Journal of Yangtze River Scientific Research Institute ›› 2023, Vol. 40 ›› Issue (1): 171-175.DOI: 10.11988/ckyyb.20210825

• HYDRAULIC STRUCTURE AND MATERIAL • Previous Articles     Next Articles

Properties of Cement-based Material Mixed with Nano-SiO2 and Calcium Carbonate Whisker

HUANG Wei1, ZHANG Yang-yang1, GE Jin-jin2, FANG Zhang-ping1   

  1. 1. School of Architecture and Arts,Huainan Union University,Huainan 232038,China;
    2. Institute of Civil Engineering and Architecture,Anhui University of Science and Technology, Huainan 232001,China
  • Received:2021-08-07 Revised:2022-01-12 Online:2023-01-01 Published:2023-02-24

Abstract: The hydration products,microstructure and thermal stability of cement-based materials prepared by mixing with nano-SiO2 and calcium carbonate whisker were effectively characterized by using SEM,XRD and TG-DSC.The mechanical properties and thermal conductivity of thermal-insulated cement mortar were also studied by adding 0%,1%,2%,3%,5% and 10% calcium carbonate whisker and 1% nano-SiO2.Test results revealed that by adding materials of nano-and-millimeter level scales,C-S-H gels were generated from the secondary hydration reaction between nano-SiO2 and Ca(OH)2 crystal,filling the voids in cement base and refining the pores in cement base.Moreover,calcium carbonate whisker has dual-function of fibers and particles,hence producing bridging effect in the cement based,forming a dense network flocculation structure inside the cement base.The strength of cement mortar can be improved by adding nano-SiO2 and calcium carbonate whisker.The compressive strength and flexural strength of thermal insulation cement mortar mixed with 3% calcium carbonate whisker and 1% nano-SiO2 is 25.6 MPa and 6.19 MPa,respectively,and the thermal conductivity is 0.456 7 W/(m·K).Both the strength and thermal conductivity are taken into consideration.

Key words: nano-SiO2, calcium carbonate whisker, microscopic analysis, mechanical properties, thermal conductivity

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