Abstract: The present invention teaches a concrete pipe joint construction which includes a steel bell and a spigot joint ring, both protected by an alkali releasing substance contained typically in a composite sleeve. When the spigot is engaged sealably into the bell an external joint recess is formed. The present advance is to add a sleeve made of a polyurethane foam material having the alkali releasing substance dispersed therein. The sleeve has an impermeable outer surface and goes around the outside of the joint and is banded sealably to both of the pipes. By this expedient, if and when ground water penetrates into the joint recess, the alkaline material is released from the sleeve to protect exposed steel from corrosion.