Coating mortars act as a physical barrier to protect the load-bearing structure against corrosion. However, not all mortars have the same protective capacity. Hydration in the early ages of manufactured mortars is a very influential parameter in their electrical resistivity values and in the evolution of their mechanical performance. In this work, the electrical resistivity data and its relationship with the evolution of the mechanical strength in different mortar dosages are analysed. From the data obtained, a predictive system with fuzzy logic is designed with the aim of predicting the value of the compressive strength of the mortar at the age of 28 days based on the electrical resistivity measurement obtained within the first seven days after its manufacture. The designed system has been validated with data from other mortar dosages not included in the design, proving to be a useful tool for establishing quality criteria for coating mortars.
