In order to improve the properties of concrete, the composition and structure of the interfacial zone must be modified. This may be done by pretreating the inert aggregate with special reagents to form a reactive surface, which will then react with the cement paste, resulting in an enhancement of the bond strength between cement paste and aggregate through the combination of the physical, chemical and mechanical interlocking effects. A cylindrical hole was drilled in a limestone cake and the surface of the hole coated with special solutions; cement slurry was then poured into the hole and the specimens were cured in a fog room. The shearing strength was determined to evaluate the effect of the aggregate pretreatment on the bond strength. The mechanical strength, porosity, electric conductivity of the concrete, orientation degree of the Ca(OH)2 and morphology in the interfacial zone were also examined. It was found that the compressive and flexural strengths increased, and the bond strength between aggregate and cement paste also increased; the porosity, average pore size, number of large harmful pores, electric conductivity and the orientation index of the Ca(OH)2 decreased.