Recycling polyethylene terephthalate wastes as short fibers in Strain-Hardening Cementitious Composites (SHCC)

Xiuyi Lin; Jing Yu; Hedong Li; Jeffery Y K Lam; Kaimin Shih; Ivan M L Sham; Christopher K Y Leung

doi:10.1016/j.jhazmat.2018.05.046

Recycling polyethylene terephthalate wastes as short fibers in Strain-Hardening Cementitious Composites (SHCC)

J Hazard Mater. 2018 Sep 5:357:40-52. doi: 10.1016/j.jhazmat.2018.05.046. Epub 2018 May 26.

Authors

Xiuyi Lin¹, Jing Yu², Hedong Li³, Jeffery Y K Lam⁴, Kaimin Shih⁵, Ivan M L Sham⁶, Christopher K Y Leung⁷

Affiliations

¹ Nano and Advanced Materials Institute, Hong Kong Science Park, Shatin, Hong Kong, China; Department of Applied Physics, The Hong Kong Polytechnic University, Hung Hom, Hong Kong, China. Electronic address: xylin@polyu.edu.hk.
² Department of Civil and Environmental Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China. Electronic address: jyuad@connect.ust.hk.
³ Nano and Advanced Materials Institute, Hong Kong Science Park, Shatin, Hong Kong, China; School of Civil Engineering and Architecture, Zhejiang Sci-Tech University, Hangzhou 310018, China. Electronic address: lihedong@zstu.edu.cn.
⁴ Nano and Advanced Materials Institute, Hong Kong Science Park, Shatin, Hong Kong, China. Electronic address: jefferylam@nami.org.hk.
⁵ Department of Civil Engineering, The University of Hong Kong, Pokfulam, Hong Kong, China. Electronic address: kshih@hku.hk.
⁶ Nano and Advanced Materials Institute, Hong Kong Science Park, Shatin, Hong Kong, China. Electronic address: ivansham@nami.org.hk.
⁷ Department of Civil and Environmental Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China. Electronic address: ckleung@ust.hk.

PMID: 29860104
DOI: 10.1016/j.jhazmat.2018.05.046

Abstract

As an important portion of the total plastic waste bulk but lack of reuse and recycling, the enormous amounts of polyethylene terephthalate (PET) solid wastes have led to serious environmental issues. This study explores the feasibility of recycling PET solid wastes as short fibers in Strain-Hardening Cementitious Composites (SHCCs), which exhibit strain-hardening and multiple cracking under tension, and therefore have clear advantages over conventional concrete for many construction applications. Based on micromechanical modeling, fiber dispersion and alkali resistance, the size of recycled PET fibers was first determined. Then the hydrophobic PET surface was treated with NaOH solution followed by a silane coupling agent to achieve the dual purpose of improving the fiber/matrix interfacial frictional bond (from 0.64 MPa to 0.80 MPa) and enhancing the alkali resistance for applications in alkaline cementitious environment. With surface treatment, recycling PET wastes as fibers in SHCCs is a promising approach to significantly reduce the material cost of SHCCs while disposing hazardous PET wastes in construction industry.

Keywords: Fiber surface treatment; Micromechanical modeling; Polyethylene terephthalate; Solid wastes recycling; Strain-Hardening Cementitious Composite.