Effects of Induction-Furnace Slag on Strength Properties of Self-Compacting Concrete

Abstract

Indiscriminate waste disposal poses a severe environmental challenge globally. Recycling of industrial wastes for concrete production is currently the utmost effective way of managing wastes for a cleaner environment and sustainable products. This study investigates the strength characteristics of self-compacting concrete (SCC) containing induction furnace slag (IFS) as a supplementary cementitious material (SCM). The materials utilized include 42.5R Portland cement, induction furnace slag as an SCM ranging from 0 to 50 % by cement weight at 10 % interval, river sand, granite, water and superplasticizer. The fresh properties were tested for filling ability, passing ability and segregation resistance, the strength characteristics measured include compressive strength, splitting tensile strength, flexural strength and Schmidt/rebound number. The oxide compositions and microstructural analysis of SCC were investigated using x-ray fluorescence analyser (XRF) and scanning electron microscopy equipped with energy-dispersive x-ray spectroscopy (SEM-EDS), respectively. Empirical correlations were statistically analyzed using MS-Excel tool. The filling ability characteristic was determined via both the slump flow test and the T50cm slump flow time test. Moreover, the passing ability characteristic was determined using L-Box test. The segregation resistance characteristic was determined using V-funnel at T5minutes test. The results of the fresh properties showed a reduction in the slump flow with increasing IFS content. On the other hand, the T50cm slump flow increased with increasing IFS content. Furthermore, the L-Box decreased with higher IFS content. On the contrary, the V-funnel at T5minutes increased considerably with greater IFS content. The strength test results revealed that the strength properties increased to 20 % IFS, with a value of 66.79 N/mm2 compressive strength at 56 days, giving a rise of 12.61 % over the control. The SCC microstructural examinations revealed the amorphous and better interface structures with increasing IFS content in the mix. The empirical correlations revealed that linear relationships exist among the measured responses (fresh and strength properties). Ultimately, IFS could be utilized as a sustainable material in producing self-compacting concrete.

Keywords

• self-compacting concrete
• concrete
• strength
• induction furnace slag
• supplementary cementitious materials