Dear All,
I want to know when does complete hydration of cement takes place?
Is it completes within moments of pouring of water or takes complete curing period for its completion?
If the first case is true then only hardening takes place during curing?
If the second case is true then there will be no hydration of interiormost particles since such parts of the cube mould appears dry on crushing even after 28 days curing period?
Kind Regards,
Gulam Dastgir
I would concur with Dr. Clark. Studies have shown that on samples conserved in good conditions (both laboratory and real-life like bridges supports), slow increase in strength can still be measured more than twenty years after concrete production.
Of course, one could argue that after such a long time, hydration is mostly complete and what we observe is a slow reorganization of the hydrated matrix.
Concerning your initial question, the fact that the concrete looks dry does not mean that hydration, that is chemical reaction with water, is not taking place. Any porous material can hold a certain amount of water (even not chemically bonded) and still look dry.
Best regards,
Dear All,
Exactly the same answer i was hoping. But there is one more
query here. We add water in cement after determining its W/C ratio
by vicat appratus. This ratio gives amount of total water required for
forming a paste of cement of required consistency. Is this required consistency means the amount of water required for hydration after leaving water loss during paste formation?
If this is so then why curing is needed, when we have already mixed water reqiured for the hydration?
Regards,
Gulam Dastgir