Mass concrete differs from ordinary concrete not because of the mix design, but because of the difference in their thermal behavior over time, which becomes a critical parameter to be regulated when volume is large.
Specifically in mass concrete, the heat generated from cement hydration accumulates internally faster than it can dissipate in the environment due to the large volume and low surface-to-volume ratio.
At the same time the outer surface loses heat to the environment which then creates a temperature gradient (core hotter than surface) that results in thermal stress.
If not quickly and efficiently regulated, such stress can cause severe thermal crack development, and compromise the durability, structural continuity, and long-term performance.
Guidance from ACI’s mass concrete practice (e.g., ACI 207.1R-05) emphasizes that the defining characteristic of mass concrete is this thermal behavior that is the need to manage heat generation and volume change due to hydration.
Special attention must be given to such thermal gradient zones by implementing Mass concrete temperature monitoring Methods to precisely map such zones and implement the necessary preventive measures to avoid compromisations with durability, strength maturity and structural integrity.
