How are the metal parts on concrete pipe protected from corrosion?

• A. Cement grout
• B. Paint
• C. Epoxy coating
• D. Mortar

Answer: (D)

Encasing metal hardware in mortar provides a solid, long-lasting barrier between the metal and the surrounding moisture and soil, which drives corrosion. Mortar—a cement-sand mix—bonds with the concrete, cures into a hard matrix, and protects embedded or attached metal parts by sealing out water, chemicals, and oxygen. It also resists burial-related stresses and won’t peel or crack as quickly as coatings in underground conditions. In contrast, coatings like paint or epoxy can fail under moisture and abrasion, and cement grout is mainly used to fill gaps rather than form a durable protective shell around hardware. So, mortar is the best choice for safeguarding metal components on concrete pipe.