Development and research on alkali-activated EAF slag concrete

This research uses an alkali-activa ted EAF (Electric Arc Furnace) ladle slag cementing material with stable soundness and a preferable resistance to sulfate corrosion which cooperates with an EAF oxidizing slag, fine aggregates to develop a technology of mass production of alk ali-activated EAF slag concrete which can efficiently solve the soundness problem of the EAF ladle slag and increase engineering properties of the concrete materials. The provision of the novel technology and products having the sustainable development, energy conservation and carbon reduction is of benefit to the iron and steel industry and the concrete-based product industry. This research executes a small scale blending test, a plant blending test and a compression test for precast concrete component drilling cores to confirm the effectiveness of the mix design of the alkali-activated slag concrete according to properties of fresh concrete and hardened concrete. The result shows that mass production of the alkali-activated slag concrete is feasible. The research observes that the alkali-activated steel slag possesses superior engineering pro perties: (1) High unit weight (the unit weight is 2650 kgf/cm²), (2) Early strength function: respective designed strength values, namely 140 kgf/cm², 175 kgf/cm² 210 kgf/cm², can be obtained at the age of 3 to 7 days, (3) Dimensional stability: according to the volume variation rate measured by a drying shrinkage test, the alkali-activated slag concrete has a small change in the volume, with the result that the concrete structure is not damaged by the drying shrinkage condition. Furthermore, an accelerated mortar bar test and an alkali-aggregate reaction test show that the alkali-activated slag concrete possesses the long term dimensional stability, (4) Good weatherability, (5) Sulfate-corrosion resistance (having good duration), etc.