Effect of Adding Carbon Nanotubes on Corrosion Rates and Steel-Concrete Bond

Abstract

This paper presents a continuation of the evaluation of utilizing Nano Carbon Tubes (CNTs) in reinforced concrete (CNT-CRETE). The compressive, tensile and bond strengths of the samples with and without CNTs were investigated. Scanning Electron Microscope (SME) was utilized to study the microstructure of the prepared samples. In addition, the corrosion resistance of CNT-CRETE, was measured and compared to traditional concrete. Four mixes were prepared, with 0.01%, 0.02%, and 0.03%, CNTs by weight of cement, along with a control mix without CNTs. The results of the experimental work showed that adding CNTs led to an increase in the compressive, tensile and bond strengths of specimens compared to those of the control specimen. SEM examination for control and CNTs specimens showed that CNTs specimen were well structured compared with the control specimen and this affirms that CNTs act as bridges across micro cracks, which explains the improvement in mechanical properties. The diameter of steel bars played a significant role in failure mechanism for pull-out testing and corrosion resistance. In general, adding CNTs to the concrete mix increased the rate of corrosion for steel bars within the low risk limits. Benefits from using CNTs were limited to moderate. Mineral/chemical admixtures or fibers provide better improvements in the mechanical properties of concrete without the problems associated with dispersing CNTs and the health hazard of handling a Nano material.

Corrosion Protection of CNTs/CNFs Modified Cement Mortars

“…The above results, meet also with the findings of Hassan et al [28] where it is assumed that CNTs have higher corrosion tendency compared to plain concrete. It is mentioned that the results of this paper come from a very accelerated test of anodic charge, where one portion of steel was exposed to corrosion environment.…”

Characterization, Processing, and Application of Heavy Fuel Oil Ash, an Industrial Waste Material – A Review

“…Due to their nanostructure and the strong covalent bond between the carbon atoms, CNTs exhibit unique chemical, physical, mechanical, thermal, and electrical properties. [88,89,90] Owing to these properties, they have a high potential for unique applications in many areas, such as electronics, [91] optics, [92] chemical/electrochemical, [93] construction materials, [94] composite materials, [95] and reinforcing additives, [96] among others. However, CNTs are highly expensive due to the complex preparation methods necessitating expensive equipment.…”

A New Route to Enhance the Packing Density of Buckypaper for Superior Piezoresistive Sensor Characteristics

“…The discovery of carbon nanotubes (CNTs) by Iijima [1] led to extensive research for the utilization of these unique structures with extraordinary properties in the field of electrical storage devices [2,3], digital electronics devices [4,5], structure health monitoring (SHM) sensors [6,7] and concrete reinforcement applications [8,9], etc. Both theoretically and experimentally, it is proved that CNTs inherit excellent physical properties having an electrical conductivity of 3 × 10 6 S/m [10,11], the thermal conductivity of 2000-3500 W/m•K [12,13], the mechanical strength of 100 GPa [14], the Young's modulus of 1 TPa [15,16] and the piezoresistive gauge factor (GF) of 2900 [17,18].…”