| Title |
Upcycled Polypropylene and Polytrimethylene Terephthalate Carpet Waste in Reinforcing Cementitious Composites |
| ID_Doc |
19208 |
| Authors |
Tran, NP; Gunasekara, C; Law, DW; Houshyar, S; Setunge, S |
| Title |
Upcycled Polypropylene and Polytrimethylene Terephthalate Carpet Waste in Reinforcing Cementitious Composites |
| Year |
2022 |
| Published |
Aci Materials Journal, 119.0, 4 |
| DOI |
10.14359/51734688 |
| Abstract |
In this study, carpet waste fibers-namely, polypropylene (PP) and polytrimethylene terephthalate (PTT) in the form of mono microfibers and lrybrid combinations-were studied. The optimization of mono fiber parameters for fiber content (0.1, 0.3, and 0.5%) and length (6, 12 and 24 mm [0.236, 0.742, and 0.945 in.]) were conducted to achieve the optimum strength properties and minimize drying shrinkage. The microstructure, pore structure, and fiber-matrix interfacial properties of the optimized samples were characterized at 7, 28, and 90 days by means of scanning electron microscopy (SEM), X-ray micro-computed tomography (CT), and nanoindentation. The research data revealed that the inclusion of either the optimized mono PP fiber (v(f) = 0.5% and 1 = 12 mm [0.472 in.]) or PTT fiber (v(f) = 0.1% and 1 = 12 mm [0.472 in.]) improved the compressive strength of 4.3% and 16.1%, and theflexural strength by 11.5% and 9.2% at 28 days, respectively. Hybrid carpet fibers (0.4% PP + 0.1% PTT) provided a greater enhancement in compressive strength of 6.6%, and flexural strength by 13% at 28 days. Drying shrinkage mitigation of mortar over 120 days was recorded as 18.4, 22.3, and 25.8%, corresponding to the addition of 0.5% PP fibers, 0.1% PTT fibers, and hybrid PP/PTT carpet fibers. A pore-refuting e f fect was also observed for mortars with 0.5% PP and hybrid PP/PTT carpet microfibers. The SEM images indicated that the trilobal cross-sectional shape of PTT carpet fibers had a stronger anchoring effect with cement hydrates than the rounded shape of PP carpet fibers. Nanoindentation identified the thickness of the fiber-matrix interfacial transition zone (ITZ) as approximately 15 mu m (5.9 x 10(-4) in.) for both mono PP and PTT fibers. Approximately 50% of the phases in the vicinity of the fiber-matrix interface comprised a porous structure at 7 days. However, the hydration of clinker over the 90-day period promoted the formation of calcium-silicate-hydrate (C-S-H) and portlandite to form a dense microstructure. |
| Author Keywords |
carpet waste; hybrid fiber combination; microstructure; nanoindentation; recycled fiber; X-ray micro-computed tomography (CT) |
| Index Keywords |
Index Keywords |
| Document Type |
Other |
| Open Access |
Open Access |
| Source |
Science Citation Index Expanded (SCI-EXPANDED) |
| EID |
WOS:000843392400008 |
| WoS Category |
Construction & Building Technology; Materials Science, Multidisciplinary |
| Research Area |
Construction & Building Technology; Materials Science |
| PDF |
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