A Study on Mechanical Characteristics of Cement Composites Fabricated with Nano-Silica and Carbon Nanotube

Autor: Baofeng Huang, Ali Raza, Manan Bhandari, Hyeong-Ki Kim, Hyeong-Min Son, I.W. Nam
Rok vydání: 2020
Předmět:
Thermogravimetric analysis
Materials science
Composite number
0211 other engineering and technologies
nano-silica
02 engineering and technology
Carbon nanotube
lcsh:Technology
law.invention
lcsh:Chemistry
chemistry.chemical_compound
Flexural strength
law
021105 building & construction
General Materials Science
carbon nanotube
cement composites
Composite material
Calcium silicate hydrate
Porosity
lcsh:QH301-705.5
Instrumentation
Fluid Flow and Transfer Processes
Cement
lcsh:T
Process Chemistry and Technology
General Engineering
mechanical strength
021001 nanoscience & nanotechnology
Microstructure
lcsh:QC1-999
Computer Science Applications
lcsh:Biology (General)
lcsh:QD1-999
chemistry
lcsh:TA1-2040
lcsh:Engineering (General). Civil engineering (General)
0210 nano-technology
thermal analysis
lcsh:Physics
Zdroj: Applied Sciences, Vol 11, Iss 152, p 152 (2021)
Applied Sciences
Volume 11
Issue 1
ISSN: 2076-3417
DOI: 10.3390/app11010152
Popis: In this study, cement composites were fabricated with various contents of added nano-silica (NS) and multi-walled carbon nanotubes (MWNTs). The compressive and flexural strengths of the resultant cement composites were examined. To explore the microstructures and MWNT distribution, electrical conductivity tests, and scanning electron microscopy were conducted. In addition, the strength results were analyzed based on thermal analysis and porosity evaluations. The electrical conductivity results indicated that MWNTs were satisfactorily distributed in the cement composites. In the mechanical strength tests, the composite with a 0.6% MWNT and 5% NS content and another with a 0.3% MWNT and 5% NS content yielded enhancements in the compressive and flexural strengths of 17.2% and 52% compared with the control samples, respectively. However, composites containing relatively large amounts of both NS and MWNTs showed degradation in the mechanical strength. The enhancement or degradation of the strength was supported by porosity evaluations and thermal analysis results. In particular, the degradation of the strength due to the incorporation of large amounts of both MWNTs and NS was explained by thermogravimetric analysis, which indicated a limited generation of calcium silicate hydrate (C-S-H) hydration products. The lower generation of C-S-H was likely due to the dense microstructure of MWNT/NS-incorporated cement hindering the reactions between calcium hydroxide and the NS.
Databáze: OpenAIRE
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