Mortar samples surrounding buried pipe.
a. Name & Location of the Project
Mortar samples surrounding buried pipe. – Water District in California.
Varying quality of two mortar samples surrounding buried pipe,
(i) “Sample in between pipe”- mortar – gray in color and strong
(ii) “Pipe joint”- mortar – whitish gray and soft
c. Evaluation by Petrographic analysis & SEM
Evaluation by SEM
Cement used in mortar appear to have elevated amount of tricalcium aluminate, C3A. In-between pipe where there was no leaked wastewater from the pipe the integrity of the mortar was maintained , whereas at the joint with sulfates in the leaked water copious amounts of ettringite was formed in voids weakening the mortar sample.