Experimental Study on Improving Compressive Strength of MWCNT Reinforced Cementitious Composites

Abstract

This experimental study was intended to improve the compressive strength of multi-walled CNT reinforced cementitious composites with efficiency. The variables considered are the degree of sonication, the amount of surfactant, the replacement ratio of silica fume, etc. Optical microscope informed that fiber dispersion of CNT was improved with the increase of sonication time, and the compressive strength was proved to be enhanced as the degree of sonication increased. When superplasticizer as a surfactant had SP/CNT ratio of 4~6, the best improvement in strength was obtained. Silica fume was shown to produce the highest compressive strength at 10% replacement. Microstructure of CNT composites was also analyzed; XRD and SEM results indicated that CNT addition hardly changed hydration products and microstructure, and MIP analysis found the reduction of total porosity as well as the increase of nano-pores with the size of tens of nm instead of the decrease of pore distribution in the region of around 10 μm and 100 nm. The results of microstructure analysis explains that the strength improvement is closely related to physical contribution rather than chemical influence by adding CNT.

Thermal response characterization and comparison of carbon nanotube-enhanced cementitious composites

“…The potential for utilizing the excellent mechanical properties, electrical conductivity, and heat conductivity of CNTs to modify and functionalize various materials has been studied [2][3][4][8][9][10][11][12][13][14][15][16][17][18]. While CNTs can be readily incorporated in polymer-based nanocomposites, it becomes considerably more challenging to incorporate them in cementbased materials.…”

“…Once CNT content exceeded 0.05%, the compressive and flexural strengths of the CNT cement mortar declined. Kang et al [16] analyzed the microscopic structure of a cement mortar mixed with MWCNTs using scanning electron microscopy (SEM) and X-ray diffraction (XRD). The results indicated that the addition of CNT led to minimal changes in hydration products within the cement mortar.…”

Heating Experiment of CNT Cementitious Composites with Single-Walled and Multiwalled Carbon Nanotubes

“…Kang and Park investigated the microscopic structure of a cement mortar mixed with MWCNTs using a scanning electron microscope (SEM) and X-ray diffraction (XRD). The results showed that the addition of CNTs led to minimal changes in the hydration products within the cement mortar [20].…”

Enhanced Detection Systems of Filling Rates Using Carbon Nanotube Cement Grout

“…A number of recent studies have focused on transforming cement-based construction materials by mixing them with nanomaterials to produce functional construction materials [1][2][3][4][5][6][7][8][9][10]. The resulting materials exhibit improved mechanical characteristics such as compressive strength and bond strength, and enhanced electrical and heat conduction [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20].…”