Regain of strength after firing of concrete

Synopsis The mechanism of regain of strength as observed in work on the glazing of concrete was investigated on fired and unfired industrially made masonry units by methods including DTA, pore size distribution, and determination of the degree of carbonation. Immediate loss of strength after firing is attributed to the dehydration of cement paste gel, and the main factor in the regain of mechanical strength in a fired block is a carbonation process facilitated by a new capillary system created in firing.