Influence of graphene oxide on mechanical behavior of polypropylene fibers reinforced cement-based composites from a macro-to-micro perspective

The mechanical behavior of graphene oxide (GO) reinforced polypropylene (PP) fibers cement-based composites was investigated by three-point bending, microscratch, and nanoindentation tests at macro, micro, and nano levels, respectively. The microstructures of the composites with GO-reinforced PP fibers were analyzed using SEM, EDS, and XRD . Both nanoindentation and microscratch tests were utilized to investigate the phase transformations in the cement matrix after adding GO. It was found that adding 0.03 wt% GO most effectively improved the mechanical properties of PP fibers cement-based composites best, and improving their strength and crack resistance of composites. In addition, statistical nanoindentation and microscratch techniques showed that GO could promoted the hydration of cement, and greatly increased the mechanical strength of hydrated calcium silicate. • The mechanical properties of PP fiber cement-based composites reinforced with different content of GO were studied. • The crack resistance of PP fiber cement-based composites was the best when the content of GO was 0.03 wt%. • The mechanical properties of each phase of cement materials were obtained by nanoindentation and microscratch techniques. • The correlation of mechanical properties of different scale GO reinforced PP fiber cement-based composites was studied. • GO makes the microstructure of fiber cement-based composites more dense.