Effect of inserting multi-walled carbon nanotubes on the physical and mechanical properties of the gypsum matrix

The growing demand for gypsum in civil construction has stimulated studies to improve flexural strength and reduce its layer with water. Therefore, the objective was to evaluate the influence of incorporating multi- walled carbon nanotubes (MWCNT) into the gypsum matrix on its physical and mechanical properties. In the production of composites, the gypsum mass was obtained by different levels of functionalized MWCNT: 0%, 0.001%, 0.002%, 0.003% and 0.004%. Apparent density, observation of water and flexural strength and analysis of the nanocomposites were verified. Replacing gypsum with MWCNT can cause water absorption by 8.33% compared to the control. The apparent density of the compounds showed an increase, with the concentration of 0.004 MWCNT showing an increase of 3.21% when compared to the reference. Compounds with contents of 0.001 and 0.003% of MWCNT showed an improvement in flexural strength values, presenting of 6 MPa. There were improvements for the insertion of 0.001 MWCNT (9 MPa) compared to the control (7 MPa). Thus, the results indicate that replacing gypsum with MWCNT is a viable alternative to improving the mechanical and physical properties of gypsum, which can increasingly expand its use in civil construction.