Mix Design
Retarder
// Definition
An admixture that delays the initial setting of concrete. Used in hot weather, long hauls, or large pours to extend the workability window.
Common retarders are sugar-based or phosphonate-based. Overdose can cause excessive delay or strength loss.
// Related Indian Standards
IS 9103
// Cross-references
Setting Time
The time it takes cement paste to lose plasticity and harden. Measured as Initial Set (start of stiffening) and Final Set (no longer deformable).
Initial Set
The point at which cement paste begins to stiffen and lose plasticity. Marks the end of the workable period.
Accelerator
An admixture that speeds up setting and early strength gain. Used in cold weather, repair work, or shotcrete.
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