Mitigate the curing problems of concrete pavements by using heated non-expansive clay particles as internal curing agent

Internal curing concrete can be used in the production of concrete road pavements, bases, etc. It reduces the formation of drying shrinkage cracks and saves lots of money and time that spend on ineffective external curing processes. Unfortunately, internal curing aggregates (ICAs) are not available in most countries. Thus the production of internal curing concrete (ICC) is limited to a few countries. This research focuses on developing an effective ICA using non-expansive clay type. Consequently, a non-expansive clay type was selected and heated at various temperatures ranging from 800∘C to 1300∘C at intervals of 100∘C. Afterwards, heated clay samples were crushed into fine aggregates. The optimum heating temperature which gives the required properties as ICA was identified as 900∘C through an extensive analysis followed by pore structure of heated clay aggregates. The produced aggregate achieved 1.8g/cm3 density value, 15.5% of water absorption. Subsequently, ICC achieved higher compressive strength and workability more than the conventional concrete without any external curing process. Moreover, the aggregate reduced the drying shrinkage of concrete.