Properties of normal-strength concrete and mortar with multi-walled carbon nanotubes

Abstract

This investigation studied the strength and performance of cementitious materials, such as concrete and mortar, with multi-walled carbon nanotubes (MWNTs). One hundred cylindrical specimens 10 cm in diameter and 20 cm in height were used to investigate strength variation and changes in the durability of concrete and mortar as a function of the weight percent (0,1 . 5 wt%) of MWNTs and the effectiveness of a dispersion method that used a sodium naphthalene sulfonate formaldehyde solution. Industrial-grade MWNTs (purity: >90%, diameter: >50 nm) were used for the test. Ball milling with 1 . 5 wt% MWNT was processed for 7 h, followed by a dilution process with 0 . 25, 0 . 5, 0 . 75, 1 . 0, 1 . 25 and 1 . 5 wt% dispersive solutions. Ultrasonication treatments were then applied to each diluted solution for 20 min. Compressive strength, splitting tensile strength, permeability, electrical conductivity and the relative dynamic modulus of the concrete cylinders were tested under a 24 MPa mix design by increasing the wt% MWNT using standard ASTM guidelines. In parallel, MWNT mortar tests were performed for compressive strength, flexural bending and shrinkage with 50 prismatic specimens (4 3 4 3 16 cm in size).

Progress in Research on Carbon Nanotubes Reinforced Cementitious Composites

“…Uniform dispersion is attainable using various types of mechanical methods, including ultrasonication, ball milling, and rubbing [60]. A 120-litre-capacity basket mill filled with 0.8 mm zirconium oxide beads was operated at 900 rpm to disperse 3.0 wt% MWNT for 7 h, and the dispersion of MWNTs was achieved in the form of condensed solution [61]. It was also observed that MWCNTs were damaged in different ways during ball milling, and a large amount of amorphous carbon was created [62].…”

Effect of nanosilica on durability and mechanical properties of high-strength concrete

“…For the construction sector, nanotechnology is defined as controlling properties at the nanometre scale to make revolutionary changes in bulk material properties by using scientific principles. Nanotechnology thus aims at manipulation of a structure at the nanometre scale in order to develop new materials that possess superior mechanical performance and durability aspects along with a range of novel properties such as low electrical resistivity, self-sensing capabilities, self-cleaning, selfhealing, high ductility and self-control of cracks (Givi et al, 2010;Kawashima et al, 2013;Li et al, 2004;Rhee and Roh, 2013;Said et al, 2012;Singh et al, 2013).…”

Mechanical and self-sensing properties of concrete reinforced with carbon nanofibres

“…The relationship between strain and resistivity was fairly linear and a gauge factor of approximately 70 was measured. In addition to the referred research, other researchers also found an improvement in the conductivity of CNT/CNF reinforced cementitious materials, and a relationship between strain and stress was found (Galao et al, 2014;Sasmal et al, 2017;Rhee and Roh, 2013).…”