Journal article
Nano-montmorillonite modified foamed paste with a high volume fly ash binder
RSC advances, Vol.7(16), pp.9803-9812
2017
Handle:
https://hdl.handle.net/2376/124256
Abstract
This laboratory study explores a cost-effective and environmental friendly foamed paste with satisfactory physical properties and outstanding thermal insulation properties. Such a composite material was made by using a high volume of class F coal fly ash as a replacement of Portland cement (70% by mass) and nano-montmorillonite as an admixture. Replacing cement with fly ash at high levels is environmentally and economically desirable, as this not only reduces the energy and carbon footprint of the foamed paste, but also diverts the coal fly ash from the waste stream. A statistical design of experiments was adopted and executed to investigate the effects of various factors on the properties of the composite. At the age of 28 days, the pastes exhibited a high compressive strength ranging from 1.77 MPa to 6.51 MPa and a low thermal conductivity in the range of 0.071 W (m−1 K−1) to 0.173 W (m−1 K−1). Two foamed mixes were chosen for further investigation as they presented the best and worst performance as a thermal insulation material. The scanning electron microscopy shed light on the best foamed mix, which contains 70% fly ash, 30% cement, and 1% nano-montmorillonite, and how its microstructure differed from that of the worst mix without nano-montmorillonite. The Ca content, Si/Ca ratio and Al/Ca ratio were obtained from energy-dispersive X-ray spectroscopy of hardened samples, and used to help explain the observed strength difference between these two mixes. X-ray diffraction was also employed to elucidate the hydration mechanism of HVFC foamed paste.
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Details
- Title
- Nano-montmorillonite modified foamed paste with a high volume fly ash binder
- Creators
- Zhipeng Li - School of Civil Engineering and Architecture, Wuhan Polytechnic University, Wuhan 430023, ChinaJing Gong - School of Civil Engineering and Architecture, Wuhan Polytechnic University, Wuhan 430023, China, College of Urban ConstructionSen Du - Laboratory for Advanced & Sustainable Cementitious Materials, Department of Civil and Environmental Engineering, Washington State University, Pullman, USAJianlin Wu - School of Civil Engineering and Architecture, Wuhan Polytechnic University, Wuhan 430023, ChinaJianfen Li - School of Chemical Engineering and Environment, Wuhan Polytechnic University, Wuhan 430023, ChinaDaniel Hoffman - Laboratory for Advanced & Sustainable Cementitious Materials, Department of Civil and Environmental Engineering, Washington State University, Pullman, USAXianming Shi - School of Civil Engineering and Architecture, Wuhan Polytechnic University, Wuhan 430023, China, Laboratory for Advanced & Sustainable Cementitious Materials
- Publication Details
- RSC advances, Vol.7(16), pp.9803-9812
- Academic Unit
- Civil and Environmental Engineering, Department of
- Identifiers
- 99900612702601842
- Language
- English
- Resource Type
- Journal article