Wikipedia entity: Concrete
Topics: Construction material; steel production; sustainability
Original sentence: Ground granulated blast furnace slag (GGBFS or GGBS): A by-product of steel production is used to partially replace Portland cement (by up to 80% by mass).
Quantified sentence: Ground granulated blast furnace slag (GGBFS or GGBS): A by-product of steel production is used to partially replace Portland cement (high level by mass).
Quantifier: largely
Percentage: 80%
Specificity: unable