Fatigue characteristics of steel-making slag concrete under compression in submerged condition

• Formulae for predicting the fatigue life of SSC under compression are proposed.
• Fracture morphology of SSC depends on the types of steel-making slag aggregates.
• Applying polished slag aggregates is found to improve the fatigue strength of SSC.
• Non-easiness of micro-crack nucleation is attributed to the improvement.

Steel-making slag concrete (SSC) is an environmental friendly material made mainly of by-products of steel industry without using Portland cement. The fatigue characteristics of SSC under compression in submerged condition are experimentally investigated, for applications to marine and harbor structures. Based on the fatigue tests, calculation formulae are proposed on the averaged fatigue life. The fatigue strength of SSC with hot metal pretreatment slag or converter slag as fine and coarse aggregates is slightly smaller than that of ordinary cement concrete, while using polished hot metal pretreatment slag (PHPS) as aggregates is found to improve the fatigue strength of SSC. The superior characteristics of SSC with PHPS against fatigue failure are studied through the measurements of strain, AE, and hardness of the materials.