Repairing performances of novel cement mortar modified with graphene oxide and polyacrylate polymer

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 (lambda (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 lambda (c) of GOPARMs reach the best comprehensive performances, which are 6.4, 46.5, 0.14, 6.73 MPa, and 1.179 x 10(-12) m(2)/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 lambda (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.

Automated summary

Most cementitious repair materials have drawbacks such as low strength, insufficient bonding, and low anti-permeability. The use of Graphene Oxide (GO) and PA copolymer (GOPARMs) as modifiers in cement mortars can improve bonding and anti-permeability, although compressive strength and component integrity may be decreased.