Fresh properties of green SCC made with recycled steel slag coarse aggregate under normal and hot weather

The steel industry results in accumulation of steel slag wastes causing severe environmental problems. These wastes can be recycled and used in concrete. In this research, natural aggregates in self-compacting concrete (SCC) are replaced, wholly or partly, by steel slag coarse aggregates (SSA) under normal and hot weather conditions. Fresh properties, (workability, stability, bleeding, air content and fresh density) are the crucial ones that affect the final properties of SCC. Therefore, it is important to evaluate the impact of SSA on the fresh properties of SCC mixes. The properties that are studied include mobility and filling ability, passing ability; stability; segregation and bleeding. In this respect, several testing methods are employed: Slump flow, V-funnel, L-box, column segregation, sieve segregation, segregation probe and VSI tests. Furthermore, air content and fresh density are measured. The effect of hot weather on all these properties is included. The results show that it is possible to produce SCC using steel slag aggregate under both normal and hot weather conditions. Hence green sustainable SCC can be produced. The fresh properties become sensitive for SSA replacement ratios exceeding 50%. These properties are more sensitive under hot weather.