Answer to Question #173315 in Civil and Environmental Engineering for Kiara

Question

Three mortars are molded in one-set of 2-in cube molds. If one mortar was broken during removal from molds or has cracks due to improper compaction, can I continue the testing of mortars for the 2 cube mortars, and just prepare another one to replace the damaged cube? 

Answer 1

Samples to be tested should be subjected to similar conditions like days for curing and other engineering requirements according to the ASTM C109. It is against the requirements to replace a broken sample with a newly prepared one to join the others subjected to different conditions. Realistic and representative results are obtained from at least three samples, and two are not a requirement. Most appropriately and preferably, three new samples should be made again and tested after the stipulated days in the same undamaged state.