Civil Engineering/need your opinion
QUESTION: Hello Sir,
I am not sure whether I can ask this question to you or not. But still I would like to take your opinion.
We have just started doing the cement plastering for the brick ( not cement blocks) walls. It is about two days we finished the plastering and started doing the curing for these walls. On some of the walls when we pour water, crack like lines will appear till the wall is wet and they go away after the wall becomes dry. These crack like lines are appearing in only some areas but not on all the surface. According to you what could be the reason.
If you want I will send some pictures of it
ANSWER: Dear Sudarshan
These cracks are due to creep which may be prevented performing curing very soon just after concreting. You should prohibit concreting in hot weather, under sun shine and I suggest to do concreting after sun set to keep the concreting situation in a favorite situation.
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QUESTION: Hi BEH,
I did not understand what did you mean by creep.
This is cement mortar used for brick masonry work prepared by mixing cement, sand and water used for the external and internal plastering of the brick walls. After the plastering with the cement mortar, I am seeing these crack like lines when we pour water for curing.
Cement mortar like concrete loose its water after application from its free surface. The water loss produces tension strains in concrete or mortar. This is a phenomenon named creep in concrete. You should prevent the water loss from the surface of mortar with either application of water powder and/or concreting in appropriate weather and temperature.