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 afrms that
CNTs act as bridges across micro cracks, which explains the improvement in mechanical properties. The
diameter of steel bars played a signifcant 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. Benefts from using CNTs were limited to moderate. Mineral/chemical
admixtures or fbers 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. |
