This research provides the analyzing case of abnormal expanding of concrete including steel slag aggregate as a recycled aggregate. To determine the reason of abnormal expansion, the components of concrete were searched and the aggregate was found out as a reason of this expansion. The aggregate used was a type of steel slag aggregate without any specific treatment for volumetric stability such as fast-cooling or aging. SEM observation of the aggregate and XRD analysis of the cement paste were conducted and it was found out that the surface of the aggregate is very rough and the cement paste contained a lot of calcium and magnesium. From this research, it is considered to contribute on providing the actual case of failure using steel slag aggregate for concrete.

• 한동엽(청주대학교 산업과학연구소) | Han, Dongyeop 교신저자
• 최영하(대구대학교 건축공학과) | Choi, Young-Wha
• 양성환(인천대학교 도시건축학부) | Yang, Seong-Hwan
• 한민철(청주대학교 건축공학과) | Han, Min-Cheol
• 한천구(청주대학교 건축공학과) | Han, Cheon-Goo