Recovered & reborn
Surkhi (brick dust)
Finely ground fired brick mixed into lime, giving the mortar a gentle chemical set (a pozzolan). India's answer to Roman volcanic ash concrete.
How it behaves
Makes lime mortars harder and water-resistant while staying breathable, which is why it lined stepwells, tanks, and terrace roofs that had to hold water without suffocating.
Where it belongs
Across pre-modern India
In a modern project
Lime-surkhi concrete for heritage-sensitive repairs and low-carbon floors; ground waste brick is an honest cement replacement in mortars.