Thesis
Use of recycled glass fiber reinforced polymer in mortar and tailoring of transition zones with nanomaterials
Washington State University
Master of Science (MS), Washington State University
08/2020
DOI:
https://doi.org/10.7273/000004253
Handle:
https://hdl.handle.net/2376/124911
Abstract
Recycling and reuse of end-of-life products containing Glass Fiber Reinforced Polymer (GFRP) is a challenge due to heterogeneous and thermoset nature. In this study, GFRP shreds mechanically processed from post-service wind turbine blades were used in two sizes, small (width o.42~0.841mm) and large (width>2.38mm), as discrete reinforcement in mortar. The mechanical performance of fiber-reinforced concrete relies on both fiber properties and matrix characteristics, as well as the interaction between fiber and matrix. To evaluate these interactions, performance of two mortar systems with low paste (LP) and high paste (HP) was evaluated using small and large GFRP load concentrations of 1, 2 and 3% volume replacement of fine aggregate in terms of compressive strength (f'c), modulus of rupture (MR), and fracture toughness energy. GFRP improved f'c by 21% for LP mix and 12% for HP mix for mortar with 3% small GFRP. GFRP also enhanced 𝑀𝑅 by up to 29% and increased toughness up to 4.8 times for the HP mix. Large GFRP showed up to 1.8 times increase in toughness compared to small GFRP shreds. In the second phase, microfillers (fly ash and silica fume), nano-silica (nSiO2), and cellulose nanofiber (CNF) in different concentrations individually and jointly were used to optimize the GFRP-mortar matrix interfacial packing density and strength to promote more frictional bond. Though fly ash decreased 28-day f'c, it improved flexural strength and toughness parameters compared to specimen with 3% GFRP. Silica fume improved f'c and toughness and residual strengths with a slight decrease in 𝑀𝑅. Compressive strength (f'c) for nSiO2 mortar showed scattered results, which may have resulted from inconsistent dispersion. Flexural strength parameters, MR, peak strength, and toughness, increased for 0.25%, 0.5%, and 1% nSiO2, whereas 2% nSiO2 showed significant decrease. Both 0.25% and 0.5% CNF, when used alone, increased f'c, peak strength, toughness, and residual strengths compared to the control. Nano silica and CNF jointly performed better compared to individual use of nSiO2 and CNF likely due to the dispersion effect of CNF with anionic surface charge and crack-bridging effect of CNF with large aspect ratio.
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Details
- Title
- Use of recycled glass fiber reinforced polymer in mortar and tailoring of transition zones with nanomaterials
- Creators
- Md Mostafa Haider
- Contributors
- SOMAYEH NASSIRI (Advisor) - Washington State University, Civil and Environmental Engineering, Department of
- Awarding Institution
- Washington State University
- Academic Unit
- Civil and Environmental Engineering, Department of
- Theses and Dissertations
- Master of Science (MS), Washington State University
- Publisher
- Washington State University
- Identifiers
- 99900896417601842
- Language
- English
- Resource Type
- Thesis