Preparation and application of the novel resin microcapsules in self-repairing cement composites with polypropylene fibers

According to this article, the novel, highly absorbent, resin microcapsules prepared by the sharp hole-bath method, together with the polypropylene fibers, were used in the cementitious materials, with an aim to study the impacts of the dosage of polypropylene fibers, the mass fraction of microcapsules and the curing age on the strength of mortar and its self-repair effect. The uniaxial compression test and the permeability test were also applied to evaluate the mechanical properties of specimens and the self-repair effect of cracks. The results showed that when the amount of microcapsules is 1.5% and the amount of polypropylene fibers is 0.17%, the specimen reaches its peak strength, meanwhile the microcapsules have no negative effect on its initial compressive strength. When the amount of microcapsules is 0.75% and the amount of polypropylene fibers is 0.17%, the strength repair rate and the seepage repair rate of cement-based materials reach the best. In addition, the strength repair rates showed that, compared with the single addition of microcapsules, the 'bridging effect' of polypropylene fibers could help microcapsules better complete the crack self-repair work.