Journal article
Synergistic Effects of Nano-Montmorillonite and Polyethylene Microfiber in Foamed Paste with High Volume Fly Ash Binder
Journal of nanoscience and nanotechnology, Vol.19(8), pp.4465-4473
08/01/2019
Handle:
https://hdl.handle.net/2376/120581
PMID: 30913737
Abstract
Foamed cement-based materials have attracted much attention as a new type of thermal insulation materials (TIMs) that may offer a sustainable solution to the built environments. This laboratory study explores the combined use of nano-montmorillonite and polyethylene microfiber in foamed paste with high volume fly ash (HVFA) binder. A total of 16 foamed HVFA paste mixtures were fabricated which consisted of 70% Class F fly ash, 30% Portland cement, 2% sodium alpha-olefin sulfonate, 0.38% Na₃PO₄, and 2% nano-montmorillonite. The dosage and type of polyethylene microfibers (90
m in diameter) were explored in the present study, with six dosages (0, 0.1%, 0.2%, 0.3%, 0.4%, 0.5% by volume) and three lengths (3 mm, 6 mm, and 9 mm) tested. Based on the experimental results, the highest 28-day rupture strength (1.51 MPa) was achieved with the use of 3-mm long PE microfibers at 0.4 vol.%. Synergistic utilization of nMMT and microfibers exhibited a great influence on the dry density and water absorption of the foamed paste. The SEM micrographs illustrated the multiple mechanisms by which the microfibers serve to reduce shrinkage-induced cracking of the foamed paste. Energy-dispersive X-ray spectroscopy was employed to obtain the contents of Ca, Si, Al, S and mole ratios of Ca/Si, Ca/(Si + Al), S/Ca, and Al/Si in the hardened pastes, which reveal the difference in hydration products near or away from the nMMT-pretreated polyethylene microfibers. The results of microhardness test were also used to elucidate such nano-/micro-synergistic effects, which improved the bonding between microfibers and foamed paste matrix. A mechanism was proposed to explain the role of various admixtures and the balanced performance of such inorganic TIMs.
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Details
- Title
- Synergistic Effects of Nano-Montmorillonite and Polyethylene Microfiber in Foamed Paste with High Volume Fly Ash Binder
- Creators
- Jing Gong - School of Civil Engineering and Architecture, Wuhan Polytechnic University, Wuhan 430023, ChinaZhipeng Li - School of Civil Engineering and Architecture, Wuhan Polytechnic University, Wuhan 430023, ChinaRongtang Zhang - School of Civil Engineering and Architecture, Wuhan Polytechnic University, Wuhan 430023, ChinaJianfen Li - School of Chemical Engineering and Environment, Wuhan Polytechnic University, Wuhan 430023, ChinaXianming Shi - Laboratory for Advanced & Sustainable Cementitious Materials, Department of Civil and Environmental Engineering, Washington State University, Pullman, WA 99164, USA
- Publication Details
- Journal of nanoscience and nanotechnology, Vol.19(8), pp.4465-4473
- Academic Unit
- Civil and Environmental Engineering, Department of
- Identifiers
- 99900612703601842
- Language
- English
- Resource Type
- Journal article