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. 2020 Oct 6;12(10):2287.
doi: 10.3390/polym12102287.

Mechanical Properties of Coal Ash Particle-Reinforced Recycled Plastic-Based Composites for Sustainable Railway Sleepers

Suhawn Ju  1 , Jinyoung Yoon  2 , Deokyong Sung  3 , Sukhoon Pyo  1
Affiliations

Mechanical Properties of Coal Ash Particle-Reinforced Recycled Plastic-Based Composites for Sustainable Railway Sleepers

Suhawn Ju et al. Polymers (Basel). .

Abstract

This experimental research investigates the mechanical properties of municipal plastic waste-based particulate composites reinforced with coal ash (CA), the by-product of thermal power plants, for sustainable railway sleepers. Six series of sustainable composites filled with inorganic mineral fillers, including CA, were prepared by a twin-screw extruder and a compression molding machine. The effect of mix design variables-such as filler type, contents and the particle size of the filler-on mechanical properties-including tensile, compression and flexural properties-and morphology were characterized. The scanning electron microscopy (SEM) was employed to examine the morphology of the composites, which revealed the uniform dispersion of fillers in the polymer matrix. The study results conclude that the recycled plastic-based composite with the addition of CA up to 60% is suitable for railway sleeper applications. This experimental study may provide new insight into the railway applications of the developed composites under service loading conditions including traffic loading and earthquake.

Keywords: coal ash; mechanical properties; morphology; municipal plastic waste; railway sleeper.

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Conflict of interest statement

The authors declare no conflict of interest.

Figures

Figure 1
Figure 1
Recycling process of municipal plastic waste (MPW).
Figure 2
Figure 2
Pelletized raw materials: (a) MPW, (b) recycled high-density polyethylene (RHDPE), (c) calcium carbonate (CaCO3) calpet filler (CCF) and (d) antistatic agent.
Figure 3
Figure 3
Images of fillers: (a) coal ash (CA) I, (b) CA II, (c) CA III and (d) slag aggregates.
Figure 3
Figure 3
Images of fillers: (a) coal ash (CA) I, (b) CA II, (c) CA III and (d) slag aggregates.
Figure 4
Figure 4
TGA results of raw plastic materials.
Figure 5
Figure 5
X-ray diffraction patterns for fillers: (a) CA I, (b) CA II and (c) CA III (M: mullite, Q: quartz, H: hematite, A: anorthite).
Figure 6
Figure 6
Particle size distribution of fillers (CA and slag aggregates).
Figure 7
Figure 7
Mechanical responses of particulate composites: (a) tensile stress–strain relationships, (b) compressive stress–strain relationships and (c) flexural stress–displacement relationships.
Figure 7
Figure 7
Mechanical responses of particulate composites: (a) tensile stress–strain relationships, (b) compressive stress–strain relationships and (c) flexural stress–displacement relationships.
Figure 8
Figure 8
Examples of tested specimens: (a) tensile test, (b) compressive test and (c) flexural test.
Figure 9
Figure 9
SEM images of the fractured surface (a) #1 and (b) #6.
See this image and copyright information in PMC

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