0.4 MPa. At 0.4 MPa, the material with an aggregate-to-binder ratio of 1.0 had the best comprehensive properties. The sound insulation layer had the best compressive strength of 29.00 MPa at a 45% fiber admixture. The composite had the best sound insulation when the thickness ratio of the sound absorption and insulation layers was 60:40, and the sound transmission loss was 38 dB. The embodied carbon (EC) and embodied energy (EE) of the new fly ash cenosphere across the whole life cycle were 57.57 kgCO2e and 477.08 MJ, respectively, which were 4.8−52.9% and 53.2−82.3% lower than other traditional sound barriers, respectively. Thus, they were environmentally friendly and had satisfactory energy-saving and environmental protection values.

Highlights

Under the challenge and objective of global carbon neutrality, this study aimed to develop a new type of cement-based composite material suitable for road sound barriers by utilizing industrial solid wastes such as fly ash cenosphere and waste glass fibers to further broaden the associated recycling methods and types of solid wastes and promote sustainable and greener development of the building material industry
Buildings 2022, 12, 322 where P refers to the open pore ratio of the specimen (%), W1 refers to the mass of the specimen under absolute dry conditions (g), W2 refers to the mass of the specimen with a surface under absolute dry conditions (g), V refers to the volume of the specimen, and ρw refers to the density of the water (g/cm3)
The compressive strength test of the fly ash cenosphere cement-based materials was carried out according to GB/T 50081-2019 Standard for Test Methods of Concrete Physical and Mechanical Properties

Summary

Introduction

With the rapid development of urbanization, the acoustic environment has been confronted with increasingly prominent quality problems and has attracted much attention [1,2]. In 2020, the competent authorities in Chinese cities received a total of 2.018 million complaints and reports on environmental noise, accounting for 41.2% of all of the reports on environmental pollution [3]. Traffic noise has affected the living quality and lifestyle of nearby residents for a long time [4–6], and the parameters affecting its emission are many [7]. Aside from the engines and flow composition, the acoustic impedance [8,9], tire model [10], pavement aging [11], pavement texture [12,13], and mixture [14,15] are all important parameters. According to many years of practice across the world, scientifically designing and planning noise reduction facilities such as sound barriers has the most remarkable effect on noise reduction and absorption [16–18]. The noise reduction of the “sound shadow area” can reach 5–15 dB, offering a flexible and controllable protection range, being easy to maintain [19–21]

Objectives

Methods

Results

Conclusion