Responses of Concrete Using Steel Slag as Coarse Aggregate Replacement under Splitting and Flexure

Experimental tests were performed to investigate the responses of coarse steel slag concrete under splitting and flexure. The name of coarse steel slag concrete (CSC) here refers to concrete using industrial byproduct steel slag as natural coarse aggregate replacement. Three CSC types were examined in this investigation as follows: CSC1, CSC2, and CSC3, having a water/cement ratio of 0.57, 0.50, and 0.45, respectively. In the compositions of the three studied CSCs, the water content by weight remained constant and other partial materials were changed, but the ratio of coarse steel slag/fine river sand was still fixed. Under splitting, three types of test methods were conducted including a cylinder splitting test, side-cube splitting test, and diagonal-cube splitting with the same sizes: the diameter of the cylinder and side of the cube were 100 mm. The orders of splitting test methods were observed for CSC2 as follows: cylinder > side-cube > diagonal-cube in terms of maximum applied load, and, cylinder > diagonal-cube > side-cube in terms of splitting strength. Additionally, there were clear size effects on the splitting strengths of CSC2 with different sizes as follows: 70 mm, 100 mm, 150 mm for cylindrical diameter, and/or cubic side. Under flexure, there was a strong co-relationship between compressive strength and flexural resistance of CSCs. The flexural engineering parameters were examined then assessed for plain CSCs, using a rectangular prism with the size of 100 × 100 × 300 mm (width × height × span-length), and, for steel-reinforced beams using CSCs with the size of 200 × 300 × 3000 mm (width × height × span-length).