In this review, the research reports on the dispersion processes of carbon nanotubes (CNTs) in aqueous cementitious materials are intensively introduced and summarized. The main processes for the CNTs dispersion in aqueous systems include high shear emulsification, ultrasonic treatment, covalent modification, and non-covalent modification. The influences of various factors on the dispersity of CNTs are evaluated, and the pros and cons of dispersion processes of CNTs are analyzed, along with the dispersion mechanism of CNTs in aqueous materials. Several novel techniques are also introduced, including arc thermal excitation and electromagnetic field-induced method, etc. In addition, the challenges when CNTs dispersion are further involved in cementitious alkali pore solution and the improvement means are also described in detail. And, the direct dispersion process (in situ growth process) of CNTs in cementitious materials has also been discussed in depth.

Structural health monitoring (SHM) technology based on the mechanical–electrical sensing effect of various intrinsic smart materials has a good application prospect. Carbon nanotube (CNT) has excellent electromechanical properties and hence can be doped into cement by appropriate dispersive means to produce CNT-modified cement-based smart material (CNTCS) with excellent electromechanical (piezoresistive/piezoelectric) capacity. CNTCS can be developed into a static/dynamic intrinsic sensor for SHM after effective packaging and calibration. Based on the characteristics of CNT, the dispersion methods and the dispersity characterization techniques of CNT in the water/cement matrix are summarized, and then the influence laws of various factors on piezoresistive and piezoelectric sensing behaviors of the corresponding CNTCS are also discussed. The full-frequency domain sensing mechanism of CNTCS is analyzed by combining its finite element model and electromechanical coupling theory, and the practicability of applying CNTCS as an SHM static/dynamic intrinsic sensor is further investigated.

Most cementitious repair materials have non-ignorable drawbacks such as low strength, insufficient bonding, and low anti-permeability. Although the bonding and anti-permeability of repair mortars modified by polymer will be substantially improved, the compressive strength and component integrity will be decreased. Hereby six groups of cement mortars modified by varied dosages of Graphene Oxide (GO) and PA copolymer (GOPARMs) were prepared. The flexural strength (f t), compressive strength (f c), f t/f c, bond strength (f b), and chloride ion migration coefficient (λ c) of GOPARMs were systematically studied by axial compressive, three-bending, pull-out, RCM method, along with microstructure analysis. When GO and PA dosages are fixed at 0.03 and 5 wt%, respectively, the f t, f c, f t/f c, f b, and λ c of GOPARMs reach the best comprehensive performances, which are 6.4, 46.5, 0.14, 6.73 MPa, and 1.179 × 10−12 m2/s. Compared with the control mortar, the f t, f c, f t /f c, and f b of GOPARMs are improved by 5.7, 12.3, 7, and 103%, respectively, and the corresponding λ c is dramatically reduced by 40.4%. Scanning electron microscope (SEM) shows that trace of GO can play a template nucleation effect on the hydration products’ morphology and microstructure of GOPARMs. Meanwhile, cured PA polymer can form hydrophobic film and fill the interfacial pores among hydration products, finally superior repairing performances of GOPARMs with optimal mix can be achieved.