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Indexed by:Journal Papers

Date of Publication:2020-03-30

Journal:CONSTRUCTION AND BUILDING MATERIALS

Included Journals:EI、SCIE

Volume:238

ISSN No.:0950-0618

Key Words:Multifunction; Electrostatic self-assembled; CNT/TiO2 composite filler; Cement-based materials

Abstract:Owing to its good conductive property, dispersion, and low water absorption property, the electrostatic self-assembled CNT/TiO2 composite filler is an excellent candidate for developing multifunctional cement-based materials. Therefore, this study fabricated multifunctional cement-based materials with a CNT/TiO2 composite filler and explored their electrical properties, thermal-resistance effect, electromagnetic shielding and absorption properties. CNT/TiO2 modified cement-based materials showed percolation characteristics through direct current (DC), alternating current (AC) resistivity methods and percolation theory, with percolation threshold zone ranging from 0.15 vol% to 0.45 vol%. The AC impedance spectrum of the CNT/TiO2 modified cement-based materials can be accurately described by equivalent circuits, which change in the percolation threshold zone. The resistivity of the CNT/TiO2 modified cement-based materials decreased with increasing temperature, which has potential application in smart infrastructures. With increasing CNT/TiO2, the rate of decrease of the electrical resistivity of the composites changed sharply during the percolation threshold zone for increasing temperature from -30 degrees C to 60 degrees C. The electromagnetic shielding effectiveness of CNT/TiO2 modified cement-based materials was up to 1.30 times greater than that of the control cement-based materials. When the CNT content was 1.16 vol%, the reflectivity of the cement-based composite reached -32.01 dB at a frequency of 16.88 GHz. (C) 2019 Elsevier Ltd. All rights reserved.