Utilization of Thermally Treated SiC Nanowhiskers and Superplasticizer for Cementitious Composite Production

Materials

Andrea Betioli¹  José Andrade Neto²  Maciej Szeląg³  Paulo de Matos⁴  Nagilla Azevedo⁴  Philippe Gleize⁴ 

[1] Academic Department of Civil Construction, Federal Institute of Santa Catarina (IFSC), Florianópolis 88020-300, Brazil;Department of Civil Engineering, Federal University of Rio Grande do Sul (UFRGS), Porto Alegre 90035-190, Brazil;Faculty of Civil Engineering and Architecture, Lublin University of Technology, 20-618 Lublin, Poland;Laboratory of Application of Nanotechnology in Civil Construction (LabNANOTEC), Department of Civil Engineering, Federal University of Santa Catarina (UFSC), Florianópolis 88040-900, Brazil;

关键词: SiC nanowhisker;    cementitious composite;    rheology;    hydration;    mechanical properties;    microstructure;   

DOI  :  10.3390/ma14154062

来源: DOAJ

【 摘 要 】

Nanomaterials are potential candidates to improve the mechanical properties and durability of cementitious composites. SiC nanowhiskers (NWs) present exceptional mechanical properties and have already been successfully incorporated into different matrices. In this study, cementitious composites were produced with a superplasticizer (SP) and 0–1.0 wt % SiC NWs. Two different NWs were used: untreated (NT-NW) and thermally treated at 500 °C (500-NW). The rheological properties, cement hydration, mechanical properties, and microstructure were evaluated. The results showed that NWs incorporation statistically increased the yield stress of cement paste (by up to 10%) while it led to marginal effects in viscosity. NWs enhanced the early cement hydration, increasing the main heat flow peak. NWs incorporation increased the compressive strength, tensile strength, and thermal conductivity of composites by up to 56%, 66%, and 80%, respectively, while it did not statistically affect the water absorption. Scanning electron microscopy showed a good bond between NWs and cement matrix in addition to the bridging of cracks. Overall, the thermal treatment increased the specific surface area of NWs enhancing their effects on cement properties, while SP improved the NWs dispersion, increasing their beneficial effects on the hardened properties.

【 授权许可】

Unknown