Potential of Carbon Nanotube Reinforced Cement Composites as Concrete Repair Material

Abstract

Carbon nanotubes (CNTs) are a virtually ideal reinforcing agent due to extremely high aspect ratios and ultra high strengths. It is evident from contemporary research that utilization of CNT in producing new cement-based composite materials has a great potential. Consequently, possible practical application of CNT reinforced cementitious composites has immense prospect in the field of applied nanotechnology within construction industry. Several repair, retrofit, and strengthening techniques are currently available to enhance the integrity and durability of concrete structures with cracks and spalling, but applicability and/or reliability is/are often limited. Therefore, there is always a need for innovative high performing concrete repair materials with good mechanical, rheological, and durability properties. Considering the mechanical properties of carbon nanotubes (CNTs) and the test results of CNT reinforced cement composites, it is apparent that such composites could be used conveniently as concrete repair material. With this end in view, the applicability of multiwalled carbon nanotube (MWNT) reinforced cement composites as concrete repair material has been evaluated in this study in terms of setting time, bleeding, and bonding strength (slant shear) tests. It has been found that MWNT reinforced cement mortar has good prospective as concrete repair material since such composites exhibited desirable behavior in setting time, bleeding, and slant shear.

Graphene Nanosheets to Improve Physico-Mechanical Properties of Bioactive Calcium Silicate Cements

“…The addition of 3 wt % of GNS to the mix resulted in significantly lower setting time for both materials compared to the control. It is feasible that carbon-based materials influence both the initial C 3 A and the C 3 S hydration products by accelerating the rate of hydration processes particularly at early stages since they act as a matrix for the development of C–S–H and calcium hydroxide [ 22 , 33 , 34 ]. The longer setting time observed for 5 and 7 wt % compared to 3 wt % may be related to the fact that, at high concentrations, carbon-based materials can agglomerate around cement grains allowing only partial hydration [ 35 ].…”

Structural Properties and Damage Detection Capability of Carbon Nanotube Modified Mortars after Freeze-Thaw

“…Over the last two decades, carbon nanotube (CNT) modified cementitious composites [1,2,3,4,5,6] have been investigated with focus on two main aspects: a) the improvement of their performance and b) the production of multifunctional, smart and self-sensing materials [7,8,9]. The ability of CNTs to bridge micro-cracks and delay their propagation [10,11,12] has been proven beneficial for the fracture behavior of cementitious materials [13,14].…”

“…Several studies suggest a beneficial role of carbon-based nano-inclusions on the microstructure [3,4,5,6,7,17,26,27] and in turn water sorption and water permeability [28,29,30] of cementitious materials. This has been mainly attributed to the refinement of pores and reduction in pore connectivity and bridging.…”

Mechano-Physical Properties and Microstructure of Carbon Nanotube Reinforced Cement Paste after Thermal Load

“…[ 5 , 6 , 7 , 8 ]. In recent years, research into the use of carbon nanotubes (CNTs) as a nano-reinforcement of cement matrix has been conducted in many countries [ 9 , 10 , 11 , 12 , 13 ].…”