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• The potential of brick waste recycling and its use in aerial lime-based mortars is investigated. • The incorporation of brick dust in lime mortars generated a pozzolanic reaction. • Brick dust improved the compressive strength. • Brick dust increased the hygric and hydric expansion of lime-based mortars. To preserve architectural heritage for future generations, restoration materials such as mortars should be compatible with the historic substrate. Pozzolanic mortars are a compromise solution between Portland cement-based mortars and aerial lime-based mortars. This paper investigates the recycling of brick waste in the Meknes region of Morocco to formulate pozzolanic mortars. Nine different mortars were made using aerial lime, sand and brick dust. They were characterized in terms of shrinkage, color, mechanical and hydric properties. The study revealed that Meknes brick dust exhibits a pozzolanic activity and reduces shrinkage. Moreover, it increases hydric and hygric expansion, enhances mechanical strength and affects the color of mortars. An appropriate recipe for restoration mortars could then be proposed to restore regional architectural heritages, depending on the properties of their historic substrates. [ABSTRACT FROM AUTHOR]

• EIS method is used to interpret chloride and chloride-sulfate ion penetration of PCCP mortar coatings. • Model parameter R c t 1 and i c o r r can be used to quantify corrosion resistance of PCCP mortar coatings. • Fly ash and silica can improve the resistance to chloride and composite chloride-sulfate ion migration. • Silica fume is substantially more effective than FA in improving corrosion of PCCP mortar coatings. • The importance of designing mortar coating following EN 206-1 (for XA3 exposure class) is deduced. This paper describes an experimental study to improve the durability of prestressed concrete cylinder pipe (PCCP) mortar coatings exposed to chemical attacks. Three mortar coating mixtures: a control, a 10% FA (fly ash), and 10% SF (silica fume) mortars were investigated. The mortar containing 10% SF was designed specifically to meet the requirements of the XA3 exposure class following EN 206-1. The specimens were immersed in a 9.5 wt% NaCl solution and a composite solution of 9.5 wt% NaCl and 34 wt% Na 2 SO 4 to simulate the most aggressive environment found in the right of way of pipelines in Morocco. Electrochemical impedance spectroscopy (EIS) was used to identify the changes in the microstructure of the mortar coatings and the reinforcement bars. Dong's electrochemical equivalent model was implemented and fitted to the experimental results. It was observed that mineral admixtures can considerably improve the durability of the PCCPs. The 10% SF mortar yielded the best result in terms of corrosion performance. Results also indicated that Dong's model is a more efficient model for describing the electrochemical system of mixtures compared to other circuit models. [ABSTRACT FROM AUTHOR]